Cerebral Tissue Oxygen Extraction as an Additional Early Indicator of Fatal Circulatory Failure in Preterm Infants with Sepsis or NEC

Abstract

Background: Current diagnostic possibilities are insufficient to detect low systemic blood flow in preterm infants. Near-infrared spectroscopy (NIRS) is a non-invasive method by which fractional cerebral tissue oxygen extraction (FTOEc), an indicator of cerebral perfusion, is calculated.Objective: To determine the prognostic value of FTOEc in addition to clinical signs of circulatory failure in the prediction of mortality in preterm infants with sepsis/NEC.Design/methods: Preterm infants with culture-proven sepsis or NEC were included. Mean values of FTOEc and a circulatory failure score (CFS) were calculated for each infant for every 12hr-period in the 36hrs following clinical presentation. The CFS was composed of five indicators of circulatory failure: tachycardia, hypotension, metabolic acidosis, raised serum lactate, and oliguria. It could range from 0-5 (no to all indicators present). The prognostic value of FTOEc as well as CFS for the prediction of mortality was determined using ROC-analyses and likelihood ratios (LR).Results: Twenty infants were included; eleven had sepsis, nine had NEC. Gestational age was 28.0 weeks median [range:25.0-35.0], birthweight 1155 grams [560-2690], postnatal age 15 days (0-72). Four infants died, all within 31hrs of clinical presentation. CFS≥2 was not a significant predictor of mortality at any timepoint. FTOEc≥0.37 was, with the highest predictive value after 24hrs (LR+:12.0 (95%CI 1.6-36)). The combination of FTOEc≥0.37 and CFS≥2 led to a better prediction of mortality in the first 12hrs after onset than both indicators separately.Conclusion: Adding FTOEc-monitoring to current diagnostic possibilities improves the early prediction of fatal circulatory failure in preterm infants with sepsis/NEC.