Studies also show that NIV may significantly decrease work of breathing, either by improving minute ventilation (COPD) or by decreasing venous return to the heart (CHF), and thereby reducing the need for intubation to 15% (although it is as high as 38% in patients with chronic respiratory disease).
However, despite it being so commonly used, and despite all the advancements in technology and equipment that have improved patient comfort, studies continue to show that anywhere from 20-30% of patients fail. Of the patients who fail, 30-40% require intubation and mechanical ventilation.
A good indication of failure, or a good predictor of who will fail, is hypercapnia after initiation of NIV.
Contou et al, however, concluded that experienced respiratory therapists may make adjustments at the patient interface (mask) or changes in settings that make the experience more comfortable and more effective, thus resulting in a reduction in NIV failure rates to under 15%, thereby reducing mortality rates to 5%.
Contou et al also showed that, by using an NIV protocol and having the patient closely monitored in by experienced personnel, including a nurse and respiratory therapist, 48% of patients who were semi-comatose responded well to NIV therapy without the need for intubation.
The study shows that trialing patients on NIV in an experienced unit where the patient was closely monitored, even those who would otherwise have been intubated, has proven to be effective, thus further reducing the need for intubation.
Likewise, the researchers reported, "it has been shown that NIV failure was not associated with an increased mortality rate in hypercapnic patients; thus, delayed intubation in some patients likely did not worsen their outcome."
The bottom line here is that NIV protocols that allow the nurse and respiratory therapist to closely monitor and adjust the settings on the NIV "might reduce the intubation rate.
- Contou, Damien, Chiara Fragnoli, Ana cordoba-Izquierdo, Florence Boissier, Christan Brun-Buisson, and Arnaud W. Thille, "Noninvasive Ventilation for Acute Hypercapnic Respiratory Failure: Intubation Rate in an Experienced Unit," Respiratory Care, December, 2013, volume 58, number 12, pages 2045-2052