EEG at One Month of Age of New Born Babies who Underwent Therapeutic Hypothermia Using Low Cost Technology in a Level 2 NICU Setting: A Profile

INTRODUCTION: EPIDEMIOLOGY: Perinatal hypoxia is one of the leading contributor to both neonatal mortality and neurodevelopmental disability. The reported incidence of perinatal hypoxia in developed countries is around 1-1.5%. The incidence of perinatal hypoxia reported in India is higher ie. , around 2.5% according to NNPD 2000 data. Perinatal hypoxia contributes to major share of neonatal deaths in India – nearly 20% of neonatal mortality. If still births were included the contribution from perinatal hypoxia will increase further. THERAPEUTIC HYPOTHERMIA: Until recently recently there is no specific treatment for perinatal hypoxia. Treatment basically involves supporting the organ systems. There were immense clinical research in various neuroprotective strategies in perinatal hypoxia. Among these therapeutic hypothermia holds promise. Within a short span of time therapeutic hypothermia become a standard of care and in many western countries registry maintained nationwide for this new procedure. AIM OF THE STUDY: To analyse the EEG pattern of neonates who suffered hypoxic ischemic encephalopathy and underwent therapeutic hypothermia as a treatment modality. OBJECTIVE OF THE STUDY: 1. To identify subclinical seizures and follow them with developmental assessment, clinical neurological examinations, anthropometric measurements. 2. To identify abnormalities in EEG associated with clinically suspected seizures and thereby treating with anticonvulsants. 3. To identify abnormalities in EEG associated with developmental delay concerns. 4. To have a baseline EEG record so that follow up serial EEG assessment can be made to prognosticate neurodevelopmental outcome in perinatal hypoxia. 5.To identify any EEG abnormalities associated with structural abnormalities. DISCUSSION: MORTALITY: From the data we can observe a relatively higher mortality rate for moderate to severe encephalopathy overall than that reported in developed countries. This can be attributed to possible high incidence of associated meconium stained liquour in considerable proportions and relatively higher incidence of bacterial sepsis and pneumonia in these babies. The overall mortality rate reported in developed countries is about 20%. The mortality rate are comparatively higher in developing countries like India. In our study the overall mortality rate for both stage II and stage III Hypoxic ischemic encephalopathy was 40%. It should be noted that stage I Hypoxic ischemic encephalopathy babies were not included in this study that would otherwise reduced the overall mortality. The mortality rate among cooled and non cooled groups were similar – around 40% and difference if any was statistically significant. Thus it can be concluded that therapeutic hypothermia in a level II nicu setting by using low cost technology does not alter the mortality rate of Hypoxic encephalopathy babies. The mortality rate was considerably higher in those babies referred to the hospital than the babies who were born at the hospital-53.85% and 35.15% respectively – although the statistical analysis showed that difference was insignificant – the probable explanation would be relative difference in the resuscitation at birth in peripheral hospital and condition prevailing during transport. These factors can adversely affect the physiological state of the newborn during admission affecting the mortality thereby. CONCLUSION: There is significant proportion of neonates who underwent therapeutic hypothermia showed abnormalities in the electroencephalogram at the age of one month. Repeated neurological examination and serial EEG and possibly MRI would aid in the management of this subgroup of neonates.