RÉSUMÉ
[Abstract] Objective To investigate the risk factors and predictive factors for acute mountain sickness (AMS) after acute exposure to high altitude. Methods Eighty-three subjects were airlifted from Chengdu (elevation 500m) to Lhasa (elevation 3700m) in 2 hours, and divided into AMS(+) group and AMS(–) group according to the LLS AMS scores (2018). Subjects were tested both in plain (Chengdu) and plateau (Lhasa). With the case report form (CRF), the demographic data, AMS related symptoms, self-rating anxiety scale (SAS) and fatigue self-assessment scale (FSAS) were collected, meanwhile the heart rate, blood pressure and percutaneous oxygen saturation (SpO2) were detected. The cardiac ultrasound was performed, and the subjects' venous blood was collected to detect vasoconstriction and vasodilatation factors with ELISA. Logistic regression analysis was performed to screen the independent risk factors for AMS. Results As 4 subjects were lost, a total of 79 subjects were eventually included in present study. After acutely exposed to high altitude, the subjects' SAS, FSAS and HR aroused obviously (P<0.05), while the SpO2 decreased markedly (P<0.05). There was also a significant increase in systemic and cerebral hemodynamics (P<0.05). Plasma levels of endothelin-1 and bradykinin increased (P<0.05), while of nitric oxide, prostaglandin E and serotonin decreased (P<0.05). Furthermore, when the subjects were located in plain area, the left ventricular end-diastolic diameter (LVEDD) was obviously higher in AMS(+) group [(47.11±2.90)mm] than in AMS(–) group [(45.51±2.17)mm, P=0.008], while after acutely exposed to high altitude, the SAS and FSAS were markedly higher in AMS(+) group than in AMS(–) group (P=0.001), and the systolic blood flow velocity of basilar artery was also higher in AMS(+) group [(70.30±15.71)cm/s] than in AMS(–) group [(63.06±11.81)cm/s, P=0.026]. With regression analysis, it is shown that LVEDD could independently indicate the occurrence of AMS in the plain area (OR=1.293, 95%CI 1.058-1.581, P=0.012), and the systolic blood flow of basilar artery (OR=1.055, 95%CI 1.005-1.107, P=0.030), right atrium diameter (RAD, OR=0.731, 95%CI 0.543-0.984, P=0.039), SAS (OR=1.219, 95%CI 1.027-1.447, P=0.023) and FSAS (OR=1.105, 95%CI 1.016-1.201, P=0.019) were closely correlated with AMS after acutely exposed to high-altitude (P<0.05). Conclusions The baseline LVEDD has predictive value for AMS in plain area. After exposure to high altitude, the posterior cerebral circulation hemodynamics, anxiety and fatigue may trigger the occurrence of AMS.