Comparison of the quality of chest compressions on a dressed versus an undressed manikin: A controlled, randomised, cross-over simulation study

Abstract

Background: Undressing the chest of a cardiac arrest victim may delay the initiation of chest compressions. Furthermore, expecting laypeople to undress the chest may increase bystander reluctance to perform cardiopulmonary resuscitation (CPR). Both of these factors might conceivably decrease survival following cardiac arrest. Therefore, the aim of this study was to examine if the presence or absence of clothes affected the quality of chest compressions during CPR on a simulator manikin.

Methods: Thirty laypeople and 18 firefighters were randomised to start CPR on the thorax of a manikin that was either clothed (three layers) or not. Data were obtained via recordings from the manikin and audio- and video-recordings. Measurements were: maximum compression depth; compression rate; percentage of compressions with correct hand positioning; percentage of compressions with complete release (< or = 10 mm), and percentage of compressions of the correct depth (range 40-50 mm). Laypeople were given a four-hour European Resuscitation Council standardised course in basic life support and tested immediately after. Firefighters were tested without additional training. Mock cardiac arrest scenarios consisted of three minutes of CPR separated by 15 minutes of rest.

Results: No significant differences were found between CPR performed on an undressed manikin compared to a dressed manikin, for laypeople or firefighters. However, undressing the manikin was associated with a mean delay in the initiation of chest compressions by laypeople of 23 seconds (N = 15, 95% CI: 19;27).

Conclusions: In this simulator manikin study, there was no benefit gained in terms of how well CPR was performed by undressing the thorax. Furthermore, undressing the thorax delayed initiation of CPR by laypeople, which might be clinically detrimental for survival.

Figure 1

Flowchart showing the distribution of participants. * Given basic life support course before randomisation; ** Due to daily activities, like dispatch to fire- and rescue-operations, during the test period; *** Due to organisation and daily activities, participants could not be identified for each roster until the test date; Randomisation was performed each day; **** Excluded from analysis for various reasons (data loss due to malfunction of manikin, misunderstanding instructions, and post-participation discovery of not fulfilling inclusion criteria. A - B: Standard CPR followed by intervention CPR. B - A: Intervention CPR followed by standard CPR.

Figure 2

Average maximum compression depth (mm) for laypeople (left) and firefighters (right) when providing chest compressions on a manikin with an undressed versus a dressed chest (present guidelines and intervention, respectively). The grey area indicates the recommended compression depth (ranging from 40-50 mm).

Figure 3

Compression rate (per min) for laypeople (left) and firefighters (right) when providing chest compressions on a manikin with an undressed versus a dressed chest (present guidelines and intervention, respectively). Grey line shows the recommended compression rate (100 per min).