Counseling Patients with Chronic Obstructive Pulmonary Disease Traveling to High Altitude

Abstract

Bloch, Konrad E., Talant M. Sooronbaev, Silvia Ulrich, Mona Lichtblau, and Michael Furian. Clinician's corner: counseling patients with chronic obstructive pulmonary disease traveling to high altitude. High Alt Med Biol. 24:158-166, 2023.-Mountain travel is increasingly popular also among patients with chronic obstructive pulmonary disease (COPD), a highly prevalent condition often associated with cardiovascular and systemic manifestations. Recent studies have shown that nonhypercapnic and only mildly hypoxemic lowlanders with moderate to severe airflow obstruction owing to COPD experience dyspnea, exercise limitation, and sleep disturbances when traveling up to 3,100 m. Altitude-related adverse health effects (ARAHE) in patients with COPD include severe hypoxemia, which may be asymptomatic but expose patients to the risk of excessive systemic and pulmonary hypertension, cardiac arrhythmia, and even myocardial or cerebral ischemia. In addition, hypobaric hypoxia may impair postural control, psycho-motor, and cognitive performance in patients with COPD during altitude sojourns. Randomized, placebo-controlled trials have shown that preventive treatment with oxygen at night or with acetazolamide reduces the risk of ARAHE in patients with COPD while preventive dexamethasone treatment improves oxygenation and altitude-induced excessive sleep apnea, and lowers systemic and pulmonary artery pressure. This clinical review provides suggestions for pretravel assessment and preparations and measures during travel that may reduce the risk of ARAHE and contribute to pleasant mountain journeys of patients with COPD.

Keywords: altitude illness; altitude travel; altitude-related adverse health effects; chronic obstructive pulmonary disease; prevention, mountain sickness.

FIG. 1.

Kaplan–Meier curves representing the results of two randomized, placebo-controlled, double-blind trials evaluating efficacy of preventive acetazolamide therapy in reducing the incidence of ARAHE in patients with (COPD, A) and AMS in healthy individuals, 40 years of age or older (B). The y-axis represents the cumulative incidence of the primary outcome ARAHE and AMS, respectively. After baseline evaluation at 760 m and randomization (R), participants started taking the study drug (either acetazolamide, 375 mg/day or placebo) on day 0, around noon. On day 1, in the morning, participants traveled by minibus to 3,100 m and arrived there in the afternoon. Night rest was from around 22:00 to 06:00 hours (black boxes). Blue lines denote data from the placebo group and red lines data from the acetazolamide group. Chi-square statistics indicated a reduced incidence of ARAHE in patients with COPD taking acetazolamide versus those taking placebo. In healthy older individuals, acetazolamide reduced the incidence of AMS compared with placebo. AMS, acute mountain sickness; ARAHE, altitude-related adverse health effects; CI, confidence interval; COPD, chronic obstructive pulmonary disease. Reproduced from Furian et al. (2022b) NEJM Evidence 2022.