Therapeutic cooling for perinatal asphyxia-Indian experience

Low Fetal Resistance to Hypoxia as a Cause of Stillbirth and Neonatal Encephalopathy

Objective: Low fetal resistance to hypoxia is a factor in stillbirth and neonatal encephalopathy. This review examines fetal movement patterns in response to hypoxia as a predictor of the likelihood of stillbirth. Monitoring the dynamics of fetal movements during maternal apnea could allow the assessment of fetal resistance to hypoxia. The goal of this study is to describe the practical application of this method by doctors and pregnant women. Mechanism: We searched relevant keywords in the international scientific literature databases Scopus and Web of Science, as well as databases for patents granted in China, India, USA, Japan, Germany, Russia and other countries. Devices, drugs and medical technologies that provide diagnosis, modeling, prevention and treatment of intrauterine fetal hypoxia, stillbirth and neonatal encephalopathy were considered. Findings in Brief: During apnea by a pregnant woman in the second half of normal pregnancy, if the maximum duration of fetal immobility exceeds 30 seconds from the onset of breath-holding, then the fetus is considered to show good resistance to hypoxia, thus preserving its health and life during vaginal delivery. On the other hand, excessive fetal movements <10 seconds after the onset of apnea in a pregnant woman indicates low fetal resistance to hypoxia. When fetal resistance to hypoxia is low, there is no alternative to immediate cesarean section for the preservation of fetal life and health. Conclusions: The monitoring of fetal movements during apnea in pregnant women allows real-time assessment of fetal resistance to intrauterine hypoxia. Obtaining timely information on fetal resistance to hypoxia is critical for determining the optimal timing and type of delivery in order to prevent encephalopathy and stillbirth.

Glimpses from My Academic Journey : Based on the 15th Dr. K. C. Chaudhuri Lifetime Achievement Award Oration Delivered on 9th October 2022

This article is based on the contents of 'Dr. K. C. Chaudhuri Lifetime Achievement Award Oration' delivered on the Indian Journal of Pediatrics Annual Day 2022. The author shares glimpses of his academic journey from a remote village to a central Institute. This includes his career as a medical teacher and developing the Department of Neonatology at JIPMER, Pondicherry. This article is primarily focused on some of the significant research conducted during his tenure, like perinatal asphyxia, therapeutic hypothermia, neonatal sepsis, intrauterine growth restriction, and human milk banking.

Therapeutic Hypothermia for Perinatal Asphyxia in India-Experience and Evidence

Therapeutic hypothermia is an established therapy with proven benefit for term neonates with moderate and severe hypoxic-ischemic encephalopathy (HIE). Many centers in India have started therapeutic cooling of asphyxiated infants. There is enough evidence for the beneficial effect of cooling from the randomized trials conducted in India. However, the recently published hypothermia for encephalopathy in low- and middle-income countries (HELIX) trial has contrasting findings. In this context, this review is written summarizing the available experience and evidence for therapeutic hypothermia for perinatal asphyxia in India.

Effects of therapeutic hypothermia on death among asphyxiated neonates with hypoxic-ischemic encephalopathy: A systematic review and meta-analysis of randomized control trials

Background

Hypoxic perinatal brain injury is caused by lack of oxygen to baby’s brain and can lead to death or permanent brain damage. However, the effectiveness of therapeutic hypothermia in birth asphyxiated infants with encephalopathy is uncertain. This systematic review and meta-analysis was aimed to estimate the pooled relative risk of mortality among birth asphyxiated neonates with hypoxic-ischemic encephalopathy in a global context.

Methods

We used the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines to search randomized control trials from electronic databases (PubMed, Cochrane library, Google Scholar, MEDLINE, Embase, Scopus, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and meta register of Current Controlled Trials (mCRT)). The authors extracted the author’s name, year of publication, country, method of cooling, the severity of encephalopathy, the sample size in the hypothermic, and non-hypothermic groups, and the number of deaths in the intervention and control groups. A weighted inverse variance fixed-effects model was used to estimate the pooled relative risk of mortality. The subgroup analysis was done by economic classification of countries, methods of cooling, and cooling devices. Publication bias was assessed with a funnel plot and Eggers test. A sensitivity analysis was also done.

Results

A total of 28 randomized control trials with a total sample of 35, 92 (1832 hypothermic 1760 non-hypothermic) patients with hypoxic-ischemic encephalopathy were used for the analysis. The pooled relative risk of mortality after implementation of therapeutic hypothermia was found to be 0.74 (95%CI; 0.67, 0.80; I² = 0.0%; p<0.996). The subgroup analysis revealed that the pooled relative risk of mortality in low, low middle, upper-middle and high income countries was 0.32 (95%CI; -0.95, 1.60; I² = 0.0%; p<0.813), 0.5 (95%CI; 0.14, 0.86; I² = 0.0%; p<0.998), 0.62 (95%CI; 0.41–0.83; I² = 0.0%; p<0.634) and 0.76 (95%CI; 0.69–0.83; I² = 0.0%; p<0.975) respectively. The relative risk of mortality was the same in selective head cooling and whole-body cooling method which was 0.74. Regarding the cooling device, the pooled relative risk of mortality is the same between the cooling cap and cooling blanket (0.74). However, it is slightly lower (0.73) in a cold gel pack.

Conclusions

Therapeutic hypothermia reduces the risk of death in neonates with moderate to severe hypoxic-ischemic encephalopathy. Both selective head cooling and whole-body cooling method are effective in reducing the mortality of infants with this condition. Moreover, low income countries benefit the most from the therapy. Therefore, health professionals should consider offering therapeutic hypothermia as part of routine clinical care to newborns with hypoxic-ischemic encephalopathy especially in low-income countries.

Effect of Therapeutic Hypothermia on the Outcome in Term Neonates with Hypoxic Ischemic Encephalopathy-A Randomized Controlled Trial

OBJECTIVE

To assess the effect of therapeutic hypothermia on the outcome in term neonates with hypoxic ischemic encephalopathy (HIE).

METHODS

A randomized controlled trial was conducted in a tertiary care teaching hospital in south India. Term infants with moderate to severe HIE were randomized to be treated with normothermia or hypothermia. Mortality, neurological abnormality or normal outcome was recorded at hospital discharge or 28 days of age, whichever was earlier, and at 18 months of age.

RESULTS

The baseline maternal and neonatal characteristics in the two groups were similar. The 78 infants in the hypothermia group had more normal survivors at discharge (38%) than the 84 infants in the normothermia group (30%), ratio 1.29 (95% confidence interval 0.84-1.99), and at 18 months of age (65% vs. 42%), ratio 1.54 (1.13-2.10). When these results were combined with those of a previous randomized trial in the same neonatal unit, there were significantly more normal survivors with hypothermia compared to normothermia at discharge, ratio 1.49 (1.18-1.88) and at 6-18 months of age, ratio 1.37 (1.17-1.60).

CONCLUSION

In term infants with HIE, therapeutic hypothermia reduced mortality and neurological abnormalities, and resulted in more normal survivors.

LAY SUMMARY

Babies who do not breathe immediately after they are born are likely to die or have brain damage. Previous studies have suggested that cooling these babies after birth might reduce the number who die or have brain damage. In this resource-limited setting, babies who were cooled were less likely to die or survive with brain damage.

Neuronal Biomarkers in Predicting Neurodevelopmental Outcome in Term Babies with Perinatal Asphyxia

OBJECTIVE

To assess whether serum levels of neuronal biomarkers (S100 calcium-binding protein B and Neuron specific enolase) correlate with the neurodevelopmental outcome of term neonates at 18 mo who had hypoxic ischemic encephalopathy and underwent therapeutic hypothermia.

METHODS

This randomized controlled trial was conducted in a tertiary care teaching hospital, south India. There were 162 term infants with moderate to severe hypoxic ischemic encephalopathy who were randomized into 2 groups (Group A and B). Neonates in Group A and B received normothermia and therapeutic hypothermia respectively. Serum levels of neuronal biomarkers were estimated at 0, 24 (±1) and 72 (±1) h after birth using sandwich ELISA in both groups. All neonates were carefully monitored till discharge. Infants who survived the neonatal period were followed up in the high risk clinic for 18 mo and neurodevelopmental assessment was done using Developmental Assessment Scale for Indian Infants (DASII). Neurodevelopmental outcomes between the two groups were compared using Chi square test and neuronal biomarker levels between the groups were compared using Mann Whitney test.

RESULTS

The baseline maternal and neonatal characteristics in both groups were comparable. There was statistically insignificant lesser mortality in therapeutic hypothermia group compared to normothermia group with Risk Ratio (RR): 0.82 (28.2% vs. 34.5%, 95% CI: 0.52-1.29, p = 0.38). Among the survivors, children in therapeutic hypothermia group had better motor and mental scores compared to those in normothermia group at 18 mo. There was no significant correlation between S100B and Neuron specific enolase levels and neurodevelopmental outcome.

CONCLUSIONS

Serum levels of neuronal biomarkers (S100B and Neuron specific enolase) do not correlate with the long term neurodevelopmental outcome among these infants.

Therapeutic Hypothermia for Birth Asphyxia in Neonates

India contributes to the highest neonatal mortality globally. Birth asphyxia is one of the leading causes of neonatal mortality in India. A large number of neonates who suffer from birth asphyxia progress to Hypoxic Ischemic Encephalopathy (HIE). The risk of a neonate progressing to severe form of HIE is many times higher in the low and middle income countries (LMICs) with ill developed health infrastructure. Till date LMICs have had a low institutional delivery rate, poor regionalization of care, lack of adequate transport facilities and ill equipped neonatal intensive care facilities. This has lead to a tremendous burden on the health care systems with a cohort of developmentally challenged neonates surviving into adulthood. Recently, Therapeutic Hypothermia (TH) has emerged as an evidence based intervention to reduce mortality and neurodevelopmental disability associated with asphyxia induced encephalopathy. TH has become the gold standard in the management of such cases in the western world. Extension of this knowledge to the LMICs and countries like India require a better understanding of the unique sociocultural issues associated with asphyxial brain injury in neonates. The high incidence of sepsis and presence of economic constraints make this problem more complex in such countries. The current review has tried to address these issues and looked at the basics of this complex topic from the perspective of a general pediatrician.

Does therapeutic hypothermia reduce acute kidney injury among term neonates with perinatal asphyxia?--a randomized controlled trial

OBJECTIVE

The objective of this study is to evaluate whether therapeutic hypothermia reduces the incidence of acute kidney injury (AKI) among term neonates perinatal asphyxia.

METHODS

This randomized controlled trial conducted in a tertiary care teaching hospital, south India included 120 term neonates with perinatal asphyxia who were randomized to receive either therapeutic hypothermia or standard supportive care. Renal parameters of neonates in both the groups were monitored and AKI was ascertained as per Acute Kidney Injury Network criteria.

RESULTS

The incidence of AKI was less in therapeutic hypothermia group compared to standard treatment group (32% versus 60%, p < 0.05). The incidence of Stages 1, 2, and 3 AKI was 22%, 5%, and 5% in therapeutic hypothermia group compared with 52%, 5%, and 3%, respectively, in the standard treatment group. The mortality was less in therapeutic hypothermia group compared with the standard treatment group (26% versus 50%, p < 0.05).

CONCLUSION

Therapeutic hypothermia reduces the incidence and severity of AKI among term neonates with perinatal asphyxia.