Predicting survival following non-invasive ventilation for hypercapnic exacerbations of chronic obstructive pulmonary disease.
Int J Clin Pract. 2012 May;66(5):434-7
Authors: Miller D, Fraser K, Murray I, Thain G, Currie GP
Abstract
Introduction:? Non-invasive ventilation (NIV) has revolutionised the management of hypercapnic exacerbations of chronic obstructive pulmonary disease (COPD). We wished to evaluate factors related to its overall success in the 'real-life' setting. Methods:? A retrospective analysis of patients receiving NIV for a hypercapnic exacerbation of COPD was performed. Demographics, laboratory data, blood gases and outcomes (hospital discharge or in-patient death) were extracted and subsequently analysed to identify factors relating to its overall success or failure. Results:? Over 6?years, 240 patients (mean age 70?years), received NIV with mean pH and pCO(2) prior to NIV 7.24 and 10.4kPa respectively; of these, 167 survived to hospital discharge with a median age (70 vs. 74; p?=?0.02) lower than non-survivors. Absolute values of pH and pCO(2) (higher and lower respectively) prior to NIV and at 1?h were both associated with successful hospital discharge. An improvement (p?=?0.02) in pH within an hour of receiving NIV - but not pCO(2) - was associated with surviving to hospital discharge. Of all laboratory data assessed, only baseline urea was significantly (p?=?0.021) associated with a successful outcome. Conclusion:? Younger patients with a lower urea, higher pH and lower pCO(2) at baseline and who demonstrate an improvement in pH within 1?h, are more likely to have a successful outcome when given NIV for a hypercapnic exacerbation of COPD on an unselected basis. Prospective studies evaluating many other parameters are now required to help identify patients in whom NIV is likely to be successful.
PMID: 22512604 [PubMed - in process]