MASK INTERMITTENT POSITIVE PRESSURE VENTILATION IN CHRONIC HYPERCAPNIC RESPIRATORY-FAILURE DUE TO CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Noninvasive ventilation in chronic obstructive pulmonary disease (COPD ) has been shown to improve arterial blood gases but its long-term rol e has not been established. We retrospectively studied 26 consecutive patients with hypercapnic ventilatory failure due to COPD in whom oxyg en therapy caused worsening hypercapnia (defined as a rise in the dayt ime arterial carbon dioxide tension (Pa,CO2) to >8.0 kPa or nocturnal transcutaneous carbon dioxide tension (Ptc,CO2) to >9 kPa), All were t reated with mask ventilation (15 with nasal and 11 face masks) at nigh t and during daytime naps, additional oxygen therapy was required in 1 5 patients, The mean annualized death rate was 10.8% with a 1 and 3 yr survival of 92 and 68%, respectively, After 1 yr the median daytime P a,CO2 had fallen be 1.35 kPa and the arterial oxygen tension (Pa,O-2) had risen by 2.4 kPa. In subjects hot using additional oxygen the medi an overnight Sa,O-2 rose by 12% and the Ptc,CO2 fell by 2.8 kPa after 1 yr. The haematocrit was significantly less than pretreatment at 6 mo nths and 1 gr, Quality of life in the domain of role limitation by phy sical health (measured using the SF-36 questionnaire) improved signifi cantly at 6 months. Survival in this selected group with clinically st able airflow obstruction unable to tolerate oxygen therapy and treated with noninvasive mask ventilation is better than historical controls and is comparable to those able to tolerate oxygen therapy, Poor survi val was associated with a low forced expiratory volume in one second, a low body mass index and a high nocturnal transcutaneous carbon dioxi de tension, No difference in survival was found between those treated with mask intermittent positive pressure ventilation alone or with mas k intermittent positive pressure and supplementary oxygen therapy.