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A Randomized Crossover Simulation Study of Prolonged Conventional Versus Modified "Koch" Chest Compressions in a
Kendra Young1, Howard Koch2, Domhnall O'Dochartaigh3
1Department of Emergency Medicine, University of Calgary, Calgary, Alberta, Canada.
Objective:
Low overhead height negatively affects chest compression performance. An adapted compression technique ("Koch") using an elbow has been evaluated. This study assesses longer duration and larger sample.
Methods:
A total of 52 first responders were paired and randomized to complete 12 minutes of Koch or conventional compressions on a Laerdal Resusci Anne manikin, alternating 2-minute cycles between partners. After rest, they crossed over. Primary outcomes were compression depth, recoil, landmarking, and overall quality score. Participant feedback was also collected.
Results:
Results were significant. The mean quality compression score was 66.6% for Koch/28.3% for conventional (W = 348, P < .001, rrb = 0.98). Koch compressions increased mean depth by 18.8 mm (95% confidence interval 15.3-22.4). No conventional method result reached the target depth, whereas 58% (n = 15) of Koch compressions did. Correct mean release was different (W = 258, P = .011, rrb = 0.59); Koch at 43.4% versus conventional at 29.4%. Percentage of correct landmarking was different (W = 307, P < .001, rrb = 0.75); Koch at 89.0% versus conventional at 78.0%. Reported physical exertion and difficulty were lower for Koch compression (z = 6.042, P < .001) and described as easier and more sustainable.
Conclusion:
Despite minimal training, Koch compressions significantly outperformed conventional and was the preferred compression method in a height-restricted setting.
