1. Impact of Hanging Motionless in Harness on Respiratory and Blood Pressure Reflex Modulation in Mountain Climbers
- Author
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Egidio Beretta, Francesca Lanfranconi, Giovanni De Vito, Manuela Bartesaghi, Lucio Tremolizzo, Luca Pollastri, M Novarina, Alessandra Ferri, Lanfranconi, F, Ferri, A, Pollastri, L, Bartesaghi, M, Novarina, M, De Vito, G, Beretta, E, and Tremolizzo, L
- Subjects
Adult ,Male ,Scientific Articles ,Time Factors ,Physiology ,harness hang syncope ,respiratory and cardiovascular reflexe ,Respiratory gas exchange ,Poison control ,Blood Pressure ,Syncope ,Suspension trauma ,BIO/09 - FISIOLOGIA ,Reflex ,medicine ,Humans ,Respiratory system ,MED/26 - NEUROLOGIA ,Reflex modulation ,business.industry ,pattern of breathing ,Respiration ,Public Health, Environmental and Occupational Health ,respiratory and cardiovascular reflexes ,General Medicine ,medicine.disease ,Healthy Volunteers ,Mountaineering ,Respiratory Function Tests ,Oxygen ,Cardiovascular reflexes ,Cross-Sectional Studies ,Blood pressure ,Anesthesia ,Breathing ,inspiratory elastic power ,Female ,business ,suspension trauma - Abstract
Harness hang syncope (HHS) is a risk that specifically affects safety of harness users in mountain climbing. Aims: To evaluate individual patterns of breathing resulting from deranged cardiovascular reflexes triggering a syncopal event when a mismatch between cerebral O2 demand and supply is present. Results: Forty healthy participants [aged 39.1 (8.2) years] were enrolled in a motionless suspension test while hanging in harness. Respiratory gas exchange values were analyzed to assess the pattern of breathing (EpInWel, respiratory elastic power) and cardiovascular parameters were monitored (BP, blood pressure). Four participants experienced HHS after 30.0 (7.6) minutes, with an early manifestation of loss of control of both a sustainable EpInWel and BP, starting after 10–12 minutes. Among the other participants, two different reactions were observed during suspension: (1) group G1 tolerated 32.7 (11.4) minutes of suspension by a favorable adaptation of the EpInWel and BP parameters and (2) group G2 showed significantly shorter time of suspension 24.0 (10.4) minutes with unfavorable increase in EpInWel and BP. Conclusions: Greater resistance to HHS occurs in people developing less marked fluctuations of both respiratory and cardiovascular reflex responses. Conversely, wider fluctuations both in control of EpInWel and BP were observed in the event of decreased suspension tolerance or in syncopal events.
- Published
- 2019