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APGAR: A Commentary
From: Columbia University
| By:
Harold E. Fox |
EDITOR'S INTRODUCTION |
No sooner does a newborn infant take its initial breath than it faces its first graded exam. Virginia Apgar was the first female full professor at Columbia University's College of Physicians and Surgeons, and her name has been immortalized in the Apgar test for newborns. First published in 1953, the test has become a standard assessment of a newborn's health in the first minutes of life. Dr. Harold Fox assesses the impact of 40 years of Apgar scores and the usefulness of the test in the medically advanced future. |
APGAR, a familiar name around the world, is immortalized in the APGAR Score (A=appearance, P=pulse, G=grimace (reflex), A=activity and R=respirations) as a descriptor of the assessment of the newborn. The simple score, requiring no technology, systematically focuses the attention of the newborn caregivers on their charge. More importantly, the score mandates an assessment of the newborn at one and five minutes of life, a critical period of transition from fetus to newborn. The score has become a focus for parents; shortly after birth the question is "What is the Apgar score?" Anything less than a perfect 10 is often perceived by parents as a failing grade, sometimes for the child but mostly for the caregiver. |
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Virginia Apgar, the first woman to hold a full professorship at the College of Physicians and Surgeons, Columbia University, was director of anesthesiology at the Presbyterian Hospital from 1938 to 1949 (the anesthesiology service being a part of the Department of Surgery). Born in New Jersey in 1909, she graduated from Mount Holyoke College in 1929, and in 1933 was awarded her medical degree from Columbia University. She was an accomplished teacher and leader in medicine as well as a skilled musician, mastering the viola and cello, and was also known as an expert in the construction of these instruments. Dr. Apgar spent more than 10 years with the March of Dimes, where her contribution to child health centered on the area of support of research programs seeking to determine the causes and treatment of birth defects. She died at the Presbyterian Hospital in 1974, leaving her "score" as part of a legacy acknowledged throughout the world. Her life and persona are wonderfully described by L.S. James.1 In the past five years, Apgar has been a part of the title of 1,271 manuscripts, and virtually every publication in the field of perinatology refers to the Apgar Score. |
Over 40 years ago, Virginia Apgar developed the systematic scoring system for the standardized assessment of the neonate's clinical condition. She had hoped to prevent unnecessary delay in identifying severely asphyxiated infants and thereby provide for the rapid institution of appropriate resuscitation efforts. In addition, she hoped to eliminate the need for unnecessary manipulation of the uncomplicated, healthy infant. The prediction of ultimate outcome was hoped for but not specifically planned. Did Virginia Apgar achieve her goals? |
As described in Dr. Apgar's first paper,2 the score is based on five easily assessed clinical parameters which are evaluated at one minute after birth. This was soon extended to include evaluations at both one and five minutes after birth.3 |
For the sake of simplicity, zero, one or two points were assigned to each of the five areas. To any clinician it is obvious that the areas of assessment interrelate; yet, the simplicity of the system outweighs the downside of interdependent relations. |
In her initial paper, Dr. Apgar concluded that the prognosis for an infant was excellent if the child received a score of 8-10 and was poor if the score was two or less, the intermediate range being non-predictive: conclusions at times based on self-fulfilling prophecy since a low Apgar score was sometimes erroneously used as an indicator to do little in support of the child, increasing the likelihood of a poor outcome. As our understanding improved, that the Apgar score is a poor predictor of long-term outcome, so did the original clarity of purpose of the Apgar score. |
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Let us look for a moment at what the Apgar score can and cannot do. The Apgar score can provide a basis for the uniform assessment of the condition of the infant at specific time periods after birth. It provides a common basis for communication between care providers and may serve as an index of successful adaptation of the fetus to the newborn state. The application of the Apgar score is highly successful as a routine simple system which focuses attention of the caregiver on the newborn during the critical stages of transition from fetus to newborn. The Apgar score successfully provides a comfortable structure upon which there are established indications for resuscitation and indices for the assessment of the efficiency of resuscitation. The Apgar score has proved to be helpful in identifying the neonatal effects of drugs used during labor, of obstetrical interventions,4 of intrauterine asphyxia,4,5 and of changes in the maternal environment. As demonstrated in the original paper in 1953, and valid to the present, the same range of predictability of the newborn's condition applies.4 As a descriptor of clinical condition at specific time intervals, the Apgar score is a great success. While the score is not successful as a predictor of long-term outcome,6,7 recall it was not originally intended for this purpose. |
The score has been used extensively and abused: abused in the medical/legal arena due to unfortunate misconceptions. Professor Apgar herself stated that the purpose of the simple application of the score was to provide "a practical method of evaluating the condition of the infant."8 Its intent was to focus attention on the infant and to serve as an index for resuscitation. It was not meant to be a predictor for long-term outcome or intended to equate with the diagnosis of birth asphyxia. Unfortunately, however, the current ICD9 code for birth asphyxia is based on the Apgar score. These definitions are misleading with reasonable sensitivity and very low specificity.
768.5 Severe birth asphyxia -- 1-minute Apgar score 0-3. Pulse less than 100 per minute at birth and falling or steady, respiration absent or gasping, color poor, muscle tone absent "White asphyxia."
768.6 Mild or moderate birth asphyxia -- 1-minute Apgar score 4- 7. "Blue asphyxia" Normal respiration not established within one minute, but heart rate 100 or above, some muscle tone present, some response to stimulation. |
There are limitations to the Apgar score and they must be recognized. The Apgar score requires systematic assessment of vital signs. Small changes may well be missed. The Apgar score does not predict survival, neurological handicap or death of the individual newborn.9 It does, however, provide scores for various functional categories that are intrinsically related. |
Gestational age influences the score and its relationship to the acid-base status of the neonate and neonatal behavior.10,11 It has been demonstrated that the greater the gestational age the more acidosis a baby can tolerate without a lowering of the Apgar scores at both one and five minutes. The inverse is also true: for premature infants a score may be low with no marker of asphyxia. The Apgar score does not address issues related to newborn behavior or latency effects, nor was it intended to. The belief that the Apgar score will predict neurologic outcome seems naive.12 |
The score as described by Dr. Apgar was assessed by an independent observer and eventually was applied by the anesthesia resident present at delivery. It was not assessed by the person delivering the infant or the person immediately responsible for the infant's care, and this speaks for another component of the Apgar score which is a source of inconsistency. The Apgar score, although described by Dr. Apgar as objective, is, in fact, quite subjective and shows a unique variation. Different members of the health care team give different scores to the same infant.8 The person assisting with the delivery of the infant, eager to provide the parent with a good score, tends to give the highest scores while the person providing neonatal care (the child's ombudsman) tends to give lower scores, in an effort to direct greater attention to the child. The subjective bias that has come to the score makes the weak correlation between outcome and the score even weaker. |
The limitations of the Apgar score have prompted reappraisals of its components, its predictive value and its relevance. Recent editorials have argued that while the general consensus is that the use of the Apgar score has led to significant progress, it may have served its purpose.13 |
Should the Apgar score be revised? Should the Apgar score be abandoned? In my opinion, the answer in both cases is a resounding no. Rarely in medicine has a simple clinical assessment been so universally accepted and applied. The original purpose of focusing attention of the neonatal caregiver on the transitional status of the child is still served and leads to the early diagnosis of cardiorespiratory maladaptation, which requires intervention and further assessment. |
We must focus on what the Apgar score is and what it is not. The low Apgar score is not synonymous with perinatal asphyxia or neurologic handicap, and the high Apgar score is not a guarantee of health, ultimate quality of survival or superior intelligence. We must keep the Apgar score in perspective. It is a descriptor of the baby's condition at specified times. It is not intended to be an accurate predictor of long-term outcome nor a diagnostic of specific disorders such as perinatal asphyxia. |
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