[Effect of noninvasive ventilation on hypercapnic encephalopathy syndrome: a Meta-analysis]

To evaluate the effect of noninvasive ventilation (NIV) on hypercapnic encephalopathy syndrome (HES) induced by acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

An extensive search of related literature from the PubMed, EMBASE, Cochrane library, CNKI and Wanfang databases up to January 2015 was performed. Randomized controlled trials (RCTs) and case control studies regarding comparison of the effect of NIV and conventional mechanical ventilation (CMV) on the HES were collected. Critical appraisal skills program (CASP) was adopted to assess the quality of the studies. Data including mortality, trachea intubation rate, duration of mechanical ventilation and complication rate were collected, and Meta-analysis was performed by RevMan 5.3.

Finally, 6 studies were included with 225 subjects, among whom 112 were in NIV group and 113 in CMV group, and the average Kelly-Matthay score was 3. Compared with CMV group, the mortality [20.5% (23/112) vs. 32.7% (37/113), risk ratio (RR) = 0.63, 95% confidential interval (95%CI) = 0.40-0.98, P = 0.04], intubation rate [35.7% (40/112) vs. 100.0% (113/113), RR = 0.38, 95%CI = 0.26-0.55, P < 0.000?01], incidence of ventilation related complications [26.2% (21/80) vs. 50.6% (42/83), RR = 0.52, 95%CI = 0.34-0.79, P = 0.002] in NIV group were significantly decreased, and the duration of mechanical ventilation was significantly shortened [days: 7.1 vs. 16.2, standard mean difference (SMD) = -0.93, 95%CI = -1.39 to -0.46, P < 0.000?1].

NIV could significantly lower the mortality rate, intubation rate, and complications in the treatment of HES induced by AECOPD under close monitoring.