ObjectivesTechnical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO). Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study.MethodsRetrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013) with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83).ResultsValues presented as median (interquartile range). Patient age was 50(36–60) years, the SOFA score 11(8–14.3) and the Murray lung injury Score 3.33(3.3–3.7). Cumulative ECMO support time 3411 days, 9(6–15) days per patient. Mechanical failure of the blood pump (n = 5), MO (n = 2) or cannula (n = 1) accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb), serum lactate dehydrogenase (LDH), n = 13) and MO (increase in pressure drop across the MO, n = 16) required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10) and device-related coagulation disorders (n = 32), either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD]), decreased platelet count; n = 24), or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8), which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection.ConclusionsThe majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop across the MO and laboratory parameters (DD, FG, platelets, LDH, frHb). These parameters should be monitored in the daily routine to reduce the risk of unexpected ECMO failure.
IntroductionVeno-venous extracorporeal membrane oxygenation (vvECMO) can be a life-saving therapy in patients with severe acute lung failure refractory to conventional therapy. Nevertheless, vvECMO is a procedure associated with high costs and resource utilization. The aim of this study was to assess published models for prediction of mortality following vvECMO and optimize an alternative model.MethodsEstablished mortality risk scores were validated to assess their usefulness in 304 adult patients undergoing vvECMO for refractory lung failure at the University Medical Center Regensburg from 2008 to 2013. A parsimonious prediction model was developed based on variables available before ECMO initiation using logistic regression modelling. We then assessed whether addition of variables available one day after ECMO implementation enhanced mortality prediction. Models were internally validated and calibrated by bootstrapping (400 runs). Predictive ability, goodness-of-fit and model discrimination were compared across the different models.ResultsIn the present study population, existing mortality prediction tools for vvECMO patients showed suboptimal performance. Evaluated before vvECMO initiation, a logistic prediction model comprising age, immunocompromised state, artificial minute ventilation, pre-ECMO serum lactate and hemoglobin concentrations showed best mortality prediction in our patients (area under curve, AUC: 0.75). Additional information about norepinephrine dosage, fraction of inspired oxygen, C-reactive protein and fibrinogen concentrations the first day following ECMO initiation further improved discrimination (AUC: 0.79, P = 0.03) and predictive ability (likelihood ratio test, P < 0.001). When classifying patients as lower (<40%) or higher (>80%) risk based on their predicted mortality, the pre-ECMO and day1-on-ECMO models had negative/positive predictive values of 76%/82% and 82%/81%, respectively.ConclusionsWhile pre-ECMO mortality prediction remains a challenge due to large patient heterogeneity, evaluation one day after ECMO initiation may improve the ability to separate lower- and higher-risk patients. Our findings support the clinical perception that chronic health condition, high comorbidity and reduced functional reserves are strongly related to survival during and following ECMO support. Renewed evaluation the first day after ECMO initiation may provide enhanced guidance for further handling of ECMO patients. Despite the usefulness of prediction models, thorough clinical evaluation should always represent the cornerstone in decision for ECMO.
Over time, miniaturized veno-venous extracorporeal membrane oxygenation therapy increasingly activates coagulation. The different types of membrane oxygenators and pumps did not significantly alter hemostasis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.