Chao Yali, Yuan Xueyan, Zhao Zhanqi, Frerichs Inéz, Li Zhe, Sun Qin, Chen Dongyu, Zhang Rui, Qiu Haibo, Liu Ling
Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, School of Medicine, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, 210009, China.
Department of Critical Care Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
BMC Pulm Med. 2024 Dec 4;24(1):600. doi: 10.1186/s12890-024-03411-0.
Prone positioning (PP) improves oxygenation in awake patients with acute hypoxemic respiratory failure (AHRF). However, the underlying mechanisms remain unclear in patients with diverse lung morphology. We aimed to determine the short-term effects of awake prone positioning (APP) in AHRF patients with focal and non-focal lung morphology.
This is a prospective physiological study. Twenty-four non-intubated patients with PaO/FiO ≤ 300 mm Hg were included. Gas exchange, ventilation and perfusion distribution, and hemodynamics variables were recorded in the supine position (SP1), 2 h after PP, and 1 h after re-supine (SP2). Lung morphology was classified as focal and non-focal patterns using computed tomography.
Twelve of the included patients were classified to the focal group and 12 to the non-focal group. PaO/FiO improved after PP in all patients (161 [137, 227] mmHg vs. 236 [202, 275] mmHg, p < 0.001). Ventilation-perfusion (V/Q) matching increased after PP in all patients (61.9 [53.9, 66.5] vs. 77.5 [68.3, 80.0], p < 0.001). Shunt exhibited a significant decrease in patients of the non-focal group (28.6 [22.5, 30.3] vs. 11.3 [9.0, 14.5], p < 0.001), whereas no difference was found in the focal group after PP. Dead space decreased significantly in patients of the focal group (25.6 [21.5, 28.4] vs. 12.0 [10.8, 14.1], p < 0.001), whereas no difference was found in the non-focal group after PP.
APP improves V/Q matching, and large-scale, bias-free studies are needed to find more definitive differences between patients with focal and non-focal lung morphyology.
The study is registered in ClinicalTrials.gov (trial No. NCT04754113, date of registration: 2021-02-15).
俯卧位通气（PP）可改善急性低氧性呼吸衰竭（AHRF）清醒患者的氧合。然而，在肺部形态各异的患者中，其潜在机制仍不清楚。我们旨在确定清醒俯卧位通气（APP）对具有局灶性和非局灶性肺部形态的AHRF患者的短期影响。
这是一项前瞻性生理学研究。纳入了24例动脉血氧分压/吸入氧分数值（PaO/FiO）≤300 mmHg的未插管患者。在仰卧位（SP1）、俯卧位通气2小时后以及重新仰卧1小时后（SP2）记录气体交换、通气和灌注分布以及血流动力学变量。使用计算机断层扫描将肺部形态分为局灶性和非局灶性模式。
纳入的患者中，12例被分类为局灶性组，12例被分类为非局灶性组。所有患者在俯卧位通气后PaO/FiO均得到改善（161[137, 227]mmHg对236[202, 275]mmHg，p<0.001）。所有患者在俯卧位通气后通气-灌注（V/Q）匹配增加（61.9[53.9, 66.5]对77.5[68.3, 80.0]，p<0.001）。非局灶性组患者的分流显著减少（28.6[22.5, 30.3]对11.3[9.0, 14.5]，p<0.001），而俯卧位通气后局灶性组未发现差异。局灶性组患者的死腔显著减少（25.6[21.5, 28.4]对12.0[10.8, 14.1]，p<0.001），而俯卧位通气后非局灶性组未发现差异。
APP可改善V/Q匹配，需要进行大规模、无偏差的研究以发现局灶性和非局灶性肺部形态患者之间更明确的差异。
该研究已在ClinicalTrials.gov注册（试验编号：NCT04754113，注册日期：2021年2月15日）。
