Awareness and prevalence of acute mountain sickness and prevalence of obstructive airflow limitation among Nepalese porters: A cross-sectional study in Khumbu Valley, Nepal

Background: Acute mountain sickness is a major public health problem in high altitudes. Similarly, anecdotal evidence suggests that there is high prevalence of tobacco smoking among this group though prevalence of obstructive airflow limitation is not known. Objectives: The main aims of the study were to measure the awareness of AMS and report the prevalence of AMS and obstructive lung diseases in high altitude Nepalese porters. Setting: This study was done with bases in Namche Bazaar (3460metres), Pheriche (4270m), Thokla pass (4830m), Gorakshep (5140m) and Everest Base Camp (5364m). Method: A cross-sectional study was conducted using standardized multiple choice questionnaires among high altitude porters working at Namche and above during May-June 2008. Total 200 porters were interviewed. Lake Louis questionnaire was used for diagnosis of AMS. Spirometry was performed in 160 porters at Namche Bazaar. Results: Awareness of AMS was medium among 50% of porters and 36% had low knowledge regarding AMS. The total prevalence of AMS was 4% among porters. The prevalence of AMS was 0.6% at 3460m, 13.3% at 4270m, 21.4% at 4830m and 28.5% at 5364m. Prevalence of tobacco smoking was 34%. Frequency of airflow limitation was 17.9% which was defined by FEV1/FVC <0.7. Vital signs (BP, PR and RR) and saturation pressure of oxygen (SpO2) were significantly associated with AMS outcome (p-value