Predictors for Early Mortality in Patients with Long-Term Oxygen Home Therapy

Abstract

The follow-up of 87 patients with long-term oxygen therapy over a 3-year period revealed a mortality of 23.7% during the first year, of 37.4% after 2 years and of 45 % after 3 years, respectively. The retrospective analysis of baseline characteristics in order to evaluate the causes for early deaths showed no difference in age, lung function tests nor the degree of respiratory insufficiency documented by serial blood gas analysis between the survivors (n = 61) and the dead (n = 26). However, in the group of early deaths there was a significant increase in pulmonary hypertension (mean pulmonary arterial pressure 40.1 ± 12.0 mm Hg) compared with the survivors, who had only mild hypertension (mean pulmonary arterial pressure 29.4 ± 8.9 mm Hg). In addition there was also a lesser response in pulmonary vasodilation during oxygen breathing in the patients who died within the first 2-year period. We conclude that marked pulmonary hypertension with poor response to oxygen breathing is a major limiting factor in the prognosis of patients with long-term oxygen therapy. In contrast neither severe airway obstruction nor pronounced hypoxemia are related to early mortality and should therefore not be considered as a criterion for rapid deterioration and fatal outcome despite oxygen therapy.

Co-morbidity contributes to predict mortality of patients with chronic obstructive pulmonary disease

“…A PA-a,O 2 Š5.4 kPa (40.8 mmHg) corresponding to the highest quartile of PA-a,O 2 distribution, while the patient was breathing air or an oxygen-enriched mixture at the prescribed oxygen concentration, was the strongest correlate of mortality and preceded chronic renal failure and ECG signs of RVH or overload. An FEV1 <590 mL corresponding to the lowest quartile of FEV1 distribution, a length of hospital stay Š33 days, corresponding to the highest quartile of the length- Number M/F Age yrs Length of hospital stay days Coma during the hospital stay n (%) Mechanical ventilation during the hospital stay n (%) Diabetes mellitus n (%) Hypertension n (%) Chronic renal failure n (%) Chronic liver disease n (%) Cerebrovascular disease n (%) Ishaemic heart disease n (%) History of myocardial infarction n (%) Charlson's co-morbidity index † Age-co-morbidity index + ECG signs of RVH or overload n (%) ECG signs of ischaemic heart disease n (%) ECG evidence of ventricular arrhythmias n (%) 224/46 67±9 28±20 24 (9) 44 (16) 39 (14) 75 (28) 17 (6) 17 (6) 9 (3) 28 (10) 11 (4) of-stay distribution, ECG signs of ischaemic heart disease, chronic liver disease, ECG evidence of ventricular arrhythmias, and a history of acute myocardial infarction were weaker correlates of mortality.…”

“…The determinants of life expectancy in chronic obstructive pulmonary disease (COPD) have been analysed in several studies both before and after the systematic introduction of oxygen-therapy in clinical practice [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Age and degree of airway obstruction, as reflected by forced expiratory volume in one second (FEV1), are the most commonly recognized prognostic factors [12].…”

“…Co-morbidity was an exclusion criterion in several studies [2, 4-6, 10, 16], while others did not provide information on co-morbid diseases or did not assess their prognostic role [1,8,9,11,[13][14][15][17][18][19][20]. Moreover, an upper age limit has frequently been adopted in selecting patients [8,10,12,24].…”

Pulmonary hypertension in COPD

“…It has been suspected, but not clearly demonstrated, that the increased life expectancy was due to the improvement of pulmonary haemodynamics. Interestingly, P pa remains an excellent prognostic factor in patients undergoing LTOT [3,27,28]. In the most recent study [3], patients with P pa .25 mmHg had a significantly lower survival rate at 5 yrs compared with patients without PH (33 versus 66%; p,0.001; fig.…”

“…candidates for lung volume reduction surgery (LVRS) and candidates for lung transplantation, had comparable results. Mild (P pa [26][27][28][29][30][31][32][33][34][35], moderate (36)(37)(38)(39)(40)(41)(42)(43)(44)(45) and severe (.45 mmHg) PH was present in 36.7, 9.8 and 3.7% of the 215 patients, respectively. In a large series of 998 patients with COPD [6] with less airway limitation and hypoxaemia than the two studies quoted above, the P pa was 20.3¡8.1 mmHg.…”