Early prediction of transition to durable mechanical circulatory support in patients undergoing peripheral veno-arterial extracorporeal membrane oxygenation for critical cardiogenic shock.

Peripheral veno-arterial extracorporeal membrane oxygenation (pVA-ECMO) has gained increasing value in the management of patients with critical cardiogenic shock (cCS), allowing time for myocardial recovery. Failure of myocardial recovery has life-altering consequences: transition to durable mechanical circulatory support (dMCS), urgent heart transplantation, or withdrawal of support. Clinical factors controlling myocardial recovery under these circumstances remain largely unknown. Using a retrospective cohort, we developed a model for early prediction of transition to dMCS in patients undergoing pVA-ECMO for cCS. To promote myocardial recovery, our clinical management centered around left ventricular pressure unloading, that is, targeting pulmonary capillary wedge pressures (PCWP) ≤18 mm Hg. We collected demographic data, laboratory findings, inotrope use, and two-dimensional transthoracic echocardiography measurements, all limited to the first 72h of pVA-ECMO (D1-3). Out of 70 patients who were alive after pVA-ECMO, 27 patients underwent implantation of dMCS. There was no significant difference in survival to hospital discharge between patients with or without transition to dMCS. Ejection fractionD1-3 (per 10% increase, OR 0.37 [0.17-0.79]) and amount of inotropic supportD1-3 (OR 4.77 [1.6-14.18]) but neither myocardial wall tension nor PCWP emerged as significant predictors of transition to dMCS. Optimism-corrected c-index (0.90 [0.89-0.90]) revealed an excellent discriminative ability of our model. In summary, our model for early prediction of transition to dMCS in patients with cCS undergoing pVA-ECMO identifies indicators of inotropic state as relevant factors. Absence of markers for myocardial oxygen consumption or left ventricular pressure loading allows us to hypothesize sufficient cardiac unloading in our cohort with PCWP-targeted management.

Predictors for acute and chronic renal failure and survival in patients supported with veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Renal failure is a common occurrence in patients with refractory cardiogenic shock including those supported with veno-arterial extracorporeal membrane oxygenation. Prevalence and outcome of acute and chronic kidney failure in extracorporeal membrane oxygenation patients have not been well documented. In this study, we investigated the occurrence of acute and chronic kidney failure in veno-arterial extracorporeal membrane oxygenation patients as well as predictors for survival. METHODS: This is a single center retrospective clinical study. We included adult patients with refractory cardiogenic shock who were supported by veno-arterial extracorporeal membrane oxygenation between 2008 and 2015. The primary endpoint of the study was acute kidney injury (KDIGO Stage 3) during extracorporeal membrane oxygenation and chronic kidney failure requiring renal replacement therapy, 30 and 90 days after extracorporeal membrane oxygenation. The secondary endpoint was in-hospital survival and 90-day survival. RESULTS: A total of 196 veno-arterial extracorporeal membrane oxygenation patients were investigated. In total, 41.8% (82/196) patients had acute renal failure requiring continuous renal replacement therapy during extracorporeal membrane oxygenation. The 30- and 90-day survival was 55.1% (108/196) and 48.5% (95/196), respectively; 21.3% (23/108) and 11.6% (11/95) patients needed renal replacement therapy after 30 and 90 days, respectively. Predictors for KDIGO Stage 3 renal failure during extracorporeal membrane oxygenation were lactate (p = 0.026) and the number of blood units transfused during extracorporeal membrane oxygenation support (p = 0.000). A predictor for renal replacement therapy after 30 and 90 days was an elevated plasma-free hemoglobin level. The in-hospital survival was 54.6% (107/196). Serum lactate of less than 4.3 mmol/L, lower age, plasma-free hemoglobin of ⩽62 mg/dL, low number of blood units transfused during extracorporeal membrane oxygenation, and the use of an intra-aortic balloon pump were predictors for in-hospital and 90-day survival.

Heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation and the role of a heparin-bonded circuit.

BACKGROUND: In patients supported with extracorporeal membrane oxygenation, and who develop heparin-induced thrombocytopenia, there is no clear evidence to support changing to a non-heparin-coated extracorporeal membrane oxygenation circuit. Our goal was to evaluate clinical outcomes of patients who were continued on heparin-bonded circuits despite diagnosed heparin-induced thrombocytopenia. METHODS: We completed a single-center retrospective study of all patients who underwent extracorporeal membrane oxygenation support from July 2008 to July 2017 and were tested heparin-induced thrombocytopenia positive while on extracorporeal membrane oxygenation support. After diagnosis of heparin-induced thrombocytopenia, mean platelet count (k/µL) was measured on consecutive days for 14 days. RESULTS: Out of 455 patients, 14 (3.1%) had a diagnosis of heparin-induced thrombocytopenia by serotonin release assay and systemic heparin treatment was discontinued in every case. In total, 11 of the heparin-induced thrombocytopenia patients (78.6%) survived to discharge. The overall survival of all 455 extracorporeal membrane oxygenation patients was 54.1%. Platelets counts after discontinuation of systemic heparin in the heparin-induced thrombocytopenia patients increased from a mean of 59.8 k/µL at time of heparin-induced thrombocytopenia diagnosis to a mean of 280.2 k/µL at 14 days after discontinuation of heparin despite continuation of the heparin-bonded circuit. Platelet count increased in heparin-induced thrombocytopenia patients on extracorporeal membrane oxygenation support after discontinuation of systemic heparin even if maintained on the heparin-bonded circuit. CONCLUSION: Discontinuation of systemic heparin but continuation of heparin-coated extracorporeal membrane oxygenation circuits appeared to be an appropriate response for our extracorporeal membrane oxygenation-supported patients who developed heparin-induced thrombocytopenia. Survival in this group was not significantly different to those patients on extracorporeal membrane oxygenation without heparin-induced thrombocytopenia. Larger studies should evaluate the safety of heparin-bonded extracorporeal membrane oxygenation systems in heparin-induced thrombocytopenia patients.

Predicting Survival in Patients Treated With Extracorporeal Membrane Oxygenation After Myocardial Infarction.

OBJECTIVES: Acute myocardial infarction is the most common cause of cardiogenic shock. Although the number of patients with acute myocardial infarction complicated by cardiogenic shock who were treated with venoarterial extracorporeal membrane oxygenation increased during the last decade, detailed data on survival are lacking. We sought to analyze covariates that were independently associated with survival in this patient population and to externally validate the newly developed prEdictioN of Cardiogenic shock OUtcome foR Acute myocardial infarction patients salvaGed by venoarterial Extracorporeal membrane oxygenation (ENCOURAGE) score. DESIGN: Retrospective clinical study. SETTING: A single academic teaching hospital. PATIENTS: Adult patients with acute myocardial infarction complicated by cardiogenic shock who were supported by venoarterial extracorporeal membrane oxygenation from June 2008 to September 2016. INTERVENTIONS: Fourteen individual variables were assessed for their association with the primary endpoint. These variables were prespecified by the study team as being the most likely to affect survival. A receiver operating characteristic analysis was also performed to test the ability of the ENCOURAGE score to predict survival in this patient cohort. MEASUREMENTS AND MAIN RESULTS: The primary endpoint of the study was in-hospital survival. A total of 61 patients were included in the analysis. Thirty-seven (60.7%) could be weaned from venoarterial extracorporeal membrane oxygenation and 36 (59.0%) survived. Survival was significantly higher in patients less than 65 years old (odds ratio, 14.6 [CI, 2.5-84.0]; p = 0.003), whose body mass index was less than 32 kg/m (odds ratio, 5.5 [CI, 1.2-25.4]; p = 0.029) and international normalized ratio was less than 2 (odds ratio, 7.3 [CI, 1.3-40.1]; p = 0.022). In patients where the first lactate drawn was less than 3 mmol/L, the survival was not significantly higher (odds ratio, 4.4 [CI, 0.6-32.6]; p = 0.147). The C-statistic for predicting survival using a modified version of the ENCOURAGE score, which replaced prothrombin activity less than 50% with an international normalized ratio greater than 2, was 0.74 (95% CI, 0.61-0.87). CONCLUSIONS: In this single-center study, several important covariates were associated with improved survival in patients with acute myocardial infarction complicated by cardiogenic shock who were supported by venoarterial extracorporeal membrane oxygenation and the ENCOURAGE score was found to be externally valid for predicting survival to hospital discharge.

Evaluation and Comparison of Hemodynamic Performance of Three ECLS Systems in a Simulated Adult Cardiogenic Shock Model.

The objective of this study was to evaluate three commercially available ECLS systems with rotary pumps in terms of circuit pressure, pressure drop, perfusion modes, and hemodynamic energy transmission in a simulated adult cardiogenic shock model. One circuit consisted of a Cardiohelp system, which included a Cardiohelp console and HLS Module Advanced 7.0 tubing set with integrated centrifugal pump and oxygenator. The alternative circuit was composed of a Quadrox-D Adult oxygenator connected in series with either an i-cor diagonal pump and console or a Rotaflow centrifugal pump and console. The circuit was primed with lactated Ringer's solution and packed red blood cells (hematocrit 40%). The trials were conducted at flow rates of 1-5 L/min with pseudo patient pressures of 60 mm Hg and 80 mm Hg. Pulsatile flow was tested when using the i-cor system. Mean pre-oxygenator pressure and pressure drop across ECLS circuit (including oxygenator and arterial tubing) were lower when using the Cardiohelp system as compared to the Rotaflow and i-cor systems (P < 0.01). The i-cor system was able to deliver more hemodynamic energy to the pseudo patient because of its ability to produce pulsatile flow (P < 0.01). The Cardiohelp HLS Module Advanced 7.0 integrated oxygenator had a lower resistance than the Quadrox-D oxygenator. Although the compact Cardiohelp system had a better hemodynamic performance when compared to Rotaflow and i-cor systems, the pulsatile flow of the i-cor system delivered more hemodynamic energy to the pseudo patient. This may render more physiological benefits in high-risk patients on ECLS.

In Vitro Hemodynamic Evaluation of an Adult Pulsatile Extracorporeal Membrane Oxygenation System.

The objective of this study was to evaluate a pulsatile extracorporeal membrane oxygenation (ECMO) system in terms of hemodynamic energy generation and transmission under various pulsatile amplitudes, flow rates, and pseudopatient pressures in a simulated adult ECMO circuit. Surplus hemodynamic energy (SHE), a measure of the quality of pulsatility, was used to quantify pulsatile flow. The circuit consisted of an i-cor diagonal pump, an adult XLung oxygenator, a 21 Fr Medtronic Biomedicus femoral arterial cannula, a 23/25 Fr Sorin RAP femoral venous cannula, and 3/8 in ID tubing for both arterial and venous lines. The circuit was primed with lactated Ringer's solution and then packed red blood cells (hematocrit 37%). Trials were conducted at 36°C with flow rates of 2-5 L/min (1 L/min increments) under nonpulsatile and pulsatile mode with pulsatile amplitudes of 1000-5000 rpm (1000 rpm increments). The pseudopatient pressure was maintained at 40-100 mm Hg (20 mm Hg increments). Real-time pressure and flow data were recorded for analysis using a custom-made data acquisition system. There was no SHE generated by the pump under nonpulsatile mode. Under pulsatile mode, SHE levels increased with increasing pulsatile amplitude and pseudopatient pressure (P < 0.01) but decreased with increasing flow rate. SHE levels were significantly higher at flow rates of 2-4 L/min. In addition, the XLung oxygenator had acceptable pressure drops (36.1-104.9 mm Hg) and percentages of total hemodynamic energy loss (19.6-43.9%) during all trials. The novel pulsatile ECMO system can create nonpulsatile and pulsatile flow in an adult ECMO model. However, pulsatility gradually weakened with increasing flow rates. Pulsatile amplitude settings were found to have a great impact on pulsatility.

Is pulseless electrical activity a reason to refuse cardiopulmonary resuscitation with ECMO support?

BACKGROUND: Cardiopulmonary resuscitation with ECMO support (ECPR) has shown to improve outcome in patients after cardiac arrest under resuscitation. Most current recommendations for ECPR do not include patients with a non-shockable rhythm such as PEA and asystole. AIM: The aim of this study was to investigate the outcome of 3 patient groups separated by initial rhythm at time of ECMO placement during CPR: asystole, PEA and shockable rhythm. METHODS: We made a retrospective single-center study of adults who underwent ECPR for in-hospital cardiac arrest between June 2008 and January 2017. Outcome and survival were identified in 3 groups of patients regarding to the heart rhythm at the time decision for ECMO support was made: 1. patients with asystole, 2. patients with pulseless electrical activity, 3. patients with a shockable rhythm. RESULT: 63 patients underwent ECPR in the mentioned time frame. Five patients were excluded due to incomplete data. Under the 58 included patients the number of cases for asystole, PEA, shockable rhythm was 7, 21 and 30 respectively. The means of CPR-time in these groups were 37, 41 and 37min. Survival to discharge was 0.0%, 23.8% and 40.0% respectively (p=0.09). All survivors to discharge had a good neurological outcome, defined as cerebral performance category 1or 2. CONCLUSION: Survival to discharge in patients with PEA as initial rhythm at the time of decision for ECPR is 23.8% while no patients with asystole as initial rhythm survived discharge. Patients with PEA should be carefully considered for ECPR.

Percutaneous Endoscopic Gastrostomy Tube in a Syncardia™ Total Artificial Heart.

As a bridge to transplant, the Syncardia™ total artificial heart (TAH) is an option for patients who are not candidates for left ventricular assist devices (LVAD) due to right ventricular failure. The need for nutritional support in these patients is essential for a favorable outcome. Low body mass indexes and albumin levels have been associated with increased morbidity and mortality in cardiac surgery patients [Alverdy 2003]. It is not uncommon for postoperative patients to have difficulty in consuming enough calories after surgery, which is further complicated by a hypermetabolic demand due to surgical stress. Enteral nutrition has typically been favored for gut mucosal integrity and bacterial flora [Alverdy 2003] [Engleman 1999]. We describe the need for prolonged enteral nutritional support in a TAH patient that was accomplished with a percutaneous endoscopic gastrostomy (PEG) tube.

The role of extracorporeal membrane oxygenation circulatory support in the 'crash and burn' patient: from implantation to weaning.

PURPOSE OF REVIEW: In advanced cardiogenic shock, early mechanical circulatory support may prevent multiorgan failure and death. In this article, we are describing our experience with extracorporeal membrane oxygenation (ECMO) application. RECENT FINDINGS: Venoarterial ECMO has been used successfully as a therapeutic option for patients with advanced cardiogenic shock and cardiac arrest. SUMMARY: In this review, based on the daily routine of the Hershey group using ECMO for therapy of advanced cardiogenic shock, the application of ECMO is described. The aim is to share our hands-on experience during emergent implantation and to contribute to the knowledge within the field of mechanical circulatory support.

Arterial complications in patients undergoing extracorporeal membrane oxygenation via femoral cannulation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) provides continuous cardiopulmonary support on a long-term basis. It has been speculated that patients undergoing ECMO via femoral arterial cannulation are more likely to develop peripheral vascular complications. The purpose of this study was to evaluate the incidence of peripheral vascular complications in this group of patients and outline the modalities used for treatment. METHODS: Data were collected for all patients who had femoral artery cannulation for ECMO therapy from June 2008 to October 2011. Primary outcome was any vascular complication. Secondary outcomes were 30-day mortality and amputation. Operative reports were reviewed to analyze the surgical procedures implied for treating vascular complications. RESULTS: One hundred one patients underwent ECMO therapy during the period of study; 63.4% were male with an average age of 47.7 years. Mean length of hospital stay was 19.8 days and average length of time on the ECMO device was 7.33 days. Indications for ECMO included cardiogenic shock in 61 patients (60.4%), pulmonary failure in 37 (36.6%), and combined cardiac and pulmonary failure in 3 (3%). Overall mortality comprised 42 patients (42%). Risk factors for peripheral arterial disease included hypertension (32%), diabetes mellitus (21.8%), hyperlipidemia (21.7%), and smoking (19.8%). Eighteen patients (17.8%) developed peripheral vascular complications (confidence interval 10‒25%). Among the patients who developed vascular complications, 78% were male and average length of time on the device was 7.16 days. Indications for ECMO were cardiac failure in 13 (72%) and pulmonary failure in 5 (28%). Two (11%) were managed nonoperatively and 16 (89%) needed surgical intervention, 8 (44.44%) of whom required femoral endarterectomy with patch angioplasty. One patient required below-knee amputation. None required distal bypass. Mortality among patients with vascular complications was 28% (P = 0.30). Indications for use of ECMO in these patients included cardiogenic shock in 13 (72%) and pulmonary failure in 5 (28%). The mortality rate was 58% among diabetic patients and 34% in nondiabetic patients (P = 0.007). CONCLUSIONS: Vascular complications occur in less then 20% of ECMO patients with the majority requiring femoral reconstruction. Development of vascular complications does not appear to increase risk of amputation or mortality. Among those patients who develop vascular complications, the most common indication for ECMO is cardiogenic shock.

Predictors of Survival for Nonhighly Selected Patients Undergoing Resuscitation With Extracorporeal Membrane Oxygenation After Cardiac Arrest.

In several case reports and case series, extracorporeal membrane oxygenation during chest compression (CPR) has been shown to be a reasonable tool to improve outcome of patients under resuscitation. Although recommendations for extracorporeal cardiopulmonary resuscitation (ECPR) include younger patients with shockable rhythm and short previous CPR-time, it remains unclear if nonhighly selected patients have a similar outcome. Aim of this study was to determine outcome in our nonhighly selected patient population treated with ECPR and investigate possible predictors of survival. We made a retrospective single-center study of adults who underwent ECPR for in-hospital cardiac arrest between June 2008 and September 2016. Outcome and predictors of survival were identified. In this period of time, 59 patients underwent ECPR due to cardiac arrest. Fifteen patients (25.4%) survived discharge of which all had a good neurological outcome (cerebral performance category ≤ 2). Survival to discharge of patients with shockable rhythm (ventricular fibrillation or ventricular tachycardia) was 40.7%. Serum lactate ≥ 8, pulseless electrical activity (PEA) or asystole and male gender could be identified as predictors for low survival rate. Age, body mass index, renal replacement-dependent kidney injury had no significant influence on survival outcome. Mean CPR-time was 41.1 minutes (interquartile range, ±29.25 minutes). Extracorporeal membrane oxygenation seems to be a useful tool to improve the outcome of CPR also in nonhighly selected patients when compared with CPR alone and could be considered in patients with refractory cardiac arrest also after longer previous CPR-time. Serum lactate and heart rhythm should be taken into account for patient selection.