25 research outputs found
Does inferior vena cava respiratory variability predict fluid responsiveness in spontaneously breathing patients?
How important is the recommended slow cuff pressure deflation rate for blood pressure measurement?
How Important is the Recommended Slow Cuff Pressure Deflation Rate for Blood Pressure Measurement?
Can a simulator that regenerates physiological waveforms evaluate oscillometric non-invasive blood pressure devices?
Effect of the shapes of the oscillometric pulse amplitude envelopes and their characteristic ratios on the differences between auscultatory and oscillometric blood pressure measurements
Automatic blood pressure measurement: The oscillometric waveform shape is a potential contributor to differences between oscillometric and auscultatory pressure measurements
OBJECTIVE: To explore the differences between oscillometric and auscultatory measurements. METHOD: From a simulator evaluation of a non-invasive blood pressure (NIBP) device regenerating 242 oscillometric blood pressure waveforms from 124 subjects, 10 waveforms were selected based on the differences between the NIBP (oscillometric) and auscultatory pressure measurements. Two waveforms were selected for each of five criteria: systolic over and underestimation; diastolic over and underestimation; and close agreement for both systolic and diastolic pressures. The 10 waveforms were presented to seven different devices and the oscillometric-auscultatory pressure differences were compared between devices and with the oscillometric waveform shapes. RESULTS: Consistent patterns of waveform-dependent over and underestimation of systolic and diastolic pressures were shown for all seven devices. The mean and standard deviation, for all devices, of oscillometric-auscultatory pressure differences were: for the systolic overestimated waveforms, 36 \ub1 28/-6 \ub1 3 and 23 \ub1 2/-1 \ub1 3 mmHg (systolic/diastolic differences); for systolic underestimated waveforms, -21 \ub1 5/-4 \ub1 3 and -11 \ub1 4/-3 \ub1 3 mmHg; for diastolic overestimated waveforms, 3 \ub1 4/12 \ub1 5 and 17 \ub1 6/10 \ub1 2 mmHg; for diastolic underestimated waveforms, 1 \ub1 4/-22 \ub1 4 and -9 \ub1 6/-29 \ub1 4 mmHg; and for the two waveforms with good agreement, 0 \ub1 6/0 \ub1 3 and -2 \ub1 4/-4 \ub1 3 mmHg. Waveforms for which devices showed good oscillometric and auscultatory agreement had smooth envelopes with clearly defined peaks, compared with the broader plateau and complex shapes of those waveforms for which devices over or underestimated pressures. CONCLUSION: By increasing the understanding of the characteristics and limitations of the oscillometric method and the effects of waveform shape on pressure measurements, simulator evaluation should lead to improvements in NIBP devices. \ua9 2008 Lippincott Williams & Wilkins, Inc