静脉-动脉体外膜肺氧合过程发生氧合器假性氧合不良的识别与处理

目的总结主动脉夹层患者在接受体外膜氧合(ECMO)支持过程中发生氧合器假性氧合不良的处理。方法1例患者清醒、自主呼吸、因心衰以“心肌炎”于外院行静脉-动脉(V-A)ECMO治疗60 h后完善彩超等检查,怀疑“马凡综合征”转入我科,ECMO辅助至第70 h患者自述呼吸困难,痰多,经皮血氧饱和度(SpO2)进行性下降至89%,调节ECMO氧浓度至100%后监测氧合器后动脉血气氧分压(PaO2)为92 mmHg,怀疑氧合器“假性氧合不良”,于氧合器动、静脉段先后使用分流量为0.7 L/min和1.4 L/min的旁路处理,并适当安抚患者,辅助至第94 h确诊主动脉夹层后,于急诊下行Bentall+二尖瓣成形+冠状动脉旁路移植术。结果ECMO总辅助时间94 h,其中院外60 h,院内34 h,平均血流量为3.5 L/min,平均氧浓度为60%,辅助至第70 h出现假性氧合不良,经处理后患者SpO2上升至100%,患者诉症状减轻,外科手术顺利,术毕顺利脱离心肺转流,经评估无需继续ECMO辅助,术后28 h苏醒,50 h脱离呼吸机,10 d后康复出院。结论熟悉插管、氧合器等参数有助于鉴别ECMO辅助过程的“假性氧合不良”现象,避免更换氧合器,节约医疗成本的同时保障了患者安全。

Identification and Management of Oxygenator Pseudo-malfunction for A Patient with Aortic Dissection under Veno-arterial Extracorporeal Membrane Oxygenation Support

Objective To summarize the management of oxygenator pseudo-malfunction for a aortic dissection patient with Standford type A under veno-arterial extracorporeal membrane oxygenation(VA ECMO)support.Methods The patient was conscious,with spontaneous breathing and cardiac shock,and receiving a VA ECMO support because of suspect myocarditis in other hospital for 60 h,and diagnosed as"Marfan syndrome"after echocardiography and transferred into our department.Continue VA ECMO support to the 70th hour,the patient complained difficulty in breathing,too much phlegm,and the percutaneous oxygen saturation(SpO2)decreased to 89%.After adjusting the ECMO oxygen concentration to 100%for 10 minutes,the arterial oxygen partial pressure(PaO2)was 92 mm Hg.Since the parameter of the blood gas analysis deteriorated progressively,oxygenator pseudo-malfunction was suspected and a bypass shunt with flow of 0.7 and 1.4 L/min successively added into the ECMO circuit.Finally the patient received a surgical repair(Bentall+mitral valvuloplasty+coronary artery bypass grafting)after confirming as an aortic dissection.Results The patient was awake without endotracheal intubation throughtout the ECMO period.The total ECMO running time was 94 hours,including 60 hours in outside hospital and 34 hours in our hospital.The average blood flow was 3.5 L/min and the average FiO2 was 60%."Oxygenator pseudo-malfunction"phenomenon was confirmed at 70th h and the problem was solved with SpO2 increased to 100%and the symptoms relived after a 1.4 L/min bypass shunt which connected from the oxygenator's arterial port to venous port was applied.After the operation,the patient was successfully from the cardiopulmonary bypass and without further ECMO assistance,then woke up 28 hours after the operation,off-ventilator 50 hours later,and discharged successfully 10 days after the surgical operation.Conclusion Handling the intubation skilled and familiarity the oxygenator and other related parameters well is helpful to identify the phenomenon of"oxygenator pseudo-malfunction"during the ECMO support,and can avoid replacement of oxygenator,save medical costs and ensure patient safety.