EFFECT OF LONG-TERM OXYGEN-THERAPY ON SURVIVAL IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE WITH MODERATE HYPOXEMIA

Background - To date only two controlled studies have been published o n the effects of domiciliary oxygen treatment on survival in patients with chronic obstructive pulmonary disease (COPD) with advanced respir atory failure. The survival in such patients despite oxygen treatment remains poor. The prescription of long term oxygen therapy (LTOT) in l ess severe disease remains controversial. The aim of this study was to evaluate the rationale for prescribing oxygen to patients with COPD w ith moderate hypoxaemia. Methods - One hundred and thirty five patient s with COPD, with Pao(2) 7.4-8.7 kPa (56-65 mmHg) and advanced airflow limitation (mean (SD) forced expiratory volume in one second (FEV1) 0 .83 (0.28) 1), were randomly allocated to a control (n = 67) and LTOT (n = 68) group. The patients were followed every three months for at l east three years or until death. Results - The cumulative survival rat e was 88% at one year, 77% at two years, and 66% at three years. No si gnificant differences were found in survival rates between patients tr eated with LTOT and controls, nor did longer oxygen use (over 15 hours per day) improve survival. Younger age, better spirometric values, an d higher body mass index predicted better survival. Conclusions - Domi ciliary oxygen treatment does not prolong survival in patients with CO PD with moderate hypoxaemia. Airway limitation seems to determine surv ival in this group of patients.