The Elusive Path of Brain Tissue Oxygenation and Cerebral Perfusion in Harness Hang Syncope in Mountain Climbers.

Autor: Lanfranconi F; 1 Laboratory of Clinical Physiology and Sport Medicine, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy ., Pollastri L; 2 PENTAVIS , Laboratory of Sport Sciences, Lecco, Italy ., Corna G; 1 Laboratory of Clinical Physiology and Sport Medicine, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy ., Bartesaghi M; 2 PENTAVIS , Laboratory of Sport Sciences, Lecco, Italy ., Novarina M; 2 PENTAVIS , Laboratory of Sport Sciences, Lecco, Italy ., Ferri A; 1 Laboratory of Clinical Physiology and Sport Medicine, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy .; 3 Clinical Exercise Science Research Program, Institute of Sport Exercise and Active Living (ISEAL), Victoria University , Melbourne, Australia ., Miserocchi GA; 1 Laboratory of Clinical Physiology and Sport Medicine, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy .
Jazyk: angličtina
Zdroj: High altitude medicine & biology [High Alt Med Biol] 2017 Dec; Vol. 18 (4), pp. 363-371. Date of Electronic Publication: 2017 Oct 05.
DOI: 10.1089/ham.2017.0028
Abstrakt: Lanfranconi, Francesca, Luca Pollastri, Giovanni Corna, Manuela Bartesaghi, Massimiliano Novarina, Alessandra Ferri, and Giuseppe Andrea Miserocchi. The elusive path of brain tissue oxygenation and cerebral perfusion in harness hang syncope in mountain climbers. High Alt Med Biol. 18:363-371, 2017.
Aim: Harness hang syncope (HHS) is a risk that specifically affects wide ranges of situations requiring safety harnesses in mountains. An irreversible orthostatic stasis could lead to death if a prompt rescue is not performed. We aimed at evaluating the risk of developing HHS and at identifying the characteristics related to the pathogenesis of HHS.
Results: Forty adults (aged 39.1 [8.2] years) were enrolled in a suspension test lasting about 28.7 (11.4) minutes. We measured cardiovascular parameters, and near infrared spectroscopy (NIRS) was used to assess cerebral hypoxia by changes in the concentration of oxyhemoglobin (Δ[HbO 2 ]) and de-oxyhemoglobin (Δ[HHb]). In the four participants who developed HHS: (1) systolic and diastolic blood pressure showed ample oscillations with a final abrupt drop (∼30 mmHg); (2) Δ[HbO 2 ] increased after 8-12 minutes of suspension and reached a plateau before HHS; and (3) Δ[HHb] decreased with a final abrupt increase before syncope.
Conclusions: Participants who developed HHS failed to activate cardiovascular reflexes that usually safeguard O 2 availability to match the metabolic needs of the brain tissue. Since cerebral hypoxia was detected as an early phenomenon by Δ[HbO 2 ] and Δ[HHb] changes, NIRS measurement appears to be the most important parameter to monitor the onset of HHS.
Databáze: MEDLINE
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