Peri-operative blood lactate concentrations in pre-term babies with necrotising enterocolitis

Aim: Hyperlactaemia has been shown to predict mortality in preterm babies undergoing intensive care. The value of such measurement has not been evaluated in babies undergoing laparotomy for necrotising enterocolitis (NEC). The aim of this study was to determine whether peri-operative blood lactate measurements (L) can be used to predict outcome in preterm babies with necrotising enterocolitis. Methods: Clinical and laboratory data in 24 babies who underwent laparotomy for NEC over 3 years were collected. The data were analysed to correlate blood lactate level with the clinical outcome. Results: There were no statistically significant differences between babies who died and those who survived in terms of gestation, birth weight, condition at birth, etc. There was no difference in pre-operative acid-base status parameters between the groups. Median (range) of pre- and post-operative blood lactate measurements (L) are shown: Pre-op Lactate: 0.9 (0.3 to 2.4) n = 15 (Survivors); 2.7 (0.5 to 10.9) n = 5, p = 0.05 (Non-survivors). Post-op Lactate: 1.2 (0.5 to 6) n = 19 (Survivors); 4.7 (0.2 to 19.5) n = 5, p = 0.06 (Non-survivors). Babies with pre-operative hyperlactaemia ([L] >1.6mmol/L) were more likely to die. (Odd's Ratio 22, Confidence Interval 1.54 to 314.3, p = 0.04). Pre-operative L was not higher in babies who subsequently had bowel resection compared to those who had no bowel resection ([L] = 0.88 mmol/L [0.3 to 10.9] vs. 1.6 mmol/L [0.6 to 2.7], [p = 0.2]). Post-operative L was generally higher than pre-operative L but was a less useful predictor of death. Conclusion: This study suggests that elevation of L in the pre-operative period carries a poor prognosis in babies with NEC. As L was not significantly different between babies who had necrotic bowel and those who had a healthy bowel, we postulate that it reflects inadequate global tissue oxygen delivery rather than local disease process. Pre-operative optimisation of oxygen delivery has been shown to reduce mortality in high-risk adult surgical patients. Babies with NEC may also benefit from further peri-operative resuscitation.