背景:肥胖患者术后肺部并发症的风险增加。CPAP已成功用于预防和治疗急性呼吸衰竭,但是在许多临床场景中,高流量鼻插管(HFNC)治疗正在成为一种可能的替代方案。我们的目的是在一项序贯研究中比较HFNC和CPAP对气体交换的影响,肺容量,和通过电阻抗断层扫描(EIT)测量的肺部内的气体分布。
方法:我们招募了15名接受腹腔镜减肥手术的受试者。术后他们接受了以下氧气治疗方案(10分钟/步):基线空气夹带面罩,HFNC在流量增加(40、60、80和100L/min)和流量减少(80、60和40L/min)时,冲洗空气夹带面罩和CPAP(10cmH2O)。主要结果是通过EIT数据处理测量的呼气末肺阻抗(ΔEELI)的变化。次要结果是通过EIT测量的全球不均匀性(GI)指数和潮汐阻抗变化(TIV)的变化,动脉氧合,二氧化碳含量,pH值,呼吸频率,和主题的舒适。
结果:13名受试者完成了研究。与基线相比,ΔEELI在10cmH2OCPAP(P=.001)和HFNC100L/min(P=.02)期间较高,以及在减少流量HFNC80、60和40L/min(P=.008,.004和.02,分别)。与HFNC60相比,HFNC100期间的GI指数较低(P=.044),HFNC60减少(P=.02)HFNC40减少(P=.01),并且在10cmH2OCPAP期间,与冲洗期(P=0.01)和HFNC40减少(P=0.03)相比。与基线相比,10cmH2OCPAP期间的TIV更高(P=.008)。与基线相比,在HFNC60时呼吸频率较低,HFNC100和HFNC80减少(P分别为.01、.02和.03)。没有检测到关于动脉氧合的差异,二氧化碳含量,pH值,和主题的舒适。
结论:HFNC在100L/min的流量下诱导减重受试者的术后肺复张,与10cmH2OCPAP相比,在肺募集和通气分布方面没有显着差异。
BACKGROUND: Patients with obesity are at increased risk of postoperative pulmonary complications.
CPAP has been used successfully to prevent and treat acute respiratory failure, but in many clinical scenarios, high-flow nasal cannula (HFNC) therapy is emerging as a possible alternative. We aimed to compare HFNC and
CPAP in a sequential study measuring their effects on gas exchange, lung volumes, and gas distribution within the lungs measured through electrical impedance tomography (EIT).
METHODS: We enrolled 15 subjects undergoing laparoscopic bariatric surgery. Postoperatively they underwent the following oxygen therapy protocol (10 min/step): baseline air-entrainment mask, HFNC at increasing (40, 60, 80, and 100 L/min) and decreasing flows (80, 60, and 40 L/min), washout air-entrainment mask and
CPAP (10 cm H2O). Primary outcome was the change in end-expiratory lung impedance (ΔEELI) measured by EIT data processing. Secondary outcomes were changes of global inhomogeneity (GI) index and tidal impedance variation (TIV) measured by EIT, arterial oxygenation, carbon dioxide content, pH, respiratory frequency, and subject\'s comfort.
RESULTS: Thirteen subjects completed the study. Compared to baseline, ΔEELI was higher during 10 cm H2O
CPAP (P = .001) and HFNC 100 L/min (P = .02), as well as during decreasing flows HFNC 80, 60, and 40 L/min (P = .008, .004, and .02, respectively). GI index was lower during HFNC 100 compared to HFNC 60increasing (P = .044), HFNC 60decreasing (P = .02) HFNC 40decreasing (P = .01), and during 10 cm H2O CPAP compared to washout period (P = .01) and HFNC 40decreasing (P = .03). TIV was higher during 10 cm H2O
CPAP compared to baseline (P = .008). Compared to baseline, breathing frequency was lower at HFNC 60increasing, HFNC 100, and HFNC 80decreasing (P = .01, .02, and .03, respectively). No differences were detected regarding arterial oxygenation, carbon dioxide content, pH, and subject\'s comfort.
CONCLUSIONS: HFNC at a flow of 100 L/min induced postoperative pulmonary recruitment in bariatric subjects, with no significant differences compared to 10 cm H2O CPAP in terms of lung recruitment and ventilation distribution.