A randomized, controlled trial of the efficacy of closed chest compressions in ambulances

Abstract

Objective. To examine the feasibility of closed chest compressions in ambulances.

Methods. Ten male emergency medical technicians performed closed chest compressions on a Laerdal Skillmeter Resusci Anne placed 1) on the ground, 2) on the stretcher of an MB 510 ALS ambulance, 3) on the stretcher of an MB 310 ambulance, and 4) on the stretcher of a VW T4 BLS ambulance for 2 minutes each. The authors noted the percentage of correct compressions as shown by the mannequin and counted the heart rate of the participants before and after each session. The authors compared the percentage of correct compressions and the increase in heart rate during the three ambulance sessions with those of the session on the ground by rank order test for paired observations. A p < 0.05 after Bonferroni correction (factor 3) was considered significant.

Results. The percentage of correct compressions was 90% ± 7% on the ground, 77% ± 19% in the MB 510,60% ± 31% in the MB 310, and 38% ± 24% in the VW T4. Heart rate increase was 18 ± 16 min⁻¹ on the ground, 23 ± 9 min^-1 in the MB 510,30 ± 16 min^-1 in the MB 310, and 32 ± 13 min^-1 in the VW T4. Only the difference in percentage of correct compressions between on the ground and the VW T4 was significant (p < 0.01 after Bonferroni correction).

Conclusions. The percentage of correct compressions in all the vehicles tested was lower when compared with the percentage on the ground, and the increase in heart rate was higher. Only one of these results was statistically significant. A further study with more participants seems warranted.

Keywords:

• closed chest compressions
• ergonomics
• emergency medical technician
• mannequin
• out-of-hospital environment.