目的:我们的研究旨在研究不同体外膜氧合(ECMO)血流速度对静脉-静脉(VV)ECMO患者肺灌注评估的影响。
方法:在这项以单一为中心的前瞻性生理研究中,符合ECMO断奶标准的VVECMO患者在不同的ECMO血流量下使用基于盐水推注的EIT评估肺灌注(从4.5L/min逐渐降低至3.5L/min,2.5L/min,1.5L/min,最后到0L/min)。肺灌注分布,死亡空间,分流,通气/灌注匹配,比较了不同流速下的再循环分数。
结果:纳入15例患者。随着ECMO血流速度从4.5L/min降至0L/min,再循环分数显著下降。基于EIT的主要发现如下。(1)感兴趣区域(ROI)2和腹侧区域的中位肺灌注显着增加[38.21(34.93-42.16)%至41.29(35.32-43.75)%,p=0.003,48.86(45.53-58.96)%到54.12(45.07-61.16)%,p=0.037,分别],而在ROI4和背侧区域[7.87(5.42-9.78)%至6.08(5.27-9.34)%显著下降,p=0.049,51.14(41.04-54.47)%至45.88(38.84-54.93)%,p=0.037,分别]。(2)死空间显著减少,腹侧和全球区域的通气/灌注匹配显着增加。(3)在区域和全球分流中未观察到显着变化。
结论:在VVECMO期间,ECMO血流速度,与再循环分数密切相关,可能会影响使用基于高渗盐水推注的EIT进行肺灌注评估的准确性。
OBJECTIVE: Our study aimed to investigate the effects of different extracorporeal membrane oxygenation (ECMO) blood flow rates on lung perfusion assessment using the saline bolus-based electrical impedance tomography (EIT) technique in patients on veno-venous (VV) ECMO.
METHODS: In this single-centered prospective physiological study, patients on VV ECMO who met the ECMO weaning criteria were assessed for lung perfusion using saline bolus-based EIT at various ECMO blood flow rates (gradually decreased from 4.5 L/min to 3.5 L/min, 2.5 L/min, 1.5 L/min, and finally to 0 L/min). Lung perfusion distribution, dead space, shunt, ventilation/perfusion matching, and recirculation fraction at different flow rates were compared.
RESULTS: Fifteen patients were included. As the ECMO blood flow rate decreased from 4.5 L/min to 0 L/min, the recirculation fraction decreased significantly. The main EIT-based findings were as follows. (1) Median lung perfusion significantly increased in region-of-interest (ROI) 2 and the ventral region [38.21 (34.93-42.16)% to 41.29 (35.32-43.75)%, p = 0.003, and 48.86 (45.53-58.96)% to 54.12 (45.07-61.16)%, p = 0.037, respectively], whereas it significantly decreased in ROI 4 and the dorsal region [7.87 (5.42-9.78)% to 6.08 (5.27-9.34)%, p = 0.049, and 51.14 (41.04-54.47)% to 45.88 (38.84-54.93)%, p = 0.037, respectively]. (2) Dead space significantly decreased, and ventilation/perfusion matching significantly increased in both the ventral and global regions. (3) No significant variations were observed in regional and global shunt.
CONCLUSIONS: During VV ECMO, the ECMO blood flow rate, closely linked to recirculation fraction, could affect the accuracy of lung perfusion assessment using hypertonic saline bolus-based EIT.