Hourly Kinetics of Critical Organ Dysfunction in Extremely Preterm Infants.

RATIONALE Use of severity of illness scores to classify patients for clinical care and research is common outside of the neonatal intensive care unit. Extremely premature (<29 weeks gestation), extremely low birth weight (<1000 grams) infants experience significant mortality and develop severe pathology during the protracted birth hospitalization. OBJECTIVE To measure at high resolution the changes in organ dysfunction that occur from birth to death or discharge home by gestational age, time, and among extremely preterm infants with and without clinically-meaningful outcomes using the neonatal sequential organ failure assessment score. METHODS A single-center, retrospective, observational cohort study of inborn, extremely preterm, extremely low birth weight infants admitted between 1/2012 and 1/2020. Neonatal sequential organ failure assessment scores were calculated every hour for every patient from admission until death or discharge. MEASUREMENTS AND MAIN RESULTS Longitudinal, granular scores from 436 infants demonstrated early and sustained discrimination of those who died versus those who survived to discharge. The discrimination for mortality by the maximum score was excellent (area under curve 0.91; 95% confidence intervals 0.88, 0.94). Among survivors with and without adverse outcomes, most score variation occurred at the patient-level. The weekly average score over the first 28 days was associated with the sum of adverse outcomes at discharge. CONCLUSIONS The neonatal sequential organ failure assessment score discriminates between survival and non-survival on the first day of life. The major contributor to score variation occurred at the patient-level. There was a direct association between scores and major adverse outcomes including death.