Validity of newborn oscillometric blood pressure.

The objective of this study was to determine the validity of oscillometric blood pressure in relation to arterial blood pressure. Thirty-one newborns were studied. Clinical characteristics, complications, and treatment interventions were documented. Arterial pressure (every 2 sec) and oscillometric pressure (every 3 min) were concurrently recorded for 1-2 h. Serial observations of oscillometric pressure followed the trend of arterial pressure in the individual newborn. However, the study averaged oscillometric pressures were lower than the arterial pressures: systolic, by 1 mmHg; mean, by 5.3 mmHg (p < 0.0001); and diastolic, by 4.6 mmHg (p < 0.0001). The variance of individual, 15-min averaged, and 1-h averaged observations of oscillometric pressure in relation to arterial pressure was examined. Variance for individual observations may be large. The least variance of oscillometric pressure was in the 1-h averaged mean pressure, in which the difference was +/- 2 mmHg in 77% and +/- 4 mmHg in 95% of observations. Clinical characteristics, with the exception of birth weight and treatment interventions, did not affect the variance of oscillometric pressure. This study implies that the offset in relation to arterial pressure should be established for each oscillometric pressure monitoring system. Hourly averaged mean oscillometric pressure is satisfactory for many newborn assessments and management circumstances. However, arterial pressure may be necessary to accurately document transient hypertension or hypotension or an unstable blood pressure.