• Hypotension
• Preterm Infants
• Mortality
• Long-term outcomes

Treatment of very preterm babies in order to try and increase their blood pressure is a widespread, and extremely variable, practice. Some centres try to maintain a mean arterial blood pressure above 30 mm Hg, others try to achieve a blood pressure above the gestational age in weeks, and others tend to be permissive, only treating when the infant shows signs of poor perfusion.1

A systematic review that we performed a few years ago2 could find no reliable evidence comparing these approaches, nor any clear evidence that ‘hypotension’ is causative for short-term or long-term morbidities, nor could we find a clear threshold for intervention, nor any evidence that intervention improves outcomes.

Evidence which has accumulated over the last few years has addressed, but has not clearly answered these questions. Evidence from a recently published large German database study,3 showed an association, among infants of less than 1500 g birth weight and <32 weeks gestation, between a mean arterial blood pressure which was below the median at some point during the first 24 h, and an increase in mortality, and also in intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD). Treatment with inotropes was strongly associated with an increased incidence of IVH and BPD. This and other published data are open to an interpretation that therapeutic interventions for low blood pressure could be a causative factor in the increased morbidity. However, in that new study the association between lower blood pressure and poorer outcomes was also seen in infants who did not receive treatment.

A study from Batton et al4 also provides new information. The authors have previously demonstrated marked variation …