Blood volume and systolic blood pressure (SBP) were measured in 43 pre
term infants. Mean (SD) blood volume was 83 (19) ml/kg (range 48-119)
and SBP 50 (9) mm Hg (range 3 9), showing a significant overall relati
onship Blood volume in infants with SBP >60 mm Hg (110 (6) ml/kg) was
significantly higher than in infants with SBP 40-60 mm Hg (78 (16) ml/
kg) and in infants with SBP <40 mm Hg (75 (10) ml/kg). In conclusion,
SBP is of limited value in detecting hypovolaemia in very low birthwei
ght infants.