Risk factors for non-invasive ventilation failure in influenza infection with acute respiratory failure in emergency department.

OBJECTIVE

Non-invasive ventilation (NIV) has been widely used in hypoxemic acute respiratory failure (ARF) due to influenza pneumonia in the emergency department (ED). However, NIV used in influenza-associated acute respiratory failure had a variable rate of failure. Previous studies have reported that prolonged use of NIV was associated with increased mortality. Our study aimed to identify risk factors for NIV failure in influenza infection with acute respiratory failure in ED.

METHOD

We performed a retrospective cohort observational study. Enrolled patients were older than 18 years who used NIV due to influenza infection with ARF between 1 January 2017 to 31 December 2018 in Ramathibodi Emergency Department. Patients characteristics, comorbidity, clinical, laboratory outcome, chest imaging, initial NIV setting, and parameters were collected in ED setting. Sequential organ failure assessment (SOFA) score and PaO2/FiO2 (PF) ratio were calculated from the first arterial blood gas in ED. We followed the outcome success or failure of the NIV used.

RESULTS

A total of 162 patients were enrolled and 72 (44%) suffered NIV failure in influenza infection with ARF. We used univariate and multivariate logistic analyses to assess risk factors for NIV failure. The ability of risk factor to predict NIV failure was analyzed using the area under the receiver operating characteristic (AUROC). Risk factors of NIV failure included SOFA score (P = 0.001), PF ratio (P = 0.001) and quadrant infiltrations in chest x-rays (CXR) (P = 0.001). SOFA score, PF ratio, and number quadrant infiltrations in chest radiography have good ability to predict NIV failure, AUROC 0.894 (95%CI 0.839-0.948), 0.828 (95%CI 0.764-0.892), and 0.792 (95%CI 0.721-0.863), respectively and no significant difference in the ability to predict NIV failure among three parameters. The use of PF ratio plus number quadrant infiltrations in chest radiography demonstrated a higher predictive ability for NIV failure in influenza infection with ARF.

CONCLUSIONS

SOFA score, PF ratio, and quadrant infiltrations in chest radiography were good predictors of NIV failure in influenza infection with ARF.