Effects of compression-to-ventilation ratio on compression force and rescuer fatigue during cardiopulmonary resuscitation

Introduction: Although increasing consecutive compressions during cardiopulmonary resuscitation (CPR) is beneficial to patients, it possibly affects the workload and, ultimately, the quality of CPR. This study examines the effects of compression-to-ventilation ratio on external chest compression performance of rescuers. Methods: Subjects were 17 health care providers. Each participant performed CPR with 3 compression-to-ventilation ratios: 15:2, 30:2, and 50:5. The duration of CPR was 5 minutes in each group, with a rest period of 50 minutes in between. The manikin was equipped with a 6-axis force load cell to measure the force applied. An 8-camera digital motion analysis system was used to collect the 3-dimensional trajectory information. Data were compared using the crossover design. Ratings of perceived exertion and body area discomfort were measured. Results: The mean compression forces (in Newtons) delivered at 1 minute 20 seconds to 1 minute 40 seconds and at 4 minutes 20 seconds to 4 minutes 40 seconds were 494.65 +/- 53.58 and 478.64 +/- 50.29, respectively (P = .047), for compression-to-ventilation ratios of 15:2; 473.57 +/- 49.69 and 435.59 +/- 56.79, respectively (P < .001), for ratios of 30:2; and 468.44 +/- 38.05 and 442.18 +/- 43.40, respectively (P = .012), for ratio of 50:5. Diminished compression force in the ratio 50:5 was observed at 1 minute 20 seconds, and in the 30:2 ratio, it was observed at 4 minutes 20 seconds. The mean joint angles in each group did not differ significantly between 1 minute 20 seconds and 4 minutes 20 seconds. The Ratings of Perceived Exertion Scale was 3.38 +/- 1.64 in 15:2, 4.06 +/- 1.43 in 30:2, and 4.35 +/- 1.54 in 50:5 (P = .045). Waist discomfort was noted in 50:5 after 4 minutes 20 seconds of external chest compression. Conclusions: Rescuer fatigue must be considered when raising the consecutive compression during CPR. Switching the compressor every 2 minutes should be followed where possible. (C) 2010 Elsevier Inc. All rights reserved.