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Reference: JAMA 2017 Jun 6;317(21):2177 (level 2 [mid-level] evidence)
- It is unclear whether or not home-based noninvasive ventilation (NIV) benefits patients after hospitalization for acute chronic obstructive pulmonary disease (COPD) exacerbation.
- This trial randomized 116 patients (mean age 66 years) with persistent hypercapnia after hospitalization for acute COPD exacerbation to home-based NIV plus oxygen therapy vs. oxygen therapy alone.
- Hospital readmission or death occurred in 63.4% with home-based NIV plus oxygen therapy vs. 80.4% with oxygen therapy alone (p ≤ 0.05, NNT 6). The difference in mortality alone (28% vs. 32%) was not significant.
NIV is the standard of care for treating patients hospitalized for acute COPD exacerbation. Some research suggests that home-based NIV added to usual care following hospitalization may also benefit some patients, but results are conflicting and it is unclear whether or not benefits may be most apparent in certain groups (GOLD 2017, Thorax 2009 Jul;64(7):561, Thorax 2014 Sep;69(9):826). A recent trial assessed home-based NIV following hospitalization for acute decompensated hypercapnic exacerbation of COPD that required NIV in the hospital. Patients were included in the trial if they had resolution of decompensated acidosis (pH > 7.3) for ≥ 2 weeks, persistent hypercapnia (PaCO2 > 53 mm Hg at 2 weeks after clinical stability), attainment of clinical stability no more than 4 weeks previously, and persistent hypoxemia. Patients were excluded if they had intubation or invasive mechanical ventilation while hospitalized, were unable to wean from NIV, had body mass index > 35 kg/m2, or had obstructive sleep apnea. In the trial, 116 patients (mean age 66 years) were randomized to home-based NIV plus oxygen therapy vs. oxygen therapy alone, in addition to their individualized therapies. Home-based NIV was to be used for 6 hours nightly, and inspiratory pressures were titrated to maximal tolerated levels (median of 24 cm H2O for these patients). Regular assessments were conducted over 12 months, during which 8.8% of patients allocated to home-based NIV and 22% allocated to oxygen therapy alone were lost to follow-up. All patients were analyzed according to their allocated group in the intention-to-treat analysis.
The risk of the composite outcome of hospital readmission or death within 12 months in the Kaplan-Meier survival analysis was 63.4% with home-based NIV plus oxygen therapy vs. 80.4% with oxygen therapy alone, with an absolute risk difference of 17% (95% CI 0.1%-34%) (NNT 6) and an adjusted hazard ratio of 0.49 (95% CI 0.31-0.77, p = 0.002). The corresponding median time until hospital readmission or death was 4.3 vs. 1.4 months. The difference between groups in mortality alone (28% vs. 32%) was not significant, but the addition of home-based NIV reduced subsequent COPD exacerbation frequency (median 3.8 vs. 5.1 per year, p = 0.03).
This trial demonstrated that the addition of home-based NIV to oxygen therapy may reduce the risk of the composite outcome of hospital readmission or death within 12 months among adults recently hospitalized for acute COPD exacerbation who had persistent hypercapnia and hypoxemia. The confidence interval in risk difference includes clinically unimportant differences. Also, although the loss to follow-up for the entire cohort was lower than that used for the power calculation, the rate in the oxygen therapy alone group reached the rate used for the power calculation and was over twice that of the home-based NIV group. The high rate in one group and discrepancy between groups leads to some uncertainty regarding effect size and, potentially, statistical significance. A previous trial did not demonstrate a significant benefit for home-based NIV (Thorax 2014 Sep;69(9):826), but it may have included patients with less severe disease as the inclusion criteria required patients to have PaCO2 > 45 mm Hg at 48 hours after clinical stability and did not require patients to have persistent hypoxemia. The stringent inclusion criteria in the current trial limit generalization, but they also help address the question of who, if anyone, may benefit from home-based NIV added to oxygen therapy following acute COPD exacerbation. This trial suggests that it may be considered in patients with hypercapnia for at least 2 weeks and hypoxemia.
See the DynaMed Plus topics COPD, Acute exacerbation of COPD, and Noninvasive positive pressure ventilation (NPPV) in adults for more information. DynaMed users click here.