Intra-arterial blood pressure reference ranges, death and morbidity in very low birthweight infants during the first seven days of life

Objectives: We aimed to: (1) assess the association of average, low, high a nd variable mean blood pressure (mbp) on death and the common morbidities o f very low birthweight infants, and in doing so, (2) to derive representati ve reference ranges for mbp in very low birthweight infants. Study design: This five year retrospective study assessed 1 min computer recordings of in tra-arterial mbp in 232 very low birthweight infants over the first 7 days of life in a tertiary NICU. Four measures of mbp were assessed: average, va riability, maximum (per time period), and percentage of time with a mean bl ood pressure less than the infant's gestation. Correlation was made with de ath and the development of intraventricular haemorrhage (IVH), periventricu lar leukomalacia (PVL) and retinopathy of prematurity (ROP). Results: The m bp increased with increasing birthweight and postnatal age (though with a S light decrease on days 6 and 7). Birthweight, gestation and colloid support (adjusted for birthweight and gestation) were the only factors significant ly associated with mbp. IVH was predominantly associated with a low and var iable mbp on the day IVH was noted or the day before, PVL and ROP were not associated with blood pressure. Conclusions: These reference ranges include more infants and data than previously published and relate mbp in this coh ort to morbidity and mortality. They could assist clinicians in judging app ropriate mbp for birthweight. (C) 1999 Elsevier Science Ireland Ltd. All ri ghts reserved.