Noninvasive, Continuous Blood Pressure Measurement by Arterial Tonometry during Anesthesia in Children

BACKGROUND: The authors' previous study of arterial tonometry in children demonstrated poor agreement of tonometric blood pressure (TBP) measurements with intraarterial blood pressure (IBP) measurements. The aim of the current study is to evaluate the feasibility of TBP measurements in children aged 1-6 yr using a newly designed pediatric sensor housing, by comparing TBP values with values obtained by IBP measurements. METHODS: Thirty-four children (aged 1-6 yr, ASA physical status 1-2) were studied undergoing elective abdominal or urologic surgery under general anesthesia. A 22- or 24-G cannula was inserted into the right radial artery. A TBP sensor housing was positioned over the left radial artery. TBP and IBP were continuously monitored and data were periodically sampled during and after intubation, during surgery, and during the recovery period. RESULTS: TBP waveforms were similar to those of IBP. Limits of agreement (bias +/- 2 SD) were 12 and -13.3 mmHg for systolic, 11.6 and -10.4 mmHg for mean, and 13.2 and -10.8 mmHg for diastolic pressures for 3,400 paired points. Measurements could not be made in ten children because of insufficient pulse contour. CONCLUSIONS: When pulse contour is sufficient for analysis, TBP monitoring provides an apparently safe and accurate method for the continuous measurement of arterial blood pressure during anesthesia in children aged 1-6 yr.