Which parameter would the nurse be assessing in a newborn by using the Apgar scoring system 5 minutes after birth?

Apgar Score

Resuscitative efforts typically precede the performance of a thorough physical examination of the neonate. Because NRP instructions require simultaneous assessment and treatment, it is important that the neonatal assessment be both simple and sensitive. In 1953, Virginia Apgar, an anesthesiologist, described a simple method for neonatal assessment that could be performed while care is being delivered.39 She suggested that this standardized and relatively objective scoring system would differentiate between infants who require resuscitation and those who need only routine care.40

The Apgar score is based on five parameters that are assessed at 1 and 5 minutes after birth. Further scoring at 5- or 10-minute intervals may be done if initial scores are low. The parameters are: heart rate, respiratory effort, muscle tone, reflex irritability, and color. A score of 0, 1, or 2 is assigned for each of these five entities (Table 9.1). A total score of 8 to 10 is normal, a score of 4 to 7 indicates moderate impairment, and a score of 0 to 3 signals the need for immediate resuscitation. Dr. Apgar emphasized that this system does not replace a complete physical examination and serial observations of the neonate for several hours after birth.41

The Apgar score is widely used to assess neonates, although its value has been questioned. The scoring system may help predict mortality and neurologic morbidity inpopulations of infants, but Dr. Apgar cautioned against the use of the Apgar score to make these predictions in anindividual infant. She noted that the risk for neonatal mortality was inversely proportional to the 1-minute score.41 In addition, the one-minute Apgar score was a better predictor of mortality within the first 2 days of life than within 2 to 28 days of life.

Several studies have challenged the notion that a low Apgar score signals perinatal asphyxia. In a prospective study of 1210 deliveries, Sykes et al.42 noted a poor correlation between the Apgar score and the umbilical cord blood pH. Other studies, including those of low-birth-weight infants, have found that a low Apgar score is a poor predictor of neonatal acidosis, although a high score is reasonably specific for excluding the presence of severe acidosis.43-49 By contrast, the fetal biophysical profile has a good correlation with the acid-base status of the fetus and the neonate (seeChapter 6).50 The biophysical profile includes performance of a nonstress test and ultrasonographic assessment of fetal tone, fetal movement, fetal breathing movements, and amniotic fluid volume.50

Additional studies have suggested that Apgar scores are poor predictors of long-term neurologic impairment.51,52 The Apgar score is more likely to predict a poor neurologic outcome when the score remains 3 or less at 10, 15, and 20 minutes. However, when a child has cerebral palsy, low Apgar scores alone are not adequate evidence that perinatal hypoxia was responsible for the neurologic injury.

The Apgar Score

The Apgar score is widely used as a part of the early assessment of the newborn (Table 22-1). A score of 0, 1, or 2 is assigned to each of the five physical signs at 1 and 5 minutes after birth. The Apgar score should not be used as a substitute for assessing the ABCs in neonatal resuscitation, and resuscitation efforts should not be delayed or interrupted to assign an Apgar score. However, the Apgar score does allow a quick and consistent way for different providers to describe an infant’s condition. A score of 7 to 10 is considered normal. If the 5-minute Apgar score is abnormal, less than 7, appropriate resuscitation measures should be continued and Apgar scores assigned every 5 minutes until the infant is stabilized.

Although the Apgar score provides a systematic way for different providers to describe an infant’s condition in the first minutes of life, it correlates poorly with future neurologic outcomes (AAP and ACOG, 1996). A poor Apgar score alone cannot be used to diagnose asphyxia in the newborn or predict the development of cerebral palsy. However, the Apgar score is correlated with early infant death. In a large population study of term infants, an abnormal 5-minute Apgar score correlated with a significantly increased risk of death in the first 28 days of life. Even in infants with the lowest scores, however, death within 28 days is uncommon, occurring in 244 of 1000 infants with 5-minute Apgar scores of 0 to 3 (Casey et al., 2001).

Apgar Score

The Apgar score is a tool that can be used objectively to define the state of an infant at given times after birth, traditionally at 1 minute and 5 minutes (Table 31.1).3,6 The Apgar score should not be used as the primary indicator for resuscitation, because it is not normally assigned until 1 minute of age. As noted, asphyxia may begin in utero and continue into the neonatal period. To minimize the chances of adverse sequelae, one should begin resuscitation as soon as there is evidence that the infant is unable to establish ventilation sufficient to maintain an adequate heart rate. Waiting until a 1-minute Apgar score is assigned before initiating resuscitation only delays potential therapies. An Apgar score at 1 minute of 0-3 often indicates the presence of secondary apnea. Infants who fail to achieve an Apgar score of 7 by 5 minutes of age should have repeated Apgar scores every 5 minutes until the score is at least 7.3 Steps taken during the resuscitation and the resulting Apgar scores should become part of the medical record (Table 31.2).3

Apgar Score

The Apgar score, a tool used to assess well-being at 1 and 5 minutes after birth, incorporates five elements: respiratory effort, heart rate, reflex irritability, muscle tone, and color. In the preterm infant, the Apgar score is directly related to birthweight and gestational age. Among premature infants, Apgar scores are significantly higher at 1 and 5 minutes in females. In addition, male premature infants frequently require more vigorous resuscitation. Higher Apgar scores in the preterm female infant may be related to the higher catecholamine levels found in female infants at birth, resulting in a more normal pressor response and improved cardiovascular stability.114

Apgar and the Language of Asphyxia

Few scientists in the twentieth century influenced the practice of neonatal resuscitation as profoundly as Apgar (1909-1974). A surgeon, she chose obstetric anesthesia for her career. Her simple scoring system inaugurated the modern era of assessing infants at birth on the basis of simple clinical examination.3 Right or wrong, the Apgar score became the language of asphyxia. It is often said that the first words heard by a newborn infant are “What's the Apgar score?” Although “giving an Apgar” has become a ritual, its profound effect has been on formalizing the process of observing, assessing, and communicating the infant status at birth in a consistent and uniform manner. This process eventually led to the formal steps of resuscitation at birth using the score. Few people know that it was also Apgar who was the first to catheterize the umbilical artery in a newborn.16 A woman of enormous energy, talent, and compassion, Apgar was honored with her depiction on a 1994 US postage stamp (Fig. 1.5).

Apgar Score

The Apgar score was initially proposed as a means of rapidly assessing the status of newborns at 1 minute after birth and as a means of determining whether a neonate required respiratory support (Apgar, 1953) (Table 17-4). As Casey and others (2001) recently suggested, “Every baby born in a modern hospital in the world is looked at first through the eyes of Virginia Apgar.” The Apgar score includes five variables with a range of scores from 0 to 2 (for a maximum of 10 points): heart rate, respiratory effort, muscle tone, reflex irritability, and color. Currently, the score is applied at 1 and 5 minutes, but in some cases the evaluation continues for as long as 20 minutes if continued resuscitative efforts are required.

The Apgar score has been demonstrated recently to be a predictor of mortality (Casey et al., 2001). In full-term infants, these authors found a mortality rate of 244 per 1000 (24.4%) for infants with 5-minute Apgar scores of 1 to 3, compared with 0.2 per 1000 (0.02%) for infants with 5-minute Apgar scores of 7 to 10. Similarly, in preterm infants of 26 to 36 weeks' gestation, the mortality rate was 315 per 1000 (31.5%) for infants with 5-minute Apgar scores of 0 to 3 and 5 per 1000 (0.5%) for infants with 5-minute Apgar scores of 7 to 10. Thus, the incidence of neonatal death was highest when the 5-minute Apgar scores were 3 or lower, independent of gestational age. Neonatal death most commonly occurred during the first day of life, with the majority of infants dying before 3 days of age. These data indicate that the Apgar score is a valid predictor of neonatal mortality. In fact, the Apgar score better predicted outcome than umbilical-artery pH of 7.0 or less. Combining a 5-minute Apgar of 0 to 3 with an umbilical artery blood pH of 7.0 or less increased the risk of death in both preterm and full-term infants. An Apgar score of 0 for longer than 10 minutes suggests that resuscitative efforts should be suspended (Jain et al., 1991). Papile (2001) stated, “At present, there is no single measure of the fetal or neonatal condition that accurately predicts later neurodevelopmental disability…but, few will deny [the Apgar score's] application at 1 minute of age accomplishes Dr. Apgar's goal of focusing attention on the condition of the infant immediately after birth.” Although outcomes vary with gestational age, with the etiology of neonatal depression, and with other factors, effective resuscitation of infants with low Apgar scores resulted in survival of about 40% to 60% of the patients and, approximately two thirds of survivors had normal neurologic function (Leuthner and Das, 2004). In 1964, the Collaborative Study on Cerebral Palsy reported a stronger relationship between the 5-minute Apgar score and neonatal mortality than the 1-minute score (Drage et al., 1964). Controversy about the Apgar score arises when people try to use the Apgar score to predict neurologic outcome. Dr. Apgar did not intend that the score be used to establish the diagnosis of asphyxia, to measure the severity of perinatal asphyxia, or to predict long-term neurologic outcome. In fact, 75% of children with cerebral palsy had normal Apgar scores at 5 minutes (Nelson and Ellenberg, 1981).

Apgar scores

The Apgar score is a scaled rating system developed by Dr Virginia Apgar in the 1950s which assesses the newborn infant's need for life support. It is scored out of 10 and based on the sum of two points for each of the systems, as shown in Table 2.3.

This assessment of the newborn infant is made at 1 minute post-birth and again after 5 minutes. Normal scores are 7 or greater at 1 minute and 8 or more at 5 minutes. An Apgar score of 7 or more indicates that the baby does not require assistance; scores between 6 and 4 indicate that help is needed; scores 3 or less signal the urgent need for resuscitation (Thomson 1993). There is strong association between Apgar scores of 0–3 at both 1 and 5 minutes with mortality and cerebral palsy (Moster et al 2001).

Children with low Apgar scores and subsequent signs of cerebral depression (but who do not develop cerebral palsy) may still have an increased risk of developing a range of neuro-developmental impairments and learning difficulties (Moster et al 2002).

23 What is the Apgar score?

The Apgar score is the most widely accepted and used system to evaluate the neonate, determine which neonates need resuscitation, and measure the success of resuscitation (Table 59-5). The score evaluates heart rate, respiratory effort, muscle tone, reflex irritability, and color, with heart rate and respiratory effort being the most important criteria. Each variable is given a score of 0 to 2, for a total score of 10. The Apgar score is measured at 1 and 5 minutes and then at 10 and 20 minutes as resuscitative efforts are continued. A score of 0 to 3 indicates a severely depressed neonate, whereas a score of 7 to 10 is considered normal.

Apgar Score

The Apgar score is named after Virginia Apgar, who invented the procedure. It is a rating of the general level of well-being of the newborn. Numerical values from 0 to 2 are given to five responses of the newborn (Table 12.2): (1) heart rate, (2) respiratory effort, (3) muscle tone, (4) reflex irritability, and (5) color of the skin. Thus, a maximal score of 10 can be obtained. A baby with a score of 7–9 is normal or only slightly depressed, with a score of 4–6 is moderately depressed, and with a score of 0–3 reflects serious health problems. About 80% of newborns in the United States receive a score of 7 or above, and usually no alarm is raised for scores of 6 or above. Newborns with low scores require intensive care immediately after delivery. The Apgar score is often repeated in a few minutes if the first score is low.

TABLE 12.2. Apgar Newborn Scoring System

Clinical Factors

The Apgar score is not a good predictor of outcome. This measure is affected by the use of maternal drugs or anesthesia, and by the vagal-induced respiratory depression that occurs from the use of suction catheters or from oropharyngeal secretions. There is also considerable variation among personnel in assigning the Apgar score, and all of the five different parameters that compose the Apgar score are not equally weighted for neurologic outcome. Although the Apgar score at 1 minute is not predictive of a poor outcome, the predictive ability does increase with a continued depressed score with increasing age of the infant. It has been shown that infants with Apgar scores of less than 6 at 5 minutes are three times more likely to have abnormalities on neurologic examination than are infants with scores greater than 6 (Levene et al, 1986). However, if the infant shows no neurologic symptoms in the perinatal period, the outcome is often normal. Ekert and colleagues (1997) built a model to predict severe adverse outcome within 4 hours of birth in neonates with HIE and found that delayed onset of breathing, need for chest compressions, and seizures had a sensitivity of 85% and specificity of 68%. In a population-based case-control study using these and expanded criteria in 84 children with spastic cerebral palsy, only 18 had 5-minute Apgar scores of less than 6, 20 required ventilation in the delivery room, and only 5 had initial pH of less than 7.00. Only 3 children had all three signs, and these 3 had neonatal seizures (Nelson and Grether, 1999).

The severity of the neurologic symptoms is helpful in assessment of the prognosis. The incidence of long-term problems is low in infants with mild HIE (Robertson and Finer, 1985). Infants with moderate encephalopathy have an abnormal outcome in 20% to 40% of cases, whereas infants with severe encephalopathy either die in the first 3 days of life or have severe deficits. Sarnat scores are a commonly used indicator of HIE and show similar predictive ability for which infants are at risk for sequelae (Volpe, 2001b). Hypotonia with depressed primitive reflexes or episodes of recurrent apnea indicate a poor outcome. The presence of seizures is perhaps the best clinical indicator of adverse outcome, especially if seizure activity occurs in the first 12 hours of life or if they are difficult to control (see Miller et al, 2002d).

The duration of the neurologic abnormalities is usually helpful in predicting long-term neurologic disability. In two separate studies, normal examination findings at 1 week of age and at 2 weeks of age correlated with a good outcome (Robertson and Finer, 1985; Sarnat and Sarnat, 1976). Other clinical tools used include the presence of impairment of other organ systems and the Score for Neonatal Acute Physiology-Perinatal Extension (SNAP-PE) score, a physiologic assessment done within the first 24 hours of life (Newton et al, 2001). As with other clinical measures, neither of these tools is able to prognosticate outcome in the moderately asphyxiated newborn.