Patients Undergoing Extracorporeal Membrane Oxygenation Support Research Articles

Evaluation of an aPTT guided versus a multimodal heparin monitoring approach in patients on extra corporeal membrane oxygenation: A retrospective cohort study.

Bleeding and thrombotic complications are common in extracorporeal membrane oxygenation (ECMO) patients and are associated with increased mortality and morbidity. The optimal anticoagulation monitoring protocol in these patients is unknown. This study aims to compare the incidence of thrombotic and hemorrhagic complications before and after a protocol change. In addition, the association between hemostatic complications, coagulation tests and risk factors is evaluated. This is a retrospective single center cohort study of adult ECMO patients. We collected demographics, ECMO parameters and coagulation test results. Outcomes of the aPTT guided and multimodal protocol, including aPTT, anti-Xa assay and rotational thromboelastometry were compared and the association between coagulation tests, risk factors and hemostatic complications was determined using a logistic regression analysis for repeated measurements. In total, 250 patients were included, 138 in the aPTT protocol and 112 in the multimodal protocol. The incidence of thrombosis (aPTT: 14%; multimodal: 12%) and bleeding (aPTT: 36%; multimodal: 40%), did not significantly differ between protocols. In the aPTT guided protocol, the aPTT was associated with thrombosis (Odds Ratio [OR] 1.015; 95% confidence interval [CI] 1.004-1.027). In both protocols, surgical interventions were risk factors for bleeding and thrombotic complications (aPTT: OR 93.2, CI 39.9-217.6; multimodal OR 17.5, CI 6.5-46.9). The incidence of hemostatic complications was similar between both protocols and surgical interventions were a risk factor for hemostatic complications. Results from this study help to elucidate the role of coagulation tests and risk factors in predicting hemostatic complications in patients undergoing ECMO support.

Anticoagulation Management in V-V ECMO Patients: A Multidisciplinary Pragmatic Protocol

(1) Background: Extracorporeal membrane oxygenation (ECMO) is a complex procedure affecting both the risk of thrombosis and bleeding. High-quality data to personalize anticoagulation management in ECMO are lacking, resulting in a high variability in practice among centers. For this reason, we review coagulation methods and monitoring and share a pragmatic proposal of coagulation management, as performed in our high-volume ECMO Referral Centre; (2) Methods: We revised the anticoagulation options and monitoring methods available for coagulation management in ECMO through PubMed search based on words including “anticoagulation,” “coagulation assays,” “ECMO,” “ELSO,” and “ISTH”; (3) Results: Actual revision of the literature was described as our routine practice regarding ECMO anticoagulation and monitoring; (4) Conclusions: No coagulation test is exclusively predictive of bleeding or thrombotic risk in patients undergoing ECMO support. An approach that allows for a tailored regimen of anticoagulation (regardless of agent used) and monitoring is mandatory. To accomplish this, we propose that the titration of anticoagulation therapies should include multiple laboratory tests, including anti-Xa, aPTT, ACT, viscoelastic tests, AT levels, platelet count, fibrinogen, and FXIII levels. Anticoagulation regimens should be tailored to a specific patient and personalized based on this complex array of essays.

Physiotherapy for patients on extracorporeal membrane oxygenation support: How, When, and Who. An international EuroELSO survey.

Extracorporeal membrane oxygenation (ECMO) continues to play an essential role in organ support in cardiogenic shock or acute respiratory distress syndrome and bridging to transplantation. The main purpose of the present survey was to define which clinical and organizational practices are adopted for the administration of physiotherapy in adult patients undergoing ECMO support worldwide. This international survey was conceived in November 2021. The survey launch was announced at the 10th EuroELSO (European ELSO chapter) Congress, London, May 2022. The survey returned 32 questionnaires from 29 centers across 14 countries. 17 centers (53.1%) had more than 30 intensive care unit beds available and most (46.8%) were able to care for five to 10 patients on extracorporeal life support simultaneously. The predominant physiotherapist-to-patient ratio was 1:>5 (37.5%); physiotherapy was available 5/7 days and 7/7 days by 31.2% and 25% respectively. Respiratory physiotherapy was not defined by a specific protocol in most centers (46.8%) while 31.2% declared that the treatment commences less than 12 h after sedation is stopped/reduced. Mostly, early physiotherapy in non-cooperative ventilated patients was provided within the first 48 h (68.6%) and consisted of as passive range of motion, in-bed positioning, and splinting. Postural passages and sitting were provided to patients and walking was included in those advanced motor activities which are part of the treatment. Physiotherapy in patients on ECLS is feasible, however substantial variability exists between centers with a trend of delivering not protocolized and understaffed rehabilitation practices.

Causes and Management of Extracorporeal Membrane Oxygenation Circuit Failure

<h3>Purpose</h3> Extracorporeal membrane oxygenation (ECMO) circuit failure is a well known complication of ECMO support. Little is documented in the literature. <h3>Methods</h3> Retrospective review of all patients underwent ECMO support and experienced circuit failure events in our two institutions between Jan 2012 and Dec 2018. <h3>Results</h3> Seven hundred forty-six patients were supported by ECMO, among these 400 venovenous ECMO (VV-ECMO), 289 patients treated with venoarterial ECMO (VA-ECMO) and 57 with VA-ECMO for ECPR. The mean support time was 161.9±2.13hours (ranged from 5 -1493 hours). Overall, 539 (72.3%) patients were separated of ECMO, among these 434 (58.2%) patients were discharged from the hospital. Eighty (10.7%) circuits needed total or partial circuit change, the total circuit was changes in 46 patients, among these 34 cases due to clotting, 5 circuits were changed due to circuit compatibility of patients transferred of outside hospital. Four circuits were changed due to large air in the circuit not amenable to simple suctioning maneuvers, 2 due to circuit tube fracture and one had mechanical pump failure. Major clotting needed total or partial circuit change occurred in 68 circuits, amongst these circuit was changed in 34 patients, Oxygenator only was changed in 30 circuits. the bladder only was changed in 4 circuits due to clotting. 46 (67.4%) major clotting needed circuit change occurred after 2 weeks of support, 17 occurred during the second week, and only 5 occurred in the first week. Air in the circuit was encountered in 13 cases, majority (9 cases) was amenable to simple suctioning maneuvers. <h3>Conclusion</h3> ECMO circuit failure occurs frequently. Major clotting needing partial or total circuit change are the most common complications, followed by air in the circuit, followed by circuit incompatibility in transferred patients. While majority of circuit clotting occur after 2 weeks, it rarely occurs in the first week.

Extracorporeal membrane oxygenation and rehabilitation in patients with COVID-19: A scoping review.

Background and purposeThe coronavirus diseases 2019 (COVID‐19) pandemic posed severe difficulties in managing critically ill patients in hospital care settings. Extracorporeal membrane oxygenation (ECMO) support has been proven to be lifesaving support during the SARS‐CoV‐2 outbreak. The purpose of this review was to describe the rehabilitative treatments provided to patients undergoing ECMO support during the COVID‐19 pandemic.MethodsWe searched PubMed and Scopus for English‐language studies published from the databases’ inception until June 30, 2021. We excluded editorials, letters to the editor, and studies that did not describe rehabilitative procedures during ECMO support. We also excluded those articles not written in English.ResultsA total of 50 articles were identified. We ultimately included nine studies, seven of which were case reports. Only two studies had more than one patient; an observational design analyzing the clinical course of 19 patients and a case series of three patients. Extracorporeal support duration varied from 9 to 49 days, and the primary indication was acute respiratory distress syndrome COVID‐19‐related. Rehabilitative treatment mainly consisted of in‐bed mobilization, postural transfers (including sitting), and respiratory exercises. After hospital discharge, patients were referred to rehabilitation facilities. Physiotherapeutic interventions provided during ECMO support and after its discontinuation were feasible and safe.ConclusionThe physiotherapeutic treatment of patients undergoing ECMO support includes several components and must be provided in a multidisciplinary context. The optimal approach depends on the patient’s status, including sedation, level of consciousness, ECMO configuration, types of cannulas, and cannulation site.

Persistent Right Ventricle Dilatation in SARS-CoV-2–Related Acute Respiratory Distress Syndrome on Extracorporeal Membrane Oxygenation Support

ObjectivesVenovenous extracorporeal membrane oxygenation (ECMO) support may be considered in experienced centers for patients with acute respiratory distress syndrome (ARDS) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection refractory to conventional treatment. In ECMO patients, echocardiography has emerged as a clinical tool for implantation and clinical management; but to date, little data are available on COVID-related ARDS patients requiring ECMO. The authors assessed the incidence of right ventricular dilatation and dysfunction (RvDys) in patients with COVID-related ARDS requiring ECMO.DesignSingle-center investigation.SettingIntensive care unit (ICU).ParticipantsA total of 35 patients with COVID-related ARDS requiring ECMO, consecutively admitted to the ICU (March 1, 2020, to February 28, 2021).InterventionsSerial echocardiographic examinations. RvDys was defined as RV end-diastolic area/LV end-diastolic area >0.6 and tricuspid annular plane excursion <15 mm.Measurements and Main ResultsThe incidence of RvDys was 15/35 (42%). RvDys patients underwent ECMO support after a longer period of mechanical ventilation (p = 0.006) and exhibited a higher mortality rate (p = 0.024) than those without RvDys. In nonsurvivors, RvDys was observed in all patients (n = nine) who died with unfavorable progression of COVID-related ARDS. In survivors, weaned from ECMO, a significant reduction in systolic pulmonary arterial pressures was detectable.ConclusionsAccording to the authors’ data, in COVID-related ARDS requiring ECMO support, RvDys is common, associated with increased ICU mortality. Overall, the data underscored the clinical role of echocardiography in COVID-related ARDS supported by venovenous ECMO, because serial echocardiographic assessments (especially focused on RV changes) are able to reflect pulmonary COVID disease severity.

Renal replacement therapy in patients on extracorporeal membrane oxygenation support: Who and how.

Patients undergoing extracorporeal membrane oxygenation (ECMO) support frequently develop renal failure requiring renal replacement therapy (RRT). RRT may be performed via a dialysis catheter based approach or via the ECMO circuit. We describe our experience with both techniques. A total of 68 patients undergoing ECMO support at our institution were retrospectively analyzed. Predictors of renal failure requiring RRT were determined. Patients undergoing RRT via a dialysis catheter were compared with those undergoing RRT via the ECMO circuit. 10 of the 68 patients required RRT support prior to ECMO. Of the remaining 58 patients, 25 (43%) required new RRT support on ECMO. Lower albumin levels and postcardiotomy shock were predictive of new renal failure requiring RRT on ECMO. RRT performed via the ECMO circuit demonstrated similar efficacy as via a dialysis catheter. Outcomes were much worse for patients requiring new RRT on ECMO support, with a doubling of the length of ECMO support and less that one-third the survival rate of patients not requiring RRT on ECMO support. New renal failure requiring RRT occurs in nearly one-half of patients on ECMO support, with poor outcomes. RRT may be performed via the ECMO circuit with similar efficacy as via a dialysis catheter.

Platelet Function During Extracorporeal Membrane Oxygenation in Adult Patients.

Objective: Hemorrhagic and thromboembolic complications are common during support with extracorporeal membrane oxygenation (ECMO). As platelets play a pivotal role in hemostasis, we aimed to clarify how ECMO support affects platelet function.Methods: We included 33 adult patients undergoing ECMO support at a tertiary ECMO referral center at Aarhus University Hospital, Denmark. Blood samples were collected on the first morning following ECMO initiation, and subsequently every morning until the 7th (±1) day. Platelet aggregation was evaluated by whole blood impedance aggregometry (Multiplate® Analyzer) using adenosine diphosphate (ADPtest), arachidonic acid (ASPItest), and thrombin-receptor-agonist-peptide-6 (TRAPtest) as agonists. A new model was applied, taking platelet count into consideration in interpretation of impedance aggregometry analyses. On the 1st and 3rd day, platelet activation was assessed by flow cytometry (Navios) using collagen-related peptide, ADP, TRAP, and arachidonic acid as agonists.Results: Blood samples from all 33 patients were analyzed on day 1 of ECMO support; 24 patients were still receiving ECMO and analyzed on day 3; 12 patients were analyzed on day 7 (±1). After ECMO initiation, platelet counts decreased significantly (p < 0.002) and remained low during ECMO support. ECMO patients demonstrated significantly reduced platelet aggregation on day 1 compared with healthy controls (all p < 0.001). However, when taking platelet count into consideration, platelet aggregation relative to platelet count did not differ from healthy controls. Flow cytometry analyses demonstrated impaired platelet activation in ECMO patients on day 1 compared with healthy controls (all p < 0.03). No substantial difference was found in platelet activation from day 1 to day 3 on ECMO support.Conclusions: Employing impedance aggregometry and flow cytometry, we found both impaired platelet aggregation and decreased platelet activation on day 1 of ECMO support compared with healthy controls. However, platelet aggregation was not impaired, when interpreted relative to the low platelet counts. Furthermore, levels of bound fibrinogen, on the surface of activated platelets in ECMO patients, were higher than in healthy controls. Together, these findings suggestively oppose that platelets are universally impaired during ECMO support. No marked difference in activation from day 1 to day 3 was seen during ECMO support.

The technique of intraoperative axillary artery cannulation for extracorporeal membrane oxygenation in lung transplantation.

To show our experiences of using the axillary artery with a side graft as a cannulation technique for the inflow of veno-arterial extracorporeal membrane oxygenation (ECMO) in lung transplantation (LTx). This method can avoid complications associated with central and femoral vessel cannulation techniques, and be convenient for the use of intraoperative ECMO into the early postoperative period. Between November 2016 and July 2017, we established intraoperative V/A-ECMO in 32 patients. Among these patients, 5 patients were performed on via axillary artery-percutaneous femoral vein cannulation (15.6%), 2 patients were performed on with veno-venous ECMO (V/V-ECMO) as a bridge to transplantation with hemodynamic instability during transplantation, and additional axillary artery cannulations were performed to establish veno-veno-arterial (V/V/A) ECMO. Mean age was 45.2±10.1 years (range, 26-71 years). In 7 patients undergoing ECMO support during operation, the ECMO was removed in 4 patients immediately after the procedure, 3 patients with "prolonged ECMO" were transferred to the ICU. There were no ECMO-related complications and no patients died. Our protocol for V/A-ECMO cannulation that uses the axillary artery for arterial cannulation provides a safe and improved means for delivering V/A-ECMO support during LTx. Also, it is helpful for prolonging the intraoperative ECMO in the early postoperative period.

Evaluation of Calcium Homeostasis and Dietary Supplementation for Pediatric and Neonatal Patients Receiving Extracorporeal Membrane Oxygenation Support.

Although the use of extracorporeal membrane oxygenation (ECMO) significantly improves survival in patients with persistent respiratory or cardiovascular failure, it also induces physiologic stress and disrupts homeostatic mechanisms. Patients undergoing ECMO support at our institution have required widely variable quantities of calcium supplementation for maintenance of normal calcium levels. Our primary objective was to assess the frequency of calcium abnormalities in pediatric and neonatal ECMO patients. Secondary objectives included quantifying electrolyte supplementation provided during ECMO and determining the relationships between calcium abnormalities and ECMO duration, mortality, and intensive care and hospital length of stay. We performed a single-center retrospective chart review of all patients less than 18 years of age who received ECMO support between July 1, 2013, and May 31, 2016. Clinical and laboratory data were reviewed for each patient for the duration of ECMO support, and the incidence of ionized calcium outside the reference range of 1.1 to 1.4 mmol/L beyond the first 24 hours of ECMO was recorded. Seventy-eight patients were included in the study: 51 patients (65%) experienced at least one reading outside the normal ionized calcium range, while 27 patients (35%) were normocalcemic during their ECMO course. There were no differences between groups in the quantities of calcium, phosphate, or vitamin D administered during ECMO. Abnormal calcium levels were associated with a longer duration of ECMO (median 9 days vs 6 days, p = 0.0054), prolonged ICU length of stay (median 33 vs 18 days, p = 0.0055), and prolonged hospital length of stay (median 52 vs 40 days, p = 0.0239). No significant differences were found in survival to decannulation or survival to hospital discharge. Calcium abnormalities occur frequently in pediatric and neonatal patients during ECMO and are associated with worse patient outcomes. The underlying physiology of these changes is thought to be related to ECMO-induced disruption of normal calcium homeostasis.

Effect of increasing mean arterial blood pressure on microcirculation in patients with cardiogenic shock supported by extracorporeal membrane oxygenation.

Little is known about the effect of mean arterial blood pressure (MAP) augmentation on the microcirculation in cardiogenic-shock patients with peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) support. We investigated the effect of increasing MAP on the microcirculation in cardiogenic-shock patients with ECMO support. A single-center prospective observational study under taken in ICU patients undergoing ECMO support for post-cardiotomy cardiogenic shock was carried out. Patients with MAP <60 mmHg treated with ECMO support were the study cohort. Inotropic and vasopressor agents (dopamine, dobutamine, norepinephrine or epinephrine) were administered to maintain the MAP at 60-90 mmHg. Hemodynamic and microcirculatory data were obtained at a baseline MAP of <60 mmHg and 1 h after target MAP was reached. As parameters of microcirculation, we measured thenar eminence tissue oxygenation (StO2) and its change during the vessel obstruction test and cerebral tissue oxygenation (rSO2) with near-infrared spectroscopy. Seventeen patients were enrolled in the study. MAP of all patients increased and reached predefined therapeutic targets (52 [50-54.5] vs.74 [70-78.5] mmHg; p < 0.001). To obtain these targets, doses of inotropic agents were increased (inotrope score increased from 14 [15.5-28] μg/kg/min; p < 0.001). No obvious changes were observed in thenarmuscleStO2 and cerebral rSO2. Thenar muscle StO2 desaturation slope and resaturation slopes during the vessel obstruction test were also unchanged. Increasing MAP from <60 mmHg to 60-90 mmHg did not affect microcirculation variables in cardiogenic-shock patients with ECMO support.

Agreement between ACT and aPTT during extracorporeal membrane oxygenation shows intra- and inter-individual variation.

We explored the relationship between activated clotting time (ACT) and activated partial thromboplastin time (aPTT) when used to monitor anticoagulation in patients undergoing extracorporeal membrane oxygenation (ECMO) support. Data obtained in patients undergoing ECMO support between October 2012 and August 2013 in a single centre were reviewed. Clinical data were extracted from our Clinical Information System and ECMO database. ACT and aPTT values were paired when taken from the same patient, with the ACT preceding the aPTT and the heparin infusion rate was kept constant between samples. The aPTT and ACT were normalized by dividing by the mean of their respective reference ranges and are referred to as APR and N-ACT, respectively. Bivariate analysis and Bland-Altman plots were used to assess correlation and agreement. Mixed effects regression was used to model the effects of variables, including platelet count, creatinine and urea levels, plasma free haemoglobin, white cell count and ECMO flow rate on concordance between APR and N-ACT measurements. The Pearson product-moment correlation coefficient in 15 patients was calculated as r=0.55. The Bland-Altman plot shows a mean difference between the APR and the N-ACT of -0.08. The 95% limits of agreement were -0.67 to 0.51. Results from mixed effects regression analysis on data from the 15 patients identified platelet count (and thrombocytopenia) and urea as significant independent predictors of concordance between APR and N-ACT. We report a moderate degree of positive correlation between APR and N-ACT. We conclude that there is poor agreement between the ACT and aPTT for the heparin concentrations in patients supported with ECMO. Our results indicate that platelet count and urea are significant independent variables affecting concordance between ACT and aPTT measurements.

Beneficial effects of levosimendan on survival in patients undergoing extracorporeal membrane oxygenation after cardiovascular surgery

BackgroundThe impact of levosimendan treatment on clinical outcome in patients undergoing extracorporeal membrane oxygenation (ECMO) support after cardiovascular surgery is unknown. We hypothesized that the beneficial effects of levosimendan might improve survival when adequate end-organ perfusion is ensured by concomitant ECMO therapy. We therefore studied the impact of levosimendan treatment on survival and failure of ECMO weaning in patients after cardiovascular surgery. MethodsWe enrolled a total of 240 patients undergoing veno-arterial ECMO therapy after cardiovascular surgery at a university-affiliated tertiary care centre into our observational single-centre registry. ResultsDuring a median follow-up period of 37 months (interquartile range 19–67 months), 65% of patients died. Seventy-five per cent of patients received levosimendan treatment within the first 24 h after initiation of ECMO therapy. Cox regression analysis showed an association between levosimendan treatment and successful ECMO weaning [adjusted hazard ratio (HR) 0.41; 95% confience interval (CI) 0.22–0.80; P=0.008], 30 day mortality (adjusted HR 0.52; 95% CI 0.30–0.89; P=0.016), and long-term mortality (adjusted HR 0.64; 95% CI 0.42–0.98; P=0.04). ConclusionsThese data suggest an association between levosimendan treatment and improved short- and long-term survival in patients undergoing ECMO support after cardiovascular surgery.

ECMO: Incidence and Outcomes of Patients Undergoing the Hybrid Procedure.

To document the extracorporeal membrane oxygenation (ECMO) incidence and outcome in patients undergoing the hybrid procedure at an institution that routinely performs this procedure. A retrospective chart review on all patients with single ventricle physiology that underwent the hybrid procedure between 7/2002 and 12/2014. Patients were excluded if they underwent the hybrid procedure after 60 days of birth or subsequently underwent a biventricular repair. A single center, tertiary pediatric hospital. One hundred eighty-one patients with single ventricle physiology that underwent the hybrid procedure between 7/2002 and 12/2014. None. We studied a total of 181 patients (105 males: 76 females). Gestational age was 37.8 ± 2.0 weeks and birth weight was 3.0 ± 0.7 kg. Underlying diagnosis was hypoplastic left heart syndrome in 149 patients and other in 32 patients. Age at surgery was 7.8 ± 6.8 days and weight at surgery was 3.1 ± 0.6 kg. Two patients underwent ECMO support after the hybrid procedure. One patient had aortic atresia/mitral atresia and weighed 2.3 kg and the other patient had aortic atresia/mitral stenosis and weighed 2.1 kg at time of surgery. Both patients died. Incidence of ECMO support after hybrid procedure was 1.3% (2/149) for the hypoplastic left heart syndrome patients and 1.1% (2/181) for the entire cohort. Mortality in patients who underwent ECMO after the hybrid procedure was higher than reported for the Norwood procedure, however, the incidence of ECMO after hybrid procedure was also significantly lower than reported for the Norwood procedure. Future studies are needed to determine how to improve outcomes in this complex patient population.

Extracorporeal membrane oxygenation induces short-term loss of high-molecular-weight von Willebrand factor multimers.

High-molecular-weight (HMW) von Willebrand factor (vWF) multimers are crucial for primary hemostasis. Increased shear stress from ventricular assist devices can provoke premature degradation of HMW vWF multimers. Whether similar loss of vWF multimers occurs during extracorporeal membrane oxygenation (ECMO) is not clear. We conducted a prospective observational study in a clinical cohort of patients who required ECMO for intractable cardiac and/or respiratory failure. The primary end point was the quantity and quality of HMW vWF multimer bands before, during, and after ECMO support. To investigate further changes in primary hemostasis, we also measured vWF antigen activity (vWF:Ag), vWF ristocetin cofactor activity (vWF:RCo), and factor VIII in 38 patients who required ECMO support before initiation of ECMO (baseline), after 24 and 48 hours on ECMO, and 24 hours after termination of ECMO therapy. Compared with baseline, vWF:Ag and vWF:RCo decreased after 24 hours of ECMO (mean ± SD, vWF:Ag, 307% ± 152% to 261% ± 138%, P = 0.002; vWF:RCo 282% ± 145% to 157% ± 103%, P < 0.0001) and remained lower during ongoing support (vWF:Ag 265% ± 128%, P = 0.025; vWF:RCo 163% ± 94%, P < 0.0001). After termination of ECMO, vWF:Ag was greater than baseline (359% ± 131%, P = 0.004) and vWF:RCo was similar to baseline levels (338% ± 142%, P = 0.046). Compared with baseline, the calculated vWF:RCo/vWF:Ag ratio decreased after 24 hours on support (0.96 ± 0.23 to 0.61 ± 0.17, P ≤ 0.0001) and remained lower during 48 hours on ECMO (0.63 ± 0.18, P ≤ 0.0001). After termination of ECMO support (0.94 ± 0.19, P = 0.437), values rapidly returned to baseline. The number of HMW vWF multimers (n) decreased from baseline after 24 hours on ECMO (21 ± 1.4 to 14 ± 1.8, P ≤ 0.0001) and after 48 hours on ECMO (15 ± 2.1, P ≤ 0.0001). Twenty-four hours after termination of ECMO support, HMW vWF multimeric pattern had returned to baseline values (21 ± 1.8, P = 0.551). Loss of HMW vWF multimer bands occurred in patients undergoing ECMO support and resolved after the termination of ECMO. Although not detectable with coagulation screening tests, a vWF:RCo/vWF:Ag ratio <0.7 during ECMO was highly indicative for loss of HMW vWF multimers. Our findings may at least in part explain increased bleeding tendency during ECMO therapy. Administration of vWF concentrates may support restoration of primary hemostasis in patients with relevant bleeding during ECMO support.

Serum butyrylcholinesterase predicts survival after extracorporeal membrane oxygenation after cardiovascular surgery

IntroductionRisk stratification in patients undergoing extracorporeal membrane oxygenation (ECMO) support after cardiovascular surgery remains challenging, because data on specific outcome predictors are limited. Serum butyrylcholinesterase demonstrated a strong inverse association with all-cause and cardiovascular mortality in non-critically ill patients. We therefore evaluated the predictive value of preoperative serum butyrylcholinesterase levels in patients undergoing venoarterial ECMO support after cardiovascular surgery.MethodsWe prospectively included 191 patients undergoing venoarterial ECMO therapy after cardiovascular surgery at a university-affiliated tertiary care center in our registry.ResultsAll-cause and cardiovascular mortality were defined as primary study end points. During a median follow-up time of 51 months (IQR, 34 to 71) corresponding to 4,197 overall months of follow-up, 65% of patients died. Cox proportional hazard regression analysis revealed a significant and independent inverse association between higher butyrylcholinesterase levels and all-cause mortality with an adjusted hazard ratio (HR) of 0.44 (95% CI, 0.25 to 0.78; P = 0.005), as well as cardiovascular mortality, with an adjusted HR of 0.38 (95% CI, 0.21 to 0.70; P = 0.002), comparing the third with the first tertile. Survival rates were higher in patients within the third tertile of butyrylcholinesterase compared with patients within the first tertile at 30 days (68% versus 44%) as well as at 6 years (47% versus 21%).ConclusionsThe current study revealed serum butyrylcholinesterase as a strong and independent inverse predictor of all-cause and cardiovascular mortality in patients undergoing venoarterial ECMO therapy after cardiovascular surgery. These findings advance the limited knowledge on risk stratification in patients undergoing ECMO support and represent a valuable addition for a comprehensive decision making before ECMO implantation.

Plasma Fatty Acid Levels in Children during Extracorporeal Membrane Oxygenation Support—A Pilot Study

Plasma fatty acids levels are markedly elevated in patients with myocardial ischemic–reperfusion injury including those after cardiopulmonary bypass (CPB). High levels of fatty acids have detrimental effects on myocardial function. Extracorporeal membrane oxygenation (ECMO) is like CPB, but much longer, to provide a life-saving support for patients with cardiac arrest. We measured plasma fatty acid levels in children during ECMO support. Five children (aged .3–36 months, median 20 months) receiving venoarterial ECMO support after cardiac arrest in 2010 and 2011 were enrolled. The study was initiated at 32–56 hours after the start of ECMO support as a result of the complicated clinical scenario. Fatty acids were measured at 8-hour intervals for 1–3 days. The dosage of inotropes and vasoactive agents was recorded concurrently. The duration of ECMO ranged from 70 to 240 hours (median 177 hours). Four patients were successfully weaned off ECMO support. One died after termination of ECMO. Levels of fatty acids were elevated compared with the normal values. Overall, fatty acid levels continuously decreased over time (p &lt; .0001), the mean being 1.03 ± .33 mmol/L in 30–50 hours, 1.01 ± .57 in 50–70 hours, .81 ± .32 in 70–90 hours, and .63 ± .23 hours. No correlation was found between fatty acid levels and other clinical variables, including age, dosage of inotropes and vasoactive agents, or ECMO duration. Plasma fatty acids levels are elevated in children during ECMO support and continuously decrease over time. Fatty acid levels may be markedly higher in the immediate hours after the initiation of ECMO. Data from more patients are needed to understand the profiles of fatty acids and the correlations with clinical variables. Metabolic manipulations to decrease fatty acids might improve myocardial recovery in patients undergoing ECMO support.

Vascular Complications in Patients Undergoing Femoral Cannulation for Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) is a well-established treatment for severe cardiopulmonary failure. Patients undergoing ECMO support through femoral vessels are prone to vascular complications. The aim of this study was to evaluate such complications to outline basic technical principles for their prevention. From January 2005 to December 2009, 174 patients underwent ECMO support through cannulation of the femoral vessels. The primary outcome was any vascular complication. Secondary outcomes were 30-day mortality and 1-year survival. A logistic regression analysis including ECMO duration, peripheral arterial disease, ECMO access (percutaneous versus open), and diabetes mellitus identified predictors for vascular complications. The venoarterial mode was used in 143 patients (82%), and venovenous in 31 patients (18%). Of the 17 (10%) observed vascular complications, 15 (88%) occurred in patients with venoarterial access, whereas 2 (12%) occurred after venovenous access (p=0.50) Two patients who had extremity ischemia required limb amputation. Thirty-day mortality and 1-year survival rates were 63% and 26%, respectively. Peripheral arterial disease was the only strong predictor of vascular complications (odds ratio, 6.95; 95% confidence interval, 1.89 to 25.59; p=0.003). Vascular complications were not associated with early or late mortality. The incidence of vascular complications in venovenous cannulation was low, whereas in arterial cannulation, it is still considerable. Peripheral arterial disease remains a risk factor, and early involvement of vascular surgeons for open vascular exposure or alternative vascular access sites can be recommended. Vascular complications after ECMO support are not associated with higher mortality rates.

Early Experience with Low-Prime (99 ml) Extracorporeal Membrane Oxygenation Support in Children

Quick setup is mandatory for cardiopulmonary resuscitation using an extracorporeal membrane oxygenation (ECMO) assist device. Our conventional ECMO circuit for pediatric patients consists of a centrifugal pump (CX-HP) and membrane oxygenator (CX10H). Because of the large priming volume (260 ml), the circuit had to be primed with donor blood and required 30 minutes for setup. We started to use a low-prime ECMO with small centrifugal pump (HPM-15) and membrane oxygenator (MENOX Alpha Cube) for induction of ECMO beginning in 2000. The priming volume of this low-prime circuit is only 99 ml. The circuit can be primed without donor blood, even in the small patient, and requires only 10 minutes to set up. We review our experiences with cardiopulmonary resuscitation for sudden cardiopulmonary collapse in pediatric patients, including postcardiotomy patients. From 1997 to 2000, 23 patients underwent ECMO support with a conventional circuit (group A). From 2000 to 2004, we used low-prime circuit for induction of ECMO in 12 patients (group B). After the induction of ECMO with low-prime circuit, ECMO was converted to conventional heparin-bonded circuit for the longer support. The results suggested that the quick induction of ECMO with low-prime circuit has significant advantages in cardiopulmonary support in pediatric patients.