TY  - JOUR
PY  - 2017//
TI  - The elusive path of brain tissue oxygenation and cerebral perfusion in harness hang syncope in mountain climbers
JO  - High altitude medicine and biology
A1  - Lanfranconi, Francesca
A1  - Pollastri, Luca
A1  - Corna, Giovanni
A1  - Bartesaghi, Manuela
A1  - Novarina, Massimiliano
A1  - Ferri, Alessandra
A1  - Miserocchi, Giuseppe Andrea
SP  - 363
EP  - 371
VL  - 18
IS  - 4
N2  - 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. 18:000-000, 2017. <br><br>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. <br><br>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[HbO2]) 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[HbO2] 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. <br><br>CONCLUSIONS: Participants who developed HHS failed to activate cardiovascular reflexes that usually safeguard O2 availability to match the metabolic needs of the brain tissue. Since cerebral hypoxia was detected as an early phenomenon by Δ[HbO2] and Δ[HHb] changes, NIRS measurement appears to be the most important parameter to monitor the onset of HHS.<p />  <p>Language: en</p>
LA  - en
SN  - 1527-0297
UR  - http://dx.doi.org/10.1089/ham.2017.0028
ID  - ref1
ER  -