The effects of flashlight guidance on performance for chest compression of cardiopulmonary resuscitation in a noisy environment

Abstract

IntroductionIn real cardiopulmonary resuscitation (CPR) situations, noise can arise from instructional voices and from environmental sounds in places such as the battlefield, industrial, commercial shopping and high traffic areas. The World Health Organization (WHO) suggested guideline limits for community noise in specific environments. In the specific environments mentioned above, noise levels were measured to be >70 dB, which can induce annoyance and hearing impairment. A simple feedback device using flashlight stimulus was designed for overcoming noise-induced stimulus saturation during CPR. This study was conducted to determine whether flashlight guidance influences CPR performance in a simulated noisy setting. Materials and MethodsWe recruited 30 senior medical students with no previous experience using flashlight-guided CPR participated in this prospective, simulation-based, cross-over study. In a simulated noisy situation, the experiment was conducted using a cardiac arrest model without ventilation. Noise was artificially generated as patrol car and fire engine sirens. Siren noise intensity was adjusted to 80 ± 5 dB, with 60 pitches/minute. The flashlight guidance emitted light pulses at the rate of 100 flashes/minute from a light-emitting diode (LED). Participants also received the instruction that suited a target rate of 100 compressions/minute. CPR was randomly performed in one of two sequences. Compression rate and depth and percentage of compression with correct hand position were recorded with a Resusci Anne® manikin with a PC skill-reporting system. Participants were asked to report rescuer’s fatigue on a visual analog scale (VAS) of 0-10. A linear mixed model for 2×2 cross-over design and evaluating changes in chest compression rate across time were used. ResultsThere were significant differences between the control and flashlight groups for mean compression rate (MCR), MCR/minute, and VAS. However, there were no significant differences for corrected compression depth (%), mean compression depth (mm), corrected hand position (%), and correctly released compression (%). The flashlight group MCR closely maintained the target 100 compressions/minute. However the control group MCR was distributed over a much wider range. The flashlight group had a tendency to maintain constant MCR, whereas the control group had a tendency to decrease MCR after 60 secondsConclusionFlashlight guidance is effective low-cost CPR feedback system for maintaining desired MCR. Flashlight-guided CPR is particularly advantageous in maintaining desired MCRs during compression-only CPR in noisy environments where metronome-pacing might not be clearly heard.