Critical care medicine
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Critical care medicine · Feb 1988
Chest wall acceleration and force measurements in simulated manual and mechanical cardiopulmonary resuscitation.
During CPR, the dynamics of the chest compression process play a major role in determining the outcome of the resuscitation effort. To quantify chest wall motion during CPR, a number of important variables must be determined, including maximum downward acceleration and velocity of the chest wall, time during which the wall is held in compression, and maximum depth and rate of chest compression. In this study, miniature accelerometers were used to record chest wall motion during simulated CPR with standard training manikins. ⋯ However, the maximum downward velocity was usually higher with manual CPR. In comparison with trained but clinically inexperienced individuals, rescuers with extensive in hospital experience produced relatively larger downward accelerations, longer "hold" times with the chest in compression, and maximum chest displacements that exceeded the current AHA recommendations. Measurements of the force transmitted through the manikin to a force platform clearly indicated the presence of a "hold" phase (if present) and the existence of large force components in the horizontal plane.
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Critical care medicine · Feb 1988
Calibration of respiratory inductive plethysmography in lambs receiving intermittent mandatory mechanical ventilation.
Respiratory inductive plethysmography (RIP) is a noninvasive method of assessing breathing pattern. We employed a single-position graphic (SPG) calibration technique for gain factor calculation in 38 studies on five sedated lambs who were receiving intermittent mandatory mechanical ventilation (IMV). The SPG technique uses selection of two breaths from a 20-sec run of breaths with different ribcage/pneumotachograph (PNT) and abdomen/PNT ratios for gain calculation. ⋯ The mean tidal volume (VT) measured by RIP corresponded well with mean VT measured by PNT with animals receiving 42.2 +/- 13.2 (SD) % of breaths over 1 min by IMV. Time for calibration and validation ranged between 15 and 30 min. The results of this study suggest that the SPG calibration technique provides an accurate method of calibration of RIP in sedated lambs receiving IMV.