Nasal high flow higher than 60 L/min in patients with acute hypoxemic respiratory failure: a physiological study.

Autor: Basile MC; Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy., Mauri T; Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. tommaso.mauri@unimi.it.; Department of Pathophysiology and Transplantation, University of Milan, Via F. Sforza 35, 20122, Milan, Italy. tommaso.mauri@unimi.it., Spinelli E; Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy., Dalla Corte F; Intensive Care Unit, Department of Morphology, Surgery and Experimental Medicine, Sant'Anna University Hospital, Ferrara, Italy., Montanari G; Intensive Care Unit, Department of Morphology, Surgery and Experimental Medicine, Sant'Anna University Hospital, Ferrara, Italy., Marongiu I; Department of Pathophysiology and Transplantation, University of Milan, Via F. Sforza 35, 20122, Milan, Italy., Spadaro S; Intensive Care Unit, Department of Morphology, Surgery and Experimental Medicine, Sant'Anna University Hospital, Ferrara, Italy., Galazzi A; Direction of Healthcare Professions, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy., Grasselli G; Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.; Department of Pathophysiology and Transplantation, University of Milan, Via F. Sforza 35, 20122, Milan, Italy., Pesenti A; Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.; Department of Pathophysiology and Transplantation, University of Milan, Via F. Sforza 35, 20122, Milan, Italy.
Jazyk: angličtina
Zdroj: Critical care (London, England) [Crit Care] 2020 Nov 23; Vol. 24 (1), pp. 654. Date of Electronic Publication: 2020 Nov 23.
DOI: 10.1186/s13054-020-03344-0
Abstrakt: Background: Nasal high flow delivered at flow rates higher than 60 L/min in patients with acute hypoxemic respiratory failure might be associated with improved physiological effects. However, poor comfort might limit feasibility of its clinical use.
Methods: We performed a prospective randomized cross-over physiological study on 12 ICU patients with acute hypoxemic respiratory failure. Patients underwent three steps at the following gas flow: 0.5 L/kg PBW/min, 1 L/kg PBW/min, and 1.5 L/kg PBW/min in random order for 20 min. Temperature and FiO 2 remained unchanged. Toward the end of each phase, we collected arterial blood gases, lung volumes, and regional distribution of ventilation assessed by electrical impedance tomography (EIT), and comfort.
Results: In five patients, the etiology was pulmonary; infective disease characterized seven patients; median PaO 2 /FiO 2 at enrollment was 213 [IQR 136-232]. The range of flow rate during NHF 1.5 was 75-120 L/min. PaO 2 /FiO 2 increased with flow, albeit non significantly (p = 0.064), PaCO 2 and arterial pH remained stable (p = 0.108 and p = 0.105). Respiratory rate decreased at higher flow rates (p = 0.014). Inhomogeneity of ventilation decreased significantly at higher flows (p = 0.004) and lung volume at end-expiration significantly increased (p = 0.007), but mostly in the non-dependent regions. Comfort was significantly poorer during the step performed at the highest flow (p < 0.001).
Conclusions: NHF delivered at rates higher than 60 L/min in critically ill patients with acute hypoxemic respiratory failure is associated with reduced respiratory rate, increased lung homogeneity, and additional positive pressure effect, but also with worse comfort.
Databáze: MEDLINE
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