Influence of high altitude after a prior ascent on physical exhaustion during cardiopulmonary resuscitation: a randomised crossover alpine field experiment

Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine

Original Research

Katharina Tscherny¹  Alexander Egger²  Maximilian Niederer³  Dominik Roth⁴  Calvin L. Kienbacher⁴  Verena Fuhrmann⁴  Harald Herkner⁴  Wolfgang Schreiber⁴  Bettina Wandl⁵  Josef Burger⁶ 

[1] Department of Anaesthesiology and Intensive Care Medicine, Hospital Scheibbs, Eisenwurzenstraße 26, 3270, Scheibbs, Austria;Department of Emergency Medicine, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria;Department of Anaesthesiology and Intensive Care Medicine, Hospital Scheibbs, Eisenwurzenstraße 26, 3270, Scheibbs, Austria;Mountain Rescue Service Austria, Baumgasse 129, 1030, Vienna, Austria;Department of Anaesthesiology and Intensive Care Medicine, Hospital Scheibbs, Eisenwurzenstraße 26, 3270, Scheibbs, Austria;Mountain Rescue Service Austria, Baumgasse 129, 1030, Vienna, Austria;Department of Emergency Medicine, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria;Department of Emergency Medicine, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria;Department of Emergency Medicine, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria;Institute of Nursing Science, Department of Nursing Science and Gerontology, UMIT TIROL – Private University for Health Sciences and Health Technology, Hall in Tyrol, Austria;Mountain Rescue Service Austria, Baumgasse 129, 1030, Vienna, Austria;Department of Paediatrics, Hospital Lienz, Emanuel von Hibler-Straße 5 A, 9900, Lienz, Austria;

关键词: Cardiopulmonary resuscitation;    High altitude;    Physical exhaustion;    Mountain medicine;    Basic life support;   

DOI  :  10.1186/s13049-023-01132-7

 received in 2023-08-10, accepted in 2023-10-15,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundPerforming cardiopulmonary resuscitation (CPR) inevitably causes significant physical, as well as psychological stress for rescuers. Physical activity at high altitude, a hypobaric and hypoxic environment, similarly adds to the level of stress and causes multiple physiological changes. Continuous measurement of pulse rate serves as an objective measure of fatigue during CPR. We therefore aimed to investigate rescuers’ heart rates as a measure of physical strain during CPR in a high-altitude alpine environment to provide a better understanding of the physiological changes under these very special conditions.MethodsTwenty experienced mountaineers performed basic life support (BLS) on a manikin for 16 min, both at baseline altitude and at high altitude (3454 m) following a quick and exhausting ascent over 1200 m. Sequence of scenarios was randomised for analysis. Heart rate was continuously measured and compared between baseline and high altitude by absolute differences and robust confidence intervals.ResultsDuring CPR at baseline, the average heart rate increased from 87 bpm (SD 16 bpm) to 104 bpm [increase 17 bpm (95% CI 8.24–24.76)], compared to an increase from 119 bpm (SD 12 bpm) to 124 bpm [increase 5 bpm (95% CI − 1.59 to 12.19)] at high altitude [difference between two groups 32 bpm (95% CI 25–39)]. Differences between periods of chest compressions and ventilations were very similar at baseline [19 bpm (95%CI 16.98–20.27)] and at high altitude [20 bpm 95% CI 18.56–21.44)], despite starting from a much higher level at high altitude. The average heart rates of rescuers at high altitude at any point were higher than those at baseline at any other point.ConclusionPerforming BLS CPR causes exhaustion both at base level and at a high altitude. A further increase during CPR might imply a physiological reserve for adapting to additional physical exertion at high altitude. Phases of ventilation are much needed recovery-periods, but heart rates remain very high. Subjective measures of exhaustion, such as the BORG-scale, might lead to rescuers’ overestimation of their own performance.

【 授权许可】

CC BY   
© Norwegian Air Ambulance Foundation 2023

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