학술논문
Physiological effects of awake prone position in acute hypoxemic respiratory failure
Document Type
Report
Author
Grieco, Domenico Luca; Delle Cese, Luca; Menga, Luca S.; Rosà, Tommaso; Michi, Teresa; Lombardi, Gianmarco; Cesarano, Melania; Giammatteo, Valentina; Bello, Giuseppe; Carelli, Simone; Cutuli, Salvatore L.; Sandroni, Claudio; De Pascale, Gennaro; Pesenti, Antonio; Maggiore, Salvatore M.; Antonelli, Massimo
Source
Critical Care. August 17, 2023, Vol. 27 Issue 1
Subject
Language
English
ISSN
1364-8535
Abstract
Author(s): Domenico Luca Grieco[sup.1,2], Luca Delle Cese[sup.1,2], Luca S. Menga[sup.1,2], Tommaso Rosà[sup.1,2], Teresa Michi[sup.1,2], Gianmarco Lombardi[sup.1,2], Melania Cesarano[sup.1,2], Valentina Giammatteo[sup.1,2], Giuseppe Bello[sup.1,2], Simone Carelli[sup.1,2], Salvatore L. Cutuli[sup.1,2], Claudio Sandroni[sup.1,2], Gennaro [...]
Background The effects of awake prone position on the breathing pattern of hypoxemic patients need to be better understood. We conducted a crossover trial to assess the physiological effects of awake prone position in patients with acute hypoxemic respiratory failure. Methods Fifteen patients with acute hypoxemic respiratory failure and PaO.sub.2/FiO.sub.2 < 200 mmHg underwent high-flow nasal oxygen for 1 h in supine position and 2 h in prone position, followed by a final 1-h supine phase. At the end of each study phase, the following parameters were measured: arterial blood gases, inspiratory effort ([DELA]P.sub.ES), transpulmonary driving pressure ([DELA]P.sub.L), respiratory rate and esophageal pressure simplified pressure-time product per minute (sPTP.sub.ES) by esophageal manometry, tidal volume (V.sub.T), end-expiratory lung impedance (EELI), lung compliance, airway resistance, time constant, dynamic strain (V.sub.T/EELI) and pendelluft extent through electrical impedance tomography. Results Compared to supine position, prone position increased PaO.sub.2/FiO.sub.2 (median [Interquartile range] 104 mmHg [76-129] vs. 74 [69-93], p < 0.001), reduced respiratory rate (24 breaths/min [22-26] vs. 27 [26-30], p = 0.05) and increased [DELA]P.sub.ES (12 cmH.sub.2O [11-13] vs. 9 [8-12], p = 0.04) with similar sPTP.sub.ES (131 [75-154] cmH.sub.2O s min.sup.-1 vs. 105 [81-129], p > 0.99) and [DELA]P.sub.L (9 [7-11] cmH.sub.2O vs. 8 [5-9], p = 0.17). Airway resistance and time constant were higher in prone vs. supine position (9 cmH.sub.2O s arbitrary units.sup.-3 [4-11] vs. 6 [4-9], p = 0.05; 0.53 s [0.32-61] vs. 0.40 [0.37-0.44], p = 0.03). Prone position increased EELI (3887 arbitrary units [3414-8547] vs. 1456 [959-2420], p = 0.002) and promoted V.sub.T distribution towards dorsal lung regions without affecting V.sub.T size and lung compliance: this generated lower dynamic strain (0.21 [0.16-0.24] vs. 0.38 [0.30-0.49], p = 0.004). The magnitude of pendelluft phenomenon was not different between study phases (55% [7-57] of V.sub.T in prone vs. 31% [14-55] in supine position, p > 0.99). Conclusions Prone position improves oxygenation, increases EELI and promotes V.sub.T distribution towards dependent lung regions without affecting V.sub.T size, [DELA]P.sub.L, lung compliance and pendelluft magnitude. Prone position reduces respiratory rate and increases [DELA]P.sub.ES because of positional increases in airway resistance and prolonged expiratory time. Because high [DELA]P.sub.ES is the main mechanistic determinant of self-inflicted lung injury, caution may be needed in using awake prone position in patients exhibiting intense [DELA]P.sub.ES. Clinical trail registeration: The study was registered on clinicaltrials.gov (NCT03095300) on March 29, 2017. Keywords: Acute respiratory failure, Awake prone position, Inspiratory effort, High-flow nasal oxygen, Patient self-inflicted lung injury
Background The effects of awake prone position on the breathing pattern of hypoxemic patients need to be better understood. We conducted a crossover trial to assess the physiological effects of awake prone position in patients with acute hypoxemic respiratory failure. Methods Fifteen patients with acute hypoxemic respiratory failure and PaO.sub.2/FiO.sub.2 < 200 mmHg underwent high-flow nasal oxygen for 1 h in supine position and 2 h in prone position, followed by a final 1-h supine phase. At the end of each study phase, the following parameters were measured: arterial blood gases, inspiratory effort ([DELA]P.sub.ES), transpulmonary driving pressure ([DELA]P.sub.L), respiratory rate and esophageal pressure simplified pressure-time product per minute (sPTP.sub.ES) by esophageal manometry, tidal volume (V.sub.T), end-expiratory lung impedance (EELI), lung compliance, airway resistance, time constant, dynamic strain (V.sub.T/EELI) and pendelluft extent through electrical impedance tomography. Results Compared to supine position, prone position increased PaO.sub.2/FiO.sub.2 (median [Interquartile range] 104 mmHg [76-129] vs. 74 [69-93], p < 0.001), reduced respiratory rate (24 breaths/min [22-26] vs. 27 [26-30], p = 0.05) and increased [DELA]P.sub.ES (12 cmH.sub.2O [11-13] vs. 9 [8-12], p = 0.04) with similar sPTP.sub.ES (131 [75-154] cmH.sub.2O s min.sup.-1 vs. 105 [81-129], p > 0.99) and [DELA]P.sub.L (9 [7-11] cmH.sub.2O vs. 8 [5-9], p = 0.17). Airway resistance and time constant were higher in prone vs. supine position (9 cmH.sub.2O s arbitrary units.sup.-3 [4-11] vs. 6 [4-9], p = 0.05; 0.53 s [0.32-61] vs. 0.40 [0.37-0.44], p = 0.03). Prone position increased EELI (3887 arbitrary units [3414-8547] vs. 1456 [959-2420], p = 0.002) and promoted V.sub.T distribution towards dorsal lung regions without affecting V.sub.T size and lung compliance: this generated lower dynamic strain (0.21 [0.16-0.24] vs. 0.38 [0.30-0.49], p = 0.004). The magnitude of pendelluft phenomenon was not different between study phases (55% [7-57] of V.sub.T in prone vs. 31% [14-55] in supine position, p > 0.99). Conclusions Prone position improves oxygenation, increases EELI and promotes V.sub.T distribution towards dependent lung regions without affecting V.sub.T size, [DELA]P.sub.L, lung compliance and pendelluft magnitude. Prone position reduces respiratory rate and increases [DELA]P.sub.ES because of positional increases in airway resistance and prolonged expiratory time. Because high [DELA]P.sub.ES is the main mechanistic determinant of self-inflicted lung injury, caution may be needed in using awake prone position in patients exhibiting intense [DELA]P.sub.ES. Clinical trail registeration: The study was registered on clinicaltrials.gov (NCT03095300) on March 29, 2017. Keywords: Acute respiratory failure, Awake prone position, Inspiratory effort, High-flow nasal oxygen, Patient self-inflicted lung injury