Comparability of oscillometric to simultaneous auscultatory blood pressure measurement in children

Objective Uncertainty exists regarding the accuracy of automated blood pressure (BP) measurement in children. We recorded oscillometric waveforms in children, derived oscillometric BPs using two standard algorithms, and compared the results to simultaneous auscultation. Patients and methods Twenty children aged 2-12 years were recruited from a tertiary-care Pediatric Nephrology Clinic. Sex, height, weight, arm circumference, history of hypertension, and clinic BP were recorded. Two, simultaneously measured, oscillometric and auscultatory BP readings were obtained 30-60 s apart. The first reading was discarded and, the second, used for analyses. Fixed-ratio and slope-based algorithms were used for BP derivation. Results Mean age was 7.95 +/- 2.82 years, 40% were female, mean arm circumference was 21.86 +/- 4.06 cm, and 50% had hypertension or a history of hypertension. Mean auscultatory BP for all participants (systolic +/- SD/diastolic +/- SD) was 93.40 +/- 11.80/50.50 +/- 9.04 mmHg, oscillometric fixed-ratio BP was 99.20 +/- 11.90/57.35 +/- 7.15 mmHg and oscillometric slope-based algorithm was 91.60 +/- 13.94/60.65 +/- 7.71 mmHg. Compared to auscultation, the fixed-ratio method differed by 5.80 +/- 12.72/6.85 +/- 7.51 mmHg (P=0.06 and <0.01) and the slope-based method differed by -1.80 +/- 13.59/10.15 +/- 8.07 mmHg (P=0.56 and <0.01). Differences from auscultation were statistically significant for diastolic BP with both fixed-ratio and slope-based methods for all age categories but of greatest magnitude in the youngest children. Conclusion Oscillometric BP derived using two commonly used algorithms differed by more than 5 mmHg in either systolic BP or diastolic BP from simultaneous auscultatory BP in children aged 2-11. These findings emphasize the need for greater understanding of the functionality and accuracy of oscillometry in children.