Early Extracorporeal CPR for Refractory Out-of-Hospital Cardiac Arrest.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation (CPR) restores perfusion and oxygenation in a patient who does not have spontaneous circulation. The evidence with regard to the effect of extracorporeal CPR on survival with a favorable neurologic outcome in refractory out-of-hospital cardiac arrest is inconclusive. METHODS: In this multicenter, randomized, controlled trial conducted in the Netherlands, we assigned patients with an out-of-hospital cardiac arrest to receive extracorporeal CPR or conventional CPR (standard advanced cardiac life support). Eligible patients were between 18 and 70 years of age, had received bystander CPR, had an initial ventricular arrhythmia, and did not have a return of spontaneous circulation within 15 minutes after CPR had been initiated. The primary outcome was survival with a favorable neurologic outcome, defined as a Cerebral Performance Category score of 1 or 2 (range, 1 to 5, with higher scores indicating more severe disability) at 30 days. Analyses were performed on an intention-to-treat basis. RESULTS: Of the 160 patients who underwent randomization, 70 were assigned to receive extracorporeal CPR and 64 to receive conventional CPR; 26 patients who did not meet the inclusion criteria at hospital admission were excluded. At 30 days, 14 patients (20%) in the extracorporeal-CPR group were alive with a favorable neurologic outcome, as compared with 10 patients (16%) in the conventional-CPR group (odds ratio, 1.4; 95% confidence interval, 0.5 to 3.5; P = 0.52). The number of serious adverse events per patient was similar in the two groups. CONCLUSIONS: In patients with refractory out-of-hospital cardiac arrest, extracorporeal CPR and conventional CPR had similar effects on survival with a favorable neurologic outcome. (Funded by the Netherlands Organization for Health Research and Development and Maquet Cardiopulmonary [Getinge]; INCEPTION ClinicalTrials.gov number, NCT03101787.).

Bilateral Femoral Cannulation Is Associated With Reduced Severe Limb Ischemia-Related Complications Compared With Unilateral Femoral Cannulation in Adult Peripheral Venoarterial Extracorporeal Membrane Oxygenation: Results From the Extracorporeal Life Support Registry.

OBJECTIVES: Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) with femoral access is obtained through unilateral or bilateral groin cannulation. Whether one cannulation strategy is associated with a lower risk for limb ischemia remains unknown. We aim to assess if one strategy is preferable. DESIGN: A retrospective cohort study based on the Extracorporeal Life Support Organization registry. SETTING: ECMO centers worldwide included in the Extracorporeal Life Support Organization registry. PATIENTS: All adult patients (≥ 18 yr) who received peripheral venoarterial ECMO with femoral access and were included from 2014 to 2020. INTERVENTIONS: Unilateral or bilateral femoral cannulation. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the occurrence of limb ischemia defined as a composite endpoint including the need for a distal perfusion cannula (DPC) after 6 hours from implantation, compartment syndrome/fasciotomy, amputation, revascularization, and thrombectomy. Secondary endpoints included bleeding at the peripheral cannulation site, need for vessel repair, vessel repair after decannulation, and in-hospital death. Propensity score matching was performed to account for confounders. Overall, 19,093 patients underwent peripheral venoarterial ECMO through unilateral ( n = 11,965) or bilateral ( n = 7,128) femoral cannulation. Limb ischemia requiring any intervention was not different between both groups (bilateral vs unilateral: odds ratio [OR], 0.92; 95% CI, 0.82-1.02). However, there was a lower rate of compartment syndrome/fasciotomy in the bilateral group (bilateral vs unilateral: OR, 0.80; 95% CI, 0.66-0.97). Bilateral cannulation was also associated with lower odds of cannulation site bleeding (bilateral vs unilateral: OR, 0.87; 95% CI, 0.76-0.99), vessel repair (bilateral vs unilateral: OR, 0.55; 95% CI, 0.38-0.79), and in-hospital mortality (bilateral vs unilateral: OR, 0.85; 95% CI, 0.81-0.91) compared with unilateral cannulation. These findings were unchanged after propensity matching. CONCLUSIONS: This study showed no risk reduction for overall limb ischemia-related events requiring DPC after 6 hours when comparing bilateral to unilateral femoral cannulation in peripheral venoarterial ECMO. However, bilateral cannulation was associated with a reduced risk for compartment syndrome/fasciotomy, lower rates of bleeding and vessel repair during ECMO, and lower in-hospital mortality.

Extracorporeal cardiopulmonary resuscitation versus standard treatment for refractory out-of-hospital cardiac arrest: a Bayesian meta-analysis.

BACKGROUND: The outcomes of several randomized trials on extracorporeal cardiopulmonary resuscitation (ECPR) in patients with refractory out-of-hospital cardiac arrest were examined using frequentist methods, resulting in a dichotomous interpretation of results based on p-values rather than in the probability of clinically relevant treatment effects. To determine such a probability of a clinically relevant ECPR-based treatment effect on neurological outcomes, the authors of these trials performed a Bayesian meta-analysis of the totality of randomized ECPR evidence. METHODS: A systematic search was applied to three electronic databases. Randomized trials that compared ECPR-based treatment with conventional CPR for refractory out-of-hospital cardiac arrest were included. The study was preregistered in INPLASY (INPLASY2023120060). The primary Bayesian hierarchical meta-analysis estimated the difference in 6-month neurologically favorable survival in patients with all rhythms, and a secondary analysis assessed this difference in patients with shockable rhythms (Bayesian hierarchical random-effects model). Primary Bayesian analyses were performed under vague priors. Outcomes were formulated as estimated median relative risks, mean absolute risk differences, and numbers needed to treat with corresponding 95% credible intervals (CrIs). The posterior probabilities of various clinically relevant absolute risk difference thresholds were estimated. RESULTS: Three randomized trials were included in the analysis (ECPR, n = 209 patients; conventional CPR, n = 211 patients). The estimated median relative risk of ECPR for 6-month neurologically favorable survival was 1.47 (95%CrI 0.73-3.32) with a mean absolute risk difference of 8.7% (- 5.0; 42.7%) in patients with all rhythms, and the median relative risk was 1.54 (95%CrI 0.79-3.71) with a mean absolute risk difference of 10.8% (95%CrI - 4.2; 73.9%) in patients with shockable rhythms. The posterior probabilities of an absolute risk difference > 0% and > 5% were 91.0% and 71.1% in patients with all rhythms and 92.4% and 75.8% in patients with shockable rhythms, respectively. CONCLUSION: The current Bayesian meta-analysis found a 71.1% and 75.8% posterior probability of a clinically relevant ECPR-based treatment effect on 6-month neurologically favorable survival in patients with all rhythms and shockable rhythms. These results must be interpreted within the context of the reported credible intervals and varying designs of the randomized trials. REGISTRATION: INPLASY (INPLASY2023120060, December 14th, 2023, https://doi.org/10.37766/inplasy2023.12.0060 ).

Transfusion of red blood cells in venoarterial extracorporeal membrane oxygenation: A multicenter retrospective observational cohort study.

BACKGROUND: Evidence-based recommendations for transfusion in patients with venoarterial extracorporeal membrane oxygenation (VA ECMO) are scarce. The current literature is limited to single-center studies with small sample sizes, therefore complicating generalizability. This study aims to create an overview of red blood cell (RBC) transfusion in VA ECMO patients. METHODS: This international mixed-method study combined a survey with a retrospective observational study in 16 centers. The survey inventoried local transfusion guidelines. Additionally, retrospective data of all adult patients with a VA ECMO run >24 h (January 2018 until July 2019) was collected of patient, ECMO, outcome, and daily transfusion parameters. All patients that received VA ECMO for primary cardiac support were included, including surgical (i.e., post-cardiotomy) and non-surgical (i.e., myocardial infarction) indications. The primary outcome was the number of RBC transfusions per day and in total. Univariable logistic regressions and a generalized linear mixed model (GLMM) were performed to assess factors associated with RBC transfusion. RESULTS: Out of 419 patients, 374 (89%) received one or more RBC transfusions. During a median ECMO run of 5 days (1st-3rd quartile 3-8), patients received a median total of eight RBC units (1st-3rd quartile 3-17). A lower hemoglobin (Hb) prior to ECMO, longer ECMO-run duration, and hemorrhage were associated with RBC transfusion. After correcting for duration and hemorrhage using a GLMM, a different transfusion trend was found among the regimens. No unadjusted differences were found in overall survival between either transfusion status or the different regimens, which remained after adjustment for potential confounders. CONCLUSION: RBC transfusion in patients on VA ECMO is very common. The sum of RBC transfusions increases rapidly after ECMO initiation, and is dependent on the Hb threshold applied. This study supports the rationale for prospective studies focusing on indications and thresholds for RBC transfusion.

The interaction of thrombocytopenia, hemorrhage, and platelet transfusion in venoarterial extracorporeal membrane oxygenation: a multicenter observational study.

BACKGROUND: Thrombocytopenia, hemorrhage and platelet transfusion are common in patients supported with venoarterial extracorporeal membrane oxygenation (VA ECMO). However, current literature is limited to small single-center experiences with high degrees of heterogeneity. Therefore, we aimed to ascertain in a multicenter study the course and occurrence rate of thrombocytopenia, and to assess the association between thrombocytopenia, hemorrhage and platelet transfusion during VA ECMO. METHODS: This was a sub-study of a multicenter (N = 16) study on transfusion practices in patients on VA ECMO, in which a retrospective cohort (Jan-2018-Jul-2019) focusing on platelets was selected. The primary outcome was thrombocytopenia during VA ECMO, defined as mild (100-150·109/L), moderate (50-100·109/L) and severe (< 50·109/L). Secondary outcomes included the occurrence rate of platelet transfusion, and the association between thrombocytopenia, hemorrhage and platelet transfusion, assessed through mixed-effect models. RESULTS: Of the 419 patients included, median platelet count at admission was 179·109/L. During VA ECMO, almost all (N = 398, 95%) patients developed a thrombocytopenia, of which a significant part severe (N = 179, 45%). One or more platelet transfusions were administered in 226 patients (54%), whereas 207 patients (49%) suffered a hemorrhagic event during VA ECMO. In non-bleeding patients, still one in three patients received a platelet transfusion. The strongest association to receive a platelet transfusion was found in the presence of severe thrombocytopenia (adjusted OR 31.8, 95% CI 17.9-56.5). After including an interaction term of hemorrhage and thrombocytopenia, this even increased up to an OR of 110 (95% CI 34-360). CONCLUSIONS: Thrombocytopenia has a higher occurrence than is currently recognized. Severe thrombocytopenia is strongly associated with platelet transfusion. Future studies should focus on the etiology of severe thrombocytopenia during ECMO, as well as identifying indications and platelet thresholds for transfusion in the absence of bleeding. TRIAL REGISTRATION: This study was registered at the Netherlands Trial Registry at February 26th, 2020 with number NL8413 and can currently be found at https://trialsearch.who.int/Trial2.aspx?TrialID=NL8413.

International survey of neuromonitoring and neurodevelopmental outcome in children and adults supported on extracorporeal membrane oxygenation in Europe.

BACKGROUND: Adverse neurological events during extracorporeal membrane oxygenation (ECMO) are common and may be associated with devastating consequences. Close monitoring, early identification and prompt intervention can mitigate early and late neurological morbidity. Neuromonitoring and neurocognitive/neurodevelopmental follow-up are critically important to optimize outcomes in both adults and children. OBJECTIVE: To assess current practice of neuromonitoring during ECMO and neurocognitive/neurodevelopmental follow-up after ECMO across Europe and to inform the development of neuromonitoring and follow-up guidelines. METHODS: The EuroELSO Neurological Monitoring and Outcome Working Group conducted an electronic, web-based, multi-institutional, multinational survey in Europe. RESULTS: Of the 211 European ECMO centres (including non-ELSO centres) identified and approached in 23 countries, 133 (63%) responded. Of these, 43% reported routine neuromonitoring during ECMO for all patients, 35% indicated selective use, and 22% practiced bedside clinical examination alone. The reported neuromonitoring modalities were NIRS (n = 88, 66.2%), electroencephalography (n = 52, 39.1%), transcranial Doppler (n = 38, 28.5%) and brain injury biomarkers (n = 33, 24.8%). Paediatric centres (67%) reported using cranial ultrasound, though the frequency of monitoring varied widely. Before hospital discharge following ECMO, 50 (37.6%) reported routine neurological assessment and 22 (16.5%) routinely performed neuroimaging with more paediatric centres offering neurological assessment (65%) as compared to adult centres (20%). Only 15 (11.2%) had a structured longitudinal follow-up pathway (defined followup at regular intervals), while 99 (74.4%) had no follow-up programme. The majority (n = 96, 72.2%) agreed that there should be a longitudinal structured follow-up for ECMO survivors. CONCLUSIONS: This survey demonstrated significant variability in the use of different neuromonitoring modalities during and after ECMO. The perceived importance of neuromonitoring and follow-up was noted to be very high with agreement for a longitudinal structured follow-up programme, particularly in paediatric patients. Scientific society endorsed guidelines and minimum standards should be developed to inform local protocols.

Coronary Angiography after Cardiac Arrest without ST-Segment Elevation.

BACKGROUND: Ischemic heart disease is a major cause of out-of-hospital cardiac arrest. The role of immediate coronary angiography and percutaneous coronary intervention (PCI) in the treatment of patients who have been successfully resuscitated after cardiac arrest in the absence of ST-segment elevation myocardial infarction (STEMI) remains uncertain. METHODS: In this multicenter trial, we randomly assigned 552 patients who had cardiac arrest without signs of STEMI to undergo immediate coronary angiography or coronary angiography that was delayed until after neurologic recovery. All patients underwent PCI if indicated. The primary end point was survival at 90 days. Secondary end points included survival at 90 days with good cerebral performance or mild or moderate disability, myocardial injury, duration of catecholamine support, markers of shock, recurrence of ventricular tachycardia, duration of mechanical ventilation, major bleeding, occurrence of acute kidney injury, need for renal-replacement therapy, time to target temperature, and neurologic status at discharge from the intensive care unit. RESULTS: At 90 days, 176 of 273 patients (64.5%) in the immediate angiography group and 178 of 265 patients (67.2%) in the delayed angiography group were alive (odds ratio, 0.89; 95% confidence interval [CI], 0.62 to 1.27; P = 0.51). The median time to target temperature was 5.4 hours in the immediate angiography group and 4.7 hours in the delayed angiography group (ratio of geometric means, 1.19; 95% CI, 1.04 to 1.36). No significant differences between the groups were found in the remaining secondary end points. CONCLUSIONS: Among patients who had been successfully resuscitated after out-of-hospital cardiac arrest and had no signs of STEMI, a strategy of immediate angiography was not found to be better than a strategy of delayed angiography with respect to overall survival at 90 days. (Funded by the Netherlands Heart Institute and others; COACT Netherlands Trial Register number, NTR4973.).

Targeted Temperature Management in Out-of-Hospital Cardiac Arrest With Shockable Rhythm: A Post Hoc Analysis of the Coronary Angiography After Cardiac Arrest Trial.

OBJECTIVES: The optimal targeted temperature in patients with shockable rhythm is unclear, and current guidelines recommend targeted temperature management with a correspondingly wide range between 32°C and 36°C. Our aim was to study survival and neurologic outcome associated with targeted temperature management strategy in postarrest patients with initial shockable rhythm. DESIGN: Observational substudy of the Coronary Angiography after Cardiac Arrest without ST-segment Elevation trial. SETTING: Nineteen hospitals in The Netherlands. PATIENTS: The Coronary Angiography after Cardiac Arrest trial randomized successfully resuscitated patients with shockable rhythm and absence of ST-segment elevation to a strategy of immediate or delayed coronary angiography. In this substudy, 459 patients treated with mild therapeutic hypothermia (32.0-34.0°C) or targeted normothermia (36.0-37.0°C) were included. Allocation to targeted temperature management strategy was at the discretion of the physician. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After 90 days, 171 patients (63.6%) in the mild therapeutic hypothermia group and 129 (67.9%) in the targeted normothermia group were alive (hazard ratio, 0.86 [95% CI, 0.62-1.18]; log-rank p = 0.35; adjusted odds ratio, 0.89; 95% CI, 0.45-1.72). Patients in the mild therapeutic hypothermia group had longer ICU stay (4 d [3-7 d] vs 3 d [2-5 d]; ratio of geometric means, 1.32; 95% CI, 1.15-1.51), lower blood pressures, higher lactate levels, and increased need for inotropic support. Cerebral Performance Category scores at ICU discharge and 90-day follow-up and patient-reported Mental and Physical Health Scores at 1 year were similar in the two groups. CONCLUSIONS: In the context of out-of-hospital cardiac arrest with shockable rhythm and no ST-elevation, treatment with mild therapeutic hypothermia was not associated with improved 90-day survival compared with targeted normothermia. Neurologic outcomes at 90 days as well as patient-reported Mental and Physical Health Scores at 1 year did not differ between the groups.

RBC Transfusion in Venovenous Extracorporeal Membrane Oxygenation: A Multicenter Cohort Study.

OBJECTIVES: In the general critical care patient population, restrictive transfusion regimen of RBCs has been shown to be safe and is yet implemented worldwide. However, in patients on venovenous extracorporeal membrane oxygenation, guidelines suggest liberal thresholds, and a clear overview of RBC transfusion practice is lacking. This study aims to create an overview of RBC transfusion in venovenous extracorporeal membrane oxygenation. DESIGN: Mixed method approach combining multicenter retrospective study and survey. SETTING: Sixteen ICUs worldwide. PATIENTS: Patients receiving venovenous extracorporeal membrane oxygenation between January 2018 and July 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the proportion receiving RBC, the amount of RBC units given daily and in total. Furthermore, the course of hemoglobin over time during extracorporeal membrane oxygenation was assessed. Demographics, extracorporeal membrane oxygenation characteristics, and patient outcome were collected. Two-hundred eight patients received venovenous extracorporeal membrane oxygenation, 63% male, with an age of 55 years (45-62 yr), mainly for acute respiratory distress syndrome. Extracorporeal membrane oxygenation duration was 9 days (5-14 d). Prior to extracorporeal membrane oxygenation, hemoglobin was 10.8 g/dL (8.9-13.0 g/dL), decreasing to 8.7 g/dL (7.7-9.8 g/dL) during extracorporeal membrane oxygenation. Nadir hemoglobin was lower on days when a transfusion was administered (8.1 g/dL [7.4-9.3 g/dL]). A vast majority of 88% patients received greater than or equal to 1 RBC transfusion, consisting of 1.6 U (1.3-2.3 U) on transfusion days. This high transfusion occurrence rate was also found in nonbleeding patients (81%). Patients with a liberal transfusion threshold (hemoglobin > 9 g/dL) received more RBC in total per transfusion day and extracorporeal membrane oxygenation day. No differences in survival, hemorrhagic and thrombotic complication rates were found between different transfusion thresholds. Also, 28-day mortality was equal in transfused and nontransfused patients. CONCLUSIONS: Transfusion of RBC has a high occurrence rate in patients on venovenous extracorporeal membrane oxygenation, even in nonbleeding patients. There is a need for future studies to find optimal transfusion thresholds and triggers in patients on extracorporeal membrane oxygenation.

Defining and understanding the "extra-corporeal membrane oxygenation gap" in the veno-venous configuration: Timing and causes of death.

In-hospital mortality of adult veno-venous extracorporeal membrane oxygenation (V-V ECMO) patients remains invariably high. However, little is known regarding timing and causes of in-hospital death, either on-ECMO or after weaning. The current review aims to investigate the timing and causes of death of adult patients during hospital admittance for V-V ECMO, and to define the V-V ECMO gap, which is represented by the patients that are successfully weaned of ECMO but still die during hospital stay. A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V-V ECMO patients from January 2006 to December 2020 were screened. Studies that did not report on at least on-ECMO mortality and discharge rate were excluded from analysis as they could not provide the required information regarding the proposed V-V ECMO-gap. Mortality rates on-ECMO and after weaning, as well as weaning and discharge rates, were analyzed as primary outcomes. Secondary outcomes were the causes of death and complications. Initially, 35 studies were finally included in this review. Merely 24 of these studies (comprising 975 patients) reported on prespecified V-V ECMO outcomes (on-ECMO mortality and discharge rate). Mortality on V-V ECMO support was 27.8% (95% confidence interval (CI) 22.5%-33.2%), whereas mortality after successful weaning was 12.7% (95% CI 8.8%-16.6%, defining the V-V ECMO gap). 72.2% of patients (95% CI 66.8%-77.5%) were weaned successfully from support and 56.8% (95% CI 49.9%-63.8%) of patients were discharged from hospital. The most common causes of death on ECMO were multiple organ failure, bleeding, and sepsis. Most common causes of death after weaning were multiorgan failure and sepsis. Although the majority of patients are weaned successfully from V-V ECMO support, a significant proportion of subjects still die during hospital stay, defining the V-V ECMO gap. Overall, timing and causes of death are poorly reported in current literature. Future studies on V-V ECMO should describe morbidity and mortality outcomes in more detail in relation to the timing of the events, to improve patient management, due to enhanced understanding of the clinical course.