Delirium as a predictor of high flow nasal cannula failure in patients with acute respiratory failure

Abstract

Background: Delirium is an important factor contributing to poor outcomes in ICU patients; however, data regarding patients treated with high flow nasal cannula (HFNC) is lacking. Objective: The present study aimed to examine the prevalence of delirium and other associated factors of treatment failure in patients treated with HFNC oxygen therapy. Methods: This was a retrospective cohort study performed at a single hospital in Japan. Consecutive patients admitted to the ICU for acute respiratory failure (ARF) requiring HFNC between April 2013 and November 2017 were included. Delirium before and during HFNC was evaluated using the confusion assessment method for the ICU (CAM-ICU). The Acute Physiology And Chronic Health Evaluation (APACHE) II score, PaO2/FiO2, comorbidities, and use of steroids were also assessed. Multivariable logistic regression analysis was used to identify the risk factors associated with treatment failure of HFNC. Results: One hundred and six patients were included in the analysis, 48 (45%) of whom exhibited delirium during HFNC oxygen therapy and 20 (19%) of whom failed HFNC. Univariate analysis revealed that a higher APACHE II score and the presence of delirium were associated with HFNC failure. Multivariable logistic regression analysis of age, APACHE II score, PaO2/FiO2, and delirium during HFNC oxygen therapy revealed that the presence of delirium was an independent risk factor for HFNC failure (Odds Ratio 5.38; 95% confidence interval 1.56-18.59; p=0.008). Conclusions: There was a high prevalence of delirium in ICU patients treated with HFNC. The presence of delirium is a strong predictor of HFNC oxygen therapy failure.