Extracorporeal Membrane Oxygenation Support for Postcardiotomy Cardiogenic Shock

Abstract: Extracorporeal membrane oxygenation (ECMO) has had promising results in life-threatening respiratory failure and postcardiotomy cardiogenic failure. From October 1994 to October 1995, 18 patients received 19 ECMOs at National Taiwan University Hospital for severe cardiogenic shock after cardiac surgery. They included patients receiving cardiac massage or repeated bolus injections of norepinephrine to maintain blood pressure (n = 10), patients who could not be weaned off cardiopulmonary bypass after several attempts despite in-traaortic balloon pumping and maximal doses of catecholamine (n = 7), and patients with progressive intractable cardiogenic shock after cardiac surgery. Venoarterial ECMO was set up via femoral artery (17 or 19 Fr cannula) and vein (19 or 21 Fr) in all patients except 2 infants. No left heart drainage was performed in any of the patients. The heparin-coated circuit (with Carmeda Bio-active Surface) was used in the last 13 patients to reduce bleeding. Ten (52.6%) of the 19 cases could be smoothly weaned off ECMO, and 6 (33.3%) of the 18 patients were discharged from the hospital in good condition. Four (80%) of the 5 patients after valvular surgery and all 3 heart transplant patients could be weaned off ECMO successfully with the survival rate being 60% and 67%, respectively. Complications included leg ischemia (n = 3), bleeding (n = 4), renal failure (n = 3), and tube rupture (n = 1). The inability to wean off ECMO was caused by multiple organ failure (n = 5), sepsis (n = 2), tube rupture (n = 1), and dysfunction of the ECMO system (n = 1). The major cause of multiple organ failure was hesitation to set up ECMO. Our preliminary results confirmed the effect of ECMO in postoperative cardiogenic shock.     

体外膜肺氧合在循环衰竭中的应用治疗体会

目的总结循环衰竭患者实施体外膜肺氧合（extracorporeal membrane oxygenation,EC-MO）支持的方法和效果。方法对3例患者实施ECMO支持,年龄17～32岁,体质量45～60 kg。3例患者中,2例为急性暴发性重症心肌炎;另一例为法洛氏四联症矫治术后低心排综合征。采用静脉-动脉转流,辅助流量40～70 ml/（kg.min）,间断检测活化凝血时间（activated coagulation time,ACT）150～200 s。结果 ECMO支持时间96～135 h,均成功脱机,康复出院。结论 ECMO支持是抢救危重循环衰竭的有效方法。     

Left Anterior Descending Coronary Artery Blood Flow and Left Ventricular Unloading During Extracorporeal Membrane Oxygenation Support in a Swine Model of Acute Cardiogenic Shock

The impact of extracorporeal membrane oxygenation (ECMO) support on coronary blood flow and left ventricular unloading is still debated. This study aimed to further characterize the influence of ECMO on coronary artery blood flow and its ability to unload the left ventricle in a short‐term model of acute cardiogenic shock. Seven anesthetized pigs were intubated and then underwent median sternotomy and cannulation for venoarterial (VA) ECMO. Flow in the left anterior descending (LAD) artery, left atrial pressure (LAP), left ventricular end‐diastolic pressure (LVEDP), and mean arterial pressure (MAP) were measured before and after esmolol‐induced cardiac dysfunction and after initiating VA‐ECMO support. Induction of acute cardiogenic shock was associated with short‐term increases in LAP from 8 ± 4 mm Hg to 18 ± 14 mm Hg (P = 0.9) and LVEDP from 5 ± 2 mm Hg to 13 ± 17 mm Hg (P = 0.9), and a decrease in MAP from 63 ± 16 mm Hg to 50 ± 24 mm Hg (P = 0.3). With VA‐ECMO support, blood flow in the LAD increased from 28 ± 25 mL/min during acute unsupported cardiogenic shock to 67 ± 50 mL/min (P = 0.003), and LAP and LVEDP decreased to 8 + 5 mm Hg (P = 0.7) and 5 ± 3 mm Hg (P = 0.5), respectively. In this swine model of acute cardiogenic shock, VA‐ECMO improved coronary blood flow and provided some degree of left ventricular unloading for the short duration of the study.     

Concurrent Implantation of Intra‐Aortic Balloon Pump and Extracorporeal Membrane Oxygenation Improved Survival of Patients With Postcardiotomy Cardiogenic Shock

The aim of this study is to report the combined application of extracorporeal membrane oxygenation (ECMO) with intra‐aortic balloon pumping (IABP) in postcardiotomy cardiac shock (PCS). A total of 60 consecutive patients who received both ECMO and IABP (concomitantly 24 hours) for PCS from February 2006 to March 2017 at Fuwai Hospital were included in our study. Clinical characteristics of the patients were collected retrospectively and compared between survivors and non‐survivors. Logistic regression analysis was used as predictors for survival to discharge. The study cohort had a mean age of 51.4±12.7 years with 75% males. ECMO was implanted intra‐operatively in 38 (63%) patients and post‐operatively in 22 (37%) patients. ECMO was implanted concurrently with IABP in 38 (63%) patients. Heart transplantation (38%) and coronary artery bypass graft (33%) were the main surgical procedures. ECMO was weaned successfully in 48% patients, and the rate of survival to discharge was 43%. Survivors showed less bedside ECMO implantation (12% vs. 41%, P=0.012) and more concurrent implantation of ECMO with IABP (81% vs. 50%, P=0.014). Concurrent implantation of IABP with ECMO (OR=0.177, P=0.015, 95% CI: 0.044‐0.718) was an independent predictor of survival to discharge. As for complications, the rate of renal failure (59% vs. 15%, P=0.001) and multiple organ dysfunction syndrome (29% vs. 0, P=0.003) was higher in patients who failed to survive to discharge. Patients who had heart transplantation had a better long‐term survival than others (P=0.0358). In summary, concurrent implantation of ECMO with IABP provides better short‐term outcome for PCS and combined application of ECMO with IABP for PCS after heart transplantation had a favorable long‐term outcome.     

Extracorporeal Membrane Oxygenation Support in Refractory Cardiogenic Shock: Treatment Strategies and Analysis of Risk Factors

Two centrifugal pumps, the RotaFlow (Maquet, Jostra Medizintechnik AG, Hirrlingen, Germany) and Levitronix CentriMag (Levitronix LCC, Waltham, MA, USA), used in central or peripheral veno‐arterial extracorporeal membrane oxygenation (ECMO) support systems have been investigated, in terms of double‐center experience, as treatment for patients with refractory cardiogenic shock (CS). Between January 2006 and December 2012, 228 consecutive adult patients were supported on RotaFlow (n = 213) or CentriMag (n = 15) ECMO, at our institutions (155 men; age 58.3 ± 10.5 years, range: 19–84 years). Indications for support were: failure to wean from cardiopulmonary bypass in the setting of postcardiotomy (n = 118) and primary donor graft failure (n = 37); postacute myocardial infarction CS (n = 27); acute myocarditis (n = 6); and CS on chronic heart failure (n = 40). A peripheral ECMO setting was established in 126 (55.2%) patients while it was established centrally in 102 (44.7%). Overall mean support time was 10.9 ± 9.7 days (range: 1–43 days). Eighty‐four (36.8%) patients died on ECMO. Overall success rate, in terms of survival on ECMO (n = 144), weaning from mechanical support (n = 107; 46.9%), bridge to mid‐long‐term ventricular assist device (n = 6; 2.6%), and bridge to heart transplantation (n = 31; 13.5%), was 63.1%. One hundred twenty‐two (53.5%) patients were successfully discharged. Stepwise logistic regression identified blood lactate level and MB isoenzyme of creatine kinase (CK‐MB) relative index at 72 h after ECMO initiation, and number of packed red blood cells (PRBCs) transfused on ECMO as significant predictors of mortality on ECMO (P = 0.010, odds ratio [OR] = 2.94; 95% confidence interval [CI] = 1.10–3.14; P = 0.010, OR = 2.82, 95% CI = 1.014–3.721; and P = 0.011, OR = 2.69; 95% CI = 1.06–4.16, respectively). Central ECMO population had significantly higher rate of continuous veno‐venous hemofiltration need and bleeding requiring surgery events compared with the peripheral ECMO setting population. No significant differences were seen by comparing the RotaFlow and CentriMag populations in terms of device performance. At follow‐up, persistent heart failure with left ventricle ejection fraction (LVEF) ≤40% was a risk factor after hospital discharge. Patients with a poor hemodynamic status may benefit from rapid central or peripheral insertion of ECMO. The blood lactate level, CK‐MB relative index, and PRBCs transfused should be strictly monitored during ECMO support. In addition, early ventricular assist device placement or urgent listing for heart transplant should be considered in patients with persistent impaired LVEF after ECMO.