Sequential use of noninvasive pressure support ventilation for acute exacerbations of COPD

Objectives:To compare the efficacy of noninvasive pressure support ventilation (NIPSV) in acute decompensation in chronic obstructive pulmonary disease (COPD) by means of a bi-level positive airway pressure support system (BiPAP) in a sequential mode with medical therapy alone; to assess the short-term physiologic effects of the device on gas exchange; and to compare patients successfully ventilated with NIPSV with those in whom NIPSV failed. Design: A prospective case series with historically matched control study. Setting: A general intensive care unit (ICU) of a university hospital. Patients: We evaluated the efficacy of administration of NIPSV in 42 COPD patients and compared this with standard treatment in 42 matched historical control COPD patients. Interventions: NIPSV was performed in a sequential mode, i.e., BiPAP in the spontaneous mode was used for at least 30 min every 3 h. Between periods of ventilation, patients could be systematically returned to BiPAP when the arterial oxygen saturation was < 0.85 or when the respiratory rate was > 30 breaths/min. Measurements and results: Success rate, mortality, duration of ventilatory assistance, and length of ICU stay were recorded. Eleven of the 42 patients (26 %) in the NIPSV group needed tracheal intubation compared with 30 of the 42 control patients (71 %). The 31 patients in whom NIPSV was successful were ventilated for a mean of 6 +/- 3 days. In-hospital mortality was not significantly different in the treated ver sus the control group, but the duration of ventilatory assistance (7 +/- 4 days vs 15 +/- 10 days, p < 0.01) and the length of ICU stay (9 +/- 4 days vs 21 +/- 12, p < 0.01) were both shortened by NIPSV. BiPAP was effective in correcting gas exchange abnormalities. The pH values, measured after 45 min of BiPAP with optimal settings, in the success (7.38 +/- 0.04) and failure (7.28 +/- 0.04) patients were significantly different (p < 0.05). Conclusions: NIPSV, performed with a sequential mode, may be used in the management of patients with acute exacerbations of COPD.