UMEM Educational Pearls

Category: Critical Care

Title: Predicting Failure of Non-invasive Ventilation and High Flow Nasal Cannula

Keywords: acute hypoxic respiratory failure, intubation, noninvasive positive pressure ventilation, high flow nasal cannula, BiPAP, vapotherm (PubMed Search)

Posted: 4/25/2018 by Kami Windsor, MD
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ED physicians frequently utilize modailities such as noninvasive positive pressure ventilation (NIV) and high flow nasal cannula (HFNC) to support and potentially avoid intubation in patients presenting with acute hypoxic respiratory failure. Unfortunately, failure of these measures, resulting in "delayed" intubation, has been associated with increased mortality.1,2

A recent post-hoc analysis of data from a multicenter randomized controlled trial evaluated 310 patients with acute hypoxic respiratory failure managed with supplemental O2 by regular nasal cannula, HFNC, or NIV.3

The following factors were predictive of eventual intubation in the different groups: 

  • For nasal cannula patients, RR > 30 at 1 hour
  • For HFNC patients, tachycardia at 1 hour (No respiratory variables were found to predict intubation).
  • For NIV patients, tidal volume > 9ml/kg predicted body weight or PaO2:FiO2 ratio < 200 at 1 hour

Of note, 45% of the 310 patients eventually required intubation, and these patients in general had a higher initial respiratory rate and lower PaO2 at presentation, and were more likely to have bilateral infiltrates on CXR. 

Bottom Line: Reevaluate your patients frequently. If RR remains high, P:F ratio remains low, or patient respiratory effort/work of breathing is not alleviated by noninvasive measures, consider pulling the trigger on intubation earlier.

 

References

  1. Kang BJ, Koh Y, Lim CM, et al. Failure of high-flow nasal cannula therapy may delay intubation and increase mortality. Intensive Care Med. 2015;41:623–632.
  2. Bellani G, Laffey JG, Pham T, et al. LUNG SAFE Investigators; ESICM Trials Group: Noninvasive ventilation of patients with acute respiratory distress syndrome. Insights from the LUNG SAFE study. Am J Respir Crit Care Med 2017;195:67–77.
  3. Frat JP, Ragot S, Coudroy R, et al. Predictors of intubation in patients with acute hypoxemic respiratory failure treated with a noninvasive oxygenation strategy. Crit Care Med. 2018;46(2):208-215.