Venoarterial Membrane Oxygenation Research Articles

Haemodynamic Assessment of Patients Supported on Veno-Arterial Membrane Oxygenation with Concurrent Evaluation of Echocardiographic Findings

Introduction: Intrinsic cardiac output is not accurately assessed with thermo-dilution or pulse contour analysis in veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Pulse pressure (PP) is thought to be a surrogate marker for intrinsic cardiac output. We compare invasive haemodynamic parameters with echocardiography (EC) findings.

Implementing an Innovative Cardiac Assist System in a Nonuniversity Hospital--Feasibility, Complications, and First Results.

To evaluate the feasibility of implementing a cardiac assist system in a nonuniversity hospital we analyzed 18 consecutive patients treated with venoarterial membrane oxygenation. The system was used electively in 5/18 (27.8%) patients during high-risk interventions. Thirteen patients (72.2%) were treated in emergency situations. The extracorporal system could be initiated successfully in all patients. Periprocedural complications were hemolysis in 3/18 (16.7%), disseminated intravascular coagulation in 2/18 (11.1%), cerebral ischemia in 1/18 (5.6%), and local infection in 2/18 (11.1%) patients. None of these led to a discontinuation of the therapy. All electively treated patients were successfully weaned from the extracorporeal system. In 9/13 (69.2%) emergency patients the system was removed successfully. The 60-day survival rate of the emergency patients was 53.8% (7/13). Our experience confirms that an innovative extracorporeal circulatory support system can be implemented in a nonuniversity hospital at a tolerable risk and a low complication and high procedural success rate.

Relapse of giant cell myocarditis supported with veno-arterial extracorporeal membrane oxygenation

Giant cell myocarditis (GCM) is a fatal form of myocarditis that often presents with acute heart failure. An inflammatory infiltrate with giant cells and myocardial necrosis is characteristic. During the acute presentation, mechanical circulatory support may be necessary for hemodynamic support while immunosuppression is initiated. We report a case of GCM relapse which was supported with veno-arterial membrane oxygenation until recovery. The patient is doing well one year after explantation.

Influence of Volume Replacement with Colloids versus Crystalloids in Neonates on Venoarterial Extracorporeal Membrane Oxygenation on Fluid Retention, Fluid Balance, and ECMO Runtime

In this retrospective study, we compared the effects of colloid versus crystalloid fluid replacement on the clinical signs of capillary leakage syndrome in 30 neonates with pulmonary hypertension due to meconium aspiration syndrome on venoarterial membrane oxygenation (VA-ECMO). Before 2000, 15 neonates received volume replacement with a pasteurized plasma protein solution (3.8% albumin); after 2000, 15 neonates received normal saline. Patient characteristics and pre-ECMO values did not differ between the two groups. Total fluid balance was also equal. Diuretic use was significantly higher in the colloid group (p < 0.001). The chest wall soft-tissue index was significantly higher in the crystalloid group (p < 0.005), as were the ventilator settings at the end of the ECMO runtime (p < 0.05). Serum colloid osmotic pressure, albumin, urea nitrogen, and creatinine were significantly higher in the colloid group (p < 0.0001, < 0.0001, < 0.001, and < 0.05, respectively). Duration of VA-ECMO, of artificial ventilation after ECMO treatment, and the mortality rate did not differ between the two groups. We conclude that volume replacement with crystalloids in neonates on VA-ECMO aggravated the edema in a preexisting situation of capillary leakage syndrome, whereas volume replacement with colloids could impair the kidney function.

Improved Results Treating Lung Allograft Failure With Venovenous Extracorporeal Membrane Oxygenation

Primary graft failure remains a significant source of mortality after lung transplantation. Extracorporeal membrane oxygenation (ECMO) provides treatment for affected recipients. We hypothesized that venovenous membrane oxygenation provides a safer alternative than venoarterial support for lung recipients suffering from primary graft failure. We conducted an analysis of 522 patients who underwent lung transplantation from April 1992 to July 2004. Twenty-three (4.5%) patients required membrane oxygenation secondary to primary graft failure unresponsive to conventional treatment. Of these recipients, 15 (65%) were treated with venoarterial, while 8 (35%) underwent venovenous membrane oxygenation. Median days to initiation and duration of membrane oxygenation did not differ between groups. Eight of 15 patients (53%) from the venoarterial group were successfully weaned from life support, with one surviving greater than 45 days. This lone long-term survivor required retransplantation 4 days after initial transplant. In contrast, all venovenous patients were weaned from support, with 7 of 8 surviving greater than 30 days. The 30-day survival for venovenous recipients (88%) approximates that of all lung recipients at our center (94%, p = 0.42). Noted complications for ECMO patients included renal failure (n = 16), neurologic catastrophes (n = 8), sepsis (n = 5), and hemorrhage (n = 10). The venoarterial recipients suffered 30 of 39 total complications. Most of the complications for venovenous recipients involved renal failure, but by hospital discharge these patients demonstrated a mean creatinine of 0.9 mg/dL. For lung recipients with primary graft failure, venovenous membrane oxygenation provides better outcomes, with fewer complications, than venoarterial membrane oxygenation.

Automatic control of a series-parallel mechanical circulatory assist system in severe uni- or biventricular failure.

Conventional peripherally invasive mechanical circulatory assist methods such as intra-aortic balloon pumping are of only limited hemodynamic benefit in cases of severe left ventricular failure. This article deals with the analysis and testing of a new pumping concept (16), that is theoretically capable of providing adequate circulatory and respiratory assistance in cases of severe uni- or biventricular failure. This assist system combines an intra-aortic balloon pump (a series form of left ventricular assistance) and pulsatile venoarterial membrane oxygenator bypass (a parallel mode of assistance). The combined pulsatile assist system is controlled by a digital microprocessor which provides appropriate phasing relative to the R wave of the ECG. This support system requires only cannulation of femoral or other easily exposed vessels. Blood-gas exchange gas diffusion or massive pulmonary embolism or other perfusion defects. This concept has been tested in a series of experiments with canine models of ventricular failure. The results of this study indicate that (1) balloon pumping becomes much more effective when combined with pulsatile veno-arterial bypass in cases of severe ventricular failure with an attendant hypotensive circulatory state, and (2) the automatic control system is effective in optimizing the performance of the combined assist system.