From a recent study:
This is a single-center retrospective cohort study of 235 patients intubated between 1 January 2012 and 30 June 2013 in a medical ICU of a university medical center. A total of 125 patients were intubated after failing NIPPV, 110 patients were intubated without a trial of NIPPV. Intubation-related data were collected prospectively through a continuous quality improvement (CQI) program and retrospectively extracted from the medical record on all patients intubated on the medical ICU. A propensity adjustment for the factors expected to affect the decision to initially use NIPPV was used, and the adjusted multivariate regression analysis was performed to evaluate the odds of a composite complication (desaturation, hypotension, or aspiration) with intubation following failed NIPPV versus primary intubation.
A propensity-adjusted multivariate regression analysis revealed that the odds of a composite complication of intubation in patients who fail NIPPV was 2.20 (CI 1.14 to 4.25), when corrected for the presence of pneumonia or acute respiratory distress syndrome (ARDS), and adjusted for factors known to increase complications of intubation (total attempts and operator experience). When a composite complication occurred, the unadjusted odds of death in the ICU were 1.79 (95% CI 1.03 to 3.12).
After controlling for potential confounders, this propensity-adjusted analysis demonstrates an increased odds of a composite complication with intubation following failed NIPPV. Further, the presence of a composite complication during intubation is associated with an increased odds of death in the ICU.
The authors go on to cite previous data showing that failed NIPPV is associated with increased mortality. Prior studies suggest that it is mainly patients with acute on chronic respiratory failure (notably COPD) who experience a net mortality benefit with the use of NIPPV. Other forms of respiratory failure (i.e. hypoxemic respiratory failure) are associated with a high rate of NIPPV failure.
The authors cite this paper, a 2012 systematic review, which concludes:
In summary, for patients with acute respiratory failure due to severe exacerbations of COPD or congestive heart failure, NPPV plus supportive care shows important reductions in mortality and intubation rates compared with supportive care alone. BPAP has been studied more rigorously, but direct comparisons of CPAP and BPAP in patients with ACPE show similar efficacy. Current evidence suggests potential benefit for patients with acute respiratory failure who are postoperative or post-transplant and as a method to facilitate weaning from invasive ventilation or prevent recurrent postextubation respiratory failure in those at high risk. However, the evidence for these indications is much weaker. Limited evidence shows similar treatment effects across different settings and the possibility of less benefit in trials designed to replicate usual clinical practice. There is a clear need for further studies in patient populations where NPPV has not been rigorously studied and to understand the role of training and effectiveness when used as part of routine clinical care.
The implication form all these studies is that NIPPV should not be used for respiratory failure other than that caused by COPD or cardiogenic pulmonary edema, though no strong recommendation is made to that effect.