Basoalto Roque, Damiani L Felipe, Jalil Yorschua, Bachmann María Consuelo, Oviedo Vanessa, Alegría Leyla, Valenzuela Emilio Daniel, Rovegno Maximiliano, Ruiz-Rudolph Pablo, Cornejo Rodrigo, Retamal Jaime, Bugedo Guillermo, Thille Arnaud W, Bruhn Alejandro
Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Diagonal Paraguay 362, 6º Piso, P.O. Box 114D, 8330077, Santiago, Chile.
Programa de Medicina Física y Rehabilitación, Red Salud UC-CHRISTUS, Santiago, Chile.
Ann Intensive Care. 2023 Oct 18;13(1):104. doi: 10.1186/s13613-023-01203-z.
Prophylactic high-flow nasal cannula (HFNC) oxygen therapy can decrease the risk of extubation failure. It is frequently used in the postextubation phase alone or in combination with noninvasive ventilation. However, its physiological effects in this setting have not been thoroughly investigated. The aim of this study was to determine comprehensively the effects of HFNC applied after extubation on respiratory effort, diaphragm activity, gas exchange, ventilation distribution, and cardiovascular biomarkers.
This was a prospective randomized crossover physiological study in critically ill patients comparing 1 h of HFNC versus 1 h of standard oxygen after extubation. The main inclusion criteria were mechanical ventilation for at least 48 h due to acute respiratory failure, and extubation after a successful spontaneous breathing trial (SBT). We measured respiratory effort through esophageal/transdiaphragmatic pressures, and diaphragm electrical activity (ΔEAdi). Lung volumes and ventilation distribution were estimated by electrical impedance tomography. Arterial and central venous blood gases were analyzed, as well as cardiac stress biomarkers.
We enrolled 22 patients (age 59 ± 17 years; 9 women) who had been intubated for 8 ± 6 days before extubation. Respiratory effort was significantly lower with HFNC than with standard oxygen therapy, as evidenced by esophageal pressure swings (5.3 [4.2-7.1] vs. 7.2 [5.6-10.3] cmHO; p < 0.001), pressure-time product (85 [67-140] vs. 156 [114-238] cmHO*s/min; p < 0.001) and ΔEAdi (10 [7-13] vs. 14 [9-16] µV; p = 0.022). In addition, HFNC induced increases in end-expiratory lung volume and PaO/FiO ratio, decreases in respiratory rate and ventilatory ratio, while no changes were observed in systemic hemodynamics, Troponin T, or in amino-terminal pro-B-type natriuretic peptide.
Prophylactic application of HFNC after extubation provides substantial respiratory support and unloads respiratory muscles. Trial registration January 15, 2021. NCT04711759.
预防性高流量鼻导管（HFNC）氧疗可降低拔管失败风险。它常用于拔管后阶段，单独使用或与无创通气联合使用。然而，其在此种情况下的生理效应尚未得到充分研究。本研究的目的是全面确定拔管后应用HFNC对呼吸功、膈肌活动、气体交换、通气分布和心血管生物标志物的影响。
这是一项针对危重症患者的前瞻性随机交叉生理研究，比较拔管后1小时的HFNC与1小时的标准氧疗。主要纳入标准为因急性呼吸衰竭接受机械通气至少48小时，且在成功进行自主呼吸试验（SBT）后拔管。我们通过食管/跨膈肌压力和膈肌电活动（ΔEAdi）来测量呼吸功。通过电阻抗断层扫描估计肺容积和通气分布。分析动脉血和中心静脉血气以及心脏应激生物标志物。
我们纳入了22例患者（年龄59±17岁；9名女性），拔管前插管时间为8±6天。HFNC组的呼吸功明显低于标准氧疗组，食管压力波动（5.3[4.2 - 7.1] vs. 7.2[5.6 - 10.3] cmH₂O；p < 0.001）、压力 - 时间乘积（85[67 - 140] vs. 156[114 - 238] cmH₂O*s/min；p < 0.001）和ΔEAdi（10[7 - 13] vs. 14[9 - 16] µV；p = 0.022）可证明这一点。此外，HFNC可导致呼气末肺容积和PaO₂/FiO₂比值增加，呼吸频率和通气比降低，而全身血流动力学、肌钙蛋白T或氨基末端前B型利钠肽未观察到变化。
拔管后预防性应用HFNC可提供显著的呼吸支持并减轻呼吸肌负担。试验注册时间：2021年1月15日。NCT04711759。
