If there is a persistent air leak, then a time-limited setting should be attempted in order to limit the inspiratory time.

Finally, if there still remains no improvement, then the clinician can use a proportional assist ventilation (PAV) mode. When viewing clinical outcomes, PAV is not different from pressure support, but this mode may be better tolerated. As a final step of therapy escalation, the patient may be changed to an assist-control (AC) setting. This particular mode is not as well tolerated but will decrease the work of breathing by delivering a set volume.³⁹

If the patient shows clinical signs of improvement during the emergency department visit, then the physician should attempt to wean the patient from ventilatory support. The clinician must take a stepwise approach by incrementally decreasing the amount of pressure support or increasing the time off of NIPPV in intervals.

Summary

Acute respiratory failure is a multifactorial presentation that the emergency physician must be able to handle deftly. Intubation of patients is a common treatment that may be necessary in patients presenting with acute respiratory failure. However, this remains a procedure that is fraught with complications in the short and long term.

NIPPV has been shown, in specific disease processes, to decrease intubation rates, as well as mortality and various indicators of morbidity. The evidence for usage in COPD, congestive heart failure, asthma, and respiratory failure in the immunocompromised patient is very compelling, and noninvasive positive pressure has become standard therapy. Support for NIPPV in other disease processes is also growing as the evidence continues to mount.

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