REHABILITATION OF HYPOXEMIC PATIENTS WITH COPD AT LOW-ALTITUDE AT THEDEAD-SEA, THE LOWEST PLACE ON EARTH

Background: In patients with COLD, oxygen therapy has been shown to im prove exercise capacity and survival. Increase in barometric pressure at low altitude can serve as a simple way to improve arterial oxygenat ion in hypoxemic patients. We have tried to evaluate the effect of sta ying at low altitude on arterial oxygenation and exercise performance in patients with COPD, Patients and method: Eleven patients with COPD (9 male, 2 female) aged 38 to 79 years (mean FEV1, 0.96 L; 36% predict ed) with hypoxemia (mean PaO2, 54.2+/-8.9 mm Hg) at Jerusalem (altitud e 800 m above sea level) were taken down to the Dead Sea area (altitud e 402 m below sea level) for 3 weeks. At both locations we tested arte rial blood exercise, 6-minute walking distance, and sleep oximetry. Th e study was repeated 2 weeks after returning to Jerusalem. Results: Sp irometry results were unchanged. Mean arterial PaO2 rose from 54.2+/-8 .9 mm Hg to 69.5+/-11 at the first week and to 66.6+/-11 at the third week of stay (p<0.001). PaCO2 rose from 43.5+/-9.8 mm Hg to 47.7+/-9 a nd 49.5+/-8.4 (p<0.006). Six-minute walking distance rose from 337+/-1 07 m to 449+/-73 and 507+/-91 in the third week (p<0.005). Maximum oxy gen consumption ((V) over dot o(2)max) rose from 901+/-257 mL/min to 1 ,099+/-255 and 1,063+/-250 mL/min (p=0.01). Sleep oximetry showed an i ncrease in mean sleep arterial oxygen saturation from 86.0+/-4.3% to 8 9.9+/-4.2% and 88.3+/-3.0 at 1 and 3 weeks, respectively (p<0.05). Fol lowing die return to Jerusalem, arterial gases returned to their basel ine levels (PaO2, 52.9+/-9.4 mm Hg) but 6-min walking distance remaine d significantly high, 453+/-47 (p<0.02) and (V) over dot o(2) well (1, 102+/-357 mL/min), although it aid not reach statistical significance. Conclusions: Decline to low altitude or staying at high oxygen enviro nment improves arterial oxygenation and exercise capacity in hypoxemic patients residing in moderate or high altitude. Low altitude (or pres surized wards) can improve pulmonary rehabilitation of hypoxemic patie nts with COPD.