Hypoxic-ischemic encephalopathy and the Apgar scoring... : Journal of Clinical Sciences (2024)

INTRODUCTION

The Apgar score was developed by Virginia Apgar in the year 1952[^1,2] to assess the well-being of newborn at birth; therefore, identifying those who need attention and immediate resuscitation. It consists basically of observation of five physical parameters with a score of 0–2 assigned to each.[³] These scores are determined in the 1^st and 5^th min of life. However, it has been modified over the years with the 10^th min and 20^th min Apgar scorings included.[⁴] To avoid ambiguity, several regulatory bodies such as the International Liaison Committee on Resuscitation recommends that the duration of Apgar scoring should be limited to the 10^th min in the absence of any sign of life; afterward, resuscitation should be called off.[⁵] Till date, controversy still persists on the scope of its utilization, while some researchers believe that it could predict long time neurologic outcome,[^6,7] others hold contrary opinion.[^8,9,10] Furthermore, the isolated use of the Apgar score for defining perinatal asphyxia has been discontinued over the years in developed countries. Therefore, the American Academy of Pediatrics and the American College of Obstetrics and Gynecology definition stipulate that other evidences of hypoxemia such as acidemia, encephalopathy, and multiorgan dysfunction should be present before the diagnosis could be made.[¹¹] Some of these guidelines are often difficult to implement in some resource-constraint settings, for instance, blood gas analysis. The pertinent question then will be done we suspend the diagnosis of perinatal asphyxia in such settings? The resounding answer will be a no. The bottom line of perinatal asphyxia is the presence of hypoxic-ischemic encephalopathy (HIE). Therefore, this study seeks to determine how efficient and effective is the 1^st and/or 5^th min Apgar scoring in defining and classifying birth asphyxia and also comparing its score with the clinical manifestation of HIE using the Sarnat-Sarnat classification.[¹²]

MATERIALS AND METHODS

This was a retrospective study of inborn neonates admitted into the Special Care Baby Unit of our health facility with a diagnosis of birth asphyxia from January 1, 2012, to December 31, 2013. Their medical records were reviewed, and information on bio-data including sex, weight, gestational age, and information on Apgar score and clinical features diagnostic of HIE were extracted and entered into the study pro forma. Newborns with Apgar scores <7 at 1^st min were included in the study; furthermore, only those scored by health personnel well trained in neonatal resuscitation were included in the study. In our institution, pediatricians attend deliveries of high-risk pregnancies, cesarean sections, and complicated labors; and they ascribe the Apgar score; however, the obstetricians and trained obstetric nurses score in noncomplicated deliveries. Files with incomplete records and nondocumented Apgar scoring were excluded in the data analysis. Infants <34 (completed) weeks' gestation were also excluded from the study.

The Apgar score is interpreted as normal (reassuring) if the score is 7–10, 6 is a fairly low score, 4–5 is low, whereas 0–3 is very/critical low in the term infant and late-preterm (near-term) infant.[^13,14] Perinatal asphyxia had been previously defined based on the Apgar scoring alone. therefore, the 5^th min Apgar score of <7[¹⁵] and the 1^st min Apgar score of <7[¹⁶] have been variedly used to define perinatal asphyxia. The severity of perinatal asphyxia was classified as mild, if the Apgar score is 6, moderate perinatal asphyxia is Apgar score of 4–5, whereas a score of 0–3 is severe perinatal asphyxia.[¹⁶] We, therefore, compared how effective was the 1^st or the 5^th min Apgar in determining newborns who subsequently develop HIE. HIE was classified using the Sarnat and Sarnat criteria.[¹²]

Data analysis

Data obtained were entered in a computer and were analyzed using Statistical Package for the Social Sciences version 16 (SPSS Inc., Chicago, Illinois, USA). Quantitative variable was summarized as a mean and standard deviation, whereas qualitative variables were summarized in percentages. The Fisher's exact test and one-sample Chi-square binomial tests were adopted as the tests of significance and P < 0.05 was adjudged statistically significant.

RESULTS

There were 1600 recorded deliveries and 142 neonates fulfilled the criteria for inclusion in the study; 86 males and 56 females with a male-to-female ratio of 1.5:1. There were 30 (21.1%) preterms and 112 (78.9%) term infants. The birth weight ranged from 1.9 kg to 4.00 kg with a mean of 2.6 + 0.5 Kg. They were all appropriate for their gestational age.

Table 1 described the 1^st and 5^th min Apgar scores and the frequency of HIE of the cases. It showed that most of the cases had a 1 min Apgar score in the range of 4–5 (62.0%); using the 5^th min Apgar score, majority of the cases had scores of 6 and more. Sixty-five (45.8%) of the subjects had HIE; Stage 1 HIE was the most recorded form of encephalopathy.

Table 2 compared the Apgar scores of the 1^st and 5^th min with the clinical stages of HIE: the 1^st min Apgar scores showed that 22 of the newborns with a score of 4–5 had Stage 1 HIE, whereas all the nine cases with Stage 3 HIE had a score of 0–3 (Fisher's exact test = 132.074; P = 0.00); furthermore, most cases with Stage 1 HIE had a 5^th min score of 6 and above; however, none had a score of 0–3, but all the cases with Stage 3 HIE had a score between 4 and 5 (Fisher's exact test = 49.024; P = 0.00).

DISCUSSION

The Apgar scoring has been applied variedly in different settings. While some use the 1^st min Apgar score in defining perinatal asphyxia,[¹²] majority use the 5^th min Apgar score.[^17,18] Therefore, this may account for the varied prevalence, and severity of perinatal asphyxia reported in several studies.[^19,20,21]

In the 1^st min Apgar score, about 62.0% of the subjects were moderately asphyxiated with only 9.9% being mildly asphyxiated; this improved significantly (P = 0.001) with no documented score of 0–3 at the 5^th min Apgar score and the score of 6–7 increased to 26.8% signifying the relevance of Apgar scoring in monitoring of resuscitation.[^22,23]

Our findings showed that a low 1^st and 5^th min Apgar score was associated with the clinical features of HIE in 45.8% of the cases, whereas the rest had no clinical manifestations of HIE. Therefore, newborns who had critically low 1^st min Apgar scores were more likely to develop severe forms of HIE (Stages 2 and 3); however, most of those whose 1^st min Apgar scores were in the moderate range (4–5) and the 5^th min scores of 4–5 and 6, respectively, mostly had Stage 1 HIE.

While efforts are made in improving the health-care system by making available basic health services, the Apgar scoring should remain a guide in determining the physiologic state of the newborn at birth and also monitoring the effectiveness of resuscitation. Although the diagnosis is based on both clinical and laboratory parameters, absence of facilities for cord blood ABG should not deter us from making a diagnosis of perinatal asphyxia in our setting.

Home deliveries common are in most resource-limited settings; and the community-based neonatal care programs which are aimed at improving the survival of newborns, especially in rural settings has significantly improved neonatal morbidity and mortality outcomes.[²⁴] In the traditional practice, absence or a weak cry at delivery has been associated with perinatal asphyxia. While this may relate with some of the characteristics of the Apgar score, there is a need of educating health-care providers on the ease and usefulness of applying the Apgar scoring system in their routine delivery and newborn assessment protocol. With constant practice, training, and retraining, consistency in scoring may be achieved.[²⁵] Even in tertiary centers, there are also concerns of interobserver variability in Apgar scoring; O'Donnell et al.[²⁶] reported significant interobserver differences in the Apgar scores of up to 2.4 points among staffs involved in newborn resuscitation; however, retraining and use of simulations can significantly improve the reliability of the Apgar score. Nadler et al.[²⁷] reported a significant correlation between reported Apgar scores by clinicians participating in simulation exercise and that of experts who designed the program.

CONCLUSION

The Apgar score still remains an important tool in newborn assessment and monitoring the progress of resuscitation in a resource-poor setting. Both the first and 5^th min Apgar scores showed a good correlation with clinical features of severe forms of HIE.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

REFERENCES