Abstract
Introduction: Dexamethasone (DEX) is used to treat cerebral edema at altitude. However, effects of DEX at altitude on cerebrovascular regulation are unknown.
Methods: 82 patients with COPD, GOLD 1-2, (mean±SD; 56±9yrs, FEV1 90±19%pred) were randomized to placebo (PLC) or DEX (2x4mg/day) one-day prior to and during an altitude sojourn. Middle cerebral artery blood flow velocity (MCAv; transcranial Doppler ultrasound) and mean blood pressure (MBP) were monitored at rest and during isometric handgrip exercise to fatigue at 760m (Bishkek, Kyrgyzstan) and 3100m (Tuja Ashu)
Results: In 44 patients receiving DEX there was no altitude-induced increase in MCAv (48.6±8.8 vs. 49.4±10.5cm·s-1) or MBP (93±9 vs. 94±9mmHg) with ascent to 3100m. In 38 patients receiving PLC, ascent increased MCAv and MBP from 47.7±10.0 to 52.2±10.4cm·s-1 and 91±12 to 97±12mmHg, respectively; both P<0.01. Treatment effect, mean difference[95%CI] was -3.8cm·s-1[-7.3;-0.2] and -5mmHg[-9;-1] for MCAv and MBP; both P<0.05.
During handgrip at 3100m, DEX blunted MCAv increase (28±14 vs. 21±13%; P≤0.01), despite a similar increase in MBP as at 760m (46±22 vs. 48±26%; P>0.05). With placebo, the MCAv and MBP during handgrip were similar between altitudes (MCAv: 30±14 vs. 28±11%; MBP: 47±27 vs. 45±20%; both P>0.05). The treatment effect was -6%[-11;0] P<0.05 and 4%[-7;15]) for MCAv and MBP, respectively.
Conclusion: In mild-moderate COPD DEX attenuated the altitude-related increase in MCAv and MBP, suggesting that DEX may have a protective role preventing an excessive rise in cerebral blood flow and pressure at altitude.
Funding: Swiss Lung Foundation, Lung Zurich, NSERC, Brenda Strafford Foundation Chair for Alzheimer Research
Footnotes
Cite this article as: European Respiratory Journal 2018 52: Suppl. 62, OA5343.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2018