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Nutritional aspects of gynecic stress
Nutritional aspects of gynecic stress WILLIAM
J.
MASAAKI
FUJINO,
EARL
B.
Galveston,
McGANITY,
DAWSON,
M.D., M.D.,
F.R.C.S.
PH.D.*
PH.D.
Texas
Changes which were a result of gynecic surgery in 95 women indicate that the blood levels of ascorbic acid were elevated significantly at the end of surgery and for the first time dropped below the presurgical values by the end of the initiaal 24 hours postoperatively. Simultaneous serial alterations in blood ascorbic acid, urine ascorbic acid, and urine vanilmandelic acid were studied throughout gynecic surgery in I6 women. Blood and urine ascorbic acid levels were observed to inerease progressively during the first 90 minutes of operation, followed by a sharp drop and a secondary rebound in blood ascorbic acid values. Urine vanilmandelic acid levels increased slightly during the first 90 minutes of surgery; then both VMA and ascorbic acid excretion increased another 60 per cent during the succeeding hour of operation. A significant correlation was observed between blood ascorbic acid and urine vanilmandelic acid levels during gynecic surgery.
NUMEROUS reports
have indicated changes in the ascorbic acid levels of blood serum and urine in response to stress such as burns,5 inand ACTH stimu1ation.l’ ju~.y,12 operation,14 An apparent disparity exists between those reports4, 12. 14, 15 indicating an increase in blood ascorbic acid levels due to ACTH induced stress and the reports 3, 5 that blood ascorbic acid levels decrease during surgical stress. Carefully controlled human studies have been performed in our laboratory to ascertain any dynamic changes in whole blood ascorbic acid levels from the preoperative period through the postoperative period of gynecological surgery. In a second study, urine vanilmandelic acid (VMA), the major metabolite of the catecholamines,l’j and urine ascorbic acid were measured concurrently to determine the degree of stress response and its relationship to blood ascorbic acid levels From the Gynecology, Branch.
Department University
during surgery. These results indicate that blood ascorbic acid levels are altered significantly during gynecic surgery. Simultaneous variations were observed to occur in urinary vanilmandelic acid metabolism. Material
and
methods
Study I. Ninety-five patients with physiologically normal benign conditions were studied in the first study during major or minor gynecologic surgery. None of these women received supplemental ascorbic acid or tetracycline medication for the week prior to operation. The total ascorbic acid (ascorbic, dehydroascorbic, and diketogulonic acids) in finger-tip capillary blood was measured the day prior to surgery; at the onset and termination of surgery, and bidaily for the 5 days following surgery. Blood ascorbic acid levels one day preoperative were considered as individual control values and served as the basis for determining subsequent changes in blood ascorbic acid levels resulting from anesthesia and surgery on the first, third, and fifth postoperative days. These changes were expressed both as milligram per cent and per cent change from control.
of Obstetrics and of Texas Medical
Presented by invitation at the Seventy-seventh Annual Meeting of the American Association of Obstetricians and Gynecologists, Hot ‘Springs, Virginia, Sept. 8-10, 1966. *McLaughlin Fellow, 1963-1965. 750
Vohne
97
Number
G
Of these 95, 38 abdominal hysterectomies, 28 vaginal hysterectomies, and 29 dilatations and curettages of the cervix and endometrial cavity were done. Vaginal hysterectomy was classified as a major vaginal surgical procedure, while dilatation and curettage was considered a minor procedure. The average ages of the women in the three groups of the first study were: abdominal 41 (22 to 64), major vaginal 44 (26 to 73), and minor vaginal 40 (20 to 60). Preoperative medications. Demerol was used most frequently with abdominal surgery. Following induction with sodium pentothal, inhalation anesthesia was employed exclusively. The patients were maintained in the third plane of surgical anesthesia with diethyl ether or cyclopropane in abdominal and major vaginal surgery, and with nitrous oxide in the minor vaginal procedures. The duration of surgical stress was in decreasing order from major abdominal, to major vaginal to minor vaginal procedures. Study II. This was designed to determine the concurrent changes in blood and urine ascorbic acid levels and the simultaneous changes in urine vanilmandelic acid (VMA) levels during anesthesia and surgical stress. Serial measurements have been carried out on 16 patients during gynecic surgery. Blood samples and urine samples from an indwelling catheter were collected at: the onset of anesthesia, the commencement of operation, 30 minute intervals during surgery, and the termination of operation. Total ascorbic acid in blood and urine was measured,Gf ’ urine vanilmandelic acid (VMA),l’ and urine creatinine.l Serial blood hematocrits were determined simultaneously. Changes in blood ascorbic acid levels have been expressed in absolute and per cent changes in the blood as well as the blood ascorbic acid,/hematocrit ratio. Urine ascorbic acid and VMA levels were computed as ratios to the simultaneous urine level of creatinine to circumvent changes in amount or rate of glomerular clearance which would affect interpretation of any urinary data. In contrast to the first study, the total anesthetic and surgery time of the major
Nutritional
aspects
of
gynecic
stress
751
vaginal averages slightly longer than the abdominal procedures, 186 versus 184 minutes, The average length of minor vaginal surgery was 68 minutes. The average patient ages of the three groups were: abdominal 36 (30-42) ; major vaginal 51 (39-71) ; and minor vaginal 38 (19-68) years. Results
Study I. The mean whole blood ascorbic acid levels of the 95 women one day prior to surgery was 0.54 k 0.31 mg. per cent and might well be considered somewhat less than adequate. The blood levels of 28 women were between 0.2 and 0.4 mg. per cent, 38 were
Fig. 1. Changes
in blood ascorbic acid levels following abdominal, major vaginal, and minor vaginal surgery. Population in parentheses.
752
McGanity,
Table
Fujino,
I. Changes
and
of blood
March 15, 1913 Am. J. Obst. & Cynw.
Dawson
ascorbic
acid following
Abdominal (38) + Mean differewes
Observed changes 1. One day preoperation to preoperation Absolute change (mg. per cent) Per cent change 2. One day preoperation to postoperation Absolute change (mg. per cent) Per cent change 3. Preoperation to postoperation Absolute change (mg. per cent) Per cent change
gynecologic Major
surgery Mi’nor
uaginal
f-28)” Mean differewes
vaginal (29) + ~___-.-I / t I
~...
t
P
Mean differewes
0.01
-0.70
n.s.
- 0.004
-0.45
n.s.
ns.
- 4.92
-1.21
ns.
-
2.27
-0.83
n.s.
n.s.
- 0.05
-2.77
0.01
- 0.06
-2.19
0.05
t
Pt
0.02
2.14
n.s.
-
2.75
1.04
p
- 0.04
-1.77
-15.40
-2.97
0.01
-18.66
-3.63
0.01
-16.00
-2.65
0.02
- 0.07
-2.83
0.01
-
-2.27
0.05
- 0.06
-1.96
us.
-17.40
-3.79
0.001
-14.97
-2.77
0.02
-14.13
-2.19
0.05
4. Postoperation to one day postoperation Absolute change (w. per cent) Per cent change
0.04
0.09
2.81
0.01
0.10
3.21
0.01
0.08
2.42
0.05
19.41
3.15
0.01
27.11
3.43
0.01
18.27
2.63
0.02
*Population. fLevels
of
significance,
n.s.
=
not
significant.
between 0.4 and 0.6 mg. per cent, and 26 were above 0.6 mg. per cent. Graphs of the results of the first study appear in Fig. 1. The mean values of both absolute and per cent changes in blood ascorbic acid levels from the end of operation through 5 days postoperation are depicted. Blood ascorbic acid levels decreased prior to surgery only in the abdominal procedures. Consequently, this initial
change must be due to some presurgical treatment and may represent the effect of preoperative medication, anesthesia hydration or the 10 minute manual manipulation of the abdomen preparatory to operation. In the vaginal procedures direct contrast, showed a slight increase above preoperative one day levels at the onset of surgery. There was a 15 to 20 per cent increase in blood ascorbic acid concentration at the
Volume Number
97 6
Nutritional
A
s
30
60 90 Time in surgery
lzo
150
aspects
of
l
Axdrblc acidkt
A
Ascorbiclcid
.
tlematccr1t
180
gynecic
stress
753
rlio
Mh.
MANURINE CIUNGESWRING SURGERY
A
-do-,
I A
Fig.
2. Mean
changes
in blood
I I I 5306090Ml5oLsl Time In Swyty
and urine
during
end of all gynecic surgical procedures. The one day postoperative levels dropped 5 per cent below preoperative levels in the abdominal and major vaginal procedures, but had returned to preoperative level in the minor vaginal procedures. A rebound phenomenon was universally observed 3 and 5 days postoperatively which was most apparent in the abdominal and minor vaginal cases. Table I is a summary of the statistical significance of the net resuhs by stages of the major changes in whole blood ascorbic acid observed in the initial study. Varying levels of significance were apparent for stages 2, 3, and 4 in all types of procedures when expressed either in absolute or relative terms. However, anesthesia, per se, did not significantly alter the blood ascorbic acid levels. The observed changes at the end of surgery and 24 hours later tended to be in decreasing order of magnitude from abdomi-
I
1
Ascorbiczcid
I Mill.
gynecological
nal 0.001
surgery.
to -
minor
vaginal
procedures
(P
<
0.05).
Study II. Group mean whole blood ascorbic acid levels one day prior to surgery were 0.66 k 0.47, 0.74 + 0.33, and 0.57 + 0.29 mg. per cent, respectively, for the abdominal, major and minor vaginal groups in the second study. Some of the blood vitamin C levels suggested “low” values7 prior to operation: none was below 0.2 mg. per cent, 5 were between 0.2 and 0.4 mg. per cent, 3 were between 0.4 and 0.6 mg. per cent, and 8 were above 0.6 mg. per cent. The measured values from blood and urine samples collected immediately prior to surgical anesthesia served as individual control levels. The mean per cent changes in the hematocrit, blood ascorbic acid, and the ratio of blood ascorbic acid to hematocrit following anesthesia and during surgery are presented graphically in the upper portion
754
McGanity,
Fujino,
and
Dawson
Am.
March 15, 1967 J. Oh. & Gym:.
ABDOMINAL SURGICAL PROCEWRES
.
-20
I A
I S
I 406090l2ll1M
I
I
Ascorbic acid/k!
I
m
ratio
Min.
Time during Surgery
ABDOMINAL SURGICAL PROCEWRES
-40
I A
I s
43
do
I
w
a Ascorbic acid
I ml
l!!o
lb
h:in.
Time durtng Surgery
Fig.
3. Mean
changes
in blood
and
urine
during
of Fig. 2. Concomitant changes in the urinary VMA and ascorbic acid/creatinine ratio are shown in the lower portion of the figure. The mean hematocrit decreased progressively from the onset of anesthesia throughout the first 60 minutes of the major surgical procedures (Figs. 3 and 4). As one would expect, minor vaginal operations did not reflect this alteration (Fig. 5). This hematocrit response would seem to be due to a combination of factors: type of analgesia and anesthesia, hemodilution from intravenous fluid transfusions, blood loss, and altered hemodynamics as an effect of surgery itself. The mean blood ascorbic acid levels declined 3 per cent during the interval from onset of anesthesia to the start of the major
abdominal
surgery.
surgical procedure. The subsequent changes in both the blood ascorbic acid and ascorbic acid/hematocrit ratio are a result of a very gradual increase in blood ascorbic acid following induction of anesthesia and throughout the first 120 minutes of surgery, then a decline to near baseline values and a secondary elevation after 150 minutes of surgery. These alterations occurred without corresponding changes in the hematocrit. After an initial drop in urinary ascorbic acid levels of almost 20 per cent from onset of anesthesia to surgical incision, there was a very gradual increase of both VMA and ascorbic acid excretion for the first 90 minutes of surgery. During the remaining 60 minutes there was an extremely rapid increase in renal excretion of both metabelites. While creatinine clearance did not
Volume h’umber
97 6
Nutritional
aspects
of
gynecic
stress
755
MAJOR VAGINAL PROCEDURES l 30
i? F Lz P
*a
l
Ascorbic ecid/Hct ratio
A
Ascorbic acid
>
Min. Time during Surgery
M&OR VAGINAL PROCEDURES
*xl
A
Fig.
4. Mean
changes
in blood
s
30
and urine
w 90 Time in Surgery
during
change significantly during surgery, the renal excretion of ascorbic acid increased linearly during the entire length of surgery with a second effort phenomenon occurring after 60 minutes of operation. There appears to be no direct correlation between the VMA and ascorbic acid renal excretion during the initial phase. An apparent time lag of 60 to 90 minutes occurs between the increase in the renal excretion of ascorbic acid and VMA. Quite possibly, this difference in time reflects the respective rates of metabolism of ascorbic acid and VMA. Wherein, the oxidative metabolism and excretion of ascorbic acid proceeds much more rapidly than that of VMA. The changes in renal excretion of both ascorbic acid and VMA during the administration of general anesthesia was similar in
major
120
vaginal
150
180
Min.
surgery.
abdominal (Fig. 3) and minor surgery (Fig. 5). However, an increase in ascorbic acid excretion occurred during the induction of anesthesia and preceding surgery, in vaginal surgery (Fig. 4). It is interesting to note that the dip in blood ascorbic acid values occurs at the time of marked increase in renal excretion of both VMA and vitamin C. The bar graph (Fig. 6) demonstrates the statistically significant relationship (P < 0.001) found between all simultaneous blood ascorbic acid and urine VMA measurements of the second study. This correlation follows an exponential function. Paired sample analysis between all other blood and urine parameters measured of their ratios able to be expressed did not disclose a similar relationship. No such relationship was found
756
McGanity,
Fujino,
and
March
Dawson
41n. J. Ohs. MINOR VAGINAL PROCEDURES
l Hematarit A Ascorbic acid l
A
s
60 90 Time in Surgery
30
120
tlcl ratio
Min.
150
MINORVACINALPROCEWRE
-a-
, A
I s
I w
I M
I w
0
VMA
A
Ascorbic acid
I 120
I 154
Min.
Time in Surgery
Fig.
5. Mean
changes
in blood
and urine
during
minor
vaginal
surgery.
0.6 N = 23
N=l
N = 17 M=6
N = 12
N=8
.I-
0
0.2
0.4 Blood
Fig. 6. Correlation between blood resents the mean values of urine range of blood ascorbic acid levels.
I
+
0.6 Ascorbic
0.8 Acid
1.0
1.2
1.4
(mg%I
ascorbic acid and urine vanilmandelic vanilmandelic acid concentration over N means the number of population.
acid. Each a 0.2 mg.
bar
rep-
per
cent
15, 1967
Bi Gynec.
Volume 97 Number 6
Table
Nutritional
II. Ascorbic
acid levels after anesthesia Blood
Abdominal surgery (5) Preanesthesia Preoperation Postoperation Major vaginal surgery (6) Preanesthesia Preoperation Postoperation Minor vaginal surgery (6) Preanesthesia Preoperation Postoperation *Significantly tSignilicantly
different different
ascorbic (w. %)
aspects
of
gynecic
stress
757
and surgery Blood
acid
ascorbic acid/ hematocrit Mean 5~ S. D.
Mean f S. D.
Hematecrit (%) Mean f S. D.
0.66 2 0.47 0.63 ?r 0.43 0.71 2 0.46*
41.10+ 1.88 39.70 + 2.77 40.50 2 3.81
0.01 2 0.011 0.01 2 0.009 0.01 + 0.010”
0.74 + 0.33 0.74 r 0.39 0.72 + 0.31
44.33 f 1.99 41.33 2 0.93+ 40.66 t 1.51t
0.01 + 0.008 0.01 2 0.009 0.01 clz0.008
0.57 5 0.29 0.54 * 0.26 0.55 2 0.25
37.50 _C6.72 37.20 f 4.82 36.20 + 4.51
0.01 t 0.007 0.01 f- 0.007 0.01 + 0.007
from presurgical level at P = 0.05. from preanesthesia level at P = 01.01.
to exist between urine creatinine and other urine or blood measurements. Thus, this relationship cannot be considered the result of renal function and must be of other metabolic origin. Statistically significant (P < 0.05 or 0.01) (Table II) effects on the blood levels as a result of anesthesia and/or surgery were the decrease in hematocrit observed in the major vaginal surgery group. This is probably due to the excessive blood loss inherent in vaginal hysterectomy. The average measured blood loss in this group was 542 ml., while the average blood loss in the abdominal surgery group was 380 ml. and 66 ml. in the minor vaginal surgery group. Blood ascorbic acid levels were not altered significantly by vaginal surgery. Both the blood ascorbic acid level and the ratio of blood ascorbic acid to hematocrit were increased significantly by abdominal surgery (P < 0.05)) probably reflecting a significant change in blood ascorbic acid concentration since the hematocrit was not significantly altered. Anesthesia per se had a significant suppressant effect on the urinary excretion of ascorbic acid during the initial phase prior to the start of the surgical procedure. The effect of central nervous system depressants upon ascorbic acid metabolism has been studied in experimental animals. Ether anesthesia increased the synthesis in dogs and rats but not in guinea pigs*, which, like man, cannot synthesize ascorbic acid. Bar-
biturates greatly increased ascorbic acid excretion in the rat.g The alterations during surgery in renal excretion of both metabolites are significantly increased for major procedures after the first hour and one half of surgical stress. The calculated absolute and per cent increase in ascorbic acid in body blood at the end of operation was based on the preanesthetic value. The average per cent increase of ascorbic acid in body blood was large in extensive surgery (i.e., major abdominal and major vaginal procedures, 13.6 and 11.4 per cent, respectively), but less obvious in the minor vaginal procedures (3.6 per cent). Calculated increases of blood ascorbic acid were 3.0 mg. in major abdominal procedures, 2.1 mg. in major vaginal procedure and 0.4 mg. in minor vaginal procedures. These values are based on a semiquantitative approximation rather than a precise quantitative determination; but the results obtained give an indication of the increase of ascorbic acid in body blood due to surgery.13 The trend of ascorbic acid increase in each surgical procedure is in agreement with both the statistical data obtained on 95 patients (Table I) and the change of the ratio of blood ascorbic acid level over hematocrit (Fig. 2). The per cent changes appear in Fig. 7. The most pronounced net change in blood ascorbic acid occurred in the abdominal procedures; however, the change due to blood loss were similar in abdominal and
758
McGanity,
Fujino,
and
h4arch 1.5. 1Yb7 Am. J. Obst. & Gym-c.
Dawson
Change of ascorbic acid in body IB%blood due to blood loss 0
Apparent % change of ascorbic acid in body blood
m
Total % change of ascorbic acid in body blood
5 1 Fm 5
10
0
Major Abdominal Fig. 7. Accumulative preanesthesia levels.
changes
Major Vaginal of
blood
ascorbic
the major vaginal procedures. As would be expected from preceding results, and least total blood ascorbic acid change occurred during minor vaginal procedures. Although it seems apparent that blood ascorbic acid increases due to surgical stress, the increase may be partially attributed to a reduction in renal clearance of ascorbic acid during surgery. Therefore, urine ascorbic acid level was expressed on the basis of urine creatinine concentration. As the renal clearance of creatinine is a criterion of renal function, the ascorbic acid clearance test has the same significance below the renal threshold of plasma ascorbic acid which is 1.4 mg. per cent or above. This level was not exceeded in our experiments. Had the increase of ascorbic acid in blood been due to decreased renal clearance of blood ascorbic acid, blood creatinine levels would increase proportionately, and, the ratio of urine ascorbic acidicreatinine would have been unchanged. However, the continuous increase of this ratio in major abdominal and major vaginal procedures excluded this possibility. The results of statistical analysis indicate the increase of this ratio during surgery was significant in major abdominal and major vaginal procedures (P < 0.05), but not in minor vaginal procedure (P < 0.05). Therefore,
Minor Vaginal acid
during
Total Surgical Procedures gynecologic
surgery
from
the
the increase of the ratio ascorbic acid,’ creatinine in urine can be attributed to the net increase in the ascorbic acid mobilization from tissues to blood in surgical stress, and to the enhanced renal clearance of ascorbic acid. Comments The patients in both studies were randomly selected from among our gynecic inpatient population. It is noteworthy that the mean preoperative blood ascorbic acid levels were within normal range although 30-33 per cent of the total population studied were in the unacceptable range.7 Whole blood ascorbic acid was measured rather than serum or leukocyte content in order to estimate the total changes in circulating ascorbic acid which could be attributed to changes in organ tissue content of ascorbic acid and to rates of excretion in the urine, Significant alterations were observed in blood ascorbic acid levels during and following surgery. In all groups of surgical patients in both studies, the concentration of circulating ascorbic acid increased during actual operation. The results of the first study show that circulating ascorbic acid concentration did not decrease until 24 hours after surgery. The extent of this decline appears directly proportional to the severity
Volume Number
97 6
of surgical stress with respect to both blood loss and duration. The subsequent increase in the circulating concentration 3 to 5 days after surgery differed in the three different surgical groups. This rebound phenomenon was most rapid following a minor vaginal surgical procedure and most prolonged after a major abdominal surgical procedure. Renal excretion of ascorbic acid increased throughout surgery, indicating an increased rate of glomerular filtration of ascorbic acid since creatinine clearance was not altered. The increases observed during surgery must necessarily represent a metabolic movement of ascorbic acid into the general circulation from tissues, primarily from the adrenal glands and probably in conjunction with catecholamine release. After leaving the tissue, the blood level of ascorbic acid appears to be suppressed to prior base-line levels or lower as it is metabolized and excreted. The patients subjected to abdominal and major vaginal surgical procedures were maintained solely with physiological infusions “saris” ascorbic acid for the first 48 hours after surgery. In contrast the minor vaginal surgical patients began eating within 24 hours following surgery. The differing rates of recovery in blood ascorbic acid levels in this study appear to reflect in part the rapidity with which the patient can resume the dietary ingestion and assimilation of ascorbic acid. Evidence that anesthesia exerted a significant effect on the measured parameters in most instances is lacking except for the decreases in hematocrit associated with major vaginal surgery and in urinary ascorbic acid excretion. Cyclopropane anesthesia has been shown to significantly increase arterial norAs cyclopropane was epinephrine levels.ll used as the main anesthestic agent in one third of the abdominal and major vaginal surgical procedures, it was considered possible that the increased renal excretion of VMA might prove statistically significant. Although urine VMA concentration progressively increased during surgery, the initial change was not significant. The significant
Nutritional
aspects
of
gynecic
stress
759
portion of the change in VMA and ascorbic acid excretion occurred after 90 minutes of continuous operation, suggesting an abrupt increase in the rates of metabolism and excretion at that time. The inverse correlation found between urine VMA and blood ascorbic acid levels indicates a very close metabolic relationship. Unfortunately, serum VMA was not studied; and a closer study of the relationship between catecholamine and ascorbic acid metabolism at the circulatory or tissue level during surgery should prove rewarding. The renal excretion of ascorbic acid was almost linear after the onset of surgery; whereas, VMA was not appreciably excreted until 90 minutes of continuous surgery had elapsed. In vitro studies by WelchI have shown that the rate of decrease in physiologic activity of oxidizing epinephrine closely parallels the rate of oxygen consumption and that reduced ascorbic acid completely stabilizes the catecholamines by preferential molecular oxidation. The observed relationship between blood ascorbic acid and urine VMA in this study appears to concur with the in vitro study and to imply that, during surgical stress, ascorbic acid functions to impede oxidation metabolism of the catecholamines to VMA. The sum of these results suggest that ascorbic acid moves from the tissues during surgical stress and is excreted much faster than the catecholamines are metabolized and excreted. In theory, perhaps, the rate of metabolic degradation of catecholamines during surgery or similar stress might be decreased by increasing the tissue concentration of ascorbic acid prior to such stress. This is being tested in our laboratory at the present time The authors are grateful to Mrs. Sue Ann Krc for her excellent technical assistance. This research was supported in part by James W. McLaughlin Fellowship Fund, University of Texas hledical Branch, Galveston, statistical analysis was performed Processing Center of the University Medical Branch.
by
Texas. All the Data of Texas
760
McGanity,
Fujino,
and
March 15. 1967 Am. J. Obst. & Gyncc.
Dawson
REFERENCES
1.
Bonsnes, R. W., and Taussky, H. D.: J. Biol. Chem. 158: 581, 1945. D. E., and Muntwyler, E.: Proc. 2. Bowman, Sot. Exper. Biol. & Med. 35: 557, 1937. J. H., Landau, B., Mikal, S., 3. Crandon, Balmanno, J., Jefferson, M., and Mahoney, N.: New England J. Med. 258: 105, 1958. R. M., Chapman, R. E., Consolazio, 4. Kark, C. F., and Nesby, C.: J. Lab. & Clin. Med. 40: 817, 1952. 5. Levenson, S. M., and Upjohn, H. L.: Ann. Surg. 146: 357, 1957. 6. Lowry, 0. H., Bessey, 0. A., and Burch, H. B.: Proc. Sot. Exper. Biol. & Med. 80: 361, 1952. 7. Manual for Nutrition Surveys, ed. 2, 1963, Interdeuartmental Committee on Nutrition for National Defense, United States Government Printing Office, Washington, D. C., p. 235. 8. Manual for Nutrition Surveys, ed. 2, 1963, Interdepartmental Committee on Nutrition for National Defense, United States Government Printing Office, Washington, D. C., p. 117.
Discussion DR.
WILLIS
E.
BROWN,
Little
Rock,
Arkansas.
I have read with interest, if not with understanding, the presentation by Dr. McGanity from the University of Texas-Medical Branch on the effect of three classifications of surgery on the blood levels of ascorbic acids and the urinary levels of vanilmandelic acid. The author has accumulated a large volume of data which he has endeavored to evaluate in relation to surgical stress. Dr. McGanity has divided his clinical material into three categories, i.e., major abdominal surgery, major vaginal surgery, and minor vaginal surgery. Ascorbic acid is stored in large amounts in the adrenal. It will fall rapidly when the gland is stressed such as with trauma or ACTH. Blood ascorbic acid rises initially under stress by release from the adrenal, while the blood ascorbic acid levels subsequently fall as the ascorbic acid is transported to the wound site and concentrations above the renal threshold are excreted. While the author has attempted to compensate for the clinical variables during the course of the surgical procedure by relating these items to blood hematocrit levels and urine creatinine levels, it would appear to me there are other variables which have not been taken into account. In terms of preoperative observations, a single preoperative blood specimen has been obtained. It would appear to be possible that the variations in ascorbic acid intake over several days
9. 10. 11.
12.
13.
14.
15. 16.
17.
Meyer, H., and Epstein, B.: Bull. Res. Council Israel 2: 318, 1952. Pisano, J. J., Crout, J. R., and Abraham, D.: Clin. Chim. acta 7: 285, 1962. Price, H. L., Lurie, A. A., Jones, R. E., Price, M. L., and Linde, H. W.: Anesthesiology 19: 619, 1958. Punty, E. T. G., Clayton, B. E., McSwiney, R. R., and Mills, I. H.: Endocrinology 8: 324, i955. Siostrand. T.: Blood Volume. in Handbook of Physiology, Section 2, Circnlation, Washington, D. C., 1962, American Physiology Society, vol. I, p. 52.. Savers. G.. Savers. M. A.. Lewis. H. L.. and Long, ‘C. N. H.: ‘Proc. Sot. Exper. Biol. & Med. 55: 238, 1944. Stewart, C. P., Horn, D. B., and Robson, J. S.: Biochem. J. 53: 254, 1953. Weiner, N.: The Catecholamines, in The Hormones, New York and London, 1964, Academic Press, Inc., vol. IV, p. 403. Welch, A. D. M.: Am. J. Physiol. 108: 360, 1934.
might alter the theoretical stores of ascorbic acid in the patient’s body. A careful nutritional history should have been taken on all patients regardless of the statement, “That none of these women received supplemental ascorbic acid,” prior to surgery. The human cannot synthesize ascorbic acid as do certain animals. He relies entirely on diet. Elderly people, especially people with a poor nutritional history, may be borderline or low in available vitamin C. The reported normal level of blood ascorbic acid, according to Cecil and Loeb in the Textbook of Medicine, is approximately 1.0 mg. per cent. On this basis, the patients of this study were low normal at the beginning of the experiment. And finally, it would have been helpful had more than one preoperative blood level been taken to provide a more reliable baseline for the calculations. A single determination places in jeopardy all subsequent calculations on this isolated sample. Perhaps information is available and Dr. McGanity can provide us with some idea of the nature of the patient’s intake of ascorbic acid for the several days prior to the preoperative sample, and the possible stabilizing effect that several days of observation might have on these base-line data. It is of interest to note that in the first several charts presented the direction and magnitude of change in blood level of ascorbic acid in the first 60 minutes of surgery is identical for the three
Volume 97 Number 6
Nutritional
.
*
p
categories of surgery studied. This would suggest to me that perhaps there is some other element playing a role in this item. Since none of these patients were apparently operated on under either local or regional block anesthesia, one wonders as to the role of systemic anesthesia in the production of these changes. The mere act of preparing for surgery, going to the operating room, and being strapped on a table is stressful enough, and when one adds the effect of anesthesia it is not surprising that the blood levels rise. One might suspect that it is these factors rather than the surgery per se that effects the initial blood ascorbic acid levels. Perhaps Dr. McGanity has some information relating to the role of anesthesia in the production of these changes which have been described: The differences in observations in ,the blood ascorbic acid levels at later time intervals following the onset of surgery between the three categories of procedure might well represent changes in depth of anesthesia, degree of tissue trauma related to the character of the surgery itself, the rate of. infusion of fluids and/or blood, the level of ascorbic acid in the blood infused, and other such variables related to the necessary features ‘of clinical care of the anesthetized patient. Perhaps some other classification of the surgical material related to degree pf dissection, etc., would be more revealing. And finally, I would like to ask Dr. McGanity if in his closing’remarks he would discuss what he believes to be the clinical significance of these observations in terms of the care of patients requiring gynecologic surgery. It is entirely possible that I have not appreciated the significance of the painstakingly recorded and presented data. DR. ROY G. HOI+Y, Philadelphia, Pennsylvania. It should be readily apparent that considerable effort has been put’ i.nto .this investigation. I ,,believe Dr. Mc.Gani’ty should be commended for initiating studies on biochemical alterations albeit nutritional changes associated with major gynecologic surgery and for investigating further the role of ascorbic acid in human nutrition. It, is my impression that we in gyne~coldgy have been remiss in our concern, reflected in the absence of carefully conducted basic clinical studies on metabolic changes associated with major surgical procedures. We have tended to rely upon studies carried -out by our surgical colleagues on wound healing and metabolic alterations related to surgical stress, trauma, and
aspeck
of
gynecic
stress
761
burns. While the investigation reported by Dr. McGanity was performed on patients with benign and relatively uncomplicated gynecologic disease the data recorded and the interpretation of these data have a more important clinical implication in the surgical approach to the patient with gynecologic malignancy, with inflammatory disease, and nutritional deficiency. Since I do not have data comparable to that presented here my discussion must of necessity be limited to a review of the data obtained by our essayist. The data are clear-cut and the interpretations suggested logical but I propose to ask two questions in’ an attempt to clarify some of the concern that I experienced as I reviewed these data. It is fair to assume that the most important conclusion to be derived from this investigation is that ascorbic acid is mobilized during gynecologic surgery, obviously to a greater extent during a major procedure, and is reflected in an increase in the plasma ascorbic acid concentration and an increase in urinary excretion of the vitamin. That this is a stress phenomenon is the obvious interpretation based upon the concomitant increase in the excretion of the principal metabolic product of catecholamine metabolism, vanilmandelic acid. As pointed out by Dr. McGanity these observations are at variance with results obtained on humans subjected to burns and trauma, either accidental or surgical, and guinea pigs subjected to experimental burns. I should add parenthetically that the guinea pig is the experimental animal of choice because it is, like the human and monkey, incapable of in vivo ascorbic acid synthesis and must rely on exogenous sources of supply. First, may I refer to the preoperative ascorbic acid values, particularly in the first study. The mean plasma ascorbic acid level of ,0.54 mg. per- 100 ml. obtained prior to surgery is somewhat low ~especially since 66 of the 95 women were. found to .be in the range of 0.2 to 0.6 mg. per 100 ml. of plasma. In my experience, normal levels range from 0.6 to 1.2 mg. per 100 ml., levels from 0.3 to 0.6 mg. are probably indicative of, a. mild deficiency of the vitamin and more serious deficiency exists when the plasma concentration falls below 0.3 mg. per 100 ml. Does this not suggest that the majority of the patients were mildly deficient in vitamin C at the time of surgery? Since these preop.erative values were used as individual controls for comparison with subsequent determinations, the fact
762
McGanity,
Fujino,
and
Dawson
that they were low in many of the patients does not, however, invalidate the experimental design nor the conclusions reached. But in this same connection, I wonder why the plasma ascorbic acid determination was used in preference to the buffy coat concentration which appears to be a more reliable index of the ascorbic acid status. The plasma value is known to be highly labile and subject to wide variation even under normal conditions. Second, I am at a loss to understand the rebound phenomenon observed during the five day postoperative period, especially the absence of any significant rebound in the patients on whom vaginal hysterectomy was performed. This has not been reported by others performing similal studies. In all other respects these patients behaved biologically in a manner similar to the major abdominal group. Is there a simple explanation for this discrepancy or does it represent the instability of the plasma ascorbic acid concentration as an experimental tool? Dr. McGanity has appropriately avoided too many conclusions on the significance of his observations. The fundamental role played by ascorbic acid in metabolic processes is unknown. Most of the evidence currently available indicates that it is not a major respiratory catalyst. Ascorbic acid is required for the normal function of fibroblasts and osteoblasts and hence the normal formation of collagen fibers and mucopolysaccharides of connective tissue. Ascorbic acid is sensitive to reversible oxidation which suggests that it may be involved in cellular oxidation and reduction, perhaps by serving as a hydrogen transport agent. Ascorbic acid may influence iron absorption, most likely by serving as a reducing substance to maintain iron in its ferrous form. Vitamin C has been implicated in the conversion of folic acid to folinic acid but here again its role is probably that of a reducing agent. The investigation reported here represents one link in the expanding chain of information about ascorbic acid and its metabolic role in the human. DR. S. LEON ISRAEL, Philadelphia, Pennsylvania. It was known before the turn of our century and was noted by many biologists that reproductive behavior in animals was markedly influenced by their nutritional state, the presence or absence of a mate, the climate, and so forth. In 1932, Hohlweg and Junkmann called our attention to the fact that castration changes of the anterior pituitary could be prevented by
transplanting that gland away from its customary site and they postulated the existence of an area of the midbrain they chose to term “Sexualzcntrum.” Four years later, in 1936, just 30 years ago, Mr. G. W. Theobald, a British obstetrician, hypothesized that the hypothalamus represrnted the sensitive area noted by Hohlweg and Junkmann and that it probably received hormonal stimuli from the gonads, nerve-transmitted ones from the periphery through the crntral nervous system, and still others from the rnvironment via the special senses. Theobald’s concf’pt icd to a re-examination of all the forces thar could possibly explain some of the bizarre performancrs of the uterus during labor, several mcmstrual disorders of odd character, and of certain aspects of anovulatory sterility. It seems fitting that 0111 proceedings should record the= fact that Mr. Theobald has been with us during this nlec+rlg as a guest of one of our fellows. Dr. Holly made reference to the rcboulrtl phenomenon noted by Dr. McGanity. May 1 comment that such rebound responses ani not unusual for endocrine organs. The testes do it well; the ovaries, on occasion, seem also to do so. Possibly, the adrenals have the same capacity. DR. MCGANITY (Closing). I need to clarify several details concerning our studies. We II~P:>sured the whole blood ascorbic acid concentration which includes both the white cell and thr plasma components. The point that Dr. Holly has made about the unreliability of plasma values alone as an indicator of vitamin C nutriturc is well taken. When one compares the concentration of ascorbic acid in absolute and relative terms one finds a preferential phenomena. Preliminary evidence indicates that the plasma and white blood cell levels ultimately will reach an n-r have independent concentration plateau. been unable to saturate either components within 3 to 5 days prior to surgery if a patient presents with values in the low range for vitamin C. Patients in each study were subjected to very careful dietary control for the five to scv(m days prior to the surgical procrdure. Thc>y were fed a diet which was devoid of interfering substances related to VMA excretion and a constant intake of 65 to 70 mg. of vitamin C per day. In the initial study determinations of whole blood ascorbic acid were performed daily for the werk prior to the surgical stress. There were not significant differences in the individual daily values as compared to either the values obtained on the day of or prior to surgery. As a result,
Volume 95
h’umber 6
in the second study we used only three preoperative observations and the preanesthetic value as our individual base-line level. The postoperative rebound phenomena which developed 3 to 5 days after surgery cannot be explained at the present time. Dr. Israel’s comments are very interesting and challenging. We reported earlier this year in the American Journal of Clinical Nutrition some observations on the interrelationship between cyclic hormonal changes occurring during the menstrual cycle and vitamin C and iron status. In closing I would like to point out a few things that our present report does not answer:
Nutritional aspects of gynecic stress763
1. We have not separated clearly the analgesic and anesthetic effects involved in surgical stress and vitamin C response. This needs to be evaluated in greater detail and depth. 2. We are not satisfied with our semiquantitative changes in blood volume during the surgical procedure. 3. We have not fully clarified the dynamics of whole blood, white blood cells, plasma or serum, and renal threshhold for vitamin C. 4. In contrast to almost all of the other vitamin nutrients the mode of action or precise site of action of vitamin C in intermediate metabolism has not been uncovered.
J.
MASAAKI
FUJINO,
EARL
B.
Galveston,
McGANITY,
DAWSON,
M.D., M.D.,
F.R.C.S.
PH.D.*
PH.D.
Texas
Changes which were a result of gynecic surgery in 95 women indicate that the blood levels of ascorbic acid were elevated significantly at the end of surgery and for the first time dropped below the presurgical values by the end of the initiaal 24 hours postoperatively. Simultaneous serial alterations in blood ascorbic acid, urine ascorbic acid, and urine vanilmandelic acid were studied throughout gynecic surgery in I6 women. Blood and urine ascorbic acid levels were observed to inerease progressively during the first 90 minutes of operation, followed by a sharp drop and a secondary rebound in blood ascorbic acid values. Urine vanilmandelic acid levels increased slightly during the first 90 minutes of surgery; then both VMA and ascorbic acid excretion increased another 60 per cent during the succeeding hour of operation. A significant correlation was observed between blood ascorbic acid and urine vanilmandelic acid levels during gynecic surgery.
NUMEROUS reports
have indicated changes in the ascorbic acid levels of blood serum and urine in response to stress such as burns,5 inand ACTH stimu1ation.l’ ju~.y,12 operation,14 An apparent disparity exists between those reports4, 12. 14, 15 indicating an increase in blood ascorbic acid levels due to ACTH induced stress and the reports 3, 5 that blood ascorbic acid levels decrease during surgical stress. Carefully controlled human studies have been performed in our laboratory to ascertain any dynamic changes in whole blood ascorbic acid levels from the preoperative period through the postoperative period of gynecological surgery. In a second study, urine vanilmandelic acid (VMA), the major metabolite of the catecholamines,l’j and urine ascorbic acid were measured concurrently to determine the degree of stress response and its relationship to blood ascorbic acid levels From the Gynecology, Branch.
Department University
during surgery. These results indicate that blood ascorbic acid levels are altered significantly during gynecic surgery. Simultaneous variations were observed to occur in urinary vanilmandelic acid metabolism. Material
and
methods
Study I. Ninety-five patients with physiologically normal benign conditions were studied in the first study during major or minor gynecologic surgery. None of these women received supplemental ascorbic acid or tetracycline medication for the week prior to operation. The total ascorbic acid (ascorbic, dehydroascorbic, and diketogulonic acids) in finger-tip capillary blood was measured the day prior to surgery; at the onset and termination of surgery, and bidaily for the 5 days following surgery. Blood ascorbic acid levels one day preoperative were considered as individual control values and served as the basis for determining subsequent changes in blood ascorbic acid levels resulting from anesthesia and surgery on the first, third, and fifth postoperative days. These changes were expressed both as milligram per cent and per cent change from control.
of Obstetrics and of Texas Medical
Presented by invitation at the Seventy-seventh Annual Meeting of the American Association of Obstetricians and Gynecologists, Hot ‘Springs, Virginia, Sept. 8-10, 1966. *McLaughlin Fellow, 1963-1965. 750
Vohne
97
Number
G
Of these 95, 38 abdominal hysterectomies, 28 vaginal hysterectomies, and 29 dilatations and curettages of the cervix and endometrial cavity were done. Vaginal hysterectomy was classified as a major vaginal surgical procedure, while dilatation and curettage was considered a minor procedure. The average ages of the women in the three groups of the first study were: abdominal 41 (22 to 64), major vaginal 44 (26 to 73), and minor vaginal 40 (20 to 60). Preoperative medications. Demerol was used most frequently with abdominal surgery. Following induction with sodium pentothal, inhalation anesthesia was employed exclusively. The patients were maintained in the third plane of surgical anesthesia with diethyl ether or cyclopropane in abdominal and major vaginal surgery, and with nitrous oxide in the minor vaginal procedures. The duration of surgical stress was in decreasing order from major abdominal, to major vaginal to minor vaginal procedures. Study II. This was designed to determine the concurrent changes in blood and urine ascorbic acid levels and the simultaneous changes in urine vanilmandelic acid (VMA) levels during anesthesia and surgical stress. Serial measurements have been carried out on 16 patients during gynecic surgery. Blood samples and urine samples from an indwelling catheter were collected at: the onset of anesthesia, the commencement of operation, 30 minute intervals during surgery, and the termination of operation. Total ascorbic acid in blood and urine was measured,Gf ’ urine vanilmandelic acid (VMA),l’ and urine creatinine.l Serial blood hematocrits were determined simultaneously. Changes in blood ascorbic acid levels have been expressed in absolute and per cent changes in the blood as well as the blood ascorbic acid,/hematocrit ratio. Urine ascorbic acid and VMA levels were computed as ratios to the simultaneous urine level of creatinine to circumvent changes in amount or rate of glomerular clearance which would affect interpretation of any urinary data. In contrast to the first study, the total anesthetic and surgery time of the major
Nutritional
aspects
of
gynecic
stress
751
vaginal averages slightly longer than the abdominal procedures, 186 versus 184 minutes, The average length of minor vaginal surgery was 68 minutes. The average patient ages of the three groups were: abdominal 36 (30-42) ; major vaginal 51 (39-71) ; and minor vaginal 38 (19-68) years. Results
Study I. The mean whole blood ascorbic acid levels of the 95 women one day prior to surgery was 0.54 k 0.31 mg. per cent and might well be considered somewhat less than adequate. The blood levels of 28 women were between 0.2 and 0.4 mg. per cent, 38 were
Fig. 1. Changes
in blood ascorbic acid levels following abdominal, major vaginal, and minor vaginal surgery. Population in parentheses.
752
McGanity,
Table
Fujino,
I. Changes
and
of blood
March 15, 1913 Am. J. Obst. & Cynw.
Dawson
ascorbic
acid following
Abdominal (38) + Mean differewes
Observed changes 1. One day preoperation to preoperation Absolute change (mg. per cent) Per cent change 2. One day preoperation to postoperation Absolute change (mg. per cent) Per cent change 3. Preoperation to postoperation Absolute change (mg. per cent) Per cent change
gynecologic Major
surgery Mi’nor
uaginal
f-28)” Mean differewes
vaginal (29) + ~___-.-I / t I
~...
t
P
Mean differewes
0.01
-0.70
n.s.
- 0.004
-0.45
n.s.
ns.
- 4.92
-1.21
ns.
-
2.27
-0.83
n.s.
n.s.
- 0.05
-2.77
0.01
- 0.06
-2.19
0.05
t
Pt
0.02
2.14
n.s.
-
2.75
1.04
p
- 0.04
-1.77
-15.40
-2.97
0.01
-18.66
-3.63
0.01
-16.00
-2.65
0.02
- 0.07
-2.83
0.01
-
-2.27
0.05
- 0.06
-1.96
us.
-17.40
-3.79
0.001
-14.97
-2.77
0.02
-14.13
-2.19
0.05
4. Postoperation to one day postoperation Absolute change (w. per cent) Per cent change
0.04
0.09
2.81
0.01
0.10
3.21
0.01
0.08
2.42
0.05
19.41
3.15
0.01
27.11
3.43
0.01
18.27
2.63
0.02
*Population. fLevels
of
significance,
n.s.
=
not
significant.
between 0.4 and 0.6 mg. per cent, and 26 were above 0.6 mg. per cent. Graphs of the results of the first study appear in Fig. 1. The mean values of both absolute and per cent changes in blood ascorbic acid levels from the end of operation through 5 days postoperation are depicted. Blood ascorbic acid levels decreased prior to surgery only in the abdominal procedures. Consequently, this initial
change must be due to some presurgical treatment and may represent the effect of preoperative medication, anesthesia hydration or the 10 minute manual manipulation of the abdomen preparatory to operation. In the vaginal procedures direct contrast, showed a slight increase above preoperative one day levels at the onset of surgery. There was a 15 to 20 per cent increase in blood ascorbic acid concentration at the
Volume Number
97 6
Nutritional
A
s
30
60 90 Time in surgery
lzo
150
aspects
of
l
Axdrblc acidkt
A
Ascorbiclcid
.
tlematccr1t
180
gynecic
stress
753
rlio
Mh.
MANURINE CIUNGESWRING SURGERY
A
-do-,
I A
Fig.
2. Mean
changes
in blood
I I I 5306090Ml5oLsl Time In Swyty
and urine
during
end of all gynecic surgical procedures. The one day postoperative levels dropped 5 per cent below preoperative levels in the abdominal and major vaginal procedures, but had returned to preoperative level in the minor vaginal procedures. A rebound phenomenon was universally observed 3 and 5 days postoperatively which was most apparent in the abdominal and minor vaginal cases. Table I is a summary of the statistical significance of the net resuhs by stages of the major changes in whole blood ascorbic acid observed in the initial study. Varying levels of significance were apparent for stages 2, 3, and 4 in all types of procedures when expressed either in absolute or relative terms. However, anesthesia, per se, did not significantly alter the blood ascorbic acid levels. The observed changes at the end of surgery and 24 hours later tended to be in decreasing order of magnitude from abdomi-
I
1
Ascorbiczcid
I Mill.
gynecological
nal 0.001
surgery.
to -
minor
vaginal
procedures
(P
<
0.05).
Study II. Group mean whole blood ascorbic acid levels one day prior to surgery were 0.66 k 0.47, 0.74 + 0.33, and 0.57 + 0.29 mg. per cent, respectively, for the abdominal, major and minor vaginal groups in the second study. Some of the blood vitamin C levels suggested “low” values7 prior to operation: none was below 0.2 mg. per cent, 5 were between 0.2 and 0.4 mg. per cent, 3 were between 0.4 and 0.6 mg. per cent, and 8 were above 0.6 mg. per cent. The measured values from blood and urine samples collected immediately prior to surgical anesthesia served as individual control levels. The mean per cent changes in the hematocrit, blood ascorbic acid, and the ratio of blood ascorbic acid to hematocrit following anesthesia and during surgery are presented graphically in the upper portion
754
McGanity,
Fujino,
and
Dawson
Am.
March 15, 1967 J. Oh. & Gym:.
ABDOMINAL SURGICAL PROCEWRES
.
-20
I A
I S
I 406090l2ll1M
I
I
Ascorbic acid/k!
I
m
ratio
Min.
Time during Surgery
ABDOMINAL SURGICAL PROCEWRES
-40
I A
I s
43
do
I
w
a Ascorbic acid
I ml
l!!o
lb
h:in.
Time durtng Surgery
Fig.
3. Mean
changes
in blood
and
urine
during
of Fig. 2. Concomitant changes in the urinary VMA and ascorbic acid/creatinine ratio are shown in the lower portion of the figure. The mean hematocrit decreased progressively from the onset of anesthesia throughout the first 60 minutes of the major surgical procedures (Figs. 3 and 4). As one would expect, minor vaginal operations did not reflect this alteration (Fig. 5). This hematocrit response would seem to be due to a combination of factors: type of analgesia and anesthesia, hemodilution from intravenous fluid transfusions, blood loss, and altered hemodynamics as an effect of surgery itself. The mean blood ascorbic acid levels declined 3 per cent during the interval from onset of anesthesia to the start of the major
abdominal
surgery.
surgical procedure. The subsequent changes in both the blood ascorbic acid and ascorbic acid/hematocrit ratio are a result of a very gradual increase in blood ascorbic acid following induction of anesthesia and throughout the first 120 minutes of surgery, then a decline to near baseline values and a secondary elevation after 150 minutes of surgery. These alterations occurred without corresponding changes in the hematocrit. After an initial drop in urinary ascorbic acid levels of almost 20 per cent from onset of anesthesia to surgical incision, there was a very gradual increase of both VMA and ascorbic acid excretion for the first 90 minutes of surgery. During the remaining 60 minutes there was an extremely rapid increase in renal excretion of both metabelites. While creatinine clearance did not
Volume h’umber
97 6
Nutritional
aspects
of
gynecic
stress
755
MAJOR VAGINAL PROCEDURES l 30
i? F Lz P
*a
l
Ascorbic ecid/Hct ratio
A
Ascorbic acid
>
Min. Time during Surgery
M&OR VAGINAL PROCEDURES
*xl
A
Fig.
4. Mean
changes
in blood
s
30
and urine
w 90 Time in Surgery
during
change significantly during surgery, the renal excretion of ascorbic acid increased linearly during the entire length of surgery with a second effort phenomenon occurring after 60 minutes of operation. There appears to be no direct correlation between the VMA and ascorbic acid renal excretion during the initial phase. An apparent time lag of 60 to 90 minutes occurs between the increase in the renal excretion of ascorbic acid and VMA. Quite possibly, this difference in time reflects the respective rates of metabolism of ascorbic acid and VMA. Wherein, the oxidative metabolism and excretion of ascorbic acid proceeds much more rapidly than that of VMA. The changes in renal excretion of both ascorbic acid and VMA during the administration of general anesthesia was similar in
major
120
vaginal
150
180
Min.
surgery.
abdominal (Fig. 3) and minor surgery (Fig. 5). However, an increase in ascorbic acid excretion occurred during the induction of anesthesia and preceding surgery, in vaginal surgery (Fig. 4). It is interesting to note that the dip in blood ascorbic acid values occurs at the time of marked increase in renal excretion of both VMA and vitamin C. The bar graph (Fig. 6) demonstrates the statistically significant relationship (P < 0.001) found between all simultaneous blood ascorbic acid and urine VMA measurements of the second study. This correlation follows an exponential function. Paired sample analysis between all other blood and urine parameters measured of their ratios able to be expressed did not disclose a similar relationship. No such relationship was found
756
McGanity,
Fujino,
and
March
Dawson
41n. J. Ohs. MINOR VAGINAL PROCEDURES
l Hematarit A Ascorbic acid l
A
s
60 90 Time in Surgery
30
120
tlcl ratio
Min.
150
MINORVACINALPROCEWRE
-a-
, A
I s
I w
I M
I w
0
VMA
A
Ascorbic acid
I 120
I 154
Min.
Time in Surgery
Fig.
5. Mean
changes
in blood
and urine
during
minor
vaginal
surgery.
0.6 N = 23
N=l
N = 17 M=6
N = 12
N=8
.I-
0
0.2
0.4 Blood
Fig. 6. Correlation between blood resents the mean values of urine range of blood ascorbic acid levels.
I
+
0.6 Ascorbic
0.8 Acid
1.0
1.2
1.4
(mg%I
ascorbic acid and urine vanilmandelic vanilmandelic acid concentration over N means the number of population.
acid. Each a 0.2 mg.
bar
rep-
per
cent
15, 1967
Bi Gynec.
Volume 97 Number 6
Table
Nutritional
II. Ascorbic
acid levels after anesthesia Blood
Abdominal surgery (5) Preanesthesia Preoperation Postoperation Major vaginal surgery (6) Preanesthesia Preoperation Postoperation Minor vaginal surgery (6) Preanesthesia Preoperation Postoperation *Significantly tSignilicantly
different different
ascorbic (w. %)
aspects
of
gynecic
stress
757
and surgery Blood
acid
ascorbic acid/ hematocrit Mean 5~ S. D.
Mean f S. D.
Hematecrit (%) Mean f S. D.
0.66 2 0.47 0.63 ?r 0.43 0.71 2 0.46*
41.10+ 1.88 39.70 + 2.77 40.50 2 3.81
0.01 2 0.011 0.01 2 0.009 0.01 + 0.010”
0.74 + 0.33 0.74 r 0.39 0.72 + 0.31
44.33 f 1.99 41.33 2 0.93+ 40.66 t 1.51t
0.01 + 0.008 0.01 2 0.009 0.01 clz0.008
0.57 5 0.29 0.54 * 0.26 0.55 2 0.25
37.50 _C6.72 37.20 f 4.82 36.20 + 4.51
0.01 t 0.007 0.01 f- 0.007 0.01 + 0.007
from presurgical level at P = 0.05. from preanesthesia level at P = 01.01.
to exist between urine creatinine and other urine or blood measurements. Thus, this relationship cannot be considered the result of renal function and must be of other metabolic origin. Statistically significant (P < 0.05 or 0.01) (Table II) effects on the blood levels as a result of anesthesia and/or surgery were the decrease in hematocrit observed in the major vaginal surgery group. This is probably due to the excessive blood loss inherent in vaginal hysterectomy. The average measured blood loss in this group was 542 ml., while the average blood loss in the abdominal surgery group was 380 ml. and 66 ml. in the minor vaginal surgery group. Blood ascorbic acid levels were not altered significantly by vaginal surgery. Both the blood ascorbic acid level and the ratio of blood ascorbic acid to hematocrit were increased significantly by abdominal surgery (P < 0.05)) probably reflecting a significant change in blood ascorbic acid concentration since the hematocrit was not significantly altered. Anesthesia per se had a significant suppressant effect on the urinary excretion of ascorbic acid during the initial phase prior to the start of the surgical procedure. The effect of central nervous system depressants upon ascorbic acid metabolism has been studied in experimental animals. Ether anesthesia increased the synthesis in dogs and rats but not in guinea pigs*, which, like man, cannot synthesize ascorbic acid. Bar-
biturates greatly increased ascorbic acid excretion in the rat.g The alterations during surgery in renal excretion of both metabolites are significantly increased for major procedures after the first hour and one half of surgical stress. The calculated absolute and per cent increase in ascorbic acid in body blood at the end of operation was based on the preanesthetic value. The average per cent increase of ascorbic acid in body blood was large in extensive surgery (i.e., major abdominal and major vaginal procedures, 13.6 and 11.4 per cent, respectively), but less obvious in the minor vaginal procedures (3.6 per cent). Calculated increases of blood ascorbic acid were 3.0 mg. in major abdominal procedures, 2.1 mg. in major vaginal procedure and 0.4 mg. in minor vaginal procedures. These values are based on a semiquantitative approximation rather than a precise quantitative determination; but the results obtained give an indication of the increase of ascorbic acid in body blood due to surgery.13 The trend of ascorbic acid increase in each surgical procedure is in agreement with both the statistical data obtained on 95 patients (Table I) and the change of the ratio of blood ascorbic acid level over hematocrit (Fig. 2). The per cent changes appear in Fig. 7. The most pronounced net change in blood ascorbic acid occurred in the abdominal procedures; however, the change due to blood loss were similar in abdominal and
758
McGanity,
Fujino,
and
h4arch 1.5. 1Yb7 Am. J. Obst. & Gym-c.
Dawson
Change of ascorbic acid in body IB%blood due to blood loss 0
Apparent % change of ascorbic acid in body blood
m
Total % change of ascorbic acid in body blood
5 1 Fm 5
10
0
Major Abdominal Fig. 7. Accumulative preanesthesia levels.
changes
Major Vaginal of
blood
ascorbic
the major vaginal procedures. As would be expected from preceding results, and least total blood ascorbic acid change occurred during minor vaginal procedures. Although it seems apparent that blood ascorbic acid increases due to surgical stress, the increase may be partially attributed to a reduction in renal clearance of ascorbic acid during surgery. Therefore, urine ascorbic acid level was expressed on the basis of urine creatinine concentration. As the renal clearance of creatinine is a criterion of renal function, the ascorbic acid clearance test has the same significance below the renal threshold of plasma ascorbic acid which is 1.4 mg. per cent or above. This level was not exceeded in our experiments. Had the increase of ascorbic acid in blood been due to decreased renal clearance of blood ascorbic acid, blood creatinine levels would increase proportionately, and, the ratio of urine ascorbic acidicreatinine would have been unchanged. However, the continuous increase of this ratio in major abdominal and major vaginal procedures excluded this possibility. The results of statistical analysis indicate the increase of this ratio during surgery was significant in major abdominal and major vaginal procedures (P < 0.05), but not in minor vaginal procedure (P < 0.05). Therefore,
Minor Vaginal acid
during
Total Surgical Procedures gynecologic
surgery
from
the
the increase of the ratio ascorbic acid,’ creatinine in urine can be attributed to the net increase in the ascorbic acid mobilization from tissues to blood in surgical stress, and to the enhanced renal clearance of ascorbic acid. Comments The patients in both studies were randomly selected from among our gynecic inpatient population. It is noteworthy that the mean preoperative blood ascorbic acid levels were within normal range although 30-33 per cent of the total population studied were in the unacceptable range.7 Whole blood ascorbic acid was measured rather than serum or leukocyte content in order to estimate the total changes in circulating ascorbic acid which could be attributed to changes in organ tissue content of ascorbic acid and to rates of excretion in the urine, Significant alterations were observed in blood ascorbic acid levels during and following surgery. In all groups of surgical patients in both studies, the concentration of circulating ascorbic acid increased during actual operation. The results of the first study show that circulating ascorbic acid concentration did not decrease until 24 hours after surgery. The extent of this decline appears directly proportional to the severity
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of surgical stress with respect to both blood loss and duration. The subsequent increase in the circulating concentration 3 to 5 days after surgery differed in the three different surgical groups. This rebound phenomenon was most rapid following a minor vaginal surgical procedure and most prolonged after a major abdominal surgical procedure. Renal excretion of ascorbic acid increased throughout surgery, indicating an increased rate of glomerular filtration of ascorbic acid since creatinine clearance was not altered. The increases observed during surgery must necessarily represent a metabolic movement of ascorbic acid into the general circulation from tissues, primarily from the adrenal glands and probably in conjunction with catecholamine release. After leaving the tissue, the blood level of ascorbic acid appears to be suppressed to prior base-line levels or lower as it is metabolized and excreted. The patients subjected to abdominal and major vaginal surgical procedures were maintained solely with physiological infusions “saris” ascorbic acid for the first 48 hours after surgery. In contrast the minor vaginal surgical patients began eating within 24 hours following surgery. The differing rates of recovery in blood ascorbic acid levels in this study appear to reflect in part the rapidity with which the patient can resume the dietary ingestion and assimilation of ascorbic acid. Evidence that anesthesia exerted a significant effect on the measured parameters in most instances is lacking except for the decreases in hematocrit associated with major vaginal surgery and in urinary ascorbic acid excretion. Cyclopropane anesthesia has been shown to significantly increase arterial norAs cyclopropane was epinephrine levels.ll used as the main anesthestic agent in one third of the abdominal and major vaginal surgical procedures, it was considered possible that the increased renal excretion of VMA might prove statistically significant. Although urine VMA concentration progressively increased during surgery, the initial change was not significant. The significant
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portion of the change in VMA and ascorbic acid excretion occurred after 90 minutes of continuous operation, suggesting an abrupt increase in the rates of metabolism and excretion at that time. The inverse correlation found between urine VMA and blood ascorbic acid levels indicates a very close metabolic relationship. Unfortunately, serum VMA was not studied; and a closer study of the relationship between catecholamine and ascorbic acid metabolism at the circulatory or tissue level during surgery should prove rewarding. The renal excretion of ascorbic acid was almost linear after the onset of surgery; whereas, VMA was not appreciably excreted until 90 minutes of continuous surgery had elapsed. In vitro studies by WelchI have shown that the rate of decrease in physiologic activity of oxidizing epinephrine closely parallels the rate of oxygen consumption and that reduced ascorbic acid completely stabilizes the catecholamines by preferential molecular oxidation. The observed relationship between blood ascorbic acid and urine VMA in this study appears to concur with the in vitro study and to imply that, during surgical stress, ascorbic acid functions to impede oxidation metabolism of the catecholamines to VMA. The sum of these results suggest that ascorbic acid moves from the tissues during surgical stress and is excreted much faster than the catecholamines are metabolized and excreted. In theory, perhaps, the rate of metabolic degradation of catecholamines during surgery or similar stress might be decreased by increasing the tissue concentration of ascorbic acid prior to such stress. This is being tested in our laboratory at the present time The authors are grateful to Mrs. Sue Ann Krc for her excellent technical assistance. This research was supported in part by James W. McLaughlin Fellowship Fund, University of Texas hledical Branch, Galveston, statistical analysis was performed Processing Center of the University Medical Branch.
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McGanity,
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March 15. 1967 Am. J. Obst. & Gyncc.
Dawson
REFERENCES
1.
Bonsnes, R. W., and Taussky, H. D.: J. Biol. Chem. 158: 581, 1945. D. E., and Muntwyler, E.: Proc. 2. Bowman, Sot. Exper. Biol. & Med. 35: 557, 1937. J. H., Landau, B., Mikal, S., 3. Crandon, Balmanno, J., Jefferson, M., and Mahoney, N.: New England J. Med. 258: 105, 1958. R. M., Chapman, R. E., Consolazio, 4. Kark, C. F., and Nesby, C.: J. Lab. & Clin. Med. 40: 817, 1952. 5. Levenson, S. M., and Upjohn, H. L.: Ann. Surg. 146: 357, 1957. 6. Lowry, 0. H., Bessey, 0. A., and Burch, H. B.: Proc. Sot. Exper. Biol. & Med. 80: 361, 1952. 7. Manual for Nutrition Surveys, ed. 2, 1963, Interdeuartmental Committee on Nutrition for National Defense, United States Government Printing Office, Washington, D. C., p. 235. 8. Manual for Nutrition Surveys, ed. 2, 1963, Interdepartmental Committee on Nutrition for National Defense, United States Government Printing Office, Washington, D. C., p. 117.
Discussion DR.
WILLIS
E.
BROWN,
Little
Rock,
Arkansas.
I have read with interest, if not with understanding, the presentation by Dr. McGanity from the University of Texas-Medical Branch on the effect of three classifications of surgery on the blood levels of ascorbic acids and the urinary levels of vanilmandelic acid. The author has accumulated a large volume of data which he has endeavored to evaluate in relation to surgical stress. Dr. McGanity has divided his clinical material into three categories, i.e., major abdominal surgery, major vaginal surgery, and minor vaginal surgery. Ascorbic acid is stored in large amounts in the adrenal. It will fall rapidly when the gland is stressed such as with trauma or ACTH. Blood ascorbic acid rises initially under stress by release from the adrenal, while the blood ascorbic acid levels subsequently fall as the ascorbic acid is transported to the wound site and concentrations above the renal threshold are excreted. While the author has attempted to compensate for the clinical variables during the course of the surgical procedure by relating these items to blood hematocrit levels and urine creatinine levels, it would appear to me there are other variables which have not been taken into account. In terms of preoperative observations, a single preoperative blood specimen has been obtained. It would appear to be possible that the variations in ascorbic acid intake over several days
9. 10. 11.
12.
13.
14.
15. 16.
17.
Meyer, H., and Epstein, B.: Bull. Res. Council Israel 2: 318, 1952. Pisano, J. J., Crout, J. R., and Abraham, D.: Clin. Chim. acta 7: 285, 1962. Price, H. L., Lurie, A. A., Jones, R. E., Price, M. L., and Linde, H. W.: Anesthesiology 19: 619, 1958. Punty, E. T. G., Clayton, B. E., McSwiney, R. R., and Mills, I. H.: Endocrinology 8: 324, i955. Siostrand. T.: Blood Volume. in Handbook of Physiology, Section 2, Circnlation, Washington, D. C., 1962, American Physiology Society, vol. I, p. 52.. Savers. G.. Savers. M. A.. Lewis. H. L.. and Long, ‘C. N. H.: ‘Proc. Sot. Exper. Biol. & Med. 55: 238, 1944. Stewart, C. P., Horn, D. B., and Robson, J. S.: Biochem. J. 53: 254, 1953. Weiner, N.: The Catecholamines, in The Hormones, New York and London, 1964, Academic Press, Inc., vol. IV, p. 403. Welch, A. D. M.: Am. J. Physiol. 108: 360, 1934.
might alter the theoretical stores of ascorbic acid in the patient’s body. A careful nutritional history should have been taken on all patients regardless of the statement, “That none of these women received supplemental ascorbic acid,” prior to surgery. The human cannot synthesize ascorbic acid as do certain animals. He relies entirely on diet. Elderly people, especially people with a poor nutritional history, may be borderline or low in available vitamin C. The reported normal level of blood ascorbic acid, according to Cecil and Loeb in the Textbook of Medicine, is approximately 1.0 mg. per cent. On this basis, the patients of this study were low normal at the beginning of the experiment. And finally, it would have been helpful had more than one preoperative blood level been taken to provide a more reliable baseline for the calculations. A single determination places in jeopardy all subsequent calculations on this isolated sample. Perhaps information is available and Dr. McGanity can provide us with some idea of the nature of the patient’s intake of ascorbic acid for the several days prior to the preoperative sample, and the possible stabilizing effect that several days of observation might have on these base-line data. It is of interest to note that in the first several charts presented the direction and magnitude of change in blood level of ascorbic acid in the first 60 minutes of surgery is identical for the three
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categories of surgery studied. This would suggest to me that perhaps there is some other element playing a role in this item. Since none of these patients were apparently operated on under either local or regional block anesthesia, one wonders as to the role of systemic anesthesia in the production of these changes. The mere act of preparing for surgery, going to the operating room, and being strapped on a table is stressful enough, and when one adds the effect of anesthesia it is not surprising that the blood levels rise. One might suspect that it is these factors rather than the surgery per se that effects the initial blood ascorbic acid levels. Perhaps Dr. McGanity has some information relating to the role of anesthesia in the production of these changes which have been described: The differences in observations in ,the blood ascorbic acid levels at later time intervals following the onset of surgery between the three categories of procedure might well represent changes in depth of anesthesia, degree of tissue trauma related to the character of the surgery itself, the rate of. infusion of fluids and/or blood, the level of ascorbic acid in the blood infused, and other such variables related to the necessary features ‘of clinical care of the anesthetized patient. Perhaps some other classification of the surgical material related to degree pf dissection, etc., would be more revealing. And finally, I would like to ask Dr. McGanity if in his closing’remarks he would discuss what he believes to be the clinical significance of these observations in terms of the care of patients requiring gynecologic surgery. It is entirely possible that I have not appreciated the significance of the painstakingly recorded and presented data. DR. ROY G. HOI+Y, Philadelphia, Pennsylvania. It should be readily apparent that considerable effort has been put’ i.nto .this investigation. I ,,believe Dr. Mc.Gani’ty should be commended for initiating studies on biochemical alterations albeit nutritional changes associated with major gynecologic surgery and for investigating further the role of ascorbic acid in human nutrition. It, is my impression that we in gyne~coldgy have been remiss in our concern, reflected in the absence of carefully conducted basic clinical studies on metabolic changes associated with major surgical procedures. We have tended to rely upon studies carried -out by our surgical colleagues on wound healing and metabolic alterations related to surgical stress, trauma, and
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burns. While the investigation reported by Dr. McGanity was performed on patients with benign and relatively uncomplicated gynecologic disease the data recorded and the interpretation of these data have a more important clinical implication in the surgical approach to the patient with gynecologic malignancy, with inflammatory disease, and nutritional deficiency. Since I do not have data comparable to that presented here my discussion must of necessity be limited to a review of the data obtained by our essayist. The data are clear-cut and the interpretations suggested logical but I propose to ask two questions in’ an attempt to clarify some of the concern that I experienced as I reviewed these data. It is fair to assume that the most important conclusion to be derived from this investigation is that ascorbic acid is mobilized during gynecologic surgery, obviously to a greater extent during a major procedure, and is reflected in an increase in the plasma ascorbic acid concentration and an increase in urinary excretion of the vitamin. That this is a stress phenomenon is the obvious interpretation based upon the concomitant increase in the excretion of the principal metabolic product of catecholamine metabolism, vanilmandelic acid. As pointed out by Dr. McGanity these observations are at variance with results obtained on humans subjected to burns and trauma, either accidental or surgical, and guinea pigs subjected to experimental burns. I should add parenthetically that the guinea pig is the experimental animal of choice because it is, like the human and monkey, incapable of in vivo ascorbic acid synthesis and must rely on exogenous sources of supply. First, may I refer to the preoperative ascorbic acid values, particularly in the first study. The mean plasma ascorbic acid level of ,0.54 mg. per- 100 ml. obtained prior to surgery is somewhat low ~especially since 66 of the 95 women were. found to .be in the range of 0.2 to 0.6 mg. per 100 ml. of plasma. In my experience, normal levels range from 0.6 to 1.2 mg. per 100 ml., levels from 0.3 to 0.6 mg. are probably indicative of, a. mild deficiency of the vitamin and more serious deficiency exists when the plasma concentration falls below 0.3 mg. per 100 ml. Does this not suggest that the majority of the patients were mildly deficient in vitamin C at the time of surgery? Since these preop.erative values were used as individual controls for comparison with subsequent determinations, the fact
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that they were low in many of the patients does not, however, invalidate the experimental design nor the conclusions reached. But in this same connection, I wonder why the plasma ascorbic acid determination was used in preference to the buffy coat concentration which appears to be a more reliable index of the ascorbic acid status. The plasma value is known to be highly labile and subject to wide variation even under normal conditions. Second, I am at a loss to understand the rebound phenomenon observed during the five day postoperative period, especially the absence of any significant rebound in the patients on whom vaginal hysterectomy was performed. This has not been reported by others performing similal studies. In all other respects these patients behaved biologically in a manner similar to the major abdominal group. Is there a simple explanation for this discrepancy or does it represent the instability of the plasma ascorbic acid concentration as an experimental tool? Dr. McGanity has appropriately avoided too many conclusions on the significance of his observations. The fundamental role played by ascorbic acid in metabolic processes is unknown. Most of the evidence currently available indicates that it is not a major respiratory catalyst. Ascorbic acid is required for the normal function of fibroblasts and osteoblasts and hence the normal formation of collagen fibers and mucopolysaccharides of connective tissue. Ascorbic acid is sensitive to reversible oxidation which suggests that it may be involved in cellular oxidation and reduction, perhaps by serving as a hydrogen transport agent. Ascorbic acid may influence iron absorption, most likely by serving as a reducing substance to maintain iron in its ferrous form. Vitamin C has been implicated in the conversion of folic acid to folinic acid but here again its role is probably that of a reducing agent. The investigation reported here represents one link in the expanding chain of information about ascorbic acid and its metabolic role in the human. DR. S. LEON ISRAEL, Philadelphia, Pennsylvania. It was known before the turn of our century and was noted by many biologists that reproductive behavior in animals was markedly influenced by their nutritional state, the presence or absence of a mate, the climate, and so forth. In 1932, Hohlweg and Junkmann called our attention to the fact that castration changes of the anterior pituitary could be prevented by
transplanting that gland away from its customary site and they postulated the existence of an area of the midbrain they chose to term “Sexualzcntrum.” Four years later, in 1936, just 30 years ago, Mr. G. W. Theobald, a British obstetrician, hypothesized that the hypothalamus represrnted the sensitive area noted by Hohlweg and Junkmann and that it probably received hormonal stimuli from the gonads, nerve-transmitted ones from the periphery through the crntral nervous system, and still others from the rnvironment via the special senses. Theobald’s concf’pt icd to a re-examination of all the forces thar could possibly explain some of the bizarre performancrs of the uterus during labor, several mcmstrual disorders of odd character, and of certain aspects of anovulatory sterility. It seems fitting that 0111 proceedings should record the= fact that Mr. Theobald has been with us during this nlec+rlg as a guest of one of our fellows. Dr. Holly made reference to the rcboulrtl phenomenon noted by Dr. McGanity. May 1 comment that such rebound responses ani not unusual for endocrine organs. The testes do it well; the ovaries, on occasion, seem also to do so. Possibly, the adrenals have the same capacity. DR. MCGANITY (Closing). I need to clarify several details concerning our studies. We II~P:>sured the whole blood ascorbic acid concentration which includes both the white cell and thr plasma components. The point that Dr. Holly has made about the unreliability of plasma values alone as an indicator of vitamin C nutriturc is well taken. When one compares the concentration of ascorbic acid in absolute and relative terms one finds a preferential phenomena. Preliminary evidence indicates that the plasma and white blood cell levels ultimately will reach an n-r have independent concentration plateau. been unable to saturate either components within 3 to 5 days prior to surgery if a patient presents with values in the low range for vitamin C. Patients in each study were subjected to very careful dietary control for the five to scv(m days prior to the surgical procrdure. Thc>y were fed a diet which was devoid of interfering substances related to VMA excretion and a constant intake of 65 to 70 mg. of vitamin C per day. In the initial study determinations of whole blood ascorbic acid were performed daily for the werk prior to the surgical stress. There were not significant differences in the individual daily values as compared to either the values obtained on the day of or prior to surgery. As a result,
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in the second study we used only three preoperative observations and the preanesthetic value as our individual base-line level. The postoperative rebound phenomena which developed 3 to 5 days after surgery cannot be explained at the present time. Dr. Israel’s comments are very interesting and challenging. We reported earlier this year in the American Journal of Clinical Nutrition some observations on the interrelationship between cyclic hormonal changes occurring during the menstrual cycle and vitamin C and iron status. In closing I would like to point out a few things that our present report does not answer:
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1. We have not separated clearly the analgesic and anesthetic effects involved in surgical stress and vitamin C response. This needs to be evaluated in greater detail and depth. 2. We are not satisfied with our semiquantitative changes in blood volume during the surgical procedure. 3. We have not fully clarified the dynamics of whole blood, white blood cells, plasma or serum, and renal threshhold for vitamin C. 4. In contrast to almost all of the other vitamin nutrients the mode of action or precise site of action of vitamin C in intermediate metabolism has not been uncovered.