LIMITATIONS OF AN OSCILLOMETRIC AMBULATORY BLOOD-PRESSURE MONITOR IN PHYSICALLY ACTIVE CHILDREN

Objective: To determine the limitations of an oscillometric device for measuring ambulatory blood pressure in physically active children. Design: Observational descriptive. Subjects: Sixty-one children 4.3 to 18.7 years of age. Interventions: Twenty-two high school students wore an ambulatory blood pressure monitor (SpaceLabs model 90202) for 24 hours. A subject-kept activity diary facilitated data interpretation. In 39 additional subjects, measurements were recorded during strenuous exercise, at rest, and after ambulation. Before and after the students wore the unit, oscillometric and auscultatory blood pressure measurements were simultaneously taken to calibrate the ambulatory blood pressure monitor, evaluate its accuracy, and assess deterioration in the calibration of the unit with use. Results: During 24-hour ambulatory monitoring, 29% of the readings were edited because of error codes, primarily because of vibratory interference. At the end of the 24-hour monitoring period, simultaneous pressures by oscillometric and auscultatory techniques agreed within 6 mm Hg in 17 of 18 cases for both systolic and diastolic blood pressures. During exercise, 88.4% of the systolic and diastolic blood pressure readings agreed within 8 mm Hg. In 20 other ambulatory subjects with 80 simultaneous oscillometric and auscultatory measurements, all systolic and 88.5% of the diastolic values agreed within 10%. Conclusions: These results indicate that the SpaceLabs model 90202 unit provides a reasonably accurate assessment of ambulatory blood pressures in mildly active and inactive children and that blood pressure can be monitored with time.