Prolonged invasive ventilation following acute ventilatory failure in COPD: weaning results, survival, and the role of noninvasive ventilation.

BACKGROUND: Invasive ventilation for COPD has significant mortality, and weaning can be difficult. At Papworth Hospital, we provide a specialist weaning service using noninvasive ventilation (NIV) for patients requiring prolonged invasive ventilation after recovery from acute illness. We analyzed our results for patients with COPD to identify factors associated with weaning outcome and survival.
METHODS: A retrospective analysis was conducted of COPD patients admitted for weaning from invasive ventilation, from 1992 to 2003. Weaning success and survival were assessed. Associations were sought between these outcomes and age, sex, spirometry, arterial blood gas levels, APACHE (acute physiology and chronic health evaluation) II score, length of stay (LOS), and the use of NIV and long-term oxygen therapy.
RESULTS: Sixty-seven patients were identified, all of whom were receiving tracheostomy ventilation on transfer to the Respiratory Support and Sleep Centre (RSSC). Sixty-four patients (95.5%) were weaned, and 62 patients survived to hospital discharge. NIV was used in weaning 40 patients and in the long term in 25 patients. Median survival was 2.5 years (interquartile range, 0.7 to 4.6 years). One-year, 2-year, and 5-year survival rates were 68%, 54%, and 25%, respectively. Long-term survival was inversely associated with age and LOS in the ICU and the RSSC. The provision of maintenance NIV after weaning was associated with better long-term survival, independent of age and LOS (hazard rate, 0.48; p = 0.03).
CONCLUSIONS: These results demonstrate that a specialist multidisciplinary approach, including the use of NIV, can be successful in weaning most COPD patients from prolonged invasive ventilation. The data also suggest that long-term NIV may improve survival in selected patients.