By Art Hsieh
EMS1 Editorial Advisor
It has always been thought that rescuer fatigue during CPR is a likely contributor to variable CPR quality during resuscitation efforts — now a new study has confirmed it.
New findings published last month from the University of Pennsylvania confirm the theory that chest compressions during CPR is strenuous, tiring, and difficult to maintain over any period of time.
The researchers in this study used real time measurements of force and rate during in-hospital cardiac arrest management, rather than manikin or simulators. They were able to determine that while the rate of compressions can be reasonably maintained, the force of compressions becomes difficult to maintain by 90 seconds of compressions.
The information helps support the AHA recommendation that personnel performing chest compressions should rotate early and often. Factors such as rescuer height and weight, along with size, weight and positioning of the victim will alter the actual duration of compressions. For these reasons, mechanical CPR devices are increasingly being used in the prehospital setting.
Variable quality
Writing in the journal, Resuscitation, the authors of the study said rescuer fatigue during CPR is a likely contributor to variable CPR quality during clinical resuscitation efforts, yet investigations into fatigue and CPR quality degradation have only been performed in simulated environments, with widely conflicting results.
“We sought to characterize CPR quality decay during actual in-hospital cardiac arrest, with regard to both chest compression (CC) rate and depth during the delivery of CCs by individual rescuers over time,” they said.
Using CPR recording technology to objectively quantify CCs and provide audiovisual feedback, they prospectively collected CPR performance data from arrest events in two hospitals.
They identified continuous CPR ''blocks’’ from individual rescuers, assessing CC rate and depth over time. One-hundred-and-thirty-five blocks of continuous CPR were identified from 42 cardiac arrests at the two institutions.
Median duration of continuous CPR blocks was 112 s (IQR 101-122), according to the study.
They wrote, “CC rate did not change significantly over single rescuer performance, with an initial mean rate of 105 +/- 11/min, and a mean rate after 3 min of 106 +/- 9/min (p = NS). However, CC depth decayed significantly between 90 s and 2 min, falling from a mean of 48.3 +/- 9.6 mm to 46.0 +/- 9.0 mm (p = 0.0006) and to 43.7 +/- 7.4 mm by 3 min (p = 0.002). During actual in-hospital CPR with audiovisual feedback, CC depth decay became evident after 90 s of CPR, but CC rate did not change.”
The researchers concluded that the data provides clinical evidence for rescuer fatigue during actual resuscitations and support current guideline recommendations to rotate rescuers during CC delivery.
While the study was confined to controlled settings of hospital critical care units, and only 42 arrests were monitored, the results are compelling and poses the question of how this data translates to the field. Do you rotate personnel during a resuscitation? Use a mechanical CPR device?
N.T. Sugerman and colleagues published their study in Resuscitation (Rescuer fatigue during actual in-hospital cardiopulmonary resuscitation with audiovisual feedback: A prospective multicenter study. Resuscitation, 2009;80(9):981-984). Additional information can be obtained by contacting B.S. Abella, University of Pennsylvania, Center Resuscitat Sci, Dept. of Emergency Medical, Sch Medical, 3400 Spruce St, Philadelphia, PA 19104, USA.
Art Hsieh, MA, NREMT-P, is Chief Executive Officer & Education Director of the San Francisco Paramedic Association, a published author of EMS textbooks and a national presenter on clinical and education subjects.