Analysis of damping characteristics of arterial catheter blood pressure monitoring in a large intensive care unit

Background. For many reasons, the invasive measurement of systolic and diastolic blood pressure should be accurate. Accuracy is determined, in part, by the damping characteristics of the arterial catheter blood pressure monitoring system. Objectives . To ascertain the damping characteristics of arterial catheter blood pressure monitoring in a large tertiary intensive care unit (ICU) and to elicit any causes of under- or over-damping of the measurement systems. Methods. A cross-sectional, observational study of arterial line measurements in a large general ICU. The coefficient of damping (CoD) was calculated from the waveform generated from a ‘fast flush’. Results . Thirty systems (19%) were adequately damped (CoD 0.4 - 0.8), 56 (37%) were overdamped, and 68 (44%) were underdamped. We did not find that poor damping characteristics were associated with the age of the arterial catheter or the type of catheter used. Conclusion. Most systems observed in this study were inappropriately damped, which would result in the inaccurate display of the waveform and systolic and diastolic pressures.