Mechanical life support algorithm for emergency management of patient receiving extracorporeal membrane oxygenation.

BACKGROUND: There are limited practical advanced life support algorithms to aid teams in the management of cardiac arrest in patients on extracorporeal membrane oxygenation (ECMO). METHODS: In our specialist tertiary referral centre we developed, by iteration, a novel resuscitation algorithm for ECMO emergencies which we validated through simulation and assessment of our multi-disciplinary team. A Mechanical Life Support course was established to provide theoretical and practical education combined with simulation to consolidate knowledge and confidence in algorithm use. We assessed these measures using confidence scoring, a key performance indicator (the time taken to resolve gas line disconnection) and a multiple choice question (MCQ) examination. RESULTS: Following this intervention the median confidence scores increased from 2 (Interquartile range IQR 2, 3) to 4 (IQR 4, 4) out of maximum 5 (n = 53, p < 0.0001). Theoretical knowledge assessed by median MCQ score increased from 8 (6, 9) to 9 (7, 10) out of maximum 11 (n = 53, p0.0001). The use of the ECMO algorithm reduced the time taken by teams in a simulated emergency to identify a gas line disconnection and resolve the problem from median 128 s (65, 180) to 44 s (31, 59) (n = 36, p 0.001) and by a mean of 81.5 s (CI 34, 116, p = 0.001). CONCLUSIONS: We present an evidence based practical ECMO resuscitation algorithm that provides guidance to clinical teams responding to cardiac arrest in ECMO patients covering both patient and ECMO troubleshooting.

Variable Sequestration of Antifungals in an Extracorporeal Membrane Oxygenation Circuit.

Fungal infections are common and frequently associated with clinical failure in patients receiving extracorporeal membrane oxygenation (ECMO). Antifungal drugs have physicochemical characteristics associated with a higher likelihood of sequestration onto ECMO circuitry potentially leading to a subtherapeutic drug concentration. The percentage of sequestration of the antifungal drugs-caspofungin, posaconazole, and voriconazole-was determined using an ex vivo ECMO model. The circuits were primed with whole human blood, sodium chloride 0.9%, and human albumin solution. Serial 2 ml samples were taken at baseline, 0.5, 1, 2, 6, 12, and 24 hours after drug addition, paired with non-ECMO controls stored in a water bath at 37°C. Mean loss from the blood-primed ECMO circuits and controls at 24 hours relative to baseline were 80% and 61% for caspofungin ( p = ns), 64% and 11% for posaconazole ( p < 0.005), and 27% and 19% for voriconazole ( p < 0.05). Calculated AUC 0-24 showed a 44% for caspofungin ( p = ns), 30.6% posaconazole ( p < 0.005), and 9% loss for voriconazole ( p = 0.003) compared with the controls, suggesting therapeutic concentrations of these antifungal agents cannot be guaranteed with standard dosing in patients on ECMO. Posaconazole exhibited the greatest loss to the ECMO circuit correlating with both high lipophilicity and protein binding of the drug.

Evaluation of the organ care system in heart transplantation with an adverse donor/recipient profile.

BACKGROUND: A severe shortage of available donor organs has created an impetus to use extended criteria organs for heart transplantation. Although such attempts increase donor organ availability, they may result in an adverse donor-recipient risk profile. The TransMedics Organ Care System (OCS) (TransMedics, Inc, Boston) allows preservation of the donor heart by perfusing the organ at 34°C in a beating state, potentially reducing the detrimental effect of cold storage and providing additional assessment options. We describe a single-center experience with the OCS in high-risk heart transplant procedures. METHODS: Thirty hearts were preserved using the OCS between February 2013 and January 2014, 26 of which (86.7%) were transplanted. Procedures were classified as high risk based on (1) donor factors, ie, transport time more than 2.5 hours with estimated ischemic time longer than 4 hours, left ventricular ejection fraction (LVEF) less than 50%, left ventricular hypertrophy (LVH), donor cardiac arrest, alcohol/drug abuse, coronary artery disease or (2) recipient factors, ie, mechanical circulatory support or elevated pulmonary vascular resistance (PVR), or both. RESULTS: Donor and recipient age was 37 ± 12 years and 43 ± 13 years, respectively. Allograft cold ischemia time was 85 ± 17 minutes and OCS perfusion time was 284 ± 90 minutes. The median intensive care unit stay was 6 days. One death (3.8%) was observed over the follow-up: 257 ± 116 (109-445 days). There was preserved allograft function in 92% of patients, with a mean LVEF of 64% ± 5%. CONCLUSIONS: Use of the OCS is associated with markedly improved short-term outcomes and transplant activity by allowing use of organs previously not considered suitable for transplantation or selection of higher risk recipients, or both.