Noninvasive positive-pressure ventilation: a utilization review of use in a teaching hospital

The use of noninvasive positive-pressure ventilation (NIPPV) for acute respiratory failure (ARF) has become more widespread over the past decade, but its prescription, use and outcomes in the clinical setting remain uncertain. The objective of this study was to review the use of NIPPV for ARF with respect to clinical indications, physician ordering, monitoring strategies and patient outcomes.

A total of 91 consecutive adult patients admitted between June 1997 and September 1998 to a university-affiliated tertiary care hospital in Hamilton, Ont., who received 95 trials of NIPPV for ARF were included in an observational cohort study. Data abstraction forms were completed in duplicate, then relevant clinical, physiologic, prescribing, monitoring and outcome data were abstracted from the NIPPV registry and hospital records.

The most common indications for NIPPV were pulmonary edema (42 of 95 trials [44.2%]) and exacerbation of chronic obstructive pulmonary disease (23 of 95 trials [24.2%]). NIPPV was started primarily in the emergency department (62.1% of trials), however, in terms of total hours of NIPPV the most frequent sites of administration were the intensive care unit (30.9% of total hours) and the clinical teaching unit (20.2% of total hours). NIPPV was stopped in 48.4% of patients because of improvement and in 25.6% because of deterioration necessitating endotracheal intubation. The median time to intubation was 3.0 hours (interquartile range 0.8-12.2 hours). The respirology service was consulted for 28.4% of the patients. Physician orders usually lacked details of NIPPV settings and monitoring methods. We found no significant predictors of the need for endotracheal intubation. The overall death rate was 28.6%. The only independent predictor of death was a decreased level of consciousness (odds ratio 2.9, 95% confidence interval 1.0-8.4).

NIPPV was used for ARF of diverse causes in many hospital settings and was started and managed by physicians with various levels of training and experience. The use of this technique outside the critical care setting may be optimized by a multidisciplinary educational practice guideline.