Non-Invasive Ventilation and Community Acquired Pneumonia
Sunday, January 8, 2012 at 08:36PM When I graduated Respiratory Therapy in 2003 I remember having a preconceived notion that non-invasive positive pressure ventilation (NIPPV) should NOT be used with patients admitted with pneumonia. Whether it was something I was specifically taught or something that I learned during my clinical placement, it seemed to be consistent with other RTs I started working with as a staff RT.
It was many years later I learned that a study published the year I graduated (2003) by Ferrer et al. showed that the use of NIPPV in patients with acute hypoxic respiratory failure (COPD patients excluded) prevented intubation, reduced the incidence of septic-shock, and improved survival when compared with high-concentration oxygen therapy. However, there was another study by Confalonieri et al. that did not show any benefit (or harm) to using NIPPV with patients without COPD.
So why did there still appear to be such a hard stance against using NIPPV with pneumonia patients?
There is this strong belief that NIPPV will effect the ability to cough and clear secretions, and this may true with a mask strapped tightly to their face (makes sense), but conversely so does being intubated. Intubation requires heavy sedation and can be much less comfortable for a patient than a properly fit mask.
Perhaps the fear of NIPPV with pneumonia patients stems from a bad experience with someone who had pneumonia that escalated to primary ARDS with bilateral infiltrates and severe hypoxemia. Although there are no RCTs specifically designed to determine the effectiveness of NIPPV with ARDS patients, in this study by Ferrer et al. the multivariate analysis of the risk factors for intubation showed an odds ratio of 28.5 (p = 0.003). If you patient has developed ARDS the likelihood of them needing intubation is very high.
In summary, if you are called to see a pneumonia patient with SpO2 <90% on an FiO2 of 0.50 (the inclusion criteria for this study) there may be a benefit to using NIPPV. There is not strong enough evidence to support its exclusive use in these patients (because of conflicting results of other studies). However, it appears that the use of NIPPV does not cause harm. There is also an increased use of high-flow nasal canula with patients, further study is needed to determine it's true benefit with these patients other than comfort.
Keep in mind that a failure to improve within 1 hour of NIPPV (resp rate, pH, PaO2, PaCO2, etc.) is a strong predictor of failure.
Side note: There was no mention in this study as to whether humidification was used with the NIPPV patients, or the control group.
Ferrer M, Esquinas A, Leon M, Gonzalez G, Alarcon A, Torres A. Noninvasive ventilation in severe acute hypoxemic respiratory fail- ure: a randomized clinical trial. Am J Respir Crit Care Med 2003; 168(12):1438-1444.
Confalonieri M, Potena A, Carbone G, Porta RD, Tolley EA, Meduri GU. Acute respiratory failure in patients with severe community- acquired pneumonia. A prospective randomized evaluation of non- invasive ventilation. Am J Respir Crit Care Med 1999;160(5 Pt 1):1585-1591.
Reader Comments (2)
I can understand its initial use in a CAP in COPD but someone presenting in the ER with deteriorating respiratory function from pneumonia (infiltrates on CXR, hypoxemia), not sure how it can be beneficial. How does one clear secretions? At least with intubation, you have a venue to remove them.
With humidity not sure if this would be of great benefit as you still have to assist in mobilization of the secretions.
Pretty vague data.
I'm not sure how deep clinicians think they are suctioning endotracheally, but it certainly isn't deep enough to clear up a pneumonia. And I don't believe there is any data that supports bronchoscopy as a means of improving outcomes in CAP.
It all comes down to clinical judgement. I think the point is that if you have obvious predictors of failure then you would be cautious, or not use NIPPV at all. They have to be able to tolerate therapy. Someone with a SpO2 of < 85% among other signs and symptoms of severe hypoxemia is probably not the best candidate.
The point of my post was that there was a generalization that seemed to be made with pneumonia (not considerig the severity) and NIPPV when I started practicing that lacked the data that would support such generalization.
A patient who has pneumonia as a primary diagnosis and otherwise has normal diaphragmatic funtion should be able to facilitate airway clearance by intermittently coming off NIPPV once they have the strength to do so (provided proper humidification was used).