Comparison of noninvasive and central arterial blood pressure measurements in ELBW infants

Abstract

The objective of this study was to evaluate the difference between noninvasive and central arterial blood pressure measurements in extremely low-birth-weight (ELBW) infants. We conducted a retrospective cohort study of infants with birth weight <or=1000 g and who were admitted to a single center in 2005. Paired noninvasive and umbilical arterial blood pressure measurements obtained in the first 72 h were compared. The primary outcome was the differential between the paired measurements. Noninvasive blood pressure (NBP) measurements were defined as clinically acceptable if the differential between the pairs was 15% or lower. We obtained 146 pairs of measurements from 38 infants. The median absolute differences between noninvasive and arterial systolic, mean and diastolic blood pressure measurements were +18.5, +12 and +10 mm Hg, respectively (percentage differential of 43, 39 and 41%, respectively). In total 75% of the noninvasive measurements of mean blood pressure were clinically unacceptable. No patient or measurement characteristic was significantly associated with clinically unacceptable noninvasive measurements. In ELBW infants, NBP measurements substantially overestimate systolic, mean and diastolic blood pressures compared with central arterial measurements.