An evaluation of short-term oxygen therapy: the prescription of oxygen to patients with chronic lung disease hypoxic at discharge from hospital.

The provision of domiciliary oxygen to patients hypoxic at hospital discharge has been termed short-term oxygen therapy (STOT). This practice appears widespread, although there is a paucity of literature and no evidence-based guidelines. We undertook this audit to examine the prescription of STOT and determine the proportion fulfilling for long-term oxygen therapy (LTOT) 2 months post-discharge. STOT was defined prospectively: resting PaO2 < or = 7.3 kPa (55 mmHg) or PaO2 between 7.3 and 8.0 kPa (60 mmHg) with any of the following: clinical evidence of cor pulmonale (pedal oedema or jugular venous distension), ECG evidence of pulmonale, echocardiogram evidence of pulmonary hypertension, haematocrit > 0.55 (adapted directly from LTOT criteria). Patients were evaluated for LTOT 2 months post-discharge when clinically stable on optimal medical management. All referrals to the Auckland Regional Oxygen Service between July 1998 and 1999 were systematically reviewed. The majority 289/405 (71%) of new referrals were for the prescription of STOT/LTOT in patients with chronic lung disease: 160/289 (55%) derived from hospitalized patients with the majority 130 (81%) fulfilling criteria for STOT, median age 73, range 24-96 years. Mean hospital stay was 10.2 days. Two months after discharge 22/127 (17%) of STOT patients had died, comparable with 4/22 (18%) not fulfilling criteria for STOT. A total of 123 patients were assessed for LTOT at 2 months; 76 (62%) fulfilled criteria for LTOT. The prescription of oxygen at hospital discharge represented a considerable proportion of our referral load. There was a high mortality in the 2-month follow-up period. A significant proportion of STOT patients did not subsequently fulfill criteria for LTOT. Further prospective studies are required in order to develop evidence-based guidelines.