A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation

Carolyn L Cason,Susan M Baxley,Cynthia Trowbridge,Mark D Ricard

doi:10.1186/1472-6955-10-15

Carolyn L Cason, Susan M Baxley + Show 2 more

Open Access

https://doi.org/10.1186/1472-6955-10-15

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Journal: BMC nursing	Publication Date: Aug 2, 2011
Citations: 31	License type: CC BY 2.0

Affiliation: The University of Texas at Arlington

Abstract

BackgroundPrevious research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only) on the quality of CPR and rescuer fatigue.MethodsFifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter® software. Blood lactate (mmol/dl) and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set a priori at 0.05.ResultsVisual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2%) than did auditory (65.4 ± 7.6%) or no feedback (44.5 ± 8.1%). Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute) was less than it was with both visual and no feedback (p < 0.05). CPR performed with no feedback (39.2 ± 0.5 mm) yielded a shallower average depth of compression and a lower percentage (55 ± 8.9%) of compressions within the accepted 38-50 mm range than did auditory or visual feedback (p < 0.05). The duty cycle for auditory feedback (39.4 ± 1.6%) was less than it was with no feedback (p < 0.05). Auditory feedback produced lower lactate concentrations than did visual feedback (p < 0.05) but there were no differences in perceived exertion.ConclusionsIn this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback. The perfect confounding of sensory modality and periodicity of feedback (visual feedback provided continuously and auditory feedback provided to correct error) leaves unanswered the question of optimal form and timing of feedback.

Highlights

Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR)
Poor quality cardiopulmonary resuscitation (CPR) in inhospital cardiac arrest among well-trained hospital staff [1] provided the impetus for the development and implementation of audiovisual feedback devices for use during clinical resuscitation
Our results indicated that auditory feedback provided by the voice-assisted manikin (VAM) decreased the average rate of compressions, increased the percent of compressions without full release of pressure, and decreased duty cycle

Summary

Introduction

Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Sugarman et al [3] attribute rescuers’ inability to maintain adequate depth of compressions with feedback to rescuer fatigue and do not relate it to the type or duration of feedback provided. Kramer-Johansen et al.’s [4] study of the use of real time automated feedback (visual waveforms and verbal messages) during out of hospital resuscitation suggest that rescuers’ inability to maintain adequate depth of compression may arise not from rescuer fatigue but from complexity of the feedback provided. Ambulance personnel were permitted to turn off auditory feedback (verbal messages and tonal prompts) and 18 percent did so but all retained the visual feedback. Kramer-Johansen et al suggest further investigation to identify the form of optimal feedback (visual, tonal, voice prompts) and the ideal hierarchy and intensity of feedback

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