High-Flow Nasal Cannula Versus Noninvasive Ventilation as Initial Treatment in Acute Hypoxia: A Propensity Score-Matched Study.

IMPORTANCE: Patients presenting to the emergency department (ED) with hypoxemia often have mixed or uncertain causes of respiratory failure. The optimal treatment for such patients is unclear. Both high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) are used. OBJECTIVES: We sought to compare the effectiveness of initial treatment with HFNC versus NIV for acute hypoxemic respiratory failure. DESIGN SETTING AND PARTICIPANTS: We conducted a retrospective cohort study of patients with acute hypoxemic respiratory failure treated with HFNC or NIV within 24 hours of arrival to the University of Michigan adult ED from January 2018 to December 2022. We matched patients 1:1 using a propensity score for odds of receiving NIV. MAIN OUTCOMES AND MEASURES: The primary outcome was major adverse pulmonary events (28-d mortality, ventilator-free days, noninvasive respiratory support hours) calculated using a win ratio. RESULTS: A total of 1154 patients were included. Seven hundred twenty-six (62.9%) received HFNC and 428 (37.1%) received NIV. We propensity score matched 668 of 1154 (57.9%) patients. Patients on NIV versus HFNC had lower 28-day mortality (16.5% vs. 23.4%, p = 0.033) and required noninvasive treatment for fewer hours (median 7.5 vs. 13.5, p < 0.001), but had no difference in ventilator-free days (median [interquartile range]: 28 [26, 28] vs. 28 [10.5, 28], p = 0.199). Win ratio for composite major adverse pulmonary events favored NIV (1.38; 95% CI, 1.15-1.65; p < 0.001). CONCLUSIONS AND RELEVANCE: In this observational study of patients with acute hypoxemic respiratory failure, initial treatment with NIV compared with HFNC was associated with lower mortality and fewer composite major pulmonary adverse events calculated using a win ratio. These findings underscore the need for randomized controlled trials to further understand the impact of noninvasive respiratory support strategies.

Focused Cardiac Ultrasound Findings of Fluid Tolerance and Fluid Resuscitation in Septic Shock.

OBJECTIVES: Compliance with the fluid bonus component of the SEP-1 (severe sepsis and septic shock management) bundle remains poor due to concerns for iatrogenic harm from fluid overload. We sought to assess whether patients who received focused cardiac ultrasound (FCU) and were found to be fluid tolerant (FT) were more likely to receive the recommended 30 mL/kg fluid bolus within 3 hours of sepsis identification. DESIGN: Retrospective, observational cohort study. SETTING: University-affiliated, tertiary-care hospital in the United States. PATIENTS: Emergency department patients presenting with septic shock from 2018 to 2021. The primary exposure was receipt of FCU with identification of fluid tolerance 3 hours from onset of septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two hundred ninety-two of 1,024 patients with septic shock received FCU within 3 hours of sepsis onset. One hundred seventy-seven were determined to be FT. One hundred fifteen patients were determined to have poor fluid tolerance (pFT). FT patients were more likely to reach the recommended 30 mL/kg fluid bolus amount compared with pFT (FT 52.0% vs. pFT 31.3%, risk difference: 20.7%, [95% CI, 9.4-31.9]). Patients who did not receive FCU met the bolus requirement 34.3% of the time. FT patients received more fluid within 3 hours (FT 2,271 mL vs. pFT 1,646 mL, mean difference 625 mL [95% CI, 330-919]). Multivariable logistic regression was used to estimate the association between fluid tolerance FCU findings and compliance with 30 mL/kg bolus after adjustment for patient characteristics and markers of hemodynamic instability. FT with associated with a higher likelihood of meeting bolus requirement (odds ratio 2.17 [1.52-3.12]). CONCLUSIONS: Patients found to be FT by FCU were more likely to receive the recommended 30 mL/kg bolus in the SEP-1 bundle when compared with patients found with pFT or those that did not receive FCU. There was no difference between groups in 28-day mortality, vasopressor requirement, or need for mechanical ventilation.

High-flow nasal cannula vs non-invasive ventilation in acute hypoxia: Propensity score matched study.

RATIONALE: The optimal treatment for early hypoxemic respiratory failure is unclear, and both high-flow nasal cannula and non-invasive ventilation are used. Determining clinically relevant outcomes for evaluating non-invasive respiratory support modalities remains a challenge. OBJECTIVES: To compare the effectiveness of initial treatment with high-flow nasal cannula versus non-invasive ventilation for acute hypoxemic respiratory failure. METHODS: We conducted a retrospective cohort study of patients with acute hypoxemic respiratory failure treated with high-flow nasal cannula or non-invasive ventilation within 24 hours of Emergency Department arrival (1/2018-12/2022). We matched patients 1:1 using a propensity score for odds of receiving non-invasive ventilation. The primary outcome was major adverse pulmonary events (28-day mortality, ventilator-free days, non-invasive respiratory support hours) calculated using a Win Ratio. MEASUREMENTS AND MAIN RESULTS: 1,265 patients met inclusion criteria. 795 (62.8%) received high-flow oxygen and 470 (37.2%) received non-invasive ventilation. We propensity score matched 736/1,265 (58.2%) patients. There was no difference between non-invasive ventilation vs high-flow nasal cannula in 28-day mortality (17.7% vs 23.1%, p=0.08) or ventilator-free days (median [Interquartile Range]: 28 [25, 28] vs 28 [13, 28], p=0.50), but patients on non-invasive ventilation required treatment for fewer hours (median 7 vs 13, p< 0.001). Win Ratio for composite major adverse pulmonary events favored non-invasive ventilation (1.26, 95%CI 1.06-1.49, p< 0.001). CONCLUSIONS: In this observational study of patients with acute hypoxemic respiratory failure, initial treatment with non-invasive ventilation was superior to high-flow nasal cannula for major pulmonary adverse events. Evaluation of composite outcomes is important in the assessment of respiratory support modalities.