Extracorporeal membrane oxygenation in diabetic ketoacidosis-related cardiac and respiratory failure.

INTRODUCTION: Diabetic ketoacidosis (DKA) is a common clinical problem. When patients develop severe shock and/or respiratory failure, extracorporeal membrane oxygenation (ECMO) may be considered. This case series describes the clinical presentation and outcomes of patients with DKA supported with ECMO. METHODS: We conducted a retrospective and anonymized review of 15 patients with DKA who required ECMO at our institution. Demographic and ECMO-specific data were collected. Additional variables include ICU length of stay (LOS), acute kidney injury and use of continuous renal replacement therapy, disposition, and mortality. RESULTS: All ECMO cannulations were performed by an intensivist using peripheral vascular access. The majority of patients were female (73%) with a median age of 27 (IQR = 21.5-45) years. A diagnosis of diabetes mellitus (DM) prior to ECMO was present in 11 (73%) patients. Venoarterial ECMO was the initial mode used in 11 (73%) patients. The median duration of ECMO support was 7 (IQR = 6-14) days. The median ICU LOS was 12 (IQR = 8.5-20.5) days, and the median hospital LOS was 21 (IQR = 11-36.5) days. Eight patients had cardiac arrest and underwent extracorporeal cardiopulmonary resuscitation (ECPR) of which 4 (50%) patients survived to discharge. Overall, 10 (66.7%) patients were successfully weaned from ECMO and survived to discharge. CONCLUSION: This is the largest case series regarding the use of ECMO for patients with refractory shock, cardiac arrest, or respiratory failure related to DKA. The findings suggest that ECMO is a viable support option for managing these patients and has excellent outcomes, including patients with cardiac arrest.

Bridging the gap: safety and outcomes of intensivist-led ECMO retrievals.

Purpose: Most extracorporeal membrane oxygenation (ECMO) cannulations are performed by cardiothoracic surgeons (CTS). Due to an increase in utilization of ECMO and limited availability of CTS, there is a mismatch between ECMO demand and CTS accessibility for remote cannulations. We report our intensivist-led program's experience in remote ECMO cannulations, retrievals, complications, and outcomes. Materials and methods: A prospective, single-center, observational study was performed on patients that required ECMO cannulation at the referring facilities and were transported to our institution between program initiation, on October 1, 2014 to September 30, 2022. Results were presented as mean ± SD, median (min - max) or number (%). Results: Since program commencement, 305 patients were accepted for ECMO retrieval. Three hundred and three patients were placed on ECMO at the 47 referring hospitals among 5 states. In our study, 185 (61%) patients required veno-arterial ECMO and 115 (38%) were placed on veno-venous ECMO. Three patients (1%) were cannulated for veno-arteriovenous ECMO. Twenty patients were cannulated under cardio-pulmonary resuscitation. Most of the patients were transported by ambulance (79%), 14% by helicopter, and 7% by airplane. Six out of the 303 patients did not leave the referring facility. All patients that left the referring hospitals arrived safely to our institution. No major complications occurred in route. Conclusion: Our study's findings indicate that non-CTS physicians can successfully cannulate and retrieve patients with a low complication profile.

The ProtekDuo in percutaneous peripheral venopulmonary-arterial ECMO and PROpella configuration for cardiogenic shock with biventricular failure.

This article describes a case study where a patient with ProtekDuo + oxygenator and Impella CP (PROpella) in biventricular failure and cardiogenic shock was reconfigured to venopulmonary-arterial (VP-A) extracorporeal membrane oxygenation (ECMO), secondary to leg ischemia. The ProtekDuo was subsequently used as double-lumen drainage cannula, returning blood into a newly percutaneously placed femoral arterial cannula, mimicking venoarterial (V-A) ECMO in VP-A configuration. The following day, an Impella 5.5 could be placed and the ProtekDuo was reconfigured back to its default venopulmonary (V-P) ECMO configuration, now again as PROpella with minimally invasive biventricular groin-free full mechanical circulatory support. However, while in VP-A, good drainage blood flows of up to 4.5 LPM could be achieved similar to the ProtekDuo forward flow. None of the lumens collapsed secondary to negative pressure in the system. Drainage through the ProtekDuo for VP-A ECMO is feasible and without complications for a 24-hour period. This new method extends the ProtekDuo's spectrum of use.

Extracorporeal life support in pregnant and postpartum women with COVID-19-related acute respiratory distress syndrome.

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is an intervention used for patients with acute respiratory distress syndrome (ARDS) from COVID-19 who have failed conventional ventilatory strategies. Very few studies have given insight into the outcomes of pregnant and postpartum patients requiring ECMO support. METHODS: Single center, retrospective, observational study of female pregnant and postpartum patients suffering COVID-19 ARDS and requiring ECMO. RESULTS: Eight SARS-CoV-2 positive patients were identified. The average age was 31 ± 4 years, with Body Mass Indices (BMI) and SOFA scores ranging between 32-49 and 8-11, respectively. Two patients were pregnant at the time of ECMO initiation, two were peripartum, and four were postpartum. Five patients (63%) had bleeding, and one patient had a hysterectomy. Seven patients (88%) were supported by V-V ECMO and one with V-A ECMO. Patients had between one and three circuit exchanges due to oxygenator failure or clots in the circuit. All patients were in ICU between 7 and 74 days, with hospital length of stay between 8 and 81 days. All patients were weaned off ECMO and were successfully discharged from the hospital. All newborns were born via cesarean section, and all survived to discharge. CONCLUSION: Our study shows a 100% neonatal and maternal survival rate demonstrating that ECMO in this patient population is safe. These patients should be transferred to experienced high-volume ECMO centers with the ability to perform emergent cesarean sections. ECMO should be considered a life-saving therapy for pregnant women with severe COVID-19 with an overall excellent maternal and neonatal survival rate.

Immune characterization of a xenogeneic human lung cross-circulation support system.

Improved approaches to expanding the pool of donor lungs suitable for transplantation are critically needed for the growing population with end-stage lung disease. Cross-circulation (XC) of whole blood between swine and explanted human lungs has previously been reported to enable the extracorporeal recovery of donor lungs that declined for transplantation due to acute, reversible injuries. However, immunologic interactions of this xenogeneic platform have not been characterized, thus limiting potential translational applications. Using flow cytometry and immunohistochemistry, we demonstrate that porcine immune cell and immunoglobulin infiltration occurs in this xenogeneic XC system, in the context of calcineurin-based immunosuppression and complement depletion. Despite this, xenogeneic XC supported the viability, tissue integrity, and physiologic improvement of human donor lungs over 24 hours of xeno-support. These findings provide targets for future immunomodulatory strategies to minimize immunologic interactions on this organ support biotechnology.

Large animal preclinical investigation into the optimal extracorporeal life support configuration for pulmonary hypertension and right ventricular failure.

INTRODUCTION: Right ventricular failure (RVF) is a major cause of mortality in pulmonary hypertension (PH). Mechanical circulatory support holds promise for patients with medically refractory PH, but there are no clinical devices for long-term right ventricular (RV) support. Investigations into optimal device parameters and circuit configurations for PH-induced RVF (PH-RVF) are needed. METHODS: Eleven sheep underwent previously published chronic PH model. We then evaluated a low-profile, ventricular assist device (VAD)-quality pump combined with a novel low-resistance membrane oxygenator (Pulmonary Assist Device, PAD) under one of four central cannulation strategies: right atrium-to-left atrium (RA-LA, N = 3), RA-to-pulmonary artery (RA-PA, N=3), pumpless pulmonary artery-to-left atrium (PA-LA, N = 2), and RA-to-ascending aorta (RA-Ao, N = 3). Acute-on-chronic RVF (AoC RVF) was induced, and mechanical support was provided for up to 6 hours at blood flow rates of 1 to 3 liter/min. Circuit parameters, physiologic, hemodynamic, and echocardiography data were collected. RESULTS: The RA-LA configuration achieved blood flow of 3 liter/min. Meanwhile, RA-PA and RA-Ao faced challenges maintaining 3 liter/min of flow due to higher circuit afterload. Pumpless PA-LA was flow-limited due to anatomical limitations inherent to this animal model. RA-LA and RA-Ao demonstrated serial RV unloading with increasing circuit flow, while RA-PA did not. RA-LA also improved left ventricular (LV) and septal geometry by echocardiographic assessment and had the lowest inotropic dependence. CONCLUSION: RA-LA and RA-Ao configurations unload the RV, while RA-LA also lowers pump speed and inotropic requirements, and improves LV mechanics. RA-PA provide inferior support for PH-RVF, while an alternate animal model is needed to evaluate PA-LA.

Extracorporeal Membrane Oxygenation Selection by Multidisciplinary Consensus: The ECMO Council.

Coronavirus disease 2019 (COVID-19) has increased the demand for extracorporeal membrane oxygenation (ECMO) and introduced distinct challenges to patient selection for ECMO. Standardized processes for patient selection amidst resource limitations are lacking, and data on ECMO consults are underreported. We retrospectively reviewed consecutive adult ECMO consults for acute respiratory failure received at a single academic medical center from April 1, 2020, to February 28, 2021, and evaluated the implementation of a multidisciplinary selection committee (ECMO Council) and standardized framework for patient selection for ECMO. During the 334-day period, there were 202 total ECMO consults; 174 (86.1%) included a diagnosis of COVID-19. Among all consults, 157 (77.7%) were declined and 41 (20.3%) resulted in the initiation of ECMO. Frequent reasons for decline included the presence of multiple relative contraindications (n = 33), age greater than 60 years (n = 32), and resource limitations (n = 27). The ECMO Council deliberated on every case in which an absolute contraindication was not present (n = 96) via an electronic teleconference platform. Utilizing multidisciplinary consensus together with a standardized process for patient selection in ECMO is feasible during a pandemic and may be reliably exercised over time. Whether such an approach is feasible at other centers remains unknown.

Simulation Versus Interactive Mobile Learning for Teaching Extracorporeal Membrane Oxygenation to Clinicians: A Randomized Trial.

OBJECTIVES: Extracorporeal membrane oxygenation has become integral to critical care. Data informing optimal extracorporeal membrane oxygenation education modalities are lacking. We aimed to compare the effect of high-fidelity simulation versus interactive mobile learning on extracorporeal membrane oxygenation knowledge acquisition and retention among clinicians. DESIGN: Observer-blinded, randomized controlled trial. SETTING: A single academic medical center. SUBJECTS: Forty-four critical care clinicians with limited extracorporeal membrane oxygenation experience. INTERVENTIONS: Participants were randomized to receive: 1) simulation: three high-fidelity training scenarios, 2) QuizTime: 15 total multiple-choice questions delivered over 3 weeks via mobile device, or 3) experiential: no formal training. Participants completed a survey, written knowledge examination, and simulation assessment prior to randomization, immediately following the intervention, and 4 month postintervention. MEASUREMENTS AND MAIN RESULTS: The primary outcome was knowledge about extracorporeal membrane oxygenation assessed by score on the immediate postintervention written examination. Secondary outcomes included performance in extracorporeal membrane oxygenation simulation postintervention and 4 months later assessed by a rater blinded to group assignment. Clinicians randomized to simulation (n = 15), QuizTime (n = 14), and experiential (n = 15) had similar baseline characteristics. Adjusting for baseline knowledge, postintervention examination scores were higher in the simulation group (90.0%; interquartile range, 85.0-90.0%) than the QuizTime group (70.0%; interquartile range, 65.0-80.0%; p = 0.0003) and the experiential group (75.0%; interquartile range, 65.0-80.0%; p = 0.001). Scores did not differ between the groups at 4 months (p > 0.05 in all analyses). In postintervention extracorporeal membrane oxygenation simulations, the simulation group demonstrated shorter time to critical action compared with QuizTime (80.0 s [interquartile range, 54.0-111.0 s] vs 300.0 s [interquartile range 85.0-300.0 s]; p = 0.02) and compared with both QuizTime (45.0 s [interquartile range, 34.0-92.5 s] vs 255.5 s [interquartile range, 102.0-300.0 s]; p = 0.008) and experiential (300.0 s [interquartile range, 58.0-300.0 s]; p = 0.009) at 4 months. CONCLUSIONS: Simulation was superior to QuizTime and experiential learning with regard to extracorporeal membrane oxygenation knowledge acquisition. Further studies are needed to ascertain the effect of these interventions on knowledge retention, clinical performance, and patient outcomes.

Cross-Circulation for Extracorporeal Liver Support in a Swine Model.

Although machine perfusion has gained momentum as an organ preservation technique in liver transplantation, persistent organ shortages and high waitlist mortality highlight unmet needs for improved organ salvage strategies. Beyond preservation, extracorporeal organ support platforms can also aid the development and evaluation of novel therapeutics. Here, we report the use of veno-arterial-venous (V-AV) cross-circulation (XC) with a swine host to provide normothermic support to extracorporeal livers. Functional, biochemical, and morphological analyses of the extracorporeal livers and swine hosts were performed over 12 hours of support. Extracorporeal livers maintained synthetic function through alkaline bile production and metabolic activity through lactate clearance and oxygen consumption. Beyond initial reperfusion, no biochemical evidence of hepatocellular injury was observed. Histopathologic injury scoring showed improvements in sinusoidal dilatation and composite acute injury scores after 12 hours. Swine hosts remained hemodynamically stable throughout XC support. Altogether, these outcomes demonstrate the feasibility of using a novel V-AV XC technique to provide support for extracorporeal livers in a swine model. V-AV XC has potential applications as a translational research platform and clinical biotechnology for donor organ salvage.

Acute Normovolemic Hemodilution-assisted Terminal Blood Procurement in Swine for Ex Vivo Organ Perfusion.

Swine (Sus scrofa domesticus) are commonly used large animal subjects for the study of disease and preclinical therapies. Organ machine perfusion is a therapy that has gained momentum as a research platform for the study of ex vivo organ preservation and therapeutics. However, complex perfusion circuits and research protocols often require large volumes of blood as perfusate. Here, we report a technique for increasing terminal blood yield during swine organ and blood procurement; our method involves acute normovolemic hemodilution and exsanguination via the femoral artery. We collected a total of 47 ± 4 mL/kg of blood and 4.3 ± 0.6 g/kg of hemoglobin, representing 73% ± 6% of the estimated blood volume and 64% ± 8% of the total estimated intravascular hemoglobin (n = 4). Neither pH, lactate, nor pO2 levels changed significantly during blood procurement. Acute normovolemic hemodilution is an effective method for increasing RBC and hemoglobin yield during blood procurement in swine.

A Large Animal Model for Pulmonary Hypertension and Right Ventricular Failure: Left Pulmonary Artery Ligation and Progressive Main Pulmonary Artery Banding in Sheep.

Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing novel therapeutics for PH requires a clinically relevant large animal model of increased pulmonary vascular resistance and RVF. This manuscript discusses the latest development of the previously published ovine PH-RVF model that utilizes left pulmonary artery (PA) ligation and main PA occlusion. This model of PH-RVF is a versatile platform to control not only the disease severity but also the RV's phenotypic response. Adult sheep (60-80 kg) underwent left PA (LPA) ligation, placement of main PA cuff, and insertion of RV pressure monitor. PA cuff and RV pressure monitor were connected to subcutaneous ports. Subjects underwent progressive PA banding twice per week for 9 weeks with sequential measures of RV pressure, PA cuff pressures, and mixed venous blood gas (SvO2). At the initiation and endpoint of this model, ventricular function and dimensions were assessed using echocardiography. In a representative group of 12 animal subjects, RV mean and systolic pressure increased from 28 ± 5 and 57 ± 7 mmHg at week 1, respectively, to 44 ± 7 and 93 ± 18 mmHg (mean ± standard deviation) by week 9. Echocardiography demonstrated characteristic findings of PH-RVF, notably RV dilation, increased wall thickness, and septal bowing. The longitudinal trend of SvO2 and PA cuff pressure demonstrates that the rate of PA banding can be titrated to elicit varying RV phenotypes. A faster PA banding strategy led to a precipitous decline in SvO2 < 65%, indicating RV decompensation, whereas a slower, more paced strategy led to the maintenance of physiologic SvO2 at 70%-80%. One animal that experienced the accelerated strategy developed several liters of pleural effusion and ascites by week 9. This chronic PH-RVF model provides a valuable tool for studying molecular mechanisms, developing diagnostic biomarkers, and enabling therapeutic innovation to manage RV adaptation and maladaptation from PH.

Venovenous extracorporeal membrane oxygenation during high-risk airway interventions.

OBJECTIVES: Practice patterns for the use of extracorporeal membrane oxygenation (ECMO) during high-risk airway interventions vary, and data are limited. We aim to characterize our recent experience using ECMO for procedural support during whole-lung lavage (WLL) and high-risk bronchoscopy for central airway obstruction (CAO). METHODS: We performed a retrospective cohort study of adults who received ECMO during WLL and high-risk bronchoscopy from 1 July 2018 to 30 March 2020. Our primary end point was successful completion of the intervention. Secondary end points included ECMO-associated complications and hospital survival. RESULTS: Eight patients received venovenous ECMO for respiratory support during 9 interventions; 3 WLLs for pulmonary alveolar proteinosis were performed in 2 patients, and 6 patients underwent 6 bronchoscopic interventions for CAO. We initiated ECMO prior to the intervention in 8 cases and during the intervention in 1 case for respiratory decompensation. All 9 interventions were successfully completed. Median ECMO duration was 17.8 h (interquartile range, 15.9-26.6) for the pulmonary alveolar proteinosis group and 1.9 h (interquartile range, 1.4-8.1) for the CAO group. There was 1 cannula-associated deep vein thrombosis; there were no other ECMO complications. Seven patients (87.5%) and 4 (50.0%) patients survived to discharge and 1 year postintervention, respectively. CONCLUSIONS: Use of venovenous ECMO to facilitate high-risk airway interventions is safe and feasible. Planned preprocedural ECMO initiation may prevent avoidable respiratory emergencies and extend therapeutic airway interventions to patients otherwise considered too high-risk to treat. Guidelines are needed to inform the utilization of ECMO during high-risk bronchoscopy and other airway interventions.

Continuous Intrathecal Morphine Infusion for Pain Management in a Polytrauma Patient: A Case Report.

Polytrauma patients are at high risk for neurologic complications as a result of the primary mechanism of their trauma and/or delirium caused by subsequent pain, sedatives and analgesic exposure, sleep disturbances, infections, metabolic derangements, organ dysfunctions, withdrawal syndromes, or other factors. The high prevalence of delirium within trauma intensive care units increases risks for both patients and providers and is associated with worsened patient outcomes. This case report explains the rationale and utilization of continuous intrathecal morphine administration to improve pain control while reducing and eliminating intravenous (IV) analgesics and sedatives to enable wakefulness in a polytrauma patient with refractory agitated delirium.

Closing the "care in the air" capability gap for severe lung injury: the Landstuhl Acute Lung Rescue Team and extracorporeal lung support.

BACKGROUND: The success of US Air Force Critical Care Air Transport Teams (CCATT) in transporting critically ill and injured patients enabled changes in military medical force deployment and casualty care practice. Even so, a subset of casualties remains who exceed even CCATT capabilities for movement. These patients led to the creation of the Landstuhl Acute Lung Rescue Team (ALeRT) to close the "care in the air" capability gap. METHODS: The ALeRT Registry was queried for the period between November 1, 2005, and June 30, 2010. Additionally, Landstuhl Regional Medical Center critical care patient transfers to host nation medical centers were reviewed for cases using extracorporeal lung support systems. RESULTS: For the review period, US Central Command activated the ALeRT on 40 occasions. The ALeRT successfully evacuated patients on 24 of 27 missions launched (89%). Three patients were too unstable for ALeRT evacuation. Of the 13 remaining activations, four patients died and nine patients improved sufficiently for standard CCATT movement. The ALeRT initiated pumpless extracorporeal lung assistance six times, but only once to facilitate evacuation. Two patients were supported with full extracorporeal membrane oxygenation support after evacuation due to progressive respiratory failure. CONCLUSIONS: ALeRT successfully transported 24 casualties from the combat zones to Germany. Without the ALeRT, these patients would have remained in the combat theater as significant consumers of limited deployed medical resources. Pumpless extracorporeal lung assistance is already within the ALeRT armamentarium, but has only been used for one aeromedical evacuation. Modern extracorporeal membrane oxygenation systems hold promise as a feasible capability for aeromedical evacuation.