Membrane Lung and Blood Pump Use During Prolonged Extracorporeal Membrane Oxygenation: Trends From 2002 to 2017.

Extracorporeal life support (ECLS) has grown in its application since its first clinical description in the 1970s. The technology has been used to support a wide variety of mechanical support modalities and diseases, including respiratory failure, cardiorespiratory failure, and cardiac failure. Over many decades and safety and efficacy studies, followed by randomized clinical trials and thousands of clinical uses, ECLS is considered as an accepted treatment option for severe pulmonary and selected cardiovascular failure. Extracorporeal life support involves the use of support artificial organs, including a membrane lung and blood pump. Over time, changes in the technology and the management of ECLS support devices have evolved. This manuscript describes the use of membrane lungs and blood pumps used during ECLS support from 2002 to 2017 in over 65,000 patients reported to the Extracorporeal Life Support Organization Registry. Device longevity and complications associated with membrane lungs and blood pump are described and stratified by age group: neonates, pediatrics, and adults.

Evaluation of an Anti-Thrombotic Continuous Lactate and Blood Pressure Monitoring Catheter in an In Vivo Piglet Model undergoing Open-Heart Surgery with Cardiopulmonary Bypass.

Blood lactate and blood pressure measurements are important predictors of life-threatening complications after infant open-heart surgeries requiring cardiopulmonary bypass (CPB). We have developed an intravascular nitric oxide (NO)-releasing 5-Fr catheter that contains a lactate sensor for continuous in-blood lactate monitoring and a dedicated lumen for third-party pressure sensor attachment. This device has antimicrobial and antithrombotic properties and can be implanted intravascularly. The importance of this design is its ability to inhibit thrombosis, due to the slow release of NO through the surface of the catheter and around the electrochemical lactate sensors, to allow continuous data acquisition for more than 48 h. An in vivo study was performed using six piglets undergoing open-heart surgery with CPB and cardioplegic arrest, in order to mimic intra-operative conditions for infants undergoing cardiac surgery with CPB. In each study of 3 h, two 5-Fr NO-releasing lactate and blood-pressure monitoring catheters were implanted in the femoral vessels (arteries and veins) and the CPB circuitry to monitor changing lactate levels and blood pressures during and immediately after aortic cross-clamp removal and separation from CBP. Electrical signals continuously acquired through the sensors were processed and displayed on the device's display and via Bluetooth to a computer in real-time with the use of a two-point in vivo calibration against blood gas results. The study results show that lactate levels measured from those sensors implanted in the CPB circuit during CPB were comparable to those acquired by arterial blood gas measurements, whereas lactate levels measured from sensors implanted in the femoral artery were closely correlated with those acquired intermittently by blood gas prior to CPB initiation, but not during CPB. Blood pressure sensors attached to one lumen of the device displayed accurate blood pressure readings compared to those measured using an FDA approved pressure sensor already on the market. We recommend that the sensor be implanted in the CPB's circuit to continuously monitor lactate during CPB, and implanted in the femoral arteries or jugular veins to monitor lactate before and after CPB. Blood pressures dramatically drop during CPB due to lower blood flow into the lower body, and we suspect that the femoral arteries are likely collapsing or constricting on the implanted catheter and disrupting the sensor-to-blood contact. This study shows that the device is able to accurately and continuously monitor lactate levels during CPB and potentially prevent post-surgery complications in infants.

Ex Vivo Heart Perfusion for 72 Hours Using Plasma Cross Circulation.

Preservation of a donor heart for transplantation is limited to 6-8 hours. Based on our demonstration of 12 hour perfusion with plasma cross circulation, this study aimed to evaluate ex vivo heart perfusion (EVHP) for up to 72 hours using cross plasma circulation (XC-plasma) from a live, awake paracorporeal sheep (PCS). Six ovine hearts were perfused for 72 hours using plasma cross circulation at a rate of 1 L/min with a live, awake PCS. Controls were seven perfused hearts without cross circulation. Experiments were electively ended at 72 hours, and epinephrine (0.1 mg) was delivered to demonstrate hormonal responsiveness. All controls failed at 6-10 hours. All six hearts perfused for 72 hours maintained normal heart function, metabolism, and responsiveness to epinephrine. Blood gases, electrolytes, and lactate levels were normal and stable throughout the study. All hearts appeared suitable for transplantation. We have demonstrated successful normothermic EVHP for 72 hours.

Low-Resistance, Concentric-Gated Pediatric Artificial Lung for End-Stage Lung Failure.

Children with end-stage lung failure awaiting lung transplant would benefit from improvements in artificial lung technology allowing for wearable pulmonary support as a bridge-to-transplant therapy. In this work, we designed, fabricated, and tested the Pediatric MLung-a dual-inlet hollow fiber artificial lung based on concentric gating, which has a rated flow of 1 L/min, and a pressure drop of 25 mm Hg at rated flow. This device and future iterations of the current design are designed to relieve pulmonary arterial hypertension, provide pulmonary support, reduce ventilator-associated injury, and allow for more effective therapy of patients with end-stage lung disease, including bridge-to-transplant treatment.