- Email: [email protected]
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA
Brit. J. Anaesth. (1970), 42, 1113
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA BY
A. G. BOND AND R. S. PARSONS SUMMARY
I
F
An increase in blood volume during halothane anaesthesia was recorded by Payne, Gardiner and Verner (1959). Morse and associates (1963) found individual changes in plasma volume during halothane anaesthesia but were unable to demonstrate statistically significant haemodilution. Grable and his colleagues (1962) compared the effects of cyclopropane and halothane. They detected a 10 per cent increase in plasma volume during halothane anaesthesia but there was no alteration when cyclopropane was used. A stastically significant fall in haemoglobin concentration during halothane anaesthesia was reported by Bond (1969a, b). Liljedahl and Rieger (1967) showed that the increase in blood volume due to post-haemorrhagic haemodilution in dogs is accompanied by an increase in the total quantity of intravascular protein. Similar observations were made by Skillman, Awwad and Moore (1967) an< i a l s ° by Adamson and Hillman in man (1968). Hyman and Steinfeld (1967) suggested that the protein concentration of plasma is maintained isotonic during changes of plasma volume and Hyman and Paldino (1954) postulated a reflex regulation of plasma protein concentration, the afferent limb of which may be controlled by colloid osmoreceptors or by systemic volume receptors. The purpose of the present study was to determine whether an increase in intravascular protein A. G.
BOND, F.F.A.R.A.C.S., D.A., D.OBST.RX.O.G.. The
Royal Hobart Hospital, Tasmania; R. S. PARSONS, D.SC., M.B., B.S., F.A.A.CB., A.R.A.C.L, Senior Research
Fellow in the Department of Chemistry, University of Tasmania.
accompanies the haemodilution which may occur during anaesthesia. METHODS
The investigation was conducted on twelve adult subjects. In each case pre-operative clinical examination revealed no abnormality other than that comprising the indication for surgery. The study was restricted to the presurgical period of anaesthesia for major surgery. Extraneous causes of blood volume change were thereby excluded. Three techniques of anaesthesia were employed. In each case thiopentone was used for induction. In three cases, anaesthesia comprised spontaneous respiration with oxygen and halothane. In seven cases a similar method was used but the patients had, in addition, lumbar epidural analgesia provided by the injection of mepivacaine. In the remaining two subjects pulmonary ventilation was controlled using halothane, nitrous oxide, oxygen and gallamine. In each case a (venous) sample of blood was taken immediately before the induction of anaesthesia. Further specimens were drawn at intervals of approximately 10 minutes throughout each test period. In sampling, certain precautions were taken. A sterile, dry syringe and needle were used on each occasion. Eisenburg (1963), showed that venous haematocrit and serum protein vary with the site of sampling and with posture. In this study, the sampling site was constant in each patient and the posture was unaltered during the test periods. The use of a tourniquet causes local intravascular elevation of the protein and haematocrit concentrations. Page and Moiruddin (1962), however, found no difference between the protein
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
A statistically significant increase in plasma volume was shown to occur during anaesthesia in twelve adult subjects. The serum protein concentration decreased due to the haemodilution although the total quantity of intravascular protein increased. The gain in circulating protein was statistically significantly related to the magnitude of the plasma volume increase.
BRITISH JOURNAL OF ANAESTHESIA
1114
mediately before the injection of thiopentone. Systolic pressure was recorded throughout at intervals of 2-3 minutes. The results were subjected to graphical integration (see Appendix). For each patient, one preinduction value of each parameter was obtained, together with a series of post-induction values. Each parameter was plotted against time. The post-induction value was that obtained by graphical integration from the moment of induction to the rime at which the last measurement was made. Pre- and post-induction values having been obtained for each parameter in each patient, the differences between them were calculated and subjected to tests of significance. RESULTS
Following induction of anaesthesia there were highly significant falls in the concentrations of haemoglobin and serum protein and in packed cell volume (table I). There were no alterations in the concentrations of sodium, potassium or chlorides. By using the records for haematocrits each change in total protein concentration discovered for serum was now re-expressed as the change occurring in whole blood. In contrast with the finding for serum protein concentrations, the whole blood protein showed no significant alteration following the induction of anaesthesia. However, the range and standard deviation of the mean change in whole blood protein concentration were wide, indicating large individual changes (table I). DISCUSSION AND CONCLUSIONS
An alteration of the whole body to venous haematocrit ratio, or the occurrence of red cell sequestration, would provide an explanation for
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
concentrations of free-flowing and occluded blood until after 2 minutes of occlusion. In the present study, sampling was facilitated by the use of a tourniquet which, however, was never left in place for more than 30 seconds. The method used depends upon the assumption that the venous to whole-body haematocrit ratio remains constant on all occasions (0.91; Chaplin, Mollison and Vetter, 1953). The constancy of the ratio during various types of anaesthesia was demonstrated by Price, Helrich and Conner (1956). Grable and associates (1962) showed that the ratio remains constant during halothane and cyclopropane anaesthesia. Further evidence for the constancy of the ratio is also presented in this paper. Haemoglobin concentration was measured on oxyhaemoglobin. Haematocrits were determined by centrifuging at 3,000 r.p.m. for 30 minutes using a Wintrobe tube. Packed cell volumes were corrected for plasma trapping using the data given by Chaplin and Mollison (1952). Total protein was estimated by the biuret method (Wooton, 1964). The concentrations of albumin and the globulins were measured by electrophoresis. Sodium and potassium concentrations were measured by flame emission using the absorption spectrophotometer. Chlorides were measured by the method of Schales and Schales (1941). All investigations were conducted under strict quality control. In the case of protein and protein electrophoresis the error is ± 1 per cent; for flame emission the error is 0.5 per cent and for the haemoglobin estimations it is ± 2 per cent Systolic blood pressure was recorded by sphygmo-oscillometer. Pre-induction pressure was taken as the mean of three, consecutive, equal measurements made at 5 minute intervals im-
TABLE I
Concentration changes during anaesthesia in twelve patients.
Haemoglobin (g/100 ml) Packed cell volume (ml/100 ml) Serum protein (g/100 ml) Whole-blood protein (g/100 ml)
Mean pre-induction
Mean post-induction
15.1 ±1.75 44.18 ±3.4
42.93 ±3.4
7.07 ±0.97
6.82 ±0.34
3.92 ±0.27
14.6 ±1.69
3.897 ±0.3
Mean dilution 0.5 ±0.21 1.25 ±0.9 0.25 ±0.2 -0.023 ±0.076 (range+0.075 to-0.12)
P <0.001 <0.001 <0.001 >0.5
1
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA
r
TABLE III the observed changes in venous haemoglobin and Correlation coefficients (r) for concentration changes packed cell volume. In this case it would be due to haemodilution. expected that the serum total protein concentration would remain unaltered, whilst the corres- Concentration change r P ponding whole blood protein concentrations would (Hb) v. serum protein >0.5 0.23 be increased. These observations were not made. PCV v. serum protein >0.5 0.36 >0.5 However, if haemodilution caused the haematocrit (Hb)t>. whole blood protein -0.34 fall, a decrease in serum protein concentration would be expected. Such a decrease was observed. concentration changes was calculated (see At the same time it would be expected that the Appendix). Measured in this way it appears that corresponding whole blood total protein concen- the haemoglobin (and haematocrit) was diluted tration would also decrease. Since this was not more than the protein by an amount of 2.66 ml found it was postulated that haemodilution had per 100 ml of blood, the difference being highly occurred but that there had also been a concur- significant statistically (table IV). The only rent increase in the total quantity of intravascular explanation for this difference is that protein is proteins. This hypothesis was examined by liberated into the circulation during the process measuring the changes in concentration of of plasma volume increase. albumin and the globulins following the induction TABLE IV of anaesthesia. Using the method of graphical Haemodilution. integration the whole blood and serum concen3.52 ± 1.6 ml/100 ml blood tration changes of each protein were calculated for Mean dilution of Hb each patient. Tests of correlation were made of Mean dilution of protein 0.86 ±1.8 ml/100 ml blood Mean difference 2.66 ± 2.6 ml/100 ml blood serum concentration changes of each protein spe- P <0.005 cies against their corresponding whole blood concentration changes (table II). In each case a highly The protein release into the circulation was significant correlation was obtained. These strong calculated by subtracting the serum protein concorrelations would not be found if the haemocentrations calculated for simple haemodilution globin and haematocrit falls were due to red cell from the concentrations actually measured (see sequestration. Appendix). The mean intravascular protein gain was 0.22 ±0.18 g/100 ml serum, this being TABLE II highly significant statistically (P<0.001). Serum protein concentration changes versus A scattergram was plotted of protein gains per blood protein concentration changes. 100 ml of serum against volumes of haemodilution r P per 100 ml of blood (fig. 1). The coefficient of Total protein 0.75 <0.005 correlation was highly significant statistically ( r = Albumin 0.97 <0.001 0.72; P = 0.005). This is evidence that during a, globulin 1.00 <0.001 a, globulin 0.99 <0.001 anaesthesia in which a plasma volume increase b globulin 0.87 <0.001 occurs, the magnitude of the haemodilution is g globulin 0.98 <0.001 directly proportional to the accompanying increase in total intravascular protein. Such a relationship If the red cells and protein were both affected strongly suggests that the protein concentration of by simple dilution, their corresponding concen- the plasma is regulated by a mechanism such as tration changes would show strong statistical cor- the colloid osmoreceptors, or circulatory volume relation. No such correlation could be detected sensors of Hyman and Paldino (1954). (table III). This implied that the extent to which The possible sequence of events associated with the protein was diluted differed from that to which the observed changes in blood volume and prothe red cells were diluted. teins can be surmised. The increase in the plasma The volume of diluting fluid required to be component of blood volume probably has a dual added to each 100 ml of blood to produce the origin, being partly associated with endocrine observed haematocrit, haemoglobin and protein changes affecting the kidney during anaesthesia
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
f
1115
BRITISH JOURNAL OF ANAESTHESIA
1116 6 iO _O XI
•3 CO
to (0
o c CD
•D
O
m
I 0
0-2
0-4
0-6
Protein gain (g/100ml serum) FIG. 1 Blood volume increase versus protein gain. PB = 0.1561B,j-0.3264 (r = 0.72; P=0.005). Blood volume increase (g/100 ml blood). Protein gain (g/100 ml serum)
and partly due to fall in mean intracapillary hydrostatic pressure (Starling, 1893). Hodge, Lowe and Vane (1966) observed that alteration of blood volume was related inversely to angiotensin concentration. Angiotensin release is a consequence of anaesthesia, being related to the associated decrease in renal blood flow (de Bono et al., 1963). Angiotensin causes an increase in blood pressure and stimulates the release of aldosterone (Laragh et al., 1960). Aldosterone causes renal sodium and water retention with consequent increase of the interstitial and plasma volumes (Ganong, 1967). Blomstedt (1967) observed an increase in blood volume 4 days after the injection of cortisone, the change being due to haemodilution by interstitial fluid. (Leighty and Osborne in 1965, however, were unable to find any alteration of blood volume following stress doses of corticosteroids.) Antidiuretic hormone is also liberated during anaesthesia and may contribute to an increase in plasma volume. Intracapillary pressure may decrease during halothane anaesthesia. Grable and associates (1962) found haemodilution during halothane anaesthesia but not during cyclopropane anaesthe-
TABLE V
Blood pressure changes (mm Hg). Mean pre-induction pressure Mean post-induction pressure Mian change P
140±20 92 ±16 48 ±21 <0.001
TABLE VI
Correlation coefficients for haemodilution versus systolic pressure changes. Dilution v. pressure fall +0.31 Dilution v. post-in^ucrion pressure —0.53
<0.5 -0.1
It therefore appears that a fall in mean intracapillary hydrostatic pressure may accompany anaesthesia. The colloid osmotic pressure is initially unaltered so that fluid enters the circulation from the interstitial compartment. At the same time the plasma volume may increase due to the effects of endocrine substances acting on the kidney. The circulating plasma proteins are diluted. The decreased colloid osmotic pressure stimulates the colloid osmoreceptors and plasma proteins are released into the circulation from the thoracic duct or via capillary transmural pores
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
E
sia. Halothane causes a fall in systemic pressure (Payne, 1963) due to a decrease in cardiac output (Price, 1969) and a peripheral vasodilatation (Black and McArdle, 1962). (The haemodilution which has been shown to accompany halothane anaesthesia must cause a fall in blood viscosity and hence itself result in hypotension.) The algebraic sum of these effects would be a net decrease in mean intracapillary hydrostatic pressure. Cyclopropane, however, is associated with the maintenance of systemic pressure, vasoconstriction in skin and muscle vessels and, in light anaesthesia, an increased cardiac output (Wylie and Churchill-Davidson, 1966). These effects of cyclopropane would result in little alteration of mean intracapillary hydrostatic pressure. In the present series, in which halothane was used, there was a highly significant fall in mean blood pressure (table V). However, because of the complexity of the relationship between systemic and intracapillary hydrostatic pressures, attempts to find correlation between the magnitude of haemodilution and the systolic blood pressure changes failed (table VI).
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA
1117
Bond, A. G. (1969a). Determination of operative blood loss: the sources of error and elimination of inaccuracy in the haemoglobin dilution technique. Anaesthesia. 24 (No. 2), 219. (1969b). Variability of haemoglobin concentration during anaesthesia. Brit. J. Anaesth., 41, 947. Chaplin, H., and MoUison, P. L. (1952). Correction for plasma trapped in red cell column of the haematocrit. Blood, 7, 1227. Vetter, H. (1953). The body/venous hematoAPPENDIX crit ratio: its constancy over a wide hematocrit Calculation of increase in plasma volume per 100 ml range. J. din. Invest., 32, 1309. blood. De Bono, E., Le:, de J., Mottram, F. R., Pickering, G. 'lOOxHb, W., Brown, J. J., Keen, H., Peart, W. S., and 100 Sanderson, P. H. (1963). The action of angiotensin Hb, in man. Clm. Sci., 25, 123. where H b ^ pre-induction Hb concentration; Eisenburg, S. (1963). Effect of posture and position of Hb, = post-induction Hb concentration. the venous sampling site on the hematocrit and serum protein concentration. J. Lab. din. Med., 61, 755. Calculation of intravascular protein gain per 100 ml Ganong, W. F. (1967). Review of Medical Physiology, serum. 3rd ed., p. 312. Los Altos: Lange. p Pb X100 Grable, R, Finck, A. J., Abrams, A. L., and Williams, " (100-H) + V J. A. (1962). The effect of cyclopropane and halowhere Pi«= serum protein concentration expected folthane on the blood volume in man. Anesthesiology. lowing a haemodilution of V ml per 100 28, 828. ml of blood; Hodge, R. L., Lowe, R. D., and Vane, J. R. (1966). The Pb= pre-induction whole blood protein; effects of alteration of blood volume on the concentration of circulating angiotensin in anaestheH = pre-induction haematocrit; tised dogs. J. Physiol. (Lond.), 185, 613. V = volume of haemodilution per 100 ml blood. Hyman, C., and Paldino, R. L. (1954). Influence of Then P g = P . m - P M reticulo-endothelial blockade and stimulation on rate of disappearance of Evans Blue from the where P t = protein gain in g per 100 ml serum; circulation. Amer. J. Physiol, 179, 594. P l m = measured post-induction serum protein. Steinfeld J. L. (1967). Regulation of plasma volume. Amer. Heart J., 74, 436. Graphical integration. Trie integral mean of each parameter was found by Jones, J. H., and Peters, D. K. (1966). Measurement of capillary permeability to plasma protein by a gelplotting its values obtained during the test period, using filtration technique. Clin. Sri., 31, 389. the y axis for time. The total area under the resultant line was obtained by direct measurement. This area was Laragh, J. H., Angers, M., Kelly, W. G., and Lieberman, S. (1960). Hypotensive agents and pressor recalculated to give a rectangle, one side of which was substances: the effect of epinephrine, norepinegiven by the time axis. The length of the other side phrinc, angiotensin II and others on secretory rate gave the integral mean value of the parameter during of aldosterone in man. J. Amer. med. Ass., 174, the test period. 234. This method of obtaining a mean is of value in comparing results obtained from different patients when the Leighty, R. D., and Osborne, R. H. (1965). Blood volume response of glucocorticoids in humans. J. intervals of observation are variable. For example, in Trauma, 5, 741. the results for haemoglobin concentrations, most cases showed a fall for the first 10-20 minutes followed by Liljedahl, S-O., and Rieger, A. (1967). Blood volume and plasma protein. IV: Importance of thoracic a steady state at the new leveL Were an arithmetical duct lymph in restitution of plasma volume and mean to be used for these results, cases with a short plasma protein after bleeding and immediate subduration of observation would be biased to give excesstitution in anaesthetised dogs. Ada. Mr. scand., sively high post-induction mean haemoglobin concenSuppl., 379, 39. trations. By using integral mean values this bias is Morse, H. T., Linde, H. W., Mishalove, R. D., and reduced. Price, H. L. (1963). Relation of blood volume and REFERENCES hemodynamic changes during halothane anesthesia in man. Anesthesiology, 24, 790. Adamson, J., and Hillrnan, R. S. (1968). Blood volume and plasma protein replacement following acute Page, I. H., and Moiruddin, M. (1962). The effect of blood loss in normal man. J. Amer. med Ass., 205, venous occlusion on serum cholesterol and total 609. protein concentration—a warning. Circulation, 25, 651. Black, G. W., and McArdle, L. (1962). The effects of halothane on the peripheral circulation in man. Payne, J. P. (1963). The circulatory effects of halothane. Brit. J. Anaesth., 34, 2. Proc. roy. Soc. Med., 56 (No. 2), 92. Blomstedt, B. (1967). The effect of cortisone on plasma Gardiner, p . , and Vemer, I. R. (1959). Cardiac volume, total blood volume and serum Protein. output during halothane anaesthesia. Brit. J. ,4CM endocr. (Kbh.), 55, 472. Anaesth., 31, 87.
(Hyman and Paldino, 1954; Jones and Peters, 1966; Youlten, 1968). The amounts of circulating fluid and proteins are thus both increased. The gain in circulating protein is similar in origin to that observed to occur in response to posthaemorrhagic haemodilution.
0-
\
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
f
BRITISH JOURNAL OF ANAESTHESIA
1118
HEMODILUTION ET PROTEINES PLASMATIQUES DURANT L'ANESTHESIE SOMMAIRE
Durant l'anesthesie chez douze sujets adultes, un accroissement statistiquement significatif du volume plasmatique a ixt dimontri. La concentration de prottines siriques s'abaissa suite a lTntmodilution, en depit du fait que la quantiti totalc de prot£incs intravasculaires augmenta. La correlation entre le gain en proteines circulantes et la grandeur de l'accroissement du volume plasmatique fut statistiquement significative. BLUTVERDONNUNG UND PLASMAPROTEINE WAHREND DER ANAESTHESIE ZUSAMMEKFASSIING
Bei 12 Erwachsenen konntc eine statistisch signifikante Zunahme des Plasmavolumens wfihrend der Anaesthesie gezeigt werden. Auf Grund der Blutverdunnung nahm die Konzentration des Serumeiweifies ab, obwohl die Gesamtmenge des intravaskularen Eiweifies zunahm. Dtese Zunahme des zirkulierenden Eiweifies stand mit dem Ausmafi der Plasmavolumenzunahme in einem statistisch gesicherten Zusammenhang.
FIFTH WORLD CONGRESS OF ANAESTHESIOLOGISTS Please note change of dates: The Congress will take place in Kyoto, Japan, on SEPTEMBER 19-23, 1972. The Belgian Professional Association of Specialists in Anaesthesia and Rcanimation is to organize a three-weeks group tour from Brussels to the Far East, open to all anaesthetists of Western Europe and their families The journey can thus be accomplished on the most advantageous terms. Booking is done on guaranteed periodical payments in advance. For further particulars apply to Dr. Et. Troch, Marcel de Backerstraat 2, Ekeren 2 (Antwerp), Belgium.
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
Price H. L. (1960). General Anesthesia and circulatory homeostasis. Physiol. Rev., 40, 187. Helrich, M., and Conner, E. H. (1956). A relation between hemodynamic and plasma volume alterations during general anesthesia in man. J. din. Invest., 35, 125. Schales, O., and Schales, S. S. (1941). Simple and accurate method for the determination of chloride in biological fluids. J. biol. Chem., 140, 879. Skillman, J. J., Awwad, H. K., and Moore, F. D. (1967). Plasma protein kinetics of the early transcapillary refill after hemorrhage in man. Surg. Gynec. Obstet., 125, 983. Starling, E. H. (1898). The production and absorption of lymph; in Textbook of Physiology (ed. Schafer, E. A.), p. 285. Edinburgh and London: Young J. Pentland. Wooton, I. D. P. (1964) Micro-methods in Medical Biochemistry, 4th ed., p. 138. London: Churchill. Wylie, W. D., and Churchill-Davidson, H. C (1966). A Practice of Anaesthesia, 2nd ed., p. 257. London: Lloyd-Luke. Youlten, L. J. (1968). The permeability to plasma proteins of skeletal muscle (rat cremaster) blood vessel walls. J. Physiol. {Lond.\ 194, 63P.
>
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA BY
A. G. BOND AND R. S. PARSONS SUMMARY
I
F
An increase in blood volume during halothane anaesthesia was recorded by Payne, Gardiner and Verner (1959). Morse and associates (1963) found individual changes in plasma volume during halothane anaesthesia but were unable to demonstrate statistically significant haemodilution. Grable and his colleagues (1962) compared the effects of cyclopropane and halothane. They detected a 10 per cent increase in plasma volume during halothane anaesthesia but there was no alteration when cyclopropane was used. A stastically significant fall in haemoglobin concentration during halothane anaesthesia was reported by Bond (1969a, b). Liljedahl and Rieger (1967) showed that the increase in blood volume due to post-haemorrhagic haemodilution in dogs is accompanied by an increase in the total quantity of intravascular protein. Similar observations were made by Skillman, Awwad and Moore (1967) an< i a l s ° by Adamson and Hillman in man (1968). Hyman and Steinfeld (1967) suggested that the protein concentration of plasma is maintained isotonic during changes of plasma volume and Hyman and Paldino (1954) postulated a reflex regulation of plasma protein concentration, the afferent limb of which may be controlled by colloid osmoreceptors or by systemic volume receptors. The purpose of the present study was to determine whether an increase in intravascular protein A. G.
BOND, F.F.A.R.A.C.S., D.A., D.OBST.RX.O.G.. The
Royal Hobart Hospital, Tasmania; R. S. PARSONS, D.SC., M.B., B.S., F.A.A.CB., A.R.A.C.L, Senior Research
Fellow in the Department of Chemistry, University of Tasmania.
accompanies the haemodilution which may occur during anaesthesia. METHODS
The investigation was conducted on twelve adult subjects. In each case pre-operative clinical examination revealed no abnormality other than that comprising the indication for surgery. The study was restricted to the presurgical period of anaesthesia for major surgery. Extraneous causes of blood volume change were thereby excluded. Three techniques of anaesthesia were employed. In each case thiopentone was used for induction. In three cases, anaesthesia comprised spontaneous respiration with oxygen and halothane. In seven cases a similar method was used but the patients had, in addition, lumbar epidural analgesia provided by the injection of mepivacaine. In the remaining two subjects pulmonary ventilation was controlled using halothane, nitrous oxide, oxygen and gallamine. In each case a (venous) sample of blood was taken immediately before the induction of anaesthesia. Further specimens were drawn at intervals of approximately 10 minutes throughout each test period. In sampling, certain precautions were taken. A sterile, dry syringe and needle were used on each occasion. Eisenburg (1963), showed that venous haematocrit and serum protein vary with the site of sampling and with posture. In this study, the sampling site was constant in each patient and the posture was unaltered during the test periods. The use of a tourniquet causes local intravascular elevation of the protein and haematocrit concentrations. Page and Moiruddin (1962), however, found no difference between the protein
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
A statistically significant increase in plasma volume was shown to occur during anaesthesia in twelve adult subjects. The serum protein concentration decreased due to the haemodilution although the total quantity of intravascular protein increased. The gain in circulating protein was statistically significantly related to the magnitude of the plasma volume increase.
BRITISH JOURNAL OF ANAESTHESIA
1114
mediately before the injection of thiopentone. Systolic pressure was recorded throughout at intervals of 2-3 minutes. The results were subjected to graphical integration (see Appendix). For each patient, one preinduction value of each parameter was obtained, together with a series of post-induction values. Each parameter was plotted against time. The post-induction value was that obtained by graphical integration from the moment of induction to the rime at which the last measurement was made. Pre- and post-induction values having been obtained for each parameter in each patient, the differences between them were calculated and subjected to tests of significance. RESULTS
Following induction of anaesthesia there were highly significant falls in the concentrations of haemoglobin and serum protein and in packed cell volume (table I). There were no alterations in the concentrations of sodium, potassium or chlorides. By using the records for haematocrits each change in total protein concentration discovered for serum was now re-expressed as the change occurring in whole blood. In contrast with the finding for serum protein concentrations, the whole blood protein showed no significant alteration following the induction of anaesthesia. However, the range and standard deviation of the mean change in whole blood protein concentration were wide, indicating large individual changes (table I). DISCUSSION AND CONCLUSIONS
An alteration of the whole body to venous haematocrit ratio, or the occurrence of red cell sequestration, would provide an explanation for
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
concentrations of free-flowing and occluded blood until after 2 minutes of occlusion. In the present study, sampling was facilitated by the use of a tourniquet which, however, was never left in place for more than 30 seconds. The method used depends upon the assumption that the venous to whole-body haematocrit ratio remains constant on all occasions (0.91; Chaplin, Mollison and Vetter, 1953). The constancy of the ratio during various types of anaesthesia was demonstrated by Price, Helrich and Conner (1956). Grable and associates (1962) showed that the ratio remains constant during halothane and cyclopropane anaesthesia. Further evidence for the constancy of the ratio is also presented in this paper. Haemoglobin concentration was measured on oxyhaemoglobin. Haematocrits were determined by centrifuging at 3,000 r.p.m. for 30 minutes using a Wintrobe tube. Packed cell volumes were corrected for plasma trapping using the data given by Chaplin and Mollison (1952). Total protein was estimated by the biuret method (Wooton, 1964). The concentrations of albumin and the globulins were measured by electrophoresis. Sodium and potassium concentrations were measured by flame emission using the absorption spectrophotometer. Chlorides were measured by the method of Schales and Schales (1941). All investigations were conducted under strict quality control. In the case of protein and protein electrophoresis the error is ± 1 per cent; for flame emission the error is 0.5 per cent and for the haemoglobin estimations it is ± 2 per cent Systolic blood pressure was recorded by sphygmo-oscillometer. Pre-induction pressure was taken as the mean of three, consecutive, equal measurements made at 5 minute intervals im-
TABLE I
Concentration changes during anaesthesia in twelve patients.
Haemoglobin (g/100 ml) Packed cell volume (ml/100 ml) Serum protein (g/100 ml) Whole-blood protein (g/100 ml)
Mean pre-induction
Mean post-induction
15.1 ±1.75 44.18 ±3.4
42.93 ±3.4
7.07 ±0.97
6.82 ±0.34
3.92 ±0.27
14.6 ±1.69
3.897 ±0.3
Mean dilution 0.5 ±0.21 1.25 ±0.9 0.25 ±0.2 -0.023 ±0.076 (range+0.075 to-0.12)
P <0.001 <0.001 <0.001 >0.5
1
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA
r
TABLE III the observed changes in venous haemoglobin and Correlation coefficients (r) for concentration changes packed cell volume. In this case it would be due to haemodilution. expected that the serum total protein concentration would remain unaltered, whilst the corres- Concentration change r P ponding whole blood protein concentrations would (Hb) v. serum protein >0.5 0.23 be increased. These observations were not made. PCV v. serum protein >0.5 0.36 >0.5 However, if haemodilution caused the haematocrit (Hb)t>. whole blood protein -0.34 fall, a decrease in serum protein concentration would be expected. Such a decrease was observed. concentration changes was calculated (see At the same time it would be expected that the Appendix). Measured in this way it appears that corresponding whole blood total protein concen- the haemoglobin (and haematocrit) was diluted tration would also decrease. Since this was not more than the protein by an amount of 2.66 ml found it was postulated that haemodilution had per 100 ml of blood, the difference being highly occurred but that there had also been a concur- significant statistically (table IV). The only rent increase in the total quantity of intravascular explanation for this difference is that protein is proteins. This hypothesis was examined by liberated into the circulation during the process measuring the changes in concentration of of plasma volume increase. albumin and the globulins following the induction TABLE IV of anaesthesia. Using the method of graphical Haemodilution. integration the whole blood and serum concen3.52 ± 1.6 ml/100 ml blood tration changes of each protein were calculated for Mean dilution of Hb each patient. Tests of correlation were made of Mean dilution of protein 0.86 ±1.8 ml/100 ml blood Mean difference 2.66 ± 2.6 ml/100 ml blood serum concentration changes of each protein spe- P <0.005 cies against their corresponding whole blood concentration changes (table II). In each case a highly The protein release into the circulation was significant correlation was obtained. These strong calculated by subtracting the serum protein concorrelations would not be found if the haemocentrations calculated for simple haemodilution globin and haematocrit falls were due to red cell from the concentrations actually measured (see sequestration. Appendix). The mean intravascular protein gain was 0.22 ±0.18 g/100 ml serum, this being TABLE II highly significant statistically (P<0.001). Serum protein concentration changes versus A scattergram was plotted of protein gains per blood protein concentration changes. 100 ml of serum against volumes of haemodilution r P per 100 ml of blood (fig. 1). The coefficient of Total protein 0.75 <0.005 correlation was highly significant statistically ( r = Albumin 0.97 <0.001 0.72; P = 0.005). This is evidence that during a, globulin 1.00 <0.001 a, globulin 0.99 <0.001 anaesthesia in which a plasma volume increase b globulin 0.87 <0.001 occurs, the magnitude of the haemodilution is g globulin 0.98 <0.001 directly proportional to the accompanying increase in total intravascular protein. Such a relationship If the red cells and protein were both affected strongly suggests that the protein concentration of by simple dilution, their corresponding concen- the plasma is regulated by a mechanism such as tration changes would show strong statistical cor- the colloid osmoreceptors, or circulatory volume relation. No such correlation could be detected sensors of Hyman and Paldino (1954). (table III). This implied that the extent to which The possible sequence of events associated with the protein was diluted differed from that to which the observed changes in blood volume and prothe red cells were diluted. teins can be surmised. The increase in the plasma The volume of diluting fluid required to be component of blood volume probably has a dual added to each 100 ml of blood to produce the origin, being partly associated with endocrine observed haematocrit, haemoglobin and protein changes affecting the kidney during anaesthesia
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
f
1115
BRITISH JOURNAL OF ANAESTHESIA
1116 6 iO _O XI
•3 CO
to (0
o c CD
•D
O
m
I 0
0-2
0-4
0-6
Protein gain (g/100ml serum) FIG. 1 Blood volume increase versus protein gain. PB = 0.1561B,j-0.3264 (r = 0.72; P=0.005). Blood volume increase (g/100 ml blood). Protein gain (g/100 ml serum)
and partly due to fall in mean intracapillary hydrostatic pressure (Starling, 1893). Hodge, Lowe and Vane (1966) observed that alteration of blood volume was related inversely to angiotensin concentration. Angiotensin release is a consequence of anaesthesia, being related to the associated decrease in renal blood flow (de Bono et al., 1963). Angiotensin causes an increase in blood pressure and stimulates the release of aldosterone (Laragh et al., 1960). Aldosterone causes renal sodium and water retention with consequent increase of the interstitial and plasma volumes (Ganong, 1967). Blomstedt (1967) observed an increase in blood volume 4 days after the injection of cortisone, the change being due to haemodilution by interstitial fluid. (Leighty and Osborne in 1965, however, were unable to find any alteration of blood volume following stress doses of corticosteroids.) Antidiuretic hormone is also liberated during anaesthesia and may contribute to an increase in plasma volume. Intracapillary pressure may decrease during halothane anaesthesia. Grable and associates (1962) found haemodilution during halothane anaesthesia but not during cyclopropane anaesthe-
TABLE V
Blood pressure changes (mm Hg). Mean pre-induction pressure Mean post-induction pressure Mian change P
140±20 92 ±16 48 ±21 <0.001
TABLE VI
Correlation coefficients for haemodilution versus systolic pressure changes. Dilution v. pressure fall +0.31 Dilution v. post-in^ucrion pressure —0.53
<0.5 -0.1
It therefore appears that a fall in mean intracapillary hydrostatic pressure may accompany anaesthesia. The colloid osmotic pressure is initially unaltered so that fluid enters the circulation from the interstitial compartment. At the same time the plasma volume may increase due to the effects of endocrine substances acting on the kidney. The circulating plasma proteins are diluted. The decreased colloid osmotic pressure stimulates the colloid osmoreceptors and plasma proteins are released into the circulation from the thoracic duct or via capillary transmural pores
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
E
sia. Halothane causes a fall in systemic pressure (Payne, 1963) due to a decrease in cardiac output (Price, 1969) and a peripheral vasodilatation (Black and McArdle, 1962). (The haemodilution which has been shown to accompany halothane anaesthesia must cause a fall in blood viscosity and hence itself result in hypotension.) The algebraic sum of these effects would be a net decrease in mean intracapillary hydrostatic pressure. Cyclopropane, however, is associated with the maintenance of systemic pressure, vasoconstriction in skin and muscle vessels and, in light anaesthesia, an increased cardiac output (Wylie and Churchill-Davidson, 1966). These effects of cyclopropane would result in little alteration of mean intracapillary hydrostatic pressure. In the present series, in which halothane was used, there was a highly significant fall in mean blood pressure (table V). However, because of the complexity of the relationship between systemic and intracapillary hydrostatic pressures, attempts to find correlation between the magnitude of haemodilution and the systolic blood pressure changes failed (table VI).
HAEMODILUTION AND PLASMA PROTEINS DURING ANAESTHESIA
1117
Bond, A. G. (1969a). Determination of operative blood loss: the sources of error and elimination of inaccuracy in the haemoglobin dilution technique. Anaesthesia. 24 (No. 2), 219. (1969b). Variability of haemoglobin concentration during anaesthesia. Brit. J. Anaesth., 41, 947. Chaplin, H., and MoUison, P. L. (1952). Correction for plasma trapped in red cell column of the haematocrit. Blood, 7, 1227. Vetter, H. (1953). The body/venous hematoAPPENDIX crit ratio: its constancy over a wide hematocrit Calculation of increase in plasma volume per 100 ml range. J. din. Invest., 32, 1309. blood. De Bono, E., Le:, de J., Mottram, F. R., Pickering, G. 'lOOxHb, W., Brown, J. J., Keen, H., Peart, W. S., and 100 Sanderson, P. H. (1963). The action of angiotensin Hb, in man. Clm. Sci., 25, 123. where H b ^ pre-induction Hb concentration; Eisenburg, S. (1963). Effect of posture and position of Hb, = post-induction Hb concentration. the venous sampling site on the hematocrit and serum protein concentration. J. Lab. din. Med., 61, 755. Calculation of intravascular protein gain per 100 ml Ganong, W. F. (1967). Review of Medical Physiology, serum. 3rd ed., p. 312. Los Altos: Lange. p Pb X100 Grable, R, Finck, A. J., Abrams, A. L., and Williams, " (100-H) + V J. A. (1962). The effect of cyclopropane and halowhere Pi«= serum protein concentration expected folthane on the blood volume in man. Anesthesiology. lowing a haemodilution of V ml per 100 28, 828. ml of blood; Hodge, R. L., Lowe, R. D., and Vane, J. R. (1966). The Pb= pre-induction whole blood protein; effects of alteration of blood volume on the concentration of circulating angiotensin in anaestheH = pre-induction haematocrit; tised dogs. J. Physiol. (Lond.), 185, 613. V = volume of haemodilution per 100 ml blood. Hyman, C., and Paldino, R. L. (1954). Influence of Then P g = P . m - P M reticulo-endothelial blockade and stimulation on rate of disappearance of Evans Blue from the where P t = protein gain in g per 100 ml serum; circulation. Amer. J. Physiol, 179, 594. P l m = measured post-induction serum protein. Steinfeld J. L. (1967). Regulation of plasma volume. Amer. Heart J., 74, 436. Graphical integration. Trie integral mean of each parameter was found by Jones, J. H., and Peters, D. K. (1966). Measurement of capillary permeability to plasma protein by a gelplotting its values obtained during the test period, using filtration technique. Clin. Sri., 31, 389. the y axis for time. The total area under the resultant line was obtained by direct measurement. This area was Laragh, J. H., Angers, M., Kelly, W. G., and Lieberman, S. (1960). Hypotensive agents and pressor recalculated to give a rectangle, one side of which was substances: the effect of epinephrine, norepinegiven by the time axis. The length of the other side phrinc, angiotensin II and others on secretory rate gave the integral mean value of the parameter during of aldosterone in man. J. Amer. med. Ass., 174, the test period. 234. This method of obtaining a mean is of value in comparing results obtained from different patients when the Leighty, R. D., and Osborne, R. H. (1965). Blood volume response of glucocorticoids in humans. J. intervals of observation are variable. For example, in Trauma, 5, 741. the results for haemoglobin concentrations, most cases showed a fall for the first 10-20 minutes followed by Liljedahl, S-O., and Rieger, A. (1967). Blood volume and plasma protein. IV: Importance of thoracic a steady state at the new leveL Were an arithmetical duct lymph in restitution of plasma volume and mean to be used for these results, cases with a short plasma protein after bleeding and immediate subduration of observation would be biased to give excesstitution in anaesthetised dogs. Ada. Mr. scand., sively high post-induction mean haemoglobin concenSuppl., 379, 39. trations. By using integral mean values this bias is Morse, H. T., Linde, H. W., Mishalove, R. D., and reduced. Price, H. L. (1963). Relation of blood volume and REFERENCES hemodynamic changes during halothane anesthesia in man. Anesthesiology, 24, 790. Adamson, J., and Hillrnan, R. S. (1968). Blood volume and plasma protein replacement following acute Page, I. H., and Moiruddin, M. (1962). The effect of blood loss in normal man. J. Amer. med Ass., 205, venous occlusion on serum cholesterol and total 609. protein concentration—a warning. Circulation, 25, 651. Black, G. W., and McArdle, L. (1962). The effects of halothane on the peripheral circulation in man. Payne, J. P. (1963). The circulatory effects of halothane. Brit. J. Anaesth., 34, 2. Proc. roy. Soc. Med., 56 (No. 2), 92. Blomstedt, B. (1967). The effect of cortisone on plasma Gardiner, p . , and Vemer, I. R. (1959). Cardiac volume, total blood volume and serum Protein. output during halothane anaesthesia. Brit. J. ,4CM endocr. (Kbh.), 55, 472. Anaesth., 31, 87.
(Hyman and Paldino, 1954; Jones and Peters, 1966; Youlten, 1968). The amounts of circulating fluid and proteins are thus both increased. The gain in circulating protein is similar in origin to that observed to occur in response to posthaemorrhagic haemodilution.
0-
\
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
f
BRITISH JOURNAL OF ANAESTHESIA
1118
HEMODILUTION ET PROTEINES PLASMATIQUES DURANT L'ANESTHESIE SOMMAIRE
Durant l'anesthesie chez douze sujets adultes, un accroissement statistiquement significatif du volume plasmatique a ixt dimontri. La concentration de prottines siriques s'abaissa suite a lTntmodilution, en depit du fait que la quantiti totalc de prot£incs intravasculaires augmenta. La correlation entre le gain en proteines circulantes et la grandeur de l'accroissement du volume plasmatique fut statistiquement significative. BLUTVERDONNUNG UND PLASMAPROTEINE WAHREND DER ANAESTHESIE ZUSAMMEKFASSIING
Bei 12 Erwachsenen konntc eine statistisch signifikante Zunahme des Plasmavolumens wfihrend der Anaesthesie gezeigt werden. Auf Grund der Blutverdunnung nahm die Konzentration des Serumeiweifies ab, obwohl die Gesamtmenge des intravaskularen Eiweifies zunahm. Dtese Zunahme des zirkulierenden Eiweifies stand mit dem Ausmafi der Plasmavolumenzunahme in einem statistisch gesicherten Zusammenhang.
FIFTH WORLD CONGRESS OF ANAESTHESIOLOGISTS Please note change of dates: The Congress will take place in Kyoto, Japan, on SEPTEMBER 19-23, 1972. The Belgian Professional Association of Specialists in Anaesthesia and Rcanimation is to organize a three-weeks group tour from Brussels to the Far East, open to all anaesthetists of Western Europe and their families The journey can thus be accomplished on the most advantageous terms. Booking is done on guaranteed periodical payments in advance. For further particulars apply to Dr. Et. Troch, Marcel de Backerstraat 2, Ekeren 2 (Antwerp), Belgium.
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on June 30, 2015
Price H. L. (1960). General Anesthesia and circulatory homeostasis. Physiol. Rev., 40, 187. Helrich, M., and Conner, E. H. (1956). A relation between hemodynamic and plasma volume alterations during general anesthesia in man. J. din. Invest., 35, 125. Schales, O., and Schales, S. S. (1941). Simple and accurate method for the determination of chloride in biological fluids. J. biol. Chem., 140, 879. Skillman, J. J., Awwad, H. K., and Moore, F. D. (1967). Plasma protein kinetics of the early transcapillary refill after hemorrhage in man. Surg. Gynec. Obstet., 125, 983. Starling, E. H. (1898). The production and absorption of lymph; in Textbook of Physiology (ed. Schafer, E. A.), p. 285. Edinburgh and London: Young J. Pentland. Wooton, I. D. P. (1964) Micro-methods in Medical Biochemistry, 4th ed., p. 138. London: Churchill. Wylie, W. D., and Churchill-Davidson, H. C (1966). A Practice of Anaesthesia, 2nd ed., p. 257. London: Lloyd-Luke. Youlten, L. J. (1968). The permeability to plasma proteins of skeletal muscle (rat cremaster) blood vessel walls. J. Physiol. {Lond.\ 194, 63P.
>