Early Initiation of Continuous Positive Airway Pressure for Severe Acute Mountain Sickness: A Novel Supportive Strategy

Background: Acute Mountain Sickness (AMS) is the commonest problem that affects the troops inducted to High Altitude Areas (HAA). In severe cases, it can cause High Altitude Cerebral Oedema (HACO) leading to excess morbidity and even mortality. AMS is diagnosed clinically based on history and physical examination findings. This includes current history of attaining altitude with complaints of headache as a pathognomonic feature along with various symptoms like altered bowel habits, tiredness, generalized weakness, giddiness and insomnia. Self-reported Lake Louise Scoring (LLS) is used across the globe as a standard to assess the severity of AMS with a score of three or more confirming the diagnosis and scores ≥ 6 constituting severe AMS. Treatment for AMS is generally symptomatic, with supplementation of Oxygen by Facemask (OFM) constituting the pivot of management. Evacuation to lower altitude is at times required for severe refractory cases not responding to treatment. There are only a handful of case reports, wherein oxygen therapy via continuous positive airway pressure (CPAP) has been used as a treatment modality, which have shown to cause a rapid abatement of symptoms. Aims and Objectives: Hence, this study was undertaken to find out the efficacy, safety and feasibility of CPAP as a modality of treatment for AMS vis-a-vis OFM. Materials and Methods: Study was done in troops deployed in High Altitude area and design is Randomized Controlled Trial. A total of 100 military and paramilitary personnel, deployed at a HAA after adequate acclimatisation, who were diagnosed with severe AMS (LLS ≥ 6) were managed at different locations. They were randomly allocated to the CPAP group and OFM group. Patients in the CPAP group were given 6-7 cm of H2O of positive airway pressure in addition to supplemental oxygen as compared to the OFM group. Results: Significant improvement in symptoms was observed in both treatment groups, as assessed by the Lake Louise Score (p < 0.001) before and after therapy. However, the improvement was significantly greater in the CPAP group compared to the OFM group. Conclusion: Use of CPAP in the management of severe AMS results in a more rapid reduction of symptom severity compared to conventional oxygen via facemask. CPAP was found to be safe, feasible and well tolerated in the high-altitude environment with no significant adverse events. Its ability to enhance oxygenation and reduce work of breathing likely contributes to the accelerated clinical recovery observed. CPAP may therefore serve as an effective adjunct or alternative to routine oxygen therapy, especially in remote high-altitude deployments where rapid symptom control is crucial.