Mortality in the neonatal intensive care setting: Do benchmarks tell the whole story?

Australian neonatal mortality data are collected and shared within collaborative networks. Individual unit outcomes are benchmarked between units and presented in quarterly or yearly reports. Low mortality is commonly interpreted as optimal performance. However, current collected data do not differentiate between death due to severe illness and death following treatment limitation. This study aims to explore the physiological condition immediately before death, and the proportion of deaths attributed to treatment limitation.

This retrospective single centre study of 100 consecutive deaths classified the physiological condition 12 h prior to death as stable or unstable using a clinical illness score based upon pH, oxygen saturation index, medications and blood product use. Documented discussions regarding expected outcomes and goals of management were reviewed for agreed upon treatment limitations and analysed against physiological stability.

Causes of death were sepsis (n = 24), congenital anomalies (n = 20), extreme prematurity (n = 19), hypoxic ischaemic encephalopathy (n = 18), intraventricular haemorrhage (n = 11) and other (n = 8). Forty-eight infants were physiologically stable at 12 h before death. In infants classified as physiologically stable, 90% of deaths were in a scenario where palliative care was discussed and intensive care treatment was ceased. These deaths accounted for 43% of total mortality in our unit.

A large portion of mortality in our unit could be attributed to treatment limitations in physiologically stable infants with high risk of neurodevelopmental impairment. Our study emphasises the need to consider the physiological status around time of death for optimal benchmarking of mortality between neonatal units.