Impact of Extracorporeal Membrane Oxygenation Bridging Duration on Lung Transplant Outcomes.

BACKGROUND: We sought to characterize the association between venovenous extracorporeal membrane oxygenation (VV-ECMO) bridging duration and outcomes in patients listed for lung transplantation. METHODS: A retrospective observational study was conducted using the Organ Procurement and Transplantation Network (OPTN) database to identify adults (≥18 years old) who were listed for lung transplantation between 2016-2020 and who were bridged with VV-ECMO. Patients were then stratified into groups, determined by risk inflection points, depending on the amount of time spent on pre-transplant ECMO: Group 1 (≤5 days), Group 2 (6-10 days), Group 3 (11-20 days), and Group 4 (>20 days). Waitlist survival between groups was analyzed using Fine-Gray competing risk models. Post-transplant survival was compared using Cox regression. RESULTS: Of 566 eligible VV-ECMO bridge-to-lung-transplant patients (median age=54, 49% male), 174 (31%), 124 (22%), 130 (23%), and 138 (24%) were categorized as Groups 1, 2, 3, and 4, respectively. Overall, median duration of VV-ECMO was 10 days (range=1-211) and 178 patients (31%) died on the waitlist. In the Fine-Gray model, compared to Group 1, patients bridged with longer ECMO durations in Groups 2 (SHR=2.95, 95%CI: 1.63-5.35), 3 (SHR=3.96, 95%CI: 2.36-6.63), and 4 (SHR=4.33, 95%CI: 2.59-7.22, all p<0.001), were more likely to die on the waitlist. Of 388 patients receiving a transplant, pre-transplant ECMO duration was not associated with one-year survival in Cox regression. CONCLUSIONS: Prolonged ECMO bridging duration was associated with worse waitlist mortality but did not impact post-lung transplant survival. Prioritization of very early transplantation may improve waitlist outcomes in this population.

Sex-Related Differences in Utilization and Outcomes of Extracorporeal Cardio-Pulmonary Resuscitation for Refractory Cardiac Arrest.

Sparse data exist on sex-related differences in extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest (rCA). We explored the role of sex on the utilization and outcomes of ECPR for rCA by retrospective analysis of the Extracorporeal Life Support Organization (ELSO) International Registry. The primary outcome was in-hospital mortality. Exploratory outcomes were discharge disposition and occurrence of any specific extracorporeal membrane oxygenation (ECMO) complications. From 1992 to 2020, a total of 7,460 adults with ECPR were identified: 30.5% women; 69.5% men; 55.9% Whites, 23.7% Asians, 8.9% Blacks, and 3.8% Hispanics. Women's age was 50.4 ± 16.9 years (mean ± standard deviation) and men's 54.7 ± 14.1 (p < 0.001). Ischemic heart disease occurred in 14.6% women vs. 18.5% men (p < 0.001). Overall, 28.5% survived at discharge, 30% women vs. 27.8% men (p = 0.138). In the adjusted analysis, sex was not associated with in-hospital mortality (odds ratio [OR] = 0.93 [confidence interval {CI} = 0.80-1.08]; p = 0.374). Female sex was associated with decreased odds of neurologic, cardiovascular, and renal complications. Despite being younger and having fewer complications during ECMO, women had in-hospital mortality similar to men. Whether these findings are driven by biologic factors or disparities in health care warrants further investigation.

Detection of Acute Brain Injury in Intensive Care Unit Patients on ECMO Support Using Ultra-Low-Field Portable MRI: A Retrospective Analysis Compared to Head CT.

Early detection of acute brain injury (ABI) is critical to intensive care unit (ICU) patient management and intervention to decrease major complications. Head CT (HCT) is the standard of care for the assessment of ABI in ICU patients; however, it has limited sensitivity compared to MRI. We retrospectively compared the ability of ultra-low-field portable MR (ULF-pMR) and head HCT, acquired within 24 h of each other, to detect ABI in ICU patients supported on extracorporeal membrane oxygenation (ECMO). A total of 17 adult patients (median age 55 years; 47% male) were included in the analysis. Of the 17 patients assessed, ABI was not observed on either ULF-pMR or HCT in eight patients (47%). ABI was observed in the remaining nine patients with a total of 10 events (8 ischemic, 2 hemorrhagic). Of the eight ischemic events, ULF-pMR observed all eight, while HCT only observed four events. Regarding hemorrhagic stroke, ULF-pMR observed only one of them, while HCT observed both. ULF-pMR outperformed HCT for the detection of ABI, especially ischemic injury, and may offer diagnostic advantages for ICU patients. The lack of sensitivity to hemorrhage may improve with modification of the imaging acquisition program.

Clinical Use of Bedside Portable Low-field Brain Magnetic Resonance Imaging in Patients on ECMO: The Results from Multicenter SAFE MRI ECMO Study.

Purpose: Early detection of acute brain injury (ABI) is critical for improving survival for patients with extracorporeal membrane oxygenation (ECMO) support. We aimed to evaluate the safety of ultra-low-field portable MRI (ULF-pMRI) and the frequency and types of ABI observed during ECMO support. Methods: We conducted a multicenter prospective observational study (NCT05469139) at two academic tertiary centers (August 2022-November 2023). Primary outcomes were safety and validation of ULF-pMRI in ECMO, defined as exam completion without adverse events (AEs); secondary outcomes were ABI frequency and type. Results: ULF-pMRI was performed in 50 patients with 34 (68%) on venoarterial (VA)-ECMO (11 central; 23 peripheral) and 16 (32%) with venovenous (VV)-ECMO (9 single lumen; 7 double lumen). All patients were imaged successfully with ULF-pMRI, demonstrating discernible intracranial pathologies with good quality. AEs occurred in 3 (6%) patients (2 minor; 1 serious) without causing significant clinical issues.ABI was observed in ULF-pMRI scans for 22 patients (44%): ischemic stroke (36%), intracranial hemorrhage (6%), and hypoxic-ischemic brain injury (4%). Of 18 patients with both ULF-pMRI and head CT (HCT) within 24 hours, ABI was observed in 9 patients with 10 events: 8 ischemic (8 observed on ULF-oMRI, 4 on HCT) and 2 hemorrhagic (1 observed on ULF-pMRI, 2 on HCT). Conclusions: ULF-pMRI was shown to be safe and valid in ECMO patients across different ECMO cannulation strategies. The incidence of ABI was high, and ULF-pMRI may more sensitive to ischemic ABI than HCT. ULF-pMRI may benefit both clinical care and future studies of ECMO-associated ABI.

Racial disparities among patients on venovenous extracorporeal membrane oxygenation in the pre-Coronavirus Disease 2019 and Coronavirus Disease 2019 eras: A retrospective registry review.

Objectives: Although many studies have addressed such disparities caused by COVID-19, to our knowledge, no study has focused on the association of race on outcomes for patients with COVID-19 requiring venovenous extracorporeal membrane oxygenation support. The goal of this study was to assess association of race on death and duration on venovenous extracorporeal membrane oxygenation in both the pre-COVID-19 and COVID-19 eras. Methods: We retrospectively reviewed the Extracorporeal Life Support Organization registry and included adults (≥18 years) who required venovenous extracorporeal membrane oxygenation between January 2019 and April 2021. We performed descriptive statistics and multivariable logistic regression. Our primary outcomes were death and extracorporeal membrane oxygenation duration. Results: A total of 7477 patients were included after excluding 340 patients (4.3%) who were missing race data. In the COVID-19 era, 1474 of 2777 COVID-19-positive patients (53.1%) died. Our regression model suggested somewhat of a protective effect on death for Black and multiple race patients. Additionally, a diagnosis of COVID-19 and patients in the COVID-19 era in general, irrespective of COVID-19 diagnosis, had higher odds of death. Hispanic patients had the longest average venovenous extracorporeal membrane oxygenation run times. Conclusions: Our study using data from the international Extracorporeal Life Support Organization Registry provides updated data on patients supported with venovenous extracorporeal membrane oxygenation in the pre-COVID-19 and COVID-19 eras between 2019 and 2021 with a focus on race. Patients in the COVID-19 era group also had higher mortality compared with those in the pre-COVID-19 era even after being adjusted for COVID-19 diagnosis. Black and multiple races appeared somewhat protective in terms of death. Hispanic race was associated with longer venovenous extracorporeal membrane oxygenation duration.

Continuous Monitoring of Cerebral Autoregulation in Adults Supported by Extracorporeal Membrane Oxygenation.

BACKGROUND: Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes. METHODS: This is a single-center prospective observational study. We measured COx, a surrogate measurement of cerebral blood flow measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure (MAP) and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT) and lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores. RESULTS: Fifteen patients (median age 57 years [interquartile range 47-69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO (VA-ECMO), and four were on veno-venous ECMO (VV-ECMO). Mean COx was higher on postcannulation day 1 than on day 2 (0.2 vs. 0.09, p < 0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO patients (0.12 vs. 0.06, p = 0.04). Median MAPOPT for the entire cohort was highly variable, ranging from 55 to 110 mm Hg. Patients with mRS scores 0-3 (good outcome) at 3 and 6 months spent less time outside MAPOPT compared with patients with mRS scores 4-6 (poor outcome) (74% vs. 82%, p = 0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on postcannulation day 1 than on day 2 (18.2% vs. 3.3%, p < 0.01). CONCLUSIONS: In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between postcannulation days 1 and 2. CA was more impaired in VA-ECMO patients than in VV-ECMO patients. Spending less time outside MAPOPT may be associated with achieving a good neurologic outcome.

Predicting Acute Brain Injury in Venoarterial Extracorporeal Membrane Oxygenation Patients with Tree-Based Machine Learning: Analysis of the Extracorporeal Life Support Organization Registry.

Objective: To determine if machine learning (ML) can predict acute brain injury (ABI) and identify modifiable risk factors for ABI in venoarterial extracorporeal membrane oxygenation (VA-ECMO) patients. Design: Retrospective cohort study of the Extracorporeal Life Support Organization (ELSO) Registry (2009-2021). Setting: International, multicenter registry study of 676 ECMO centers. Patients: Adults (≥18 years) supported with VA-ECMO or extracorporeal cardiopulmonary resuscitation (ECPR). Interventions: None. Measurements and Main Results: Our primary outcome was ABI: central nervous system (CNS) ischemia, intracranial hemorrhage (ICH), brain death, and seizures. We utilized Random Forest, CatBoost, LightGBM and XGBoost ML algorithms (10-fold leave-one-out cross-validation) to predict and identify features most important for ABI. We extracted 65 total features: demographics, pre-ECMO/on-ECMO laboratory values, and pre-ECMO/on-ECMO settings.Of 35,855 VA-ECMO (non-ECPR) patients (median age=57.8 years, 66% male), 7.7% (n=2,769) experienced ABI. In VA-ECMO (non-ECPR), the area under the receiver-operator characteristics curves (AUC-ROC) to predict ABI, CNS ischemia, and ICH was 0.67, 0.67, and 0.62, respectively. The true positive, true negative, false positive, false negative, positive, and negative predictive values were 33%, 88%, 12%, 67%, 18%, and 94%, respectively for ABI. Longer ECMO duration, higher 24h ECMO pump flow, and higher on-ECMO PaO2 were associated with ABI.Of 10,775 ECPR patients (median age=57.1 years, 68% male), 16.5% (n=1,787) experienced ABI. The AUC-ROC for ABI, CNS ischemia, and ICH was 0.72, 0.73, and 0.69, respectively. The true positive, true negative, false positive, false negative, positive, and negative predictive values were 61%, 70%, 30%, 39%, 29% and 90%, respectively, for ABI. Longer ECMO duration, younger age, and higher 24h ECMO pump flow were associated with ABI. Conclusions: This is the largest study predicting neurological complications on sufficiently powered international ECMO cohorts. Longer ECMO duration and higher 24h pump flow were associated with ABI in both non-ECPR and ECPR VA-ECMO.

Post-Cardiac Arrest Care in Adult Patients After Extracorporeal Cardiopulmonary Resuscitation.

OBJECTIVES: Extracorporeal cardiopulmonary resuscitation (ECPR) serves as a lifesaving intervention for patients experiencing refractory cardiac arrest. With its expanding usage, there is a burgeoning focus on improving patient outcomes through optimal management in the acute phase after cannulation. This review explores systematic post-cardiac arrest management strategies, associated complications, and prognostication in ECPR patients. DATA SOURCES: A PubMed search from inception to 2023 using search terms such as post-cardiac arrest care, ICU management, prognostication, and outcomes in adult ECPR patients was conducted. STUDY SELECTION: Selection includes original research, review articles, and guidelines. DATA EXTRACTION: Information from relevant publications was reviewed, consolidated, and formulated into a narrative review. DATA SYNTHESIS: We found limited data and no established clinical guidelines for post-cardiac arrest care after ECPR. In contrast to non-ECPR patients where systematic post-cardiac arrest care is shown to improve the outcomes, there is no high-quality data on this topic after ECPR. This review outlines a systematic approach, albeit limited, for ECPR care, focusing on airway/breathing and circulation as well as critical aspects of ICU care, including analgesia/sedation, mechanical ventilation, early oxygen/C o2 , and temperature goals, nutrition, fluid, imaging, and neuromonitoring strategy. We summarize common on-extracorporeal membrane oxygenation complications and the complex nature of prognostication and withdrawal of life-sustaining therapy in ECPR. Given conflicting outcomes in ECPR randomized controlled trials focused on pre-cannulation care, a better understanding of hemodynamic, neurologic, and metabolic abnormalities and early management goals may be necessary to improve their outcomes. CONCLUSIONS: Effective post-cardiac arrest care during the acute phase of ECPR is paramount in optimizing patient outcomes. However, a dearth of evidence to guide specific management strategies remains, indicating the necessity for future research in this field.

Characterizing the Racial Discrepancy in Hypoxemia Detection in VV-ECMO: An ELSO Registry Analysis.

Importance: Skin pigmentation influences peripheral oxygen saturation (SpO2) measured by pulse oximetry compared to the arterial saturation of oxygen (SaO2) measured via arterial blood gas analysis. However, data on SpO2-SaO2 discrepancy are limited in venovenous-extracorporeal membrane oxygenation (VV-ECMO) patients. Objective: To determine whether there is racial/ethnical discrepancy between SpO2 and SaO2 in patients receiving VV-ECMO. We hypothesized VV-ECMO cannulation, in addition to race/ethnicity, accentuates the SpO2-SaO2 discrepancy due to significant hemolysis. Design: Retrospective cohort study of the Extracorporeal Life Support Organization Registry from 1/2018-5/2023. Setting: International, multicenter registry study including over 500 ECMO centers. Participants: Adults (≥ 18 years) supported with VV-ECMO with concurrently measured SpO2 and SaO2 measurements. Exposure: Race/ethnicity and ECMO cannulation. Main outcomes and measures: Occult hypoxemia (SaO2 ≤ 88% with SpO2 ≥ 92%) was our primary outcome. Multivariable logistic regressions were performed to examine whether race/ethnicity was associated with occult hypoxemia in pre-ECMO and on-ECMO SpO2-SaO2 calculations. Covariates included age, sex, temporary mechanical circulatory support, pre-vasopressors, and pre-inotropes for pre-ECMO analysis, plus single-lumen versus double-lumen cannulation, hemolysis, hyperbilirubinemia, ECMO pump flow rate, and on-ECMO 24h lactate for on-ECMO analysis. Results: Of 13,171 VV-ECMO patients (median age = 48.6 years, 66% male), there were 7,772 (59%) White, 2,114 (16%) Hispanic, 1,777 (14%) Black, and 1,508 (11%) Asian patients. The frequency of on-ECMO occult hypoxemia was 2.0% (N = 233). Occult hypoxemia was more common in Black and Hispanic versus White patients (3.1% versus 1.7%, P < 0.001 and 2.5% versus 1.7%, P = 0.025, respectively).In multivariable logistic regression, Black patients were at higher risk of pre-ECMO occult hypoxemia versus White patients (adjusted odds ratio [aOR] = 1.55, 95% confidence interval [CI] = 1.18-2.02, P = 0.001). For on-ECMO occult hypoxemia, Black patients (aOR = 1.79, 95%CI = 1.16-2.75, P = 0.008) and Hispanic patients (aOR = 1.71, 95%CI = 1.15-2.55, P = 0.008) had higher risk versus White patients. Furthermore, higher pump flow rate (aOR = 1.29, 95%CI = 1.08-1.55, P = 0.005) and higher on-ECMO 24h lactate (aOR = 1.06, 95%CI = 1.03-1.10, P < 0.001) significantly increased the risk of on-ECMO occult hypoxemia. Conclusions and Relevance: Hispanic and Black VV-ECMO patients experienced occult hypoxemia more than White patients. SaO2 should be carefully monitored during ECMO support for Black and Hispanic patients especially for those with high pump flow and lactate values at risk for occult hypoxemia.

Atraumatic Polycompartment Syndrome Secondary to Cardiogenic Shock: A Case Report.

We report the case of a 53-year-old male who developed polycompartment syndrome (PCS) secondary to cardiogenic shock. After suffering a cardiac arrest, a self-perpetuating cycle of intra-abdominal hypertension (IAH) and vital organ damage led to abdominal compartment syndrome (AbCS), which then contributed to the precipitation of extremity compartment syndrome (CS) in bilateral thighs, legs, forearms, and hands. This report is followed by a review of the literature regarding the pathophysiology of this rare sequela of cardiogenic shock. While the progression from cardiogenic shock to AbCS and ultimately to PCS has been hypothesized, no prior case reports demonstrate this. Furthermore, this case suggests more generally that IAH may be a risk factor for extremity CS. Future studies should examine the potential interplay between IAH and extremity CS in patients at risk, such as polytrauma patients with tibial fractures.

Continuous Monitoring of Cerebral Autoregulation in Adults Supported by Extracorporeal Membrane Oxygenation.

Background: Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes. Methods: This is a single-center prospective observational study. We measured Cox, a surrogate measurement of cerebral blood flow, measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT), lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores. Results: Fifteen patients (median age=57 years [IQR=47-69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO and 4 on veno-venous. Mean COx was higher on post-cannulation day 1 than on day 2 (0.2 vs 0.09, p<0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO (0.12 vs 0.06, p=0.04). Median MAPOPT for entire cohort was highly variable, ranging 55-110 mmHg. Patients with mRS 0-3 (good outcome) at 3 and 6 months spent less time outside of MAPOPT compared to patients with mRS 4-6 (poor outcome) (74% vs 82%, p=0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on post-cannulation day 1 than on day 2 (18.2% vs 3.3%, p<0.01). Conclusions: In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between post-cannulation days 1 and 2. CA was more impaired in VA-ECMO than VV-ECMO. Spending less time outside of MAPOPT may be associated with achieving a good neurologic outcome.

Extracorporeal Membrane Oxygenation Physiological Factors Influence Pulse Oximetry and Arterial Oxygen Saturation Discrepancies.

BACKGROUND: Cannulation strategy, vasopressors, and hemolysis are important physiological factors that influence hemodynamics in extracorporeal membrane oxygenation (ECMO). We hypothesized these factors influence the discrepancy between oxygen saturation measured by pulse oximetry (Spo2) and arterial blood gas (Sao2) in patients on ECMO. METHODS: We retrospectively analyzed adults (aged ≥18 years) on venoarterial or venovenous ECMO at a tertiary academic ECMO center. Spo2-Sao2 pairs with oxygen saturation ≥70% and measured within 10 minutes were included. Occult hypoxemia was defined as Sao2 ≤88% with a time-matched Spo2 ≥92%. Adjusted linear mixed-effects modeling was used to assess the Spo2-Sao2 discrepancy with preselected demographics and time-matched laboratory variables. Vasopressor use was quantified by vasopressor dose equivalences. RESULTS: Of 139 venoarterial-ECMO and 88 venovenous-ECMO patients, we examined 20,053 Spo2-Sao2 pairs. The Spo2-Sao2 discrepancy was greater in venovenous-ECMO (1.15%) vs venoarterial-ECMO (-0.35%, P < .001). Overall, 81 patients (35%) experienced occult hypoxemia during ECMO. Occult hypoxemia was more common in venovenous-ECMO (65%) than in venoarterial-ECMO (17%, P < .001). In linear mixed-effects modeling, Spo2 underestimated Sao2 by 9.48% in central vs peripheral venoarterial-ECMO (95% CI, -17.1% to -1.79%; P = .02). Higher vasopressor dose equivalences significantly worsened the Spo2-Sao2 discrepancy (P < .001). In linear mixed-effects modeling, Spo2 overestimated Sao2 by 25.43% in single lumen-cannulated vs double lumen-cannulated venovenous-ECMO (95% CI, 5.27%-45.6%; P = .03). Higher vasopressor dose equivalences and lactate dehydrogenase levels significantly worsened the Spo2-Sao2 discrepancy (P < .001). CONCLUSIONS: Venovenous-ECMO patients are at higher risk for occult hypoxemia compared with venoarterial-ECMO. A higher vasopressor requirement and different cannulation strategies (central venoarterial-ECMO; single-lumen venovenous-ECMO) were significant factors for clinically significant Spo2-Sao2 discrepancy in both ECMO modes.

What Factors Are Associated With Arterial Line-Related Limb Ischemia in Patients on Extracorporeal Membrane Oxygenation? A Single-Center Retrospective Cohort Study.

OBJECTIVES: The primary purpose of this study was to identify factors associated with the development of arterial line-related limb ischemia in patients on extracorporeal membrane oxygenation (ECMO). The authors also sought to characterize and report the outcomes of patients who developed arterial line-related limb ischemia. DESIGN: Retrospective cohort study. SETTING: A single academic tertiary referral ECMO center. PARTICIPANTS: Consecutive patients who were treated with ECMO over 6 years. INTERVENTIONS: Use of arterial line. MEASUREMENTS AND MAIN RESULTS: A total of 278 consecutive ECMO patients were included, with 19 (7%) patients developing arterial line-related limb ischemia during the ECMO run. Postcannulation Sequential Organ Failure Assessment (SOFA) (adjusted odds ratio [aOR] 1.20, 95% CI 1.08-1.32), Acute Physiology and Chronic Health Evaluation-II (aOR 0.84, 95% CI 0.74-0.95), and adjusted Vasopressor Dose Equivalence (aOR 1.03, 95% CI 1.01-1.05) scores were independently associated with the development of arterial line-associated limb ischemia. A SOFA score of ≥17 at the time of ECMO cannulation had an 80% sensitivity and 87% specificity for predicting arterial line-related limb ischemia. CONCLUSIONS: Arterial line-related limb ischemia is much more common in ECMO patients than in the typical intensive care unit setting. The SOFA score may be useful in identifying which patients may be at risk for arterial line-related limb ischemia. As this was a single-center retrospective study, these results are inherently exploratory, and prospective multicenter studies are necessary to validate these results.

Palliative Care Utilization in Patients Requiring Extracorporeal Membrane Oxygenation: An Observational Study.

Palliative care (PC) is a model of care centered around improving the quality of life for individuals with life-limiting illnesses. Few studies have examined its impact in patients on extracorporeal membrane oxygenation (ECMO). We aimed to describe demographics, clinical characteristics, and complications associated with PC consultation in adult patients requiring ECMO support. We analyzed data from an ECMO registry, including patients aged 18 years and older who have received either venoarterial (VA)- or venovenous (VV)-ECMO support between July 2016 and September 2021. We used analysis of variance and Fisher exact tests to identify factors associated with PC consultation. Of 256, 177 patients (69.1%) received VA-ECMO support and 79 (30.9%) received VV-ECMO support. Overall, 115 patients (44.9%) received PC consultation while on ECMO. Patients receiving PC consultation were more likely to be non-white (47% vs. 53%, p = 0.016), have an attending physician from a medical versus surgical specialty (65.3% vs. 39.6%), have VV-ECMO (77.2% vs. 30.5%, p < 0.001), and have longer ECMO duration (6.2 vs. 23.0, p < 0.001). Patients were seen by the PC team on an average of 7.6 times (range, 1-35), with those who died having significantly more visits (11.2 vs. 5.6, p < 0.001) despite the shorter hospital stay. The average time from cannulation to the first PC visit was 5.3 ± 5 days. Congestive heart failure in VA-ECMO, coronavirus disease 2019 infection in VV-ECMO, and non-white race and longer ECMO duration for all patients were associated with PC consultation. We found that despite the benefits of PC, it is underused in this population.

Trends on Near-Infrared Spectroscopy Associated With Acute Brain Injury in Venoarterial Extracorporeal Membrane Oxygenation.

We aimed to determine the association between cerebral regional oxygen saturation (rSO 2 ) trends from cerebral near-infrared spectroscopy (cNIRS) and acute brain injury (ABI) in adult venoarterial extracorporeal membrane oxygenation (VA-ECMO) patients. ABI was defined as intracranial hemorrhage, ischemic stroke, hypoxic ischemic brain injury, or brain death during ECMO. rSO 2 values were collected from left and right cerebral oximetry sensors every hour from ECMO cannulation. Cerebral desaturation was defined as consecutive hours of rSO 2 < 40%. rSO 2 asymmetry was determined by (a) averaging left/right rSO 2 difference over the entire ECMO run; (b) consecutive hours of rSO 2 asymmetry. Sixty-nine VA-ECMO patients (mean age 56 years, 65% male) underwent cNIRS. Eighteen (26%) experienced ABI. When the mean rSO 2 asymmetry was >8% there was significantly increased odds of ABI (aOR = 39.4; 95% CI = 4.1-381.4). Concurrent rSO 2 < 40% and rSO 2 asymmetry >10% for >10 consecutive hours (asymmetric desaturation) was also significantly associated with ABI (aOR = 5.2; 95% CI = 1.2-22.2), but neither criterion alone were. Mean rSO 2 asymmetry>8% exhibited 39% sensitivity and 98% specificity for detecting ABI, with an area under the curve (AUC) of 0.86, and asymmetric desaturation had 33% sensitivity and 88% specificity, with an AUC of 0.72. These trends on NIRS monitoring may help detect ABI in VA-ECMO patients.

Racial and ethnical discrepancy in hypoxemia detection in patients on extracorporeal membrane oxygenation.

Objective: To determine whether there is racial/ethnical discrepancy between pulse oximetry (SpO2) and oxygen saturation (SaO2) in patients receiving extracorporeal membrane oxygenation (ECMO). Methods: This was a retrospective observational study at a tertiary academic ECMO center with adults (>18 years) on venoarterial (VA) or venovenous (VV) ECMO. Datapoints were excluded if oxygen saturation ≤70% or SpO2-SaO2 pairs were not measured within 10 minutes. The primary outcome was the presence of a SpO2-SaO2 discrepancy between different races/ethnicities. Bland-Altman analyses and linear mixed-effects modeling, adjusting for prespecified covariates, were used to assess the SpO2-SaO2 discrepancy between races/ethnicities. Occult hypoxemia was defined as SaO2 <88% with a time-matched SpO2 ≥92%. Results: Of 139 patients receiving VA-ECMO and 57 patients receiving VV-ECMO, we examined 16,252 SpO2-SaO2 pairs. The SpO2-SaO2 discrepancy was greater in VV-ECMO (1.4%) versus VA-ECMO (0.15%). In VA-ECMO, SpO2 overestimated SaO2 in Asian (0.2%), Black (0.94%), and Hispanic (0.03%) patients and underestimated SaO2 in White (-0.06%) and nonspecified race (-0.80%) patients. The proportion of SpO2-SaO2 measurements considered occult hypoxemia was 70% from Black compared to 27% from White patients (P < .0001). In VV-ECMO, SpO2 overestimated SaO2 in Asian (1.0%), Black (2.9%), Hispanic (1.1%), and White (0.50%) patients and underestimated SaO2 in nonspecified race patients (-0.53%). In linear mixed-effects modeling, SpO2 overestimated SaO2 by 0.19% in Black patients (95% confidence interval, 0.045%-0.33%, P = .023). The proportion of SpO2-SaO2 measurements considered occult hypoxemia was 66% from Black compared with 16% from White patients (P < .0001). Conclusions: SpO2 overestimates SaO2 in Asian, Black, and Hispanic versus White patients, and this discrepancy was greater in VV-ECMO versus VA-ECMO, suggesting the need for physiological studies.

Characteristics of delirium and its association with sedation and in-hospital mortality in patients with COVID-19 on veno-venous extracorporeal membrane oxygenation.

Background: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been used in patients with COVID-19 acute respiratory distress syndrome (ARDS). We aim to assess the characteristics of delirium and describe its association with sedation and in-hospital mortality. Methods: We retrospectively reviewed adult patients on VV-ECMO for severe COVID-19 ARDS in the Johns Hopkins Hospital ECMO registry in 2020-2021. Delirium was assessed by the Confusion Assessment Method for the ICU (CAM-ICU) when patients scored-3 or above on the Richmond Agitation-Sedation Scale (RASS). Primary outcomes were delirium prevalence and duration in the proportion of days on VV-ECMO. Results: Of 47 patients (median age = 51), 6 were in a persistent coma and 40 of the remaining 41 patients (98%) had ICU delirium. Delirium in the survivors (n = 21) and non-survivors (n = 26) was first detected at a similar time point (VV-ECMO day 9.5(5,14) vs. 8.5(5,21), p = 0.56) with similar total delirium days on VV-ECMO (9.5[3.3, 16.8] vs. 9.0[4.3, 28.3] days, p = 0.43). Non-survivors had numerically lower RASS scores on VV-ECMO days (-3.72[-4.42, -2.96] vs. -3.10[-3.91, -2.21], p = 0.06) and significantly prolonged delirium-unassessable days on VV-ECMO with a RASS of -4/-5 (23.0[16.3, 38.3] vs. 17.0(6,23), p = 0.03), and total VV-ECMO days (44.5[20.5, 74.3] vs. 27.0[21, 38], p = 0.04). The proportion of delirium-present days correlated with RASS (r = 0.64, p < 0.001), the proportions of days on VV-ECMO with a neuromuscular blocker (r = -0.59, p = 0.001), and with delirium-unassessable exams (r = -0.69, p < 0.001) but not with overall ECMO duration (r = 0.01, p = 0.96). The average daily dosage of delirium-related medications on ECMO days did not differ significantly. On an exploratory multivariable logistic regression, the proportion of delirium days was not associated with mortality. Conclusion: Longer duration of delirium was associated with lighter sedation and shorter paralysis, but it did not discern in-hospital mortality. Future studies should evaluate analgosedation and paralytic strategies to optimize delirium, sedation level, and outcomes.

Challenges in determining death by neurologic criteria in extracorporeal membrane oxygenation - A single center experience.

INTRODUCTION: Apnea test (AT) in patients on extracorporeal membrane oxygenation (ECMO) support is challenging, leading to variation in determining death by neurologic criteria (DNC). We aim to describe the diagnostic criteria and barriers for DNC in adults on ECMO in a tertiary care center. METHODS: A retrospective review of a prospective observational standardized neuromonitoring study was conducted in adult VA- and VV-ECMO patients at a tertiary center from June 2016 to March 2022. Brain death was defined according to the 2010 American Academy of Neurology guidelines and following the 2020 World Brain Death Project recommendations for performing AT in ECMO patients. RESULTS: Eight (2.7%) ECMO patients (median age = 44 years, 75% male, 50% VA-ECMO) met criteria for DNC, six (75%) of whom were determined with AT. In the other two patients who did not undergo AT due to safety concerns, ancillary tests (transcranial doppler and electroencephalography) were consistent with DNC. An additional seven (2.3%) patients (median age = 55 years, 71% male, 86% VA-ECMO) were noted to have absent brainstem reflexes but failed to complete determination of DNC as they underwent withdrawal of life-sustaining treatment (WLST) before a full evaluation was completed. In these patients, AT was never performed, and ancillary tests were inconsistent with either neurological exam findings and/or neuroimaging supporting DNC, or with each other. CONCLUSION: AT was used safely and successfully in 6 of the 8 ECMO patients diagnosed with DNC and was always consistent with the neurological exam and imaging findings, as opposed to ancillary tests alone.

Is Fasciotomy Associated With Increased Mortality in Extracorporeal Cardiopulmonary Resuscitation?

Our primary objective was to identify if fasciotomy was associated with increased mortality in patients who developed acute compartment syndrome (ACS) on extracorporeal cardiopulmonary resuscitation (ECPR). Additionally, we sought to identify any additional risk factors for mortality in these patients and report the amputation-free survival following fasciotomy. We retrospectively reviewed adult ECPR patients from the Extracorporeal Life Support Organization registry who were diagnosed with ACS between 2013 and 2021. Of 764 ECPR patients with limb complications, 127 patients (17%) with ACS were identified, of which 78 (63%) had fasciotomies, and 14 (11%) had amputations. Fasciotomy was associated with a 23% rate of amputation-free survival. There were no significant differences in demographics or baseline laboratory values between those with and without fasciotomy. Overall, 88 of 127 (69%) patients with ACS died. With or without fasciotomy, the mortality of ACS patients was similar, 68% vs. 71%. Multivariable logistic regression demonstrated that body mass index (BMI; adjusted odds ratio [aOR] = 1.22, 95% confidence interval [CI] = 1.01-1.48) and 24 hour mean blood pressure (BP; aOR = 0.93, 95% CI = 0.88-0.99) were independently associated with mortality. Fasciotomy was not an independent risk factor for mortality (aOR = 0.24, 95% CI = 0.03-1.88). The results of this study may help guide surgical decision-making for patients who develop ACS after ECPR. However, the retrospective nature of this study does not preclude selection bias in patients who have received fasciotomy. Thus, prospective studies are necessary to confirm these findings.

A case series evaluating the effect of esmolol therapy to treat hypoxemia in COVID-19 patients on VV-ECMO.

When COVID-19 ARDS abolishes pulmonary function, VV-ECMO can provide gas exchange. If oxygenation remains insufficient despite maximal VV-ECMO support, the addition of esmolol has been proposed. Conflict exists, however, as to the oxygenation level which should trigger beta-blocker initiation. We evaluated the effect of esmolol therapy on oxygenation and oxygen delivery in patients with negligible native lung function and various degrees of hypoxemia despite maximal VV-ECMO support. We found that, in COVID-19 patients with negligible pulmonary gas exchange, the generalized use of esmolol administration to raise arterial oxygenation by slowing heart rate and thereby match native cardiac output to maximal attainable VV ECMO flows actually reduces systemic oxygen delivery in many cases.