Background: High quality cardiopulmonary resuscitation is a key factor in survival with good overall quality of life after out-of-hospital cardiac arrest. Current evidence is predominantly based on studies conducted at low altitude, and do not take into account the special circumstances of alpine rescue missions. We therefore aimed to investigate the influence of physical strain at high altitude on the quality of cardiopulmonary resuscitation. Methods: Alpine field study. Twenty experienced mountaineers of the Austrian Mountain Rescue Service trained in Basic Life Support (BLS) performed BLS on a manikin in groups of two for 16 min. The scenario was executed at baseline altitude and immediately after a quick ascent over an altitude difference of 1200 m at 3454 m above sea level. The sequence of scenarios was randomised for a cross over analysis. Quality of CPR and exhaustion of participants (vital signs, Borg-Scale, Nine hole peg test) were measured and compared between high altitude and baseline using random-effects linear regression models. Results: The primary outcome of chest compression depth significantly decreased at high altitude compared to baseline by 1 cm (95% CI 0.5 to 1.3 cm, p < 0.01). There was a significant reduction in the proportion of chest compressions in the target depth (at least 5 cm pressure depth) by 55% (95% CI 29 to 82%, p < 0.01) and in the duration of the release phase by 75 ms (95% CI 48 to 101 ms, p < 0.01). No significant difference was found regarding hands-off times, compression frequency or exhaustion. Conclusion: Physical strain during a realistic alpine rescue mission scenario at high altitude led to a significant reduction in quality of resuscitation. Resuscitation guidelines developed at sea level are not directly applicable in the mountain terrain.

Background Cardiopulmonary resuscitation in mountain environment is challenging. Continuous chest compressions during transport or hoist rescue are almost impossible without mechanical chest compression devices. Current evidence is predominantly based on studies conducted by urbane ambulance service. Therefore, we aimed to investigate the feasibility of continuous mechanical chest compression during alpine terrestrial transport using three different devices. Methods Randomized triple crossover prospective study in an alpine environment. Nineteen teams of the Austrian Mountain Rescue Service trained according to current ERC guidelines performed three runs each of a standardised alpine rescue-scenario, using three different devices for mechanical chest compression. Quality of CPR, hands-off-time and displacement of devices were measured. Results The primary outcome of performed work (defined as number of chest compressions x compression depth) was 66,062 mm (2832) with Corpuls CPR, 65,877 mm (6163) with Physio-Control LUCAS 3 and 40,177 mm (4396) with Schiller Easy Pulse. The difference both between LUCAS 3 and Easy Pulse (Δ 25,700; 95% confidence interval 21,118 – 30,282) and between Corpuls CPR and Easy Pulse (Δ 25,885; 23,590 – 28,181) was significant. No relevant differences were found regarding secondary outcomes. Conclusion Mechanical chest compression devices provide a viable option in the alpine setting. For two out of three devices (Corpuls CPR and LUCAS 3) we found adequate quality of CPR. Those devices also maintained a correct placement of the piston even during challenging terrestrial transport. Adequate hands-off-times and correct placement could be achieved even by less trained personnel.