Ling Lowell, Chan Kai Man
Department of Anaesthesia and Intensive Care, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.
Perfusion. 2018 Jul;33(5):339-345. doi: 10.1177/0267659118755888. Epub 2018 Feb 7.
There is a lack of consensus on the timing of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) liberation. VA-ECMO weaning usually consists of serial decrements until an idling flow is achieved, supported by echocardiographic and haemodynamic assessments. Even with minimal idling flow, right ventricular (RV) preload is reduced and, hence, right heart function is not fully tested under adequate loading conditions. Following the use of a novel technique called Pump Controlled Retrograde Trial Off (PCRTO) in neonate VA-ECMO weaning, we report the use of this technique in seven adult patients on VA-ECMO.
We retrospectively reviewed all adult VA-ECMO patients treated at a tertiary teaching hospital in Hong Kong since 2010. Clinical data, including diagnosis, echocardiography findings, ECMO configuration, PCRTO settings, survival after veno-arterial ECMO (SAVE) score and outcomes, were collected. Mortality and death due to cardiac failure was compared between PCRTO and conventional weaning.
Seven patients underwent PCRTO, with a mean SAVE score of -4.4 ± 5.9. All seven patients were successfully decannulated without haemodynamic deterioration. In all cases, no clots or fibrin deposits were found in the circuit after the trial. There was no difference in mean SAVE scores among the seven patients in PCRTO and the 23 patients in the conventional group (-3.6, 95% CI -8.8 to 1.5). The number of deaths due to cardiac failure in the PCRTO group and the conventional group were 0 and 3, respectively (0% vs. 13%, p=0.99). Mortality after decannulation for PCRTO was 42.9% vs. conventional weaning 34.8% (p=0.99).
Our study suggests that PCRTO is a simple, safe and reversible alternative weaning method. It may have a particular role in the assessment of patients who have marginal recovery and right heart failure. Prospective controlled studies are needed to establish the potential role of PCRTO in the liberation of patients from VA-ECMO support.
关于静脉 - 动脉体外膜肺氧合（VA - ECMO）撤机时机尚无共识。VA - ECMO撤机通常包括逐步减量，直至达到空转流量，并通过超声心动图和血流动力学评估提供支持。即使空转流量最小，右心室（RV）前负荷也会降低，因此，右心功能在充足的负荷条件下无法得到充分测试。在新生儿VA - ECMO撤机中使用了一种名为泵控逆行试验脱离（PCRTO）的新技术后，我们报告了该技术在7例接受VA - ECMO治疗的成年患者中的应用情况。
我们回顾性分析了自2010年以来在香港一家三级教学医院接受治疗的所有成年VA - ECMO患者。收集了临床数据，包括诊断、超声心动图检查结果、ECMO配置、PCRTO设置、静脉 - 动脉ECMO后生存率（SAVE）评分及结局。比较了PCRTO组和传统撤机组的死亡率及因心力衰竭导致的死亡情况。
7例患者接受了PCRTO，平均SAVE评分为 - 4.4 ± 5.9。所有7例患者均成功拔管，且血流动力学未恶化。在所有病例中，试验后回路中均未发现血栓或纤维蛋白沉积。PCRTO组的7例患者与传统组的23例患者的平均SAVE评分无差异（-3.6，95%CI - 8.8至1.5）。PCRTO组和传统组因心力衰竭导致的死亡人数分别为0例和3例（0%对13%，p = 0.99）。PCRTO组拔管后的死亡率为42.9%，传统撤机组为34.8%（p = 0.99）。
我们的研究表明，PCRTO是一种简单、安全且可逆的替代撤机方法。它可能在评估恢复边缘和右心衰竭的患者中具有特殊作用。需要进行前瞻性对照研究以确定PCRTO在VA - ECMO支持下患者撤机中的潜在作用。
