THE EFFECT OF LOW FLOW OXYGEN-THERAPY ON THE CHEMICAL CONTROL OF VENTILATION IN PATIENTS WITH HYPOXEMIC COPD

Publisher Website
Google Scholar
Abstract
To determine whether the decreased hypoxic responses present in patients with hypoxemic chronic obstructive pulmonary disease (COPD) were reversible with correction of their hypoxemia, ventilatory and P0.1 [pressure developed 0.1 ms after a breath hold] responses to CO2 and hypoxia were measured in 30 such patients. These patients were then randomly allocated to 24 h continuous O2 or 12 h nocturnal O2 therapy. Responses to CO2 and hypoxia were then remeasured in all patients after 6 mo. of O2 therapy and in 13 patients after 1 yr of O2 therapy. The blunt hypoxic responses showed no increase after either regimen of O2 therapy and were further reduced after 6 mo. of 12 h nocturnal O2. The decreased hypoxic response in patients with hypoxemic COPD appears nonreversible with the relief of the hypoxemia. Responses to CO2 were depressed after 6 mo. of 24 h O2 therapy and associated with a significant increase in PaC02 [arterial CO2 pressure]. The change in PaCO2 after O2 therapy was nonpredictable in terms of the initial responses to hypoxia or CO2. Minute ventilation (VE) and mean inspiratory flow during resting breathing at an arterial O2 saturation of 95% decreased after 6 mo. of 24 h O2 therapy, indicating a reduction in central ventilatory drive.

This publication has 2 references indexed in Scilit: