G8 CORRELATION OF CONTINUOUS VIDEO EEG MONITORING AND SERIAL LACTATE MEASUREMENTS IN HYPOXIC ISCHAEMIC ENCEPHALOPATHY

D. M. Murray¹, G. B. Boylan¹, S. Connolly², B. P. Murphy¹, C. A. Ryan¹.¹United Maternity Services, Cork, Ireland; ²St Vincent’s University Hospital, Dublin, Ireland

Background: EEG monitoring is useful in the early diagnosis and prognosis of hypoxic ischaemic encephalopathy (HIE) but is not always available in the neonatal intensive care unit. Arterial lactate measurements at 30 min of age have shown promise in predicting which infants are at increased risk of HIE, and proton magnetic resonance spectroscopy has shown persistently raised cerebral lactate up to 1 month post-delivery in infants with HIE.

Aim: To establish the relationship between initial and serial lactate measurements and the severity of EEG changes in full term babies with hypoxic ischaemic encephalopathy.

Method: A prospective study from a large maternity service (6000 deliveries per annum). Continuous video EEG monitoring for 24–72 hours was performed within 6 hours of birth. Encephalopathy was graded as mild, moderate, or severe from analysis of the EEG data, or if unavailable, by Sarnat scoring. EEG seizures if present were measured and the total seizure burden was calculated for each baby. Initial blood gas measurements of pH, base deficit (BD), and lactate were taken within 1 hour of delivery. Subsequent blood gas measurements were taken as clinically required.

Statistical Analysis: Correlation between independent variables was calculated using Spearman’s bivariate analysis. Means were compared using students t test. The threshold for statistical significance was p<0.05.

Results: Twenty four full term babies with HIE were enrolled over an 18 month period; 20 had continuous EEG monitoring. Initial blood gas parameters, pH, Base deficit (BD), and initial lactate measurements did not differ between grades of encephalopathy. Initial lactate was raised in all cases (mean 12.9 (SD 3.98) mmol/l). Lactate clearance rate …