Physiological Comparison of High-Flow Nasal Cannula and Helmet Noninvasive Ventilation in Acute Hypoxemic Respiratory Failure.

Abstract

Rationale: High-flow nasal cannula (HFNC) and helmet noninvasive ventilation (NIV) are used for the management of acute hypoxemic respiratory failure.Objectives: Physiological comparison of HFNC and helmet NIV in patients with hypoxemia.Methods: Fifteen patients with hypoxemia with PaO2/FiO2 < 200 mm Hg received helmet NIV (positive end-expiratory pressure ≥ 10 cm H2O, pressure support = 10-15 cm H2O) and HFNC (50 L/min) in randomized crossover order. Arterial blood gases, dyspnea, and comfort were recorded. Inspiratory effort was estimated by esophageal pressure (Pes) swings. Pes-simplified pressure-time product and transpulmonary pressure swings were measured.Measurements and Main Results: As compared with HFNC, helmet NIV increased PaO2/FiO2 (median [interquartile range]: 255 mm Hg [140-299] vs. 138 [101-172]; P = 0.001) and lowered inspiratory effort (7 cm H2O [4-11] vs. 15 [8-19]; P = 0.001) in all patients. Inspiratory effort reduction by NIV was linearly related to inspiratory effort during HFNC (r = 0.84; P < 0.001). Helmet NIV reduced respiratory rate (24 breaths/min [23-31] vs. 29 [26-32]; P = 0.027), Pes-simplified pressure-time product (93 cm H2O ⋅ s ⋅ min-1 [43-138] vs. 200 [168-335]; P = 0.001), and dyspnea (visual analog scale 3 [2-5] vs. 8 [6-9]; P = 0.002), without affecting PaCO2 (P = 0.80) and comfort (P = 0.50). In the overall cohort, transpulmonary pressure swings were not different between treatments (NIV = 18 cm H2O [14-21] vs. HFNC = 15 [8-19]; P = 0.11), but patients exhibiting lower inspiratory effort on HFNC experienced increases in transpulmonary pressure swings with helmet NIV. Higher transpulmonary pressure swings during NIV were associated with subsequent need for intubation.Conclusions: As compared with HFNC in hypoxemic respiratory failure, helmet NIV improves oxygenation, reduces dyspnea, inspiratory effort, and simplified pressure-time product, with similar transpulmonary pressure swings, PaCO2, and comfort.

• Authors: Domenico Luca Grieco, Luca S Menga, Valeria Raggi, Filippo Bongiovanni, Gian Marco Anzellotti, Eloisa S Tanzarella, Maria Grazia Bocci, Giovanna Mercurio, Antonio M Dell'Anna, Davide Eleuteri, Giuseppe Bello, Riccardo Maviglia, Giorgio Conti, Salvatore Maurizio Maggiore, Massimo Antonelli
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 201 Issue 3 Pg. 303-312 (02 01 2020) ISSN: 1535-4970 [Electronic] United States
• PMID: 31687831 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Topics

• Acute Disease
• Aged
• Cannula
• Cross-Over Studies
• Female
• Humans
• Hypoxia (complications, physiopathology, therapy)
• Male
• Middle Aged
• Noninvasive Ventilation (instrumentation)
• Respiratory Insufficiency (complications, physiopathology, therapy)