Postural Control in Lowlanders With COPD Traveling to 3100 m: Data From a Randomized Trial Evaluating the Effect of Preventive Dexamethasone Treatment

Abstract

Objective: To evaluate the effects of acute exposure to high altitude and preventive dexamethasone treatment on postural control in patients with chronic obstructive pulmonary disease (COPD).Methods: In this randomized, double-blind parallel-group trial, 104 lowlanders with COPD GOLD 1-2 age 20–75 years, living near Bishkek (760 m), were randomized to receive either dexamethasone (2 × 4 mg/day p.o.) or placebo on the day before ascent and during a 2-day sojourn at Tuja-Ashu high altitude clinic (3100 m), Kyrgyzstan. Postural control was assessed with a Wii Balance BoardTM at 760 m and 1 day after arrival at 3100 m. Patients were instructed to stand immobile on both legs with eyes open during five tests of 30 s each, while the center of pressure path length (PL) was measured.Results: With ascent from 760 to 3100 m the PL increased in the placebo group from median (quartiles) 29.2 (25.8; 38.2) to 31.5 (27.3; 39.3) cm (P < 0.05); in the dexamethasone group the corresponding increase from 28.8 (22.8; 34.5) to 29.9 (25.2; 37.0) cm was not significant (P = 0.10). The mean difference (95% CI) between dexamethasone and placebo groups in altitude-induced changes (treatment effect) was -0.3 (-3.2 to 2.5) cm, (P = 0.41). Multivariable regression analysis confirmed a significant increase in PL with higher altitude (coefficient 1.6, 95% CI 0.2 to 3.1, P = 0.031) but no effect of dexamethasone was shown (coefficient -0.2, 95% CI -0.4 to 3.6, P = 0.925), even when controlled for several potential confounders. PL changes were related more to antero-posterior than lateral sway. Twenty-two of 104 patients had an altitude-related increase in the antero-posterior sway velocity of >25%, what has been associated with an increased risk of falls in previous studies.Conclusion: Lowlanders with COPD travelling from 760 to 3100 m revealed postural instability 24 h after arriving at high altitude, and this was not prevented by dexamethasone.Trial Registration: clinicaltrials.gov Identifier: NCT02450968.

Effect of Acetazolamide on Postural Control in Patients with COPD Travelling to 3100 m Randomized Trial

“…During high altitude travel, patients with COPD may be particularly susceptible to impairments in PC as their lung disease may result in more pronounced hypoxemia at a given altitude compared to healthy individuals. Consistently, in lowlanders with COPD, we observed significantly increased postural instability measured by a balance board at 3100 m [ 11 ]. For prevention of dangerous events, such as falls, especially at high altitude with little access to healthcare facilities, it would be desirable to have an effective means to prevent the risks of PC instability.…”

“…The current study is the first investigating the effect of acetazolamide on PC in lowlanders with COPD travelling to high altitude. Whereas previous studies regarding PC under hypoxic conditions addressed mainly young, healthy mountaineers, Muralt and coworkers [ 11 ] were the first to show an altitude-related increase in COPL and antero-posterior velocity in mild to moderate COPD patients. The predominance of an altitude-induced impairment in control of body movements in the antero-posterior over the medio-lateral plane was also observed in the current study, which was consistent with previous studies in healthy individuals in various settings and with different devices [ 3 , 6 , 7 , 23 ].…”

Visuomotor performance at high altitude in COPD patients. Randomized placebo-controlled trial of acetazolamide

“…Previous studies on the effects of acute altitude exposure on cognitive and motor function in COPD patients are scarce and comparisons are hampered by differences in protocols, altitude and cognitive tasks used. In a study performed in 104 lowlanders with mild to moderate COPD staying for 2 days at 3100 m, we did not observe high altitude-induced changes in psychomotor vigilance reaction time although we noted impairment in postural control ( Muralt et al, 2018 ; Furian et al, 2019 ). In another study in 32 patients with moderate to severe COPD staying for 2 days at 2590 m, psychomotor reaction time and performance in a trail making test were not affected by altitude ( Latshang et al, 2019 ).…”

Effect of Nocturnal Oxygen Therapy on Daytime Pulmonary Hemodynamics in Patients With Chronic Obstructive Pulmonary Disease Traveling to Altitude: A Randomized Controlled Trial

“…During flights, a partial pressure of oxygen (PaO 2 ) of at least 50 mmHg should be maintained, and patients with an oxygen saturation (SpO 2 ) above 95% at rest and SpO 2 > 84% during the 6-min walking test at sea level are usually able to travel without supplemental oxygen. Recommendations for altitude sojourns in COPD patients are lacking; meanwhile, several studies on COPD patients and altitude travel have been conducted ( Furian et al,2018b,c , 2019 ; Muralt et al, 2018 ; Latshang et al, 2019 ; Lichtblau et al,2019a,b , 2020 ; Schwarz et al, 2019 ; Tan et al, 2020 ; Carta et al, 2021 ). It is known that patients with COPD may suffer from hypoxemia when traveling to altitude and that altitude travel increases PAP, induces the occurrence of intracardiac and intrapulmonary right-to-left shunts, and reduces exercise capacity ( Furian et al,2018a,b ; Lichtblau et al, 2018 , 2019b , 2020 ; Latshang et al, 2019 ; Schwarz et al, 2019 ).…”