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Apgar index: A statistical tool
Apgar index: A statistical tool RAYMOND
J, JENNETT,
HARRY
S. WARFORD.
CAROL
KREINICK,
GLENN
W.
Phornw.
.4~izona
M.D. PH.D.
M.A.
WATERKOTTE,
M.D.
Twenty-seven years has elapsed since Virginia Apgar proposed a new method of evaluation of the newborn infant. The proposal gained rapid and almost universal acceptance and has stood the test of time. Considered at first to be both a guide for resuscitation and a statistical tool, the latter is now its main use. Although the original score was applied at 1 minute of age, both a i-minute scoring and a Sminute scoring are now the general custom. There is, however, no general consensus as to which is the better indicator of outcome. Use of both as separate entities is cumbersome. A method which with a single number gives weight to both the i-minute score and the B-minute score and also to the relative change is described. An analysis of selected variables with the use of this index is presented. (AM. J. OBSTET. GYNECOL. 140206, 1981.)
TWENTY-SEVEN YEARS has elapsed since Virginia Apgar’ proposed a new method for evaluation of the newborn infant. She recommended that five objective signs, which could be determined easily and without interfering with the care of the infant, be substituted for the generally used end points of “breathing time” and “crying time.” The signs chosen, each with a rating of 0, 1, or 2, were heart rate, respiratory effort, reflex irritability, muscle tone, and color. The proposal gained almost universal acceptance and appears to have stood the test of time. Proposals such as Chamberlain’s,’ to simplify the score by using what he and others viewed as the two most important criteria, heart rate and reHex irritability, have had little general acceptance. Although the original recommendation was for a “grading” at 1 minute of age, suggestions that scores be given at later ages soon followed. Of these, the 5-minute score has the most usage. Opinions as to the significance of the score have varied. Although once considered as a guide to resuscitation, few would now so regard it. Apgar’s stated purpose for proposing the scoring system was the establishment
From the Division of Reproductive Hospital and Medical Center.
Medicine,
St. Joseph’s
Presented at the Forty-seventh Annual Meeting of the PaciJic Coast Obstetrical and Gynecological Society, Monterey, California, October 6 I1 1 1980. Reprint requests: Raymond J. Jennett, M.D., Reproductive Medicine, St. Joseph:< Hospital Center, Phoenix, Arizona 85013.
206
Diubion oj and Medical
of a simple, clear classification of newborn infants which could be used for comparison of the results of obstetric practice and the effects of resuscitation. It is this statistical use of a newborn score which has been her unique contribution. Few if any pertinent papers are published that do not use the score as an outcome criterion. Whether the l-minute score or the 5-minute score is the preferred criterion is much less clear, and there is no general agreement as to the physiologic significance of the score. Reflecting on the addition of a 5-minute score by others, Apgar remarked that although the l-minute score was a reflection of acid-base status, the S-minute score might be more predictive of survival.” Gregory,’ on the other hand, was of the opinion that the one minute score correlated well with both acidosis and survival. He observed that the five minute score might possibly correlate with brain damage but that vigorous resuscitation should reverse this trend. It was our observation that such resuscitation increased the trend toward the clustering of .5-minute scores in the high range. This in turn suggested that the common practice of using a 5-minute score of 7 or more as an indicator of satisfactory outcome was of questionable validity. Brettschneider and associates,’ in reporting on the relationship of fetal acceleration determinations and perinatal outcome, admitted that their study might be criticized for the use of the 5-minute Apgar score as an indicator of morbidity. They justified the use on the basis that it had been used by others for similar studies. Based on these observations and with the postulate 0002-9378/81/100206+07$00.70/0
0
1981
‘The C:. V. Mosby
Co.
Volume Number
Apgar index
140 2
1 MINUTE
10
9
8
7
25
27
28
28
APMR
6
207
SCORE
5
4
3
2
10
6 5 MINUTE APGAR SCORE
5
2
4
\
4567776h420
\\ \ Fig. 1. Rounded Apgar indices. that change during the first 5 minutes of life would be more indicative of the infant’s condition than a single score, a method was sought to determine an index of this change and to provide a dynamic rather than a static statement of the neonate’s condition.
Material and methods That a dynamic rather than a static evaluation is desirable is attested to by the custom of reporting both a l-minute score and a 5-minute score in individual case reports. To do the same for statistical reports is unacceptably cumbersome since there are 12 1 possible combinations. A computer works best with a single number and, since our data were computer stored, such a single number was sought. A simple product of the two scores was considered but discarded since it would not differentiate between a rising trend and a falling trend. A score of 6 at 1 minute and 9 at 5 minutes would have a much different significance than the reverse. The formula that was finally selected for testing was (A 1 x A5) [ 1 + O.l(A5 - Al)]. Simply stated, the product of the l-minute score and the 5-minute score is increased by 10% for each point of rise or decreased by 10% for each point of fall. A score of 5 at 1 minute and 7 at 5 minutes is expressed as 5 x 7 x 1.2 = 42. Conversely, a score of 7 at 1 minute and 5 at 5
minutes results in 7 X 5 X 0.8 = 28. Fig. 1 is a nomograph of the possible combinations with decimals eliminated by rounding to the nearest whole number. Numbers within the diagonal lines result from identical l- and 5-minute scores. Numbers above the lines represent rising scores while the numbers below the lines reflect falling scores. This number will be referred to as the index. The Arizona Perinatal Program’s computerized perinatal data system has been previously described.6 Data from more than 52,000 deliveries from throughout the state are now stored. However, only data from St. Joseph’s Hospital where the system has been in full operation since January, 1977, were used in this study. From this date through June 15, 1980, 11,519 live births with verified length of stay were recorded. These infants were divided into five gestational age groups. Estimated gestational age was recorded by the obstetrician at the time of maternal admission. All infants were assigned a neonatal estimated gestational age by the method of Ballard and associates7 upon nursery admission by a nurse trained in the technique. If the two estimates agreed within 2 weeks, the obstetric assessment was used for group assignment. If the discrepancy was greater, infant weight was used as an arbitration factor for group assignment. Gestational age
208
Jennett
Table
et
al.
I. Distribution
by gestational
age and mode of delivery Total
(krtntional agf (weeks)
Arbitration weight (gm)
>36 33-36 29-32 26-28 <26
>2,750 1,751-2,750 1,251-1.750 75 1- I.250 (75 1
Vuginul
delirvq
C mrean
.sectmi
NO.
%
h’o.
R
A’(/.
R
10.122 I ,02Y 227 105 36 11,519
87.9 8.Y 2.0 0.9 0.3
8.810 809 141 78 35 9,873
87 .o 78.6 62.1 74.3 97.2
I.312 220 X6 27 1 1.646
1X0 2 I .4 37-Y 25.7 2.8
Overall cesarean section rate: 14.3%. Table
II. Long stay: Group 1 -Minute
of ‘7%of
No. Score
total
infants
Apgar
Lntr dkcharge
10 9 8 7 6 5 4 3 9 1-o
14 3519 3120 743 236 95 72 41 34 25
0.2 44.6 39.5 9.4 3.0 1.2 0.9 0.5 0.4 0.3
0 84 145 47 20 10 11 9 8 11
*With
verified
length
of‘ stay.
Table
III.
Blood
A infants-discharged scow
alive* (n = 7,899) 5.Minute
Apgar Late discharge
7~ of latr discharge
No. of infants
% of
0.0 24.4 42.0 13.6 5.8 2.9 3.2 2.6 2.3 3.2
728 6371 636 101 35 13 6 4 4 1
9.2 80.7 8.0 1.3 0.4 0.2 0.08 0.05 0.05 0.02
total
scow
Index % oflate
No.
discharge
infants
19 239 50 14 8 4 5 2 4 0
5.5 69.3 14.5 4.0 2.3 1.2 1.4 0.6 1.2 0.0
of
727 2879 3420 486 165 76 53 46 32 15
7~ of
Late
total
discharge
9.2 36.5 43.3 6.1 2.0 1.o 0.7 0.6 0.4 0.2
19 69 160 33 17 11 : 12 10
R
of late
discharge 5.5 20.0 46.4 9.6 4.9 3.2 2.0 2.0 3.5 2.9
Index go- 100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
pH: First hour (all age groups)
I -Minute
Apgar
score
ii-Minute
score
Index
% of
% of SCOW
Apgar
X0??
% of
% of % of
SC-Ore
Score
Total
Low QH
group
low value
Total
Low pH
group
low v&r
Total
10 9 8 7 6 5 4 3 2 1-O
I 24 88 55 39 34 37 18 23 24
0 5 14 21 11 19 15 8 11 15
0.0 20.8 15.9 38.2 28.2 55.9 40.5 44.4 47.8 62.5
0.0 4.2 11.8 17.6 9.2 16.0 12.6 6.7 9.2 12.6
10 129 91 42 36 15 7 5 3 5
2 28 31 22 17 9 2 2 2 4
20.0 21.7 34.0 52.4 42.2 60.0 28.5 40.0 66.6 80.0
1.7 23.5 26.0 18.5 14.3 7.6 1.7 1.7 1.7 3.4
7 20 92 64 30 33 22 28 23 24
group criteria and distribution by gestational age group and delivery mode are shown in Table I. The effectiveness of the l-minute Apgar score, the 5minute Apgar score, and the above-described index in predicting outcome was tested using as outcome criteria the length of nursery stay (group A by vaginal delivery), neonatal deaths (all groups), and blood pH determinations during the first hour of life (all groups).
Results Distribution by I-minute and j-minute scores and index fitr group A (term) infants born by vaginal deliv-
R of
Low pH
group
low value
In&x
1 4 15 28 10 17 8 11 14 14
14.3 20.0 16.3 43.7 33.3 51.5 36.4 39.3 60.9 58.3
0.8 3.4 12.6 23.5 8.4 14.8 6.7 9.2 11.8 11.8
go-100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 IO-19 o-9
ery and with verified length of stay is shown in Table II. The l-minute scores were more evenly distributed than the S-minute scores with 93.7% of the scores being 7 or greater. Of the remainder, 1.35% had a score of 3 or less. The clustering of j-minute scores is obvious by comparison. Fully 8 1% had a score of 9 and 99% had a score of 7 or greater. Only nine infants (0.12%) had a score of 3 or less. Although the index decides are not strictly comparable, distribution is quite similar to that of the l-minute score with 95.1% in the upper four deciles and 1.2% of the infants in the three lowest deciles.
Volume Number
140
Table
IV. Neonatal
Apgar
index
209
2
deaths:
Group
A
I -Minute Apgar score
5-Minute
Apgar
Deaths Score
No. of birth.s
No.
10 9
21 4,203
!: 6 5 4 3 2 1-o
4,108 1,019 332 139 115 73 58 56
Table
V. Neonatal
Deaths
90-100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
Deaths
%
No.
%
No. of births
0 0
0.0 0.0
974 8,018
0 3
0.0 0.04
23 2 2 2 2 1 9
0.20 0.07 0.6 1.4 1.7 2.7 1.7 16.0
857 153 64 24 12 7 6 9
23 2 3 2 1
0.2 2.0 3.1 12.5 16.6 14.3
No.
%
970 3,382
0 0
0.0 0.0
90-100 80-89
4,524 645 232 116 84’ 77 53 41
2 1 3 0 2 3 10
0.31 0.04 0.43 2.6 0.0 2.6 5.7 25.4
70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
I?ldJ?x
deaths A
Group
B
Deaths decile
Index
No. of births
Group
h&x
score
No. of births 970 3382 4524 645 232 116 84 77 53 41
C
Deaths
No.
Rate
No. of births
0 8
0.0 0.0 0.04 0.3 0.4 2.6 0.0 2.6 5.7 24.4
53 186 468 145 48 45 24 25 16 19
2 1 3 0 2 3 10
Group
Deaths
_ No.
Rate
No. of births
0 0 6 4 0 2 0 1 1 3
0.0 0.0 1.3 2.7 0.0 4.4 0.0 4.0 6.2 15.8
7 12 46 33 14 12 8 10 18 20
Early discharge of normal infants is the prevailing practice in this hospital so that 32% were discharged within the first 24 hours, 58.2% were discharged during the second day, and 5.5% were discharged during the third day. Only 4.3% remained in the nursery for 4 or more days, which was designated as a long stay. Distribution for these 345 infants by l-minute and 5-minute scores and index is also shown in Table II. Although only 6.3% of the infants had a l-minute score of less than 7, 20% of infants with long stays were segregated into this group. By contrast, only 6.7% of infants were similarly segregated by the 5-minute score. The efficiency of the index in predicting long stay was comparable to that of the l-minute score. Since low Apgar scores are considered to be a reflection of acidosis, distribution of infants by blood pH during the first hour of life was analyzed and is displayed in Table III. Storage of blood gas data was added some time after the inception of the computer system but results for 343 infants were available. A pH of less than 7.2 1 was designated as low. The clustering effect in the high range is again evident for the 5-minute score. Seventy-nine percent of these infants,
Group
No.
Rate
0 2 10 8 1 4 1 6 11 13
0.0 16.6 21.7 24.2 7.4 33.3 12.5 60.0 61.0 65.0
D Death-s
No. of births 3 1 12 11 4 11 1 7 8 26
No.
Rate
2 1 6 2 4 8 1 7 7 25
66.6 100.0 50.0 18.2 100.0 72.7 100.0 100.0 87.5 96.1
including 83 of the infants with a low pH value, had a 5-minute score of 7 or greater. Only eight infants (6.8%) were segregated into the group with a score of 3 or less. Of particular note, more than half of 46 infants with a 5-minute score of 7 had a low pH. The l-minute score placed 28.6% of the infants with low pH in the group with a score of 3 or less. The index was even more definitive, placing 38.2% of the infants with low pH into the three lowest deciles. Twenty-three of the group A infants died. Breakdown for the overall neonatal mortality rate of 0.23% is given in Table IV. Fifteen of the deaths are segregated in the lower three deciles of the index group. Nine of the infants had a l-minute score of 3 or less while only eight had a similar 5-minute score. The tentative conclusion from these observations was that both the l-minute score and the index were much superior to the 5-minute score for predicting suboptima1 neonatal outcome by the criteria used. The index in turn appeared to be moderately more discriminatory than the l-minute score and, therefore, warranted further evaluation as a statistical tool. Correlation of index groups with neonatal mortality
210
Jenneti et al.
Table
VI. Composite
long-stay
and mortality
croup Index de&
Long-Jtuy
rate
High
60-69 50-59 40-49 30-39 20-29
Middle
decile and range:
Groups
.4
Range
90-100 80-89 70-79
rates by index
Group Neonatal
death rate
0.02
0.02
0.56
0.56
LOW
10-19
A and B
5.9
Range
i”r’ronatal death rate
Range
High
High
Middle
Middle
Low
Low
H
Lmg-.5tay
rate
Index d&u go- 100 80-89 70-79 tiO-6’) 50-59 40-49 30-39 20-29
IO-19
5.9
o-9
o-9
Group A long-stay rate is for vaginal deliveries only. All others are for combined vaginal and cesarean section deliveries. Table VII. Eftects of selected variables on index distribution
High Middle Low
89.0 9.8
92.7 6.9
1.2
0.4
94.2 5.6 0.2
FHR: Fetal heart rate. for gestational age groups A. B, C, and D is shown in Table V. For all age groups there is a generally inverse relationship between deaths (and death rate) and the index. This is particularly noted in group C where 30 of the 56 deaths were in the lowest three deciles for a mortality rate of 62.5%. Consideration was next given to whether the data allowed the classification of the index into reasonabl) clear-cut range grouping. Review of the blood pH data in Table III suggested a rather sharp increase in 10x1 values in the 60 to 69 index group over the 70 to 79 group. Additionally, there was a significant increase in the mortality rate fin- infants in group C with an index ill the three lowest deciles. Based on this, the decile groups were divided into high, middle, and low ranges, as shown in Table VI, which also compares long-stav rate and neonatal mortality rate for infants in groups A and B by this method. Long stay for infants in group A was -I days or more, as previousiy described. Long stay t’or infants in group B was defined as more than 7 days. Both long-stay rates and neonatal rilortality rates increased signilicantly for the middIe and low ranges fox both age groups. The eff’cct of’ selected variables on the Apgar index was tested. All infants in group A born by vaginal delivery were used as the standard. First, infants with possible fetal distress suggested by the presence of
mec:oniurn-stdiIied amniotic fluid or lt,tal heart rate decelerations were deleted. As shown iI1 ‘l‘able VII. there was a modest shift of’ infants into the high range. \vith only 0.4% remaining in the low range. Deletion of illfants whose mothers had received Ilarcotic-s or a paracervical block during labor resultrd in a ful-ther shift of infants into the high range, as also slm~in in Table VII. This ideal group had onl! 0.31!7( in the low range. The trend was the opposite when the effect of paracervical block was analyzed. Paracervical block without a subsequent bradycardia resulted in only a moderate downward shift, as depicted in Table VIII. However, if bradycardia was associated, the downward shift was marked, with 24.3% of the infants falling into the middle and low ranges. When the common practice of accepting a 5-minute score of 7 01‘ greater as evidence of satisfactory outcome is followed, 94.5% of infants exhibiting bradycardia after paracervical block had a score in this range. Effects similar to those of paracerG:al block were noted for meconium staining of amniotic fluid and ma)be compared in Table VIII. Thick meconium was assoclated with a marked shift to the middle and IOH range>.
Comment An index has been proposed which with a single number gives weight to both the I-minute i\pgar score and the .5-minute Apgar score and also to the relative change. As Virginia Apgar herself pointed out in her reflections and advice on her method of evaluating the newborn infant, if it is to be expected that the longer asphyxia exists, the more likely it is that death or permanent damage will occur, then a grading that reflects this w&d seem to be a more valid method of statistical evaluation than a single score, be it either at one minute or at 5 minutes.”
Volume 140 Number 2
Table VIII.
Apgar index
Effects of selected variables
on index
distribution Paracmical
“Standard” Range
High (70-100) Middle (30-69) Low (O-29) *Percentage of bradycardia:
(N = 8,810)
89.0 9.8 1.2
No bradycardia (N = 2,203)
(group
A-vaginal
211
births) Meconium
block Bradycardia * (N = 235)
Light 717)
(N =
86.5
75.7
82.7
11.9 1.6
20.0 4.3
14.3 3.0
Thick (N = 402)
74.6 19.2 6.2
9.6.
Comparison of l-minute scores, 5-minute scores, and index with the use of length of nursery stay, blood pH in the first hour of life, and neonatal mortality rates demonstrates a clear superiority of the l-minute score and the index over the 5-minute score in assessing neonatal condition. There appears to be little support for the common practice of reporting a 5-minute Apgar score of 7 or greater as an indicator of satisfactory outcome. The index appears to be moderately more discriminatory in segregating infants with suboptimal outcome into the lower ranges. This is in large part due to a mathematical characteristic of the method. For
example, a J-point rise from a l-minute score of 3 to a 5-minute score of 6 yields an index of 23, which would keep the infant in the lowest range. A similar S-point rise from a l-minute score of 6 to a 5-minute score of 9 results in an index of 70, which would shift the infant to the high range. The validity of this is supported by the data presented. The use of the index as a statistical tool should serve Virginia Apgar’s goal of “the reestablishment of simple, clear classification or ‘grading’ of newborn infants which can be used as a basis for discussion and comparison of the results of obstetric practices, types of maternal pain relief and the effects of resuscitation.“’
REFERENCES
1. Apgar, V.: A proposal for a new method of evaluation of the newborn infant, Anesth. Analg. 32:260, 1953. 2. Chamberlain, G.: Assessment of the Apgar score, Lancet 2:1225, 1974. 3. Apgar, V.: The newborn (Apgar) scoring system. Reflections and Advice, Pediatr. Clin. North Am. 13:645, 1966. 4. Gregory, G. A.: Resuscitation of the newborn, Anesthesiology.43:225, 1975.
Discussion N. SMIITH, San Francisco, California. Great beauty can be found in simplicity. Virginia Apgar made a significant contribution to medicine by introducing a simple newborn scoring system. Originally this assessment was intended to aid in the comparison of obstetric techniques and the effects of drugs and aggressive forms of resuscitation of the infant. A number of authors have attempted to modify her evaluations. Dr. Jennett alluded to Chamberlain’s idea of reducing the number of objective signs to be observed. The original proposal outlined by Apgar continues to stand in most institutions, although the addition of a 5-minute score is common. Dr. Jennett and his colleagues were able to compare results in a large number of newborn infants by utilizing a computer. One-minute and five-minute scores were used in a formula designed to reveal the significance of changes occurring in that interval of time. This formula was designed because of the inability of DR.
ROBERT
5. Brettschneider, F., Goldstein, P., Baer, D., Kimball, A., and London, R.: Fetal acceleration and perinatal outcome, J. Reprod. Med. 25: 10, 1980. 6. Jennett, R. J,, Gall, D., Waterkotte, G. W., and Warford, H. S.: A computerized perinatal data system for a region, AM. J. OBSTET. GYNECOL. 131:157, 1978. 7. Ballard, J., Kazmaier, K., and Driver, M.: A simplified assessment of gestational age, Pediatr. Res. 11:374, 1977.
the computer to accept more than one number. One cannot but wonder if the results would have been altered if the computer could have accepted two, three, or more numbers. The outcome of this study seemed to be predictable, i.e., babies with higher Apgar scores did better than babies with low scores regardless of the groups in which they were placed. In the group A babies, the criterion of outcome was length of hospital stay. Was an attempt made to ascertain if there were maternal reasons for a prolonged stay, i.e., recuperation from cesarean section or other maternal morbidity? Why was a long stay defined as 4 days for group A babies and 7 days for group B babies? Again, could maternal factors have influenced this length of stay? The cesarean section rate was indeed considerably higher in group B. Who was involved in the original scoring process? Was it done by the nursing staff or by the physician? If done by a physician, was it the obstetrician, pediatri-
212
Jennett et al.
May 15, 1983 .4m. J. Obstet.
cian, or anesthesiologist? We have found in our own institution that scoring done by one group frequently varies from scoring done by another. The accuracy and consistency of information fed into a computer is going to be reflected in the output by the computer. The preceding 25 years has witnessed a remarkable awareness and interest in the welfare of the newborn infant. Dr. Apgar’s method of scoring these infants for purposes of comparison gave great impetus to the study of better anesthetic techniques, drug usage or nonusage, and methods of infant resuscitation. The natural extension of that interest is to the welfare of rhe fetus, particularly in high-risk mothers. The inaccessibility of the fetus has hindered past efforts to extend methods of prenatal evaluation but advances in technology, i.e., electronic fetal monitoring and ultrasonography, have made the fetus more readily available for evaluation. Manning and colleagues’ recently proposed an antepartum fetal evaluation with the use of five objective biophysical signs: fetal breathing movements, fetal movements, fetal tone, and qualitative amniotic fluid volume combined with a nonstress test. The fetal biophysical profile which they studied represents an appropriate extension to the fetus. I would hope that Dr. Jennett and his group will continue their efforts and present to us in the future another report stressing evaluation of the fetus. REFERENCE
1. Manning, F. A., Platt, L. D., and Sipos, L.: Antepartum fetal evaluation: Development of a fetal biophysical profile, AM. J. OBSTET. GYNECOL. 136:787, 1980.
DR. JAWS DAVIS, Inglewood, California. Dr. Jennett and his group have done a fantastic piece of work culminating in this paper. Without detracting at all from the paper, I would just like to make three critical points. First, they have taken an admittedly subjective index and tried to convert it to a highly objective score. As Dr. Smith was trying to point out, we have often seen several different observers give as many as three scores, particularly at low levels, for example, 4, 5, and 6. Obviously, to take those three numbers and to try to proceed with them mathematically are very difficult, if not impossible. My second point is that I disagree with their conclusion that the Apgar score is not used as a guide for resuscitation. I submit that it is a score that at least helps to determine how vigorous we are in utilizing tubing and suctioning, choosing a method of oxygenation, and obtaining pH values-in short, in resus-
G~necnl.
citation. My third point regards using the length ot hospital sray as the criterion for outcome. There are so many variables, for example, feeding problems, prematurity, jaundice, and even social problems, such as sickness in the home, requiring that the baby remain in the hospital. However, in spite of these criticisms, Dr. Jennett, I think that if there is a need for statistical analysis to convert to one score, you have undoubtedly given us the method. DR. LESTER HIBBARD, Los Angeles, California. Several years ago, while making a film on resuscitation of newborn infants for the American College of Obstetricians and Gynecologists, I observed rather closely a number of infants being resuscitated and I noted a couple of things. One, if a distressed infant is born, nobody determines an Apgar score. That determination is retrospective, and not particularly accurate either, as several other discussants have suggested. The other thing is that the two critical observations that are utilized in the decision for resuscitation are heart rate and muscle tone. The rest of the Apgar score does not really matter at this moment of stress. DR. JENNETT (Closing). Dr. Smith’s question, echoed by Dr. Davis, regarding the reason for selecting 4 days as a long stay when such things as cesarean section and other maternal complications might be the reason is pertinent. However, I remind you that the group A long-stay data were for vaginal deliveries only and that with 8,000 infants, social and other reasons for long stay would be sufficiently diluted. The observation that the index attempts to make an objective statement about a somewhat subjective score has some truth to it. Dr. Hibbard’s observation that when the infant is in severe distress. a score is generally given later also speaks to some subjectivity. It is a common belief among obstetricians that neonatologists give lower l-minute scores and higher 5-minute scores than obstetricians. This can lead to unpleasant disagreements. This is one of the good features of the index. By factoring in change, some of these discrepancies tend to even out. As our staff have come to understand this, they have become more relaxed about the score. Whether this will impress lawyers when this is part of malpractice considerations remains to be seen. Dr. Davis suggested that increased length of stay might be related to the occurrence of jaundice as one possible factor. This is again pertinent, but we need to know if early hypoxia and acidosis may not be related to these complications. Finally, I want to assure Dr. Smith that since we are computer enthusiasts, we will continue to massage the data and report our results.
J, JENNETT,
HARRY
S. WARFORD.
CAROL
KREINICK,
GLENN
W.
Phornw.
.4~izona
M.D. PH.D.
M.A.
WATERKOTTE,
M.D.
Twenty-seven years has elapsed since Virginia Apgar proposed a new method of evaluation of the newborn infant. The proposal gained rapid and almost universal acceptance and has stood the test of time. Considered at first to be both a guide for resuscitation and a statistical tool, the latter is now its main use. Although the original score was applied at 1 minute of age, both a i-minute scoring and a Sminute scoring are now the general custom. There is, however, no general consensus as to which is the better indicator of outcome. Use of both as separate entities is cumbersome. A method which with a single number gives weight to both the i-minute score and the B-minute score and also to the relative change is described. An analysis of selected variables with the use of this index is presented. (AM. J. OBSTET. GYNECOL. 140206, 1981.)
TWENTY-SEVEN YEARS has elapsed since Virginia Apgar’ proposed a new method for evaluation of the newborn infant. She recommended that five objective signs, which could be determined easily and without interfering with the care of the infant, be substituted for the generally used end points of “breathing time” and “crying time.” The signs chosen, each with a rating of 0, 1, or 2, were heart rate, respiratory effort, reflex irritability, muscle tone, and color. The proposal gained almost universal acceptance and appears to have stood the test of time. Proposals such as Chamberlain’s,’ to simplify the score by using what he and others viewed as the two most important criteria, heart rate and reHex irritability, have had little general acceptance. Although the original recommendation was for a “grading” at 1 minute of age, suggestions that scores be given at later ages soon followed. Of these, the 5-minute score has the most usage. Opinions as to the significance of the score have varied. Although once considered as a guide to resuscitation, few would now so regard it. Apgar’s stated purpose for proposing the scoring system was the establishment
From the Division of Reproductive Hospital and Medical Center.
Medicine,
St. Joseph’s
Presented at the Forty-seventh Annual Meeting of the PaciJic Coast Obstetrical and Gynecological Society, Monterey, California, October 6 I1 1 1980. Reprint requests: Raymond J. Jennett, M.D., Reproductive Medicine, St. Joseph:< Hospital Center, Phoenix, Arizona 85013.
206
Diubion oj and Medical
of a simple, clear classification of newborn infants which could be used for comparison of the results of obstetric practice and the effects of resuscitation. It is this statistical use of a newborn score which has been her unique contribution. Few if any pertinent papers are published that do not use the score as an outcome criterion. Whether the l-minute score or the 5-minute score is the preferred criterion is much less clear, and there is no general agreement as to the physiologic significance of the score. Reflecting on the addition of a 5-minute score by others, Apgar remarked that although the l-minute score was a reflection of acid-base status, the S-minute score might be more predictive of survival.” Gregory,’ on the other hand, was of the opinion that the one minute score correlated well with both acidosis and survival. He observed that the five minute score might possibly correlate with brain damage but that vigorous resuscitation should reverse this trend. It was our observation that such resuscitation increased the trend toward the clustering of .5-minute scores in the high range. This in turn suggested that the common practice of using a 5-minute score of 7 or more as an indicator of satisfactory outcome was of questionable validity. Brettschneider and associates,’ in reporting on the relationship of fetal acceleration determinations and perinatal outcome, admitted that their study might be criticized for the use of the 5-minute Apgar score as an indicator of morbidity. They justified the use on the basis that it had been used by others for similar studies. Based on these observations and with the postulate 0002-9378/81/100206+07$00.70/0
0
1981
‘The C:. V. Mosby
Co.
Volume Number
Apgar index
140 2
1 MINUTE
10
9
8
7
25
27
28
28
APMR
6
207
SCORE
5
4
3
2
10
6 5 MINUTE APGAR SCORE
5
2
4
\
4567776h420
\\ \ Fig. 1. Rounded Apgar indices. that change during the first 5 minutes of life would be more indicative of the infant’s condition than a single score, a method was sought to determine an index of this change and to provide a dynamic rather than a static statement of the neonate’s condition.
Material and methods That a dynamic rather than a static evaluation is desirable is attested to by the custom of reporting both a l-minute score and a 5-minute score in individual case reports. To do the same for statistical reports is unacceptably cumbersome since there are 12 1 possible combinations. A computer works best with a single number and, since our data were computer stored, such a single number was sought. A simple product of the two scores was considered but discarded since it would not differentiate between a rising trend and a falling trend. A score of 6 at 1 minute and 9 at 5 minutes would have a much different significance than the reverse. The formula that was finally selected for testing was (A 1 x A5) [ 1 + O.l(A5 - Al)]. Simply stated, the product of the l-minute score and the 5-minute score is increased by 10% for each point of rise or decreased by 10% for each point of fall. A score of 5 at 1 minute and 7 at 5 minutes is expressed as 5 x 7 x 1.2 = 42. Conversely, a score of 7 at 1 minute and 5 at 5
minutes results in 7 X 5 X 0.8 = 28. Fig. 1 is a nomograph of the possible combinations with decimals eliminated by rounding to the nearest whole number. Numbers within the diagonal lines result from identical l- and 5-minute scores. Numbers above the lines represent rising scores while the numbers below the lines reflect falling scores. This number will be referred to as the index. The Arizona Perinatal Program’s computerized perinatal data system has been previously described.6 Data from more than 52,000 deliveries from throughout the state are now stored. However, only data from St. Joseph’s Hospital where the system has been in full operation since January, 1977, were used in this study. From this date through June 15, 1980, 11,519 live births with verified length of stay were recorded. These infants were divided into five gestational age groups. Estimated gestational age was recorded by the obstetrician at the time of maternal admission. All infants were assigned a neonatal estimated gestational age by the method of Ballard and associates7 upon nursery admission by a nurse trained in the technique. If the two estimates agreed within 2 weeks, the obstetric assessment was used for group assignment. If the discrepancy was greater, infant weight was used as an arbitration factor for group assignment. Gestational age
208
Jennett
Table
et
al.
I. Distribution
by gestational
age and mode of delivery Total
(krtntional agf (weeks)
Arbitration weight (gm)
>36 33-36 29-32 26-28 <26
>2,750 1,751-2,750 1,251-1.750 75 1- I.250 (75 1
Vuginul
delirvq
C mrean
.sectmi
NO.
%
h’o.
R
A’(/.
R
10.122 I ,02Y 227 105 36 11,519
87.9 8.Y 2.0 0.9 0.3
8.810 809 141 78 35 9,873
87 .o 78.6 62.1 74.3 97.2
I.312 220 X6 27 1 1.646
1X0 2 I .4 37-Y 25.7 2.8
Overall cesarean section rate: 14.3%. Table
II. Long stay: Group 1 -Minute
of ‘7%of
No. Score
total
infants
Apgar
Lntr dkcharge
10 9 8 7 6 5 4 3 9 1-o
14 3519 3120 743 236 95 72 41 34 25
0.2 44.6 39.5 9.4 3.0 1.2 0.9 0.5 0.4 0.3
0 84 145 47 20 10 11 9 8 11
*With
verified
length
of‘ stay.
Table
III.
Blood
A infants-discharged scow
alive* (n = 7,899) 5.Minute
Apgar Late discharge
7~ of latr discharge
No. of infants
% of
0.0 24.4 42.0 13.6 5.8 2.9 3.2 2.6 2.3 3.2
728 6371 636 101 35 13 6 4 4 1
9.2 80.7 8.0 1.3 0.4 0.2 0.08 0.05 0.05 0.02
total
scow
Index % oflate
No.
discharge
infants
19 239 50 14 8 4 5 2 4 0
5.5 69.3 14.5 4.0 2.3 1.2 1.4 0.6 1.2 0.0
of
727 2879 3420 486 165 76 53 46 32 15
7~ of
Late
total
discharge
9.2 36.5 43.3 6.1 2.0 1.o 0.7 0.6 0.4 0.2
19 69 160 33 17 11 : 12 10
R
of late
discharge 5.5 20.0 46.4 9.6 4.9 3.2 2.0 2.0 3.5 2.9
Index go- 100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
pH: First hour (all age groups)
I -Minute
Apgar
score
ii-Minute
score
Index
% of
% of SCOW
Apgar
X0??
% of
% of % of
SC-Ore
Score
Total
Low QH
group
low value
Total
Low pH
group
low v&r
Total
10 9 8 7 6 5 4 3 2 1-O
I 24 88 55 39 34 37 18 23 24
0 5 14 21 11 19 15 8 11 15
0.0 20.8 15.9 38.2 28.2 55.9 40.5 44.4 47.8 62.5
0.0 4.2 11.8 17.6 9.2 16.0 12.6 6.7 9.2 12.6
10 129 91 42 36 15 7 5 3 5
2 28 31 22 17 9 2 2 2 4
20.0 21.7 34.0 52.4 42.2 60.0 28.5 40.0 66.6 80.0
1.7 23.5 26.0 18.5 14.3 7.6 1.7 1.7 1.7 3.4
7 20 92 64 30 33 22 28 23 24
group criteria and distribution by gestational age group and delivery mode are shown in Table I. The effectiveness of the l-minute Apgar score, the 5minute Apgar score, and the above-described index in predicting outcome was tested using as outcome criteria the length of nursery stay (group A by vaginal delivery), neonatal deaths (all groups), and blood pH determinations during the first hour of life (all groups).
Results Distribution by I-minute and j-minute scores and index fitr group A (term) infants born by vaginal deliv-
R of
Low pH
group
low value
In&x
1 4 15 28 10 17 8 11 14 14
14.3 20.0 16.3 43.7 33.3 51.5 36.4 39.3 60.9 58.3
0.8 3.4 12.6 23.5 8.4 14.8 6.7 9.2 11.8 11.8
go-100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 IO-19 o-9
ery and with verified length of stay is shown in Table II. The l-minute scores were more evenly distributed than the S-minute scores with 93.7% of the scores being 7 or greater. Of the remainder, 1.35% had a score of 3 or less. The clustering of j-minute scores is obvious by comparison. Fully 8 1% had a score of 9 and 99% had a score of 7 or greater. Only nine infants (0.12%) had a score of 3 or less. Although the index decides are not strictly comparable, distribution is quite similar to that of the l-minute score with 95.1% in the upper four deciles and 1.2% of the infants in the three lowest deciles.
Volume Number
140
Table
IV. Neonatal
Apgar
index
209
2
deaths:
Group
A
I -Minute Apgar score
5-Minute
Apgar
Deaths Score
No. of birth.s
No.
10 9
21 4,203
!: 6 5 4 3 2 1-o
4,108 1,019 332 139 115 73 58 56
Table
V. Neonatal
Deaths
90-100 80-89 70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
Deaths
%
No.
%
No. of births
0 0
0.0 0.0
974 8,018
0 3
0.0 0.04
23 2 2 2 2 1 9
0.20 0.07 0.6 1.4 1.7 2.7 1.7 16.0
857 153 64 24 12 7 6 9
23 2 3 2 1
0.2 2.0 3.1 12.5 16.6 14.3
No.
%
970 3,382
0 0
0.0 0.0
90-100 80-89
4,524 645 232 116 84’ 77 53 41
2 1 3 0 2 3 10
0.31 0.04 0.43 2.6 0.0 2.6 5.7 25.4
70-79 60-69 50-59 40-49 30-39 20-29 10-19 o-9
I?ldJ?x
deaths A
Group
B
Deaths decile
Index
No. of births
Group
h&x
score
No. of births 970 3382 4524 645 232 116 84 77 53 41
C
Deaths
No.
Rate
No. of births
0 8
0.0 0.0 0.04 0.3 0.4 2.6 0.0 2.6 5.7 24.4
53 186 468 145 48 45 24 25 16 19
2 1 3 0 2 3 10
Group
Deaths
_ No.
Rate
No. of births
0 0 6 4 0 2 0 1 1 3
0.0 0.0 1.3 2.7 0.0 4.4 0.0 4.0 6.2 15.8
7 12 46 33 14 12 8 10 18 20
Early discharge of normal infants is the prevailing practice in this hospital so that 32% were discharged within the first 24 hours, 58.2% were discharged during the second day, and 5.5% were discharged during the third day. Only 4.3% remained in the nursery for 4 or more days, which was designated as a long stay. Distribution for these 345 infants by l-minute and 5-minute scores and index is also shown in Table II. Although only 6.3% of the infants had a l-minute score of less than 7, 20% of infants with long stays were segregated into this group. By contrast, only 6.7% of infants were similarly segregated by the 5-minute score. The efficiency of the index in predicting long stay was comparable to that of the l-minute score. Since low Apgar scores are considered to be a reflection of acidosis, distribution of infants by blood pH during the first hour of life was analyzed and is displayed in Table III. Storage of blood gas data was added some time after the inception of the computer system but results for 343 infants were available. A pH of less than 7.2 1 was designated as low. The clustering effect in the high range is again evident for the 5-minute score. Seventy-nine percent of these infants,
Group
No.
Rate
0 2 10 8 1 4 1 6 11 13
0.0 16.6 21.7 24.2 7.4 33.3 12.5 60.0 61.0 65.0
D Death-s
No. of births 3 1 12 11 4 11 1 7 8 26
No.
Rate
2 1 6 2 4 8 1 7 7 25
66.6 100.0 50.0 18.2 100.0 72.7 100.0 100.0 87.5 96.1
including 83 of the infants with a low pH value, had a 5-minute score of 7 or greater. Only eight infants (6.8%) were segregated into the group with a score of 3 or less. Of particular note, more than half of 46 infants with a 5-minute score of 7 had a low pH. The l-minute score placed 28.6% of the infants with low pH in the group with a score of 3 or less. The index was even more definitive, placing 38.2% of the infants with low pH into the three lowest deciles. Twenty-three of the group A infants died. Breakdown for the overall neonatal mortality rate of 0.23% is given in Table IV. Fifteen of the deaths are segregated in the lower three deciles of the index group. Nine of the infants had a l-minute score of 3 or less while only eight had a similar 5-minute score. The tentative conclusion from these observations was that both the l-minute score and the index were much superior to the 5-minute score for predicting suboptima1 neonatal outcome by the criteria used. The index in turn appeared to be moderately more discriminatory than the l-minute score and, therefore, warranted further evaluation as a statistical tool. Correlation of index groups with neonatal mortality
210
Jenneti et al.
Table
VI. Composite
long-stay
and mortality
croup Index de&
Long-Jtuy
rate
High
60-69 50-59 40-49 30-39 20-29
Middle
decile and range:
Groups
.4
Range
90-100 80-89 70-79
rates by index
Group Neonatal
death rate
0.02
0.02
0.56
0.56
LOW
10-19
A and B
5.9
Range
i”r’ronatal death rate
Range
High
High
Middle
Middle
Low
Low
H
Lmg-.5tay
rate
Index d&u go- 100 80-89 70-79 tiO-6’) 50-59 40-49 30-39 20-29
IO-19
5.9
o-9
o-9
Group A long-stay rate is for vaginal deliveries only. All others are for combined vaginal and cesarean section deliveries. Table VII. Eftects of selected variables on index distribution
High Middle Low
89.0 9.8
92.7 6.9
1.2
0.4
94.2 5.6 0.2
FHR: Fetal heart rate. for gestational age groups A. B, C, and D is shown in Table V. For all age groups there is a generally inverse relationship between deaths (and death rate) and the index. This is particularly noted in group C where 30 of the 56 deaths were in the lowest three deciles for a mortality rate of 62.5%. Consideration was next given to whether the data allowed the classification of the index into reasonabl) clear-cut range grouping. Review of the blood pH data in Table III suggested a rather sharp increase in 10x1 values in the 60 to 69 index group over the 70 to 79 group. Additionally, there was a significant increase in the mortality rate fin- infants in group C with an index ill the three lowest deciles. Based on this, the decile groups were divided into high, middle, and low ranges, as shown in Table VI, which also compares long-stav rate and neonatal mortality rate for infants in groups A and B by this method. Long stay for infants in group A was -I days or more, as previousiy described. Long stay t’or infants in group B was defined as more than 7 days. Both long-stay rates and neonatal rilortality rates increased signilicantly for the middIe and low ranges fox both age groups. The eff’cct of’ selected variables on the Apgar index was tested. All infants in group A born by vaginal delivery were used as the standard. First, infants with possible fetal distress suggested by the presence of
mec:oniurn-stdiIied amniotic fluid or lt,tal heart rate decelerations were deleted. As shown iI1 ‘l‘able VII. there was a modest shift of’ infants into the high range. \vith only 0.4% remaining in the low range. Deletion of illfants whose mothers had received Ilarcotic-s or a paracervical block during labor resultrd in a ful-ther shift of infants into the high range, as also slm~in in Table VII. This ideal group had onl! 0.31!7( in the low range. The trend was the opposite when the effect of paracervical block was analyzed. Paracervical block without a subsequent bradycardia resulted in only a moderate downward shift, as depicted in Table VIII. However, if bradycardia was associated, the downward shift was marked, with 24.3% of the infants falling into the middle and low ranges. When the common practice of accepting a 5-minute score of 7 01‘ greater as evidence of satisfactory outcome is followed, 94.5% of infants exhibiting bradycardia after paracervical block had a score in this range. Effects similar to those of paracerG:al block were noted for meconium staining of amniotic fluid and ma)be compared in Table VIII. Thick meconium was assoclated with a marked shift to the middle and IOH range>.
Comment An index has been proposed which with a single number gives weight to both the I-minute i\pgar score and the .5-minute Apgar score and also to the relative change. As Virginia Apgar herself pointed out in her reflections and advice on her method of evaluating the newborn infant, if it is to be expected that the longer asphyxia exists, the more likely it is that death or permanent damage will occur, then a grading that reflects this w&d seem to be a more valid method of statistical evaluation than a single score, be it either at one minute or at 5 minutes.”
Volume 140 Number 2
Table VIII.
Apgar index
Effects of selected variables
on index
distribution Paracmical
“Standard” Range
High (70-100) Middle (30-69) Low (O-29) *Percentage of bradycardia:
(N = 8,810)
89.0 9.8 1.2
No bradycardia (N = 2,203)
(group
A-vaginal
211
births) Meconium
block Bradycardia * (N = 235)
Light 717)
(N =
86.5
75.7
82.7
11.9 1.6
20.0 4.3
14.3 3.0
Thick (N = 402)
74.6 19.2 6.2
9.6.
Comparison of l-minute scores, 5-minute scores, and index with the use of length of nursery stay, blood pH in the first hour of life, and neonatal mortality rates demonstrates a clear superiority of the l-minute score and the index over the 5-minute score in assessing neonatal condition. There appears to be little support for the common practice of reporting a 5-minute Apgar score of 7 or greater as an indicator of satisfactory outcome. The index appears to be moderately more discriminatory in segregating infants with suboptimal outcome into the lower ranges. This is in large part due to a mathematical characteristic of the method. For
example, a J-point rise from a l-minute score of 3 to a 5-minute score of 6 yields an index of 23, which would keep the infant in the lowest range. A similar S-point rise from a l-minute score of 6 to a 5-minute score of 9 results in an index of 70, which would shift the infant to the high range. The validity of this is supported by the data presented. The use of the index as a statistical tool should serve Virginia Apgar’s goal of “the reestablishment of simple, clear classification or ‘grading’ of newborn infants which can be used as a basis for discussion and comparison of the results of obstetric practices, types of maternal pain relief and the effects of resuscitation.“’
REFERENCES
1. Apgar, V.: A proposal for a new method of evaluation of the newborn infant, Anesth. Analg. 32:260, 1953. 2. Chamberlain, G.: Assessment of the Apgar score, Lancet 2:1225, 1974. 3. Apgar, V.: The newborn (Apgar) scoring system. Reflections and Advice, Pediatr. Clin. North Am. 13:645, 1966. 4. Gregory, G. A.: Resuscitation of the newborn, Anesthesiology.43:225, 1975.
Discussion N. SMIITH, San Francisco, California. Great beauty can be found in simplicity. Virginia Apgar made a significant contribution to medicine by introducing a simple newborn scoring system. Originally this assessment was intended to aid in the comparison of obstetric techniques and the effects of drugs and aggressive forms of resuscitation of the infant. A number of authors have attempted to modify her evaluations. Dr. Jennett alluded to Chamberlain’s idea of reducing the number of objective signs to be observed. The original proposal outlined by Apgar continues to stand in most institutions, although the addition of a 5-minute score is common. Dr. Jennett and his colleagues were able to compare results in a large number of newborn infants by utilizing a computer. One-minute and five-minute scores were used in a formula designed to reveal the significance of changes occurring in that interval of time. This formula was designed because of the inability of DR.
ROBERT
5. Brettschneider, F., Goldstein, P., Baer, D., Kimball, A., and London, R.: Fetal acceleration and perinatal outcome, J. Reprod. Med. 25: 10, 1980. 6. Jennett, R. J,, Gall, D., Waterkotte, G. W., and Warford, H. S.: A computerized perinatal data system for a region, AM. J. OBSTET. GYNECOL. 131:157, 1978. 7. Ballard, J., Kazmaier, K., and Driver, M.: A simplified assessment of gestational age, Pediatr. Res. 11:374, 1977.
the computer to accept more than one number. One cannot but wonder if the results would have been altered if the computer could have accepted two, three, or more numbers. The outcome of this study seemed to be predictable, i.e., babies with higher Apgar scores did better than babies with low scores regardless of the groups in which they were placed. In the group A babies, the criterion of outcome was length of hospital stay. Was an attempt made to ascertain if there were maternal reasons for a prolonged stay, i.e., recuperation from cesarean section or other maternal morbidity? Why was a long stay defined as 4 days for group A babies and 7 days for group B babies? Again, could maternal factors have influenced this length of stay? The cesarean section rate was indeed considerably higher in group B. Who was involved in the original scoring process? Was it done by the nursing staff or by the physician? If done by a physician, was it the obstetrician, pediatri-
212
Jennett et al.
May 15, 1983 .4m. J. Obstet.
cian, or anesthesiologist? We have found in our own institution that scoring done by one group frequently varies from scoring done by another. The accuracy and consistency of information fed into a computer is going to be reflected in the output by the computer. The preceding 25 years has witnessed a remarkable awareness and interest in the welfare of the newborn infant. Dr. Apgar’s method of scoring these infants for purposes of comparison gave great impetus to the study of better anesthetic techniques, drug usage or nonusage, and methods of infant resuscitation. The natural extension of that interest is to the welfare of rhe fetus, particularly in high-risk mothers. The inaccessibility of the fetus has hindered past efforts to extend methods of prenatal evaluation but advances in technology, i.e., electronic fetal monitoring and ultrasonography, have made the fetus more readily available for evaluation. Manning and colleagues’ recently proposed an antepartum fetal evaluation with the use of five objective biophysical signs: fetal breathing movements, fetal movements, fetal tone, and qualitative amniotic fluid volume combined with a nonstress test. The fetal biophysical profile which they studied represents an appropriate extension to the fetus. I would hope that Dr. Jennett and his group will continue their efforts and present to us in the future another report stressing evaluation of the fetus. REFERENCE
1. Manning, F. A., Platt, L. D., and Sipos, L.: Antepartum fetal evaluation: Development of a fetal biophysical profile, AM. J. OBSTET. GYNECOL. 136:787, 1980.
DR. JAWS DAVIS, Inglewood, California. Dr. Jennett and his group have done a fantastic piece of work culminating in this paper. Without detracting at all from the paper, I would just like to make three critical points. First, they have taken an admittedly subjective index and tried to convert it to a highly objective score. As Dr. Smith was trying to point out, we have often seen several different observers give as many as three scores, particularly at low levels, for example, 4, 5, and 6. Obviously, to take those three numbers and to try to proceed with them mathematically are very difficult, if not impossible. My second point is that I disagree with their conclusion that the Apgar score is not used as a guide for resuscitation. I submit that it is a score that at least helps to determine how vigorous we are in utilizing tubing and suctioning, choosing a method of oxygenation, and obtaining pH values-in short, in resus-
G~necnl.
citation. My third point regards using the length ot hospital sray as the criterion for outcome. There are so many variables, for example, feeding problems, prematurity, jaundice, and even social problems, such as sickness in the home, requiring that the baby remain in the hospital. However, in spite of these criticisms, Dr. Jennett, I think that if there is a need for statistical analysis to convert to one score, you have undoubtedly given us the method. DR. LESTER HIBBARD, Los Angeles, California. Several years ago, while making a film on resuscitation of newborn infants for the American College of Obstetricians and Gynecologists, I observed rather closely a number of infants being resuscitated and I noted a couple of things. One, if a distressed infant is born, nobody determines an Apgar score. That determination is retrospective, and not particularly accurate either, as several other discussants have suggested. The other thing is that the two critical observations that are utilized in the decision for resuscitation are heart rate and muscle tone. The rest of the Apgar score does not really matter at this moment of stress. DR. JENNETT (Closing). Dr. Smith’s question, echoed by Dr. Davis, regarding the reason for selecting 4 days as a long stay when such things as cesarean section and other maternal complications might be the reason is pertinent. However, I remind you that the group A long-stay data were for vaginal deliveries only and that with 8,000 infants, social and other reasons for long stay would be sufficiently diluted. The observation that the index attempts to make an objective statement about a somewhat subjective score has some truth to it. Dr. Hibbard’s observation that when the infant is in severe distress. a score is generally given later also speaks to some subjectivity. It is a common belief among obstetricians that neonatologists give lower l-minute scores and higher 5-minute scores than obstetricians. This can lead to unpleasant disagreements. This is one of the good features of the index. By factoring in change, some of these discrepancies tend to even out. As our staff have come to understand this, they have become more relaxed about the score. Whether this will impress lawyers when this is part of malpractice considerations remains to be seen. Dr. Davis suggested that increased length of stay might be related to the occurrence of jaundice as one possible factor. This is again pertinent, but we need to know if early hypoxia and acidosis may not be related to these complications. Finally, I want to assure Dr. Smith that since we are computer enthusiasts, we will continue to massage the data and report our results.