Bleeding and Thrombosis in Patients With Out-of-Hospital Ventricular Tachycardia/Ventricular Fibrillation Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Extracorporeal cardiopulmonary resuscitation improves outcomes after out-of-hospital cardiac arrest. However, bleeding and thrombosis are common complications. We aimed to describe the incidence and predictors of bleeding and thrombosis and their association with in-hospital mortality.

METHODS AND RESULTS

Consecutive patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest between December 2015 and March 2022 who met the criteria for extracorporeal cardiopulmonary resuscitation initiation at our center were included. Major bleeding was defined by the Extracorporeal Life Support Organization's criteria. Adjusted analyses were done to seek out risk factors for bleeding and thrombosis and evaluate their association with mortality. Major bleeding occurred in 135 of 200 patients (67.5%), with traumatic bleeding from cardiopulmonary resuscitation in 73 (36.5%). Baseline demographics and arrest characteristics were similar between groups. In multivariable analysis, decreasing levels of fibrinogen were independently associated with bleeding (adjusted hazard ratio [aHR], 0.98 per every 10 mg/dL rise [95% CI, 0.96-0.99]). Patients who died had a higher rate of bleeds per day (0.21 versus 0.03, P<0.001) though bleeding was not significantly associated with in-hospital death (aHR, 0.81 [95% CI. 0.55-1.19]). A thrombotic event occurred in 23.5% (47/200) of patients. Venous thromboembolism occurred in 11% (22/200) and arterial thrombi in 15.5% (31/200). Clinical characteristics were comparable between groups. In adjusted analyses, no risk factors for thrombosis were identified. Thrombosis was not associated with in-hospital death (aHR, 0.65 [95% CI, 0.42-1.03]).

CONCLUSIONS

Bleeding is a frequent complication of extracorporeal cardiopulmonary resuscitation that is associated with decreased fibrinogen levels on admission whereas thrombosis is less common. Neither bleeding nor thrombosis was significantly associated with in-hospital mortality.

Need for a Cardiogenic Shock Team Collaborative-Promoting a Team-Based Model of Care to Improve Outcomes and Identify Best Practices

Cardiogenic shock continues to carry a high mortality rate despite contemporary care, with no breakthrough therapies shown to improve survival over the past few decades. It is a time-sensitive condition that commonly results in cardiovascular complications and multisystem organ failure, necessitating multidisciplinary expertise. Managing patients with cardiogenic shock remains challenging even in well-resourced settings, and an important subgroup of patients may require cardiac replacement therapy. As a result, the idea of leveraging the collective cognitive and procedural proficiencies of multiple providers in a collaborative, team-based approach to care (the "shock team") has been advocated by professional societies and implemented at select high-volume clinical centers. A slowly maturing evidence base has suggested that cardiogenic shock teams may improve patient outcomes. Although several registries exist that are beginning to inform care, particularly around therapeutic strategies of pharmacologic and mechanical circulatory support, none of these are currently focused on the shock team approach, multispecialty partnership, education, or process improvement. We propose the creation of a Cardiogenic Shock Team Collaborative-akin to the successful Pulmonary Embolism Response Team Consortium-with a goal to promote sharing of care protocols, education of stakeholders, and discovery of how process and performance may influence patient outcomes, quality, resource consumption, and costs of care.

Left ventricular hemodynamics with veno-arterial extracorporeal membrane oxygenation

BACKGROUND

There is considerable debate about the hemodynamic effects of veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

AIMS

To evaluate the changes in left ventricular (LV) function, volumes, and work in patients treated with VA-ECMO using invasive LV catheterization and three-dimensional echocardiographic volumes.

METHODS

Patients on VA-ECMO underwent invasive hemodynamic evaluation due to concerns regarding candidacy for decannulation. Hemodynamic parameters were reported as means±standard deviations or medians (interquartile ranges) after evaluating for normality. Paired comparisons were done to evaluate hemodynamics at the baseline (highest) and lowest tolerated levels of VA-ECMO support.

RESULTS

Twenty patients aged 52.3 ± 15.8 years were included. All patients received VA-ECMO for refractory cardiogenic shock (5/20 SCAI stage D, 15/20 SCAI stage E). At 3.0 (2.0, 4.0) days after VA-ECMO cannulation, the baseline LV ejection fraction was 20% (15%, 27%). The baseline and lowest VA-ECMO flows were 4.0 ± 0.6 and 1.5 ± 0.6 L/min, respectively. Compared to the lowest flow, full VA-ECMO support reduced LV end-diastolic volume [109 ± 81 versus 134 ± 93 mL, p = 0.001], LV end-diastolic pressure (14 ± 9 vs. 19 ± 9 mmHg, p < 0.001), LV stroke work (1858 ± 1413 vs. 2550 ± 1486 mL*mmHg, p = 0.002), and LV pressure-volume area (PVA) (4507 ± 1910 vs. 5193 ± 2388, p = 0.03) respectively. Mean arterial pressure was stable at the highest and lowest flows (80 ± 16 vs. 75 ± 14, respectively; p = 0.08) but arterial elastance was higher at the highest VA-ECMO flow (4.9 ± 2.2 vs lowest flow 2.7 ± 1.6; p < 0.001).

CONCLUSIONS

High flow VA-ECMO support significantly reduced LV end-diastolic pressure, end-diastolic volume, stroke work, and PVA compared to minimal support. The Ea was higher and MAP was stable or minimally elevated on high flow.

2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Cardiac arrest is common and deadly, affecting up to 700 000 people in the United States annually. Advanced cardiac life support measures are commonly used to improve outcomes. This "2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support" summarizes the most recent published evidence for and recommendations on the use of medications, temperature management, percutaneous coronary angiography, extracorporeal cardiopulmonary resuscitation, and seizure management in this population. We discuss the lack of data in recent cardiac arrest literature that limits our ability to evaluate diversity, equity, and inclusion in this population. Last, we consider how the cardiac arrest population may make up an important pool of organ donors for those awaiting organ transplantation.

Cerebral hemodynamic effects of head-up CPR in a porcine model

AIM

To assess the hemodynamic effects of head elevation on cerebral perfusion during cardiopulmonary resuscitation (CPR) in a porcine model of cardiac arrest.

METHODS

VF was induced in eight 65 kg pigs that were treated with CPR after five minutes of no flow. Mean arterial pressure (MAP) was measured at the descending thoracic aorta. Internal carotid artery blood flow (CBF) was measured with an ultrasound probe. Cerebral perfusion pressure (CerPP) was calculated in two ways (CerPPICAP and CerPPreported) using the same intracranial pressure (ICP) measurement. CePPreported was calculated as MAP-ICP. CerPPICAP was calculated by using intracranial arterial pressure (ICAP) - ICP. The animals were switched between head up (HUP) and supine (SUP) CPR every five minutes for a total of twenty minutes of resuscitation.

RESULTS

MAP and coronary perfusion pressure measurements were similar in both CPR positions (p = 0.36 and p = 0.1, respectively). ICP was significantly lower in the HUP CPR group (14.7 ± 1 mm Hg vs 26.9 ± 1 mm Hg, p < 0.001) as was ICAP (30.1 ± 2 mm Hg vs 42.6 ± 1 mmHg, p < 0.001). The proportional decrease in ICP and ICAP resulted in similar CerPPICAP comparing HUP and SUPCPR (p = 0.7). CBF was significantly lower during HUPCPR when compared to SUPCPR (58.5 ± 3 ml/min vs 78 ± 4 ml/min, p < 0.001). A higher CerPPreported was found during the HUP compared to SUP-CPR, when MAP was used (36.6 ± 2 mm Hg vs 23 ± 2 mm Hg, p < 0.001) without correcting for the hydrostatic pressure drop.

CONCLUSION

HUP did not affect cerebral perfusion pressure and it significantly decreased internal carotid blood flow.

Wolf Creek XVII Part 7: Mechanical circulatory support

Introduction

Failure to restore spontaneous circulation remains a major cause of death for cardiac arrest (CA) patients. Mechanical circulatory support, specifically extracorporeal cardiopulmonary resuscitation (ECPR), has emerged as a feasible and efficacious rescue strategy for selected refractory CA patients.

Methods

Mechanical Circulatory Support was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top 5 knowledge gaps included optimal patient selection, pre-ECPR treatments, logistical and programmatic characteristics of ECPR programs, generalizability and effectiveness of ECPR, and prevention of reperfusion injury. Top 5 barriers to translation included cost/resource limitations, technical challenges, collaboration across multiple disciplines, limited patient population, and early identification of eligible patients. Top 5 research priorities focused on comparing the outcomes of prehospital/rapid transport strategies vs in-hospital ECPR initiation, implementation of high-performing ECPR system vs standard care, rapid patient identification tools vs standard clinical judgment, post-cardiac arrest bundled care vs no bundled care, and standardized ECPR clinical protocol vs routine care.

Conclusion

This overview can serve as an innovative guide to transform the care and outcome of patients with refractory CA.

Impact of age on survival for patients receiving ECPR for refractory out-of-hospital VT/VF cardiac arrest

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve neurologically favorable survival for patients with refractory ventricular tachycardia (VT)/ventricular fibrillation (VF) out-of-hospital cardiac arrest. Prior studies of the impact of age on outcomes in ECPR have demonstrated mixed results and we aim to investigate this relationship.

METHODS

Patients treated with ECPR at the University of Minnesota Medical Center for refractory out-of-hospital VT/VF arrest from December 2015 to February 2023 were included. The primary endpoints included neurologically favorable survival to discharge. A receiver operating characteristic curve was used to determine an optimal predictive age limit with the highest accuracy for neurologically favorable survival.

RESULTS

391 consecutive patients were included: 22% (n = 86) were female and the mean age was 56.9 ± 11.8 years. Age was independently associated with neurologically favorable survival to discharge, with a 30% decrease in survival with every 10-year increase in age (OR 0.7 (0.57-0.87), p = 0.001. Among those with neurologically favorable survival to discharge, older patients had longer length of hospital stay compared to younger age groups (p = 0.002) while patients who failed to achieve neurologically favorable survival to discharge had similar length of stay independent of age (p = 0.51).

CONCLUSIONS

Age is associated with neurologically favorable survival to discharge for patients receiving ECPR for refractory out-of-the-hospital VT/VF cardiac arrest. However, with a survival rate of 23% in the oldest age group, caution should be used when choosing age criteria for patient selection.

Case Report: Correlation between pulmonary capillary wedge pressure and left-ventricular diastolic pressure during treatment with veno-arterial extracorporeal membrane oxygenation

Background

Pulmonary capillary wedge pressure (PCWP) is often used as a surrogate for left-ventricular end-diastolic pressure in patients (LVEDP) who are on veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support for cardiogenic shock and cardiac arrest. However, the correlation between PCWP and LVEDP is not clear in the setting of V-A ECMO usage. We sought to evaluate this correlation in this case series.

Methods

Patients were referred to our cardiac catheterization laboratory for invasive hemodynamic studies to assess their readiness for VA-ECMO decannulation. All patients underwent simultaneous left and right heart catheterization. Using standard techniques, we measured PCWP and LVEDP simultaneously. Continuous variables were reported as medians with interquartile ranges. The correlation between PCWP and LVEDP was evaluated using simple linear regression and reported as R2.

Results

Four patients underwent invasive hemodynamic studies 4 (2.5, 7) days after VA-ECMO cannulation. All four patients had suffered in-hospital cardiac arrest and had been put on VA-ECMO. At the baseline level of VA-ECMO flow of 4.1 (3.8, 4.4) L/min, the median LVEDP and PCWP were 6 (4, 7.5) mmHg and 12 (6.5, 16) mmHg, respectively. At the lowest level of VA-ECMO flow of 1.9 (1.6, 2.0) L/min, the median LVEDP and PCWP was 13.5 (8.5, 16) mmHg and 15 (13, 18) mmHg, respectively. There was a poor correlation between the simultaneously measured PCWP and LVEDP (R2 = 0.03, p = 0.66).

Conclusions

The PCWP may not correlate well with LVEDP in patients treated with VA-ECMO, particularly at high levels of VA-ECMO support.

Extracorporeal membrane oxygenation for the treatment of massive pulmonary embolism. An analysis of the ELSO database

AIM

Extracorporeal membrane oxygenation (ECMO) may be beneficial in treatment of massive pulmonary embolus (PE), however the current evidence to guide its use is limited. We aimed to compare the incidence, characteristics, treatments, and outcomes of patients with massive PE by mode of ECMO from a large international registry.

METHODS

Retrospective observational study of the Extracorporeal Life Support Organization (ELSO) database.

RESULTS

A total of 821 patients underwent 833 ECMO episodes for PE. Mean age was 49 (±15) years, 408 (50.1%) were female, and 450 (54.7%) had a cardiac arrest prior to ECMO initiation. Venoarterial (VA) ECMO was the most common mode in 489 (58.7%), followed by extracorporeal cardiopulmonary resuscitation (ECPR) in 229 (27.4%) and venovenous (VV) ECMO in 85 (10.2%). The number of episodes per year increased over the study period, predominantly driven by an increase in ECPR. In-hospital mortality was the highest for ECPR 156/229 (68.1%), followed by VA ECMO 209/498 (42.7%) and VV ECMO 24/85 (28.2%) P < 0.001. After controlling for univariate and clinically significant variables at the time of ECMO initiation, increasing age (OR 1.02 (1.00-1.03), lower pH (OR 0.18 (0.03-0.44), lower diastolic blood pressure (OR 0.99 (0.97-1.00) and ECPR mode (OR 3.67 (1.46-9.230) were independently associated with in-hospital mortality.

CONCLUSION

ECMO use for massive PE is increasing globally, and overall mortality rates compare favorably with other indications of ECMO. The use of ECPR and worsening metabolic status at initiation were associated with higher in-hospital mortality, suggesting delays in initiating ECMO should be avoided.

Temperature Management for Comatose Adult Survivors of Cardiac Arrest: A Science Advisory From the American Heart Association

Targeted temperature management has been a cornerstone of post-cardiac arrest care for patients remaining unresponsive after return of spontaneous circulation since the initial trials in 2002 found that mild therapeutic hypothermia improves neurological outcome. The suggested temperature range expanded in 2015 in response to a large trial finding that outcomes were not better with treatment at 33° C compared with 36° C. In 2021, another large trial was published in which outcomes with temperature control at 33° C were not better than those of patients treated with a strategy of strict normothermia. On the basis of these new data, the International Liaison Committee on Resuscitation and other organizations have altered their treatment recommendations for temperature management after cardiac arrest. The new American Heart Association guidelines on this topic will be introduced in a 2023 focused update. To provide guidance to clinicians while this focused update is forthcoming, the American Heart Association's Emergency Cardiovascular Care Committee convened a writing group to review the TTM2 trial (Hypothermia Versus Normothermia After Out-of-Hospital Cardiac Arrest) in the context of other recent evidence and to present an opinion on how this trial may influence clinical practice. This science advisory was informed by review of the TTM2 trial, consideration of other recent influential studies, and discussion between cardiac arrest experts in the fields of cardiology, critical care, emergency medicine, and neurology. Conclusions presented in this advisory statement do not replace current guidelines but are intended to provide an expert opinion on novel literature that will be incorporated into future guidelines and suggest the opportunity for reassessment of current clinical practice.

The Impact Of BMI On Arrest Characteristics and Survival of Patients with Out-Of-Hospital Cardiac Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation

AIM

To assess the impact of body mass index (BMI) on survival to hospital discharge of patients presenting with refractory ventricular fibrillation treated with extracorporeal cardiopulmonary resuscitation. We hypothesize that due to limitations in pre-hospital care delivery, people with high BMI have worse survival after prolonged resuscitation and ECPR.

METHODS

This study is a retrospective single-centre study that included patients suffering refractory VT/VF OHCA from December 2015 to October 2021 and had a BMI calculated at hospital admission. We compared the baseline characteristics and survival between patients with obesity (>30 kg/m²) and those without (≤30kg/m²).

RESULTS

Two-hundred eighty-three patients were included in this study, and two-hundred twenty-four required mechanical support with veno-arterial extracorporeal cardiopulmonary membrane oxygenation (VA ECMO). Patients with BMI >30 (n = 133) had significantly prolonged CPR duration compared to their peers with BMI ≤30kg/m² (n = 150) and were significantly more likely to require support with VA ECMO (85.7% vs 73.3%, p = 0.015). Survival to hospital discharge was significantly higher in patients with BMI≤30 kg/m² (48% vs. 29.3%, p <0.001). BMI was an independent predictor of mortality in a multivariable logistic regression analysis. The four-year mortality rate was low and not significantly different between the two groups (p=0.32).

CONCLUSION

ECPR yields clinically meaningful long-term survival in patients with BMI>30kg/m². However, the resuscitation time is significantly prolonged, and the overall survival significantly lower compared to patients with BMI≤30 kg/m². ECPR should, therefore, not be withheld for this population, but faster transport to an ECMO capable centre is mandated to improve survival to hospital discharge.

Supraglottic Airway Devices are Associated with Asphyxial Physiology After Prolonged CPR in Patients with Refractory Out-of-Hospital Cardiac Arrest Presenting for Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Multiple randomized clinical trials have compared specific airway management strategies during ACLS with conflicting results. However, patients with refractory cardiac arrest died in almost all cases without the availability of extracorporeal cardiopulmonary resuscitation (ECPR). Our aim was to determine if endotracheal intubation (ETI) was associated with improved outcomes compared to supraglottic airways (SGA) in patients with refractory cardiac arrest presenting for ECPR.

METHODS

We retrospectively studied 420 consecutive adult patients with refractory out-of-hospital cardiac arrest due to shockable presenting rhythms presenting to the University of Minnesota ECPR program. We compared outcomes between patients receiving ETI (n=179) and SGA (n=204). The primary outcome was the pre-cannulation arterial PaO₂ upon arrival to the ECMO cannulation center. Secondary outcomes included neurologically favorable survival to hospital discharge and eligibility for VA-ECMO based upon resuscitation continuation criteria applied upon arrival to the ECMO cannulation center.

RESULTS

Patients receiving ETI had significantly higher median PaO₂ (71 vs. 58 mmHg, p=0.001), lower median PaCO₂ (55 vs. 75 mmHg, p<0.001), and higher median pH (7.03 vs. 6.93, p<0.001) compared to those receiving SGA. Patients receiving ETI were also significantly more likely to meet VA-ECMO eligibility criteria (85% vs. 74%, p=0.008). Of patients eligible for VA-ECMO, patients receiving ETI had significantly higher neurologically favorable survival compared to SGA (42% vs. 29%, p=0.02).

CONCLUSIONS

ETI was associated with improved oxygenation and ventilation after prolonged CPR. This resulted in increased rate of candidacy for ECPR and increased neurologically favorable survival to discharge with ETI compared to SGA. Short Title: Airway Effects in Refractory Cardiac Arrest.

Acute lung injury and recovery in patients with refractory VT/VF cardiac arrest treated with prolonged CPR and veno-arterial extracorporeal membrane oxygenation

AIM

Describe the lung injury patterns among patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest (VT/VF OHCA) supported with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) facilitated resuscitation.

METHODS

In this retrospective single-center cohort study including VT/VF OHCA patients supported with VA ECMO, we compared OHCA characteristics, post-arrest computed tomography (CT) scans, ventilator parameters, and other lung-related pathology between survivors, patients who developed brain death, and those with other causes of death.

RESULTS

Among 138 patients, 48/138 (34.8%) survived, 31/138 (22.4%) developed brain death, and 59/138 (42.7%) died of other causes. Successful extubation was achieved in 39/138 (28%) with a median time to extubation of 8.0 days (6.0, 11.0) in those who survived. Tracheostomy was required in 15/48 (31.3%) survivors. Chest CT obtained on all patients showed lung injury in at least one lung area in 124/135 (91.8%) patients, predominantly in the dependent posterior areas. There was no association between the number of affected areas and survival. Lung compliance was low on admission [26 (19,33) ml/cmH₂0], improved throughout hospitalization (p = 0.03), and recovered faster in survivors compared to those who died (p < 0.001). VA-ECMO allowed the use of lung-protective ventilation while maintaining normalized PaO₂ and PaCO₂. Patients treated with V-A ECMO and either IABP or Impella had lower pulmonary compliance and more affected areas on their CT compared to those treated with V-A ECMO alone.

CONCLUSIONS

Lung injury is common among patients with refractory VT/VF OHCA requiring V-A ECMO, but imaging severity is not associated with survival. Reductions in lung compliance accompany post-arrest lung injury while compliance recovery is associated with survival.

Initial Hospital Length of Stay and Long-Term Survival of Patients Successfully Resuscitated Using ECPR for Refractory Out-of-Hospital Cardiac Arrest

Background

The long-term outcomes of patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) for refractory ventricular tachycardia/ventricular fibrillation (VT/VF) out-of-hospital cardiac arrest (OHCA) remain poorly defined. The purpose of this study was to describe the hospital length of stay and long-term survival of patients who were successfully rescued with ECPR after refractory VT/VF OHCA.

Methods

In this retrospective cohort study, the length of index admission and long-term survival of patients treated with ECPR after OHCA at a single center were evaluated. In a sensitivity analysis, survival of patients managed with left ventricular assist device (LVAD) implantation or heart transplantation during the same period was also evaluated.

Results

Between 1/1/2016 and 12/1/2020, 193 patients were transferred for ECPR considerations and 160 underwent peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation. Of these, 54 (33.7%) survived the index admission. These survivors required a median 16 days of intensive care and 24 days total hospital stay. The median follow-up time of the survivors was 1,216 [683, 1461] days. 79.6% and 72.2% were alive at one and four years, respectively. Most deaths within the first year occurred among the patients requiring discharge to a long-term acute care facility. Overall survival rates at four years were similar in the ECPR and LVAD cohorts (p = 0.30) but were significantly higher for transplant recipients (p &lt; 0.001).

Conclusions

This data suggest that the lengthy index hospitalization required to manage OHCA patients with ECPR is rewarded by excellent long-term clinical outcomes in an expert ECPR program.

Right Ventricular Dysfunction is Associated with Increased Mortality in Patients Requiring Venovenous Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019

Respiratory failure caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is associated with mortality. Patients unresponsive to conventional therapy may benefit from temporary venovenous extracorporeal membrane oxygenation (VV-ECMO). We investigated clinical and echocardiographic characteristics, particularly, right ventricular dysfunction, with survival in patients with respiratory failure caused by SARS-CoV-2. We performed a single-center retrospective cohort study of patients requiring VV-ECMO for respiratory failure from COVID-19 infection between January 2020 and December 2020. Demographics, comorbidities, laboratory parameters, and echocardiographic features of left and right ventricular (LV/RV) function were compared between patients who survived and those who could not be weaned from VV-ECMO. In addition, we evaluated outcomes in a separate population managed with venoarterial extracorporeal membrane oxygenation (VA-ECMO). In total, 10/17 patients failed to wean from VV-ECMO and died in the hospital on average 41.5 ± 10.9 days post admission. Seven were decannulated (41%) and survived to hospital discharge. There were no significant differences in demographics, comorbidities, and laboratory parameters between groups. Moderate to severe RV dysfunction was significantly more in those who died (8/10, 80%) compared to survivors (0/7, 0%) (p = 0.002). Patients supported with VA-ECMO had superior survival with 5/9 patients (56%) decannulated and discharged. Moderate to severe RV dysfunction is associated with increased mortality in patients with respiratory failure requiring VV-ECMO for COVID-19.

The association of modifiable mechanical ventilation settings, blood gas changes and survival on extracorporeal membrane oxygenation for cardiac arrest

RESEARCH QUESTION

Given the relative independence of ventilator settings from gas exchange and plasticity of blood gas values during extracorporeal cardiopulmonary resuscitation (ECPR), do mechanical ventilation parameters and blood gas values influence survival?

METHODS

Observational cohort study of 7488 adult patients with ECPR from the Extracorporeal Life Support Organization (ELSO) Registry. We performed case-mix adjustment for severity of illness and patient type using generalized estimating equation logistic regression to determine factors associated with hospital survival accounting for clustering by center, standardizing variables by 1 standard deviation (SD) of their values. We examined non-linear relationships between ventilatory and blood gas values with hospital survival.

RESULTS

Hospital survival was decreased with higher PaO2 on ECMO (OR 0.69, per 1SD increase [95% CI 0.64, 0.74]; p < 0.001) and with any relative changes in PaCO2 (pre-arrest to on-ECMO) in a non-linear fashion. Survival was worsened with any peak inspiratory pressure >20 cmH20 (OR 0.69, per 1SD [0.64, 0.75]; p < 0.001) and above 40% fraction of inspired oxygen (OR 0.75, per 1SD [0.69, 0.82]; p < 0.001), and with higher dynamic driving pressure (OR 0.72, per 1 SD increase [0.65, 0.79]; <0.001). Ventilation settings and blood gas values varied widely across hospitals, but were not associated with annual hospital ECPR case volume.

CONCLUSION

Lower ventilatory pressures, avoidance of hyperoxia, and relatively unchanged CO2 (pre- to on-ECMO) were all associated with survival in patients after ECPR, yet varied across hospitals. Our findings represent potential targets for prospective trials for this rapidly growing therapy to test if these associations have causality.

Concomitant Respiratory Failure Can Impair Myocardial Oxygenation in Patients with Acute Cardiogenic Shock Supported by VA-ECMO

Venous-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for acute cardiogenic shock in patients who also have acute lung injury predisposes development of a serious complication called "north-south syndrome" (NSS) which causes cerebral hypoxia. NSS is poorly characterized and hemodynamic studies have focused on cerebral perfusion ignoring the heart. We hypothesized in NSS the heart would be more likely to receive hypoxemic blood than the brain due to the proximity of the coronary arteries to the aortic annulus. To test this, we conducted a computational fluid dynamics simulation of blood flow in a human supported by VA-ECMO. Simulations quantified the fraction of blood at each aortic branching vessel originating from residual native cardiac output versus VA-ECMO. As residual cardiac function was increased, simulations demonstrated myocardial hypoxia would develop prior to cerebral hypoxia. These results illustrate the conditions where NSS will develop and the relative cardiac function that will lead to organ-specific hypoxia. Illustration of the impact of north-south syndrome on organ-specific oxygen delivery. Patients on VA-ECMO have two sources of blood flow, one from the VA-ECMO circuit and one from the residual cardiac function. When there is no residual cardiac function, all organs are perfused with oxygenated blood. As myocardial recovery progresses, blood supply from the two sources will begin to mix resulting in non-homogeneous mixing and differential oxygenation based upon the anatomical site of branching vessels.

Enhancing cardiac arrest survival with extracorporeal cardiopulmonary resuscitation: insights into the process of death

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging method of cardiopulmonary resuscitation to improve outcomes from cardiac arrest. This approach targets patients with out-of-hospital cardiac arrest previously unresponsive and refractory to standard treatment, combining approximately 1 h of standard CPR followed by venoarterial extracorporeal membrane oxygenation (VA-ECMO) and coronary artery revascularization. Despite its relatively new emergence for the treatment of cardiac arrest, the approach is grounded in a vast body of preclinical and clinical data that demonstrate significantly improved survival and neurological outcomes despite unprecedented, prolonged periods of CPR. In this review, we detail the principles behind VA-ECMO-facilitated resuscitation, contemporary clinical approaches with outcomes, and address the emerging new understanding of the process of death and capability for neurological recovery.

Impact of AKI in Patients with Out-of-Hospital Cardiac Arrest Managed with VA ECMO

AKI is associated with a high rate of mortality in patients managed with VA ECMO after out-of-hospital cardiac arrest.Therapeutic hypothermia is associated with hypokalemia and hypophosphatemia.During rewarming after hypothermia, hyperphosphatemia and hyperkalemia can develop. Electrolyte replacement should be carefully monitored.

Coronary artery disease burden relation with the presentation of acute cardiac events and ventricular fibrillation

OBJECTIVES

Evaluate the differences in coronary artery disease (CAD) burden between patients with ischemic resuscitated, ischemic refractory VT/VF OHCA events and N/STEMI.

BACKGROUND

Refractory out-of-hospital cardiac arrest patients presenting with initial shockable rhythms (VT/VF OHCA) have the highest mortality among patients with acute cardiac events. No predictors of VT/VF OHCA refractoriness have been identified.

METHODS

A retrospective cohort design was used to assess baseline characteristics, clinical outcomes, and the angiographic severity of disease among patients with VT/VF OHCA undergoing emergent coronary angiography at the University of Minnesota Medical Center. The Gensini score was calculated for all patients to assess the angiographic burden of CAD. For patients with ischemia-related cardiac arrest, outcomes were further compared to an independent non-OHCA population presenting with N/STEMI.

RESULTS

During the study period, 538 patients were admitted after VT/VF OHCA. Among them, 305 presented with resuscitated, and 233 with refractory VT/VF. 66% of resuscitated and 70% of refractory VT/VF had an underlying, angiographically documented, ischemic etiology. Ischemic resuscitated and refractory VT/VF had significant differences in Gensini score, (80.7 ± 3.6 and 127.6 ± 7.1, respectively, p < 0.001) and survival (77.3% and 30.0%, respectively, p < 0.001). Both groups had a higher CAD burden and worse survival than the non-OHCA N/STEMI population (360 patients). Ischemic refractory VT/VF was significantly more likely to present with chronic total occlusion in comparison to both N/STEMI and ischemic resuscitated VT/VF.

CONCLUSION

Ischemia-related, refractory VT/VF OHCA has a higher burden of CAD and the presence of CTOs compared to resuscitated VT/VF OHCA and N/STEMI.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

ST-Elevation Myocardial Infarction Complicated by Out-of-Hospital Cardiac Arrest

5-10% of ST-elevated myocardial infarctions (STEMI) present with out-of-hospital cardiac arrest (OHCA). Although this subgroup of patients carries the highest in-hospital mortality among the STEMI population, it is the least likely to undergo coronary angiography and revascularization. Due to the concomitant neurologic injury, patients with OHCA STEMI require prolonged hospitalization and adjustments to standard MI management. This review systematically assesses the course of patients with OHCA STEMI from development of the arrest to hospital discharge, assesses the limiting factors for their treatment access, and presents the evidence-based optimal intervention strategy for this high-risk MI population.

Outcomes associated with delayed enteral feeding after cardiac arrest treated with veno-arterial extracorporeal membrane oxygenation and targeted temperature management

INTRODUCTION

While early enteral nutrition is generally preferred in critically ill patients, the optimal timing of feeding among refractory cardiac arrest patients is unknown. We examined the association between timing of enteral nutrition and patient survival and safety outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) who were treated with extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

We performed a retrospective analysis of 142 consecutive patients presenting with OHCA due to ventricular fibrillation or ventricular tachycardia treated with ECPR and targeted temperature management (TTM). Neurologically favorable survival and clinical outcomes were compared between patients who received early enteral nutrition (<48 h after admission to the intensive care unit) and patients receiving delayed enteral nutrition (initiated >48 h after admission).

RESULTS

Enteral nutrition was initiated in 90/142 (63%) patients. Early enteral nutrition was provided in 34/90 (38%) while delayed nutrition occurred in 56/90 (62%). In adjusted analysis including patients who received nutrition, delayed enteral feeding was associated with increased odds of neurologically favorable survival (29 vs 54%, CI 1.04-7.25, p = 0.04). There were no significant differences in the incidence of pneumonia (18 vs 27%, p = 0.16), gastrointestinal bleeding (5.9 vs 3.6%, p = 0.42), intestinal ischemia (5.9 vs 5.4%, p = 0.90), ileus (12 vs 11%, p = 0.98), or need for tracheostomy (15 vs 20%, p = 0.81) between early and late feeding groups.

CONCLUSION

In patients with refractory OHCA treated with ECPR and TTM, delayed enteral nutrition was associated with improved neurologically favorable survival. Adverse events related to enteral feeding were not associated with timing of feeding initiation.

Extracorporeal Cardiopulmonary Resuscitation in Adults. Interim Guideline Consensus Statement From the Extracorporeal Life Support Organization

DISCLAIMER

Veno-arterial extracorporeal membrane oxygenation (ECMO) is increasingly being deployed for selected patients in cardiac arrest who do not attain a native circulation with conventional CPR (ECPR). This ELSO guideline is intended to be a practical guide to implementing ECPR and the early management following establishment of ECMO support. Where a paucity of high-quality evidence exists, a consensus has been reached amongst the authors to provide guidance to the clinician. This guideline will be updated as further evidence in this field becomes available.

Poloxamer 188 Protects Isolated Adult Mouse Cardiomyocytes from Reoxygenation Injury

Reperfusion injury is a complex pathological event involving processes that can lead to further disruption of the cell membrane and function following an ischemic event. Return of blood flow allows for the needed reperfusion; however, for a period of time before remaining viable cells stabilize, reperfusion results in additional cellular injury. In cardiomyocytes, loss of membrane integrity allows abnormal influx of extracellular calcium, leading to hyper-contracture and cell death. Methods to improve the membrane integrity of cardiomyocytes overwhelmed by pathological disruptions, such as reperfusion injury, are needed to prevent cell death, because of the myocardium's limited ability to regenerate. Research has shown administration of the copolymer P(oloxamer) 188 before ischemia/reperfusion can protect cardiomyocytes through membrane stabilization. This study sought to determine whether the administration of P188 at the beginning of the clinically more relevant time of reperfusion after ischemia will attenuate any additional damage to cardiomyocytes by stabilizing membrane integrity to allow the cells to maintain function. Using an in-vitro cardiomyocyte model subjected to hypoxia/reoxygenation to simulate ischemia/reperfusion injury, we show that reoxygenation significantly potentiates the injury caused by hypoxia itself. P188, with its unique combination of hydrophobic and hydrophilic chemical properties, and only delivered at the beginning of reoxygenation, dose-dependently protected cardiomyocytes from injury due to reoxygenation by repairing cell membranes, decreasing calcium influx, and maintaining cellular morphology. Our study also shows the hydrophobic portion of P188 is necessary for the stabilization of cell membrane integrity in providing protection to cardiomyocytes against reoxygenation injury.

The Minnesota mobile extracorporeal cardiopulmonary resuscitation consortium for treatment of out-of-hospital refractory ventricular fibrillation: Program description, performance, and outcomes

BACKGROUND

We describe implementation, evaluate performance, and report outcomes from the first program serving an entire metropolitan area designed to rapidly deliver extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation to patients with refractory ventricular fibrillation/ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA).

METHODS

This observational cohort study analyzed consecutive patients prospectively enrolled in the Minnesota Mobile Resuscitation Consortium's ECMO-facilitated resuscitation program. Entry criteria included: 1) adults (aged 18-75), 2) VF/VT OHCA, 3) no return of spontaneous circulation following 3 shocks, 4) automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System (LUCAS™), and 5) estimated transfer time of < 30 min. The primary endpoint was functionally favorable survival to hospital discharge with Cerebral Performance Category (CPC) 1 or 2. Secondary endpoints included 3-month functionally favorable survival, program benchmarks, ECMO cannulation rate, and safety. Essential program components included emergency medical services, 3 community ECMO Initiation Hospitals with emergency department ECMO cannulation sites and 24/7 cardiac catheterization laboratories, a 24/7 mobile ECMO cannulation team, and a single, centralized ECMO intensive care unit.

FINDINGS

From December 1, 2019 to April 1, 2020, 63 consecutive patients were transported and 58 (97%) met criteria and were treated by the mobile ECMO service. Mean age was 57 ± 1.8 years; 46/58 (79%) were male. Program benchmarks were variably met, 100% of patients were successfully cannulated, and no safety issues were identified. Of the 58 patients, 25/58 (43% [CI:31-56%]) were both discharged from the hospital and alive at 3 months with CPC 1 or 2.

INTERPRETATION

This first, community-wide ECMO-facilitated resuscitation program in the US demonstrated 100% successful cannulation, 43% functionally favorable survival rates at hospital discharge and 3 months, as well as safety. The program provides a potential model of this approach for other communities.

FUNDING

The Helmsley Charitable Trust.

Rationale and methods of the Advanced R2Eperfusion STrategies for Refractory Cardiac Arrest (ARREST) trial

BACKGROUND

Venoarterial extracorporeal membrane oxygenation has emerged as a prominent therapy for patients with refractory cardiac arrest. However, the optimal time of initiation remains unknown.

AIM

The aim was to assess the rate of survival to hospital discharge in adult patients with refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest treated with 1 of 2 local standards of care: (1) early venoarterial extracorporeal membrane oxygenation-facilitated resuscitation for circulatory support and percutaneous coronary intervention, when needed, or (2) standard advanced cardiac life support resuscitation.

DESIGN

Phase II, single-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial.

POPULATION

Adults (aged 18-75), initial out-of-hospital cardiac arrest rhythm of ventricular fibrillation/pulseless ventricular tachycardia, no ROSC following 3 shocks, body morphology to accommodate a Lund University Cardiac Arrest System automated cardiopulmonary resuscitation device, and transfer time of <30 minutes.

SETTING

Hospital-based.

OUTCOMES

Primary: survival to hospital discharge. Secondary: safety, survival, and functional assessment at hospital discharge and 3 and 6 months, and cost.

SAMPLE SIZE

Assuming success rates of 12% versus 37% in the 2 arms and 90% power, a type 1 error rate of .05, and a 15% rate of withdrawal prior to hospital discharge, the required sample size is N = 174 evaluated patients.

CONCLUSIONS

The ARREST trial will generate safety/effectiveness data and comparative costs associated with extracorporeal cardiopulmonary resuscitation, informing broader implementation and a definitive Phase III clinical trial.

Increased QT Dispersion Is Linked to Worse Outcomes in Patients Hospitalized for Out-of-Hospital Cardiac Arrest

Background The incidence and mortality of out-of-hospital cardiac arrest (OHCA) remains high, but predicting outcomes is challenging. Being able to better assess prognosis of hospitalized patients after return of spontaneous circulation would enable improved management of survival expectations. In this study, we assessed the predictive value of ECG indexes in hospitalized patients with OHCA. Methods and Results PR interval and QT interval corrected by the Bazett formula (QTc) for all leads were calculated from standard 12-lead ECGs 24 hours after return of spontaneous circulation in 93 patients who were hospitalized following OHCA. PR interval and QT and QTc duration did not differentiate OHCA survivors and nonsurvivors. However, QT and QTc dispersion was significantly increased in patients who died during hospitalization compared with survivors discharged from the hospital (P<0.01). Logistic regression indicated a strong association between increased QT dispersion and in-hospital mortality (P<0.0001; area under the curve, 0.8918 for QT dispersion and 0.8673 for QTc dispersion). Multinomial logistic regression indicated that the increase of QTc dispersion correlated with worse Cerebral Performance Category scores at discharge (P<0.001; likelihood ratio, 51.42). There was also significant correlation between dispersion measures and serum potassium at the time of measurement and between dispersion measures and cumulative epinephrine administration. No difference existed regarding the number of measurable leads. Conclusions Lesser QT and QTc dispersion at 24 hours after return of spontaneous circulation was significantly associated with survival and neurologic status at discharge. Routine evaluation of QT and QTc dispersion during hospitalization following return of spontaneous circulation might improve outcome prognostication for patients hospitalized for OHCA.

Closed-loop machine-controlled CPR system optimises haemodynamics during prolonged CPR

Objectives

We evaluated the feasibility of optimising coronary perfusion pressure (CPP) during cardiopulmonary resuscitation (CPR) with a closed-loop, machine-controlled CPR system (MC-CPR) that sends real-time haemodynamic feedback to a set of machine learning and control algorithms which determine compression/decompression characteristics over time.

Background

American Heart Association CPR guidelines (AHA-CPR) and standard mechanical devices employ a “one-size-fits-all” approach to CPR that fails to adjust compressions over time or individualise therapy, thus leading to deterioration of CPR effectiveness as duration exceeds 15–20 ​min.

Methods

CPR was administered for 30 ​min in a validated porcine model of cardiac arrest. Intubated anaesthetised pigs were randomly assigned to receive MC-CPR (6), mechanical CPR conducted according to AHA-CPR (6), or human-controlled CPR (HC-CPR) (10). MC-CPR directly controlled the CPR piston’s amplitude of compression and decompression to maximise CPP over time. In HC-CPR a physician controlled the piston amplitudes to maximise CPP without any algorithmic feedback, while AHA-CPR had one compression depth without adaptation.

Results

MC-CPR significantly improved CPP throughout the 30-min resuscitation period compared to both AHA-CPR and HC-CPR. CPP and carotid blood flow (CBF) remained stable or improved with MC-CPR but deteriorated with AHA-CPR. HC-CPR showed initial but transient improvement that dissipated over time.

Conclusion

Machine learning implemented in a closed-loop system successfully controlled CPR for 30 ​min in our preclinical model. MC-CPR significantly improved CPP and CBF compared to AHA-CPR and ameliorated the temporal haemodynamic deterioration that occurs with standard approaches.

Echocardiographic evaluation of cardiac recovery after refractory out-of-hospital cardiac arrest

BACKGROUND

The mechanisms and degree of myocardial recovery during treatment with venoarterial extracorporeal membrane oxygenation (VA-ECMO) are unclear. We performed a descriptive study to evaluate myocardial recovery and changes in parameters of myocardial loading using echocardiography.

METHODS

We retrospectively evaluated patients with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest who were treated with the Minnesota Resuscitation Consortium protocol. Left ventricular ejection fraction (LVEF), end-diastolic diameter (LVEDD), end-systolic diameter (LVESD), and fractional shortening were assessed using serial echocardiography. One-way analysis of variance (ANOVA) was used to compare parameters over six hospitalization stages. Two-way ANOVA was used to compare these parameters between patients that survived the index hospitalization and those that died.

RESULTS

77 patients had >1 echocardiographic turndown evaluations. Thirty-eight patients survived to discharge and 39 patients died. Of 39 in-hospital deaths, 17 patients died before VA-ECMO decannulation and 22 patients died after VA-ECMO decannulation. Among all patients, LVEF improved from 9.7 ± 10.1% from the first echocardiogram after rewarming to 43.1 ± 13.1% after decannulation (p < 0.001) and fractional shortening ratio improved from 0.14 ± 0.12 to 0.31 ± 0.14 (p < 0.001). The LVEDD and LVESD remained stable (p = 0.36 and p = 0.12, respectively). Patients that died had a lower LVEF by an average of 6.93% (95% confidence interval: -10.0 to -3.83, p < 0.001), but other parameters were similar.

CONCLUSION

Refractory cardiac arrest patients treated with VA-ECMO experience significant recovery of ventricular function during treatment. We postulate that this primarily occurs via reduction of LV preload.

Patients treated with venoarterial extracorporeal membrane oxygenation have different baseline risk and outcomes dependent on indication and route of cannulation

OBJECTIVES

To investigate the baseline risk of patients treated with Extracorporeal Cardiopulmonary Membrane Oxygenation (ECMO) in relation to cannulation strategy and indication for ECMO as well as the relation of cannulation strategy with survival and secondary hospitalization outcomes.

METHODS

Severity of illness and predicted mortality risk were assessed in 317 patients. Central cannulation was used in 52 patients unable to wean off cardiopulmonary bypass after cardiac surgery. Peripheral cannulation was used in 179 patients for extracorporeal cardiopulmonary resuscitation (eCPR) and in 86 patients who received ECMO for refractory cardiogenic shock (RCS).

RESULTS

Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were significantly worse (P < 0.01) for peripheral ECMO eCPR (23.2) vs central ECMO (14.6) and vs peripheral ECMO for RCS (18.9). Survival After Venoarterial ECMO (SAVE) scores were significantly worse for peripheral ECMO for eCPR (-7.85) and RCS (-10.38) vs central ECMO (-3.97), and P < 0.01. Peripherally cannulated patients had significantly worse renal function. No significant difference existed for survival to discharge (peripheral ECMO for eCPR, 31%; central ECMO, 44%; peripheral ECMO for refractory cardiac shock, 39.5%; and P = 0.176), although centrally cannulated patients had significantly longer treatment durations compared with peripheral ECMO for eCPR.

CONCLUSIONS

Peripherally cannulated patients with eCPR had significantly worse APACHE II and SAVE scores compared to peripherally cannulated RCS or patients with central ECMO, despite having similar mortality.

Kounis Syndrome Leading to Cardiac Arrest After Iodinated Contrast Exposure

Immune-mediated coronary spasm, called Kounis syndrome (KS), is not rare but is underdiagnosed. In this report, we present a case of KS induced by iodinated contrast resulting in cardiac arrest, requiring temporary mechanical circulatory support. We show angiographic evidence of KS and outline commonly associated clinical features that may predict KS. (Level of Difficulty: Beginner.).

Sodium Nitroprusside-Enhanced Cardiopulmonary Resuscitation Improves Blood Flow by Pulmonary Vasodilation Leading to Higher Oxygen Requirements

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SNPeCPR improves coronary perfusion pressure, tissue perfusion, and carotid blood flow compared to epinephrine-based standard advanced cardiac life support.

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In a porcine model of prolonged resuscitation, SNPeCPR was associated with decreased arterial oxygen saturation but improved tissue oxygen delivery due to improvement in blood flow.

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Oxygen supplementation led to alleviation of hypoxemia and maintenance of the SNPeCPR hemodynamic benefits.

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Arterial oxygen saturation must be a safety endpoint that will be prospectively assessed in the first SNPeCPR clinical trial in humans.

Sodium nitroprusside–enhanced cardiopulmonary resuscitation has shown superior resuscitation rates and neurologic outcomes in large animal models supporting the need for a randomized human clinical trial. This study is the first to show nonselective pulmonary vasodilation as a potential mechanism for the hemodynamic benefits. The pulmonary shunting that is created requires increased oxygen treatment, but the overall improvement in blood flow increases minute oxygen delivery to tissues. In this context, hypoxemia is an important safety endpoint and a 100% oxygen ventilation strategy may be necessary for the first human clinical trial.

Improved Survival With Extracorporeal Cardiopulmonary Resuscitation Despite Progressive Metabolic Derangement Associated With Prolonged Resuscitation

The likelihood of neurologically favorable survival declines with prolonged resuscitation. However, the ability of extracorporeal cardiopulmonary resuscitation (ECPR) to modulate this decline is unknown. Our aim was to examine the effects of resuscitation duration on survival and metabolic profile in patients who undergo ECPR for refractory ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest.

Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium

Pulmonary embolism (PE) is a life-threatening condition and a leading cause of morbidity and mortality. There have been many advances in the field of PE in the last few years, requiring a careful assessment of their impact on patient care. However, variations in recommendations by different clinical guidelines, as well as lack of robust clinical trials, make clinical decisions challenging. The Pulmonary Embolism Response Team Consortium is an international association created to advance the diagnosis, treatment, and outcomes of patients with PE. In this consensus practice document, we provide a comprehensive review of the diagnosis, treatment, and follow-up of acute PE, including both clinical data and consensus opinion to provide guidance for clinicians caring for these patients.

The Evolving Role of the Cardiac Catheterization Laboratory in the Management of Patients With Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association

Coronary artery disease is prevalent in different causes of out-of-hospital cardiac arrest (OHCA), especially in individuals presenting with shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT). The purpose of this report is to review the known prevalence and potential importance of coronary artery disease in patients with OHCA and to describe the emerging paradigm of treatment with advanced perfusion/reperfusion techniques and their potential benefits on the basis of available evidence. Although randomized clinical trials are planned or ongoing, current scientific evidence rests principally on observational case series with their potential confounding selection bias. Among patients resuscitated from VF/pVT OHCA with ST-segment elevation on their postresuscitation ECG, the prevalence of coronary artery disease has been shown to be 70% to 85%. More than 90% of these patients have had successful percutaneous coronary intervention. Conversely, among patients resuscitated from VF/pVT OHCA without ST-segment elevation on their postresuscitation ECG, the prevalence of coronary artery disease has been shown to be 25% to 50%. For these patients, early access to the cardiac catheterization laboratory is associated with a 10% to 15% absolute higher functionally favorable survival rate compared with more conservative approaches of late or no access to the cardiac catheterization laboratory. In patients with VF/pVT OHCA refractory to standard treatment, a new treatment paradigm is also emerging that uses venoarterial extracorporeal membrane oxygenation to facilitate return of normal perfusion and to support further resuscitation efforts, including coronary angiography and percutaneous coronary intervention. The burden of coronary artery disease is high in this patient population, presumably causative in most patients. The strategy of venoarterial extracorporeal membrane oxygenation, coronary angiography, and percutaneous coronary intervention has resulted in functionally favorable survival rates ranging from 9% to 45% in observational studies in this patient population. Patients with VF/pVT should be considered at the highest severity in the continuum of acute coronary syndromes. These patients have a significant burden of coronary artery disease and acute coronary thrombotic events. Evidence from randomized trials will further define optimal clinical practice.

Surviving refractory out-of-hospital ventricular fibrillation cardiac arrest: Critical care and extracorporeal membrane oxygenation management

BACKGROUND

Resuscitation of refractory out-of-hospital ventricular fibrillation/ventricular tachycardia (VF/VT) cardiac arrest using extracorporeal membrane oxygenation (ECMO) establishes a complex patient population. We aimed to describe the critical care strategies and outcomes in this population.

METHODS

Between December 1, 2015 and January 1, 2018, 100 consecutive adult patients with refractory VF/VT out-of-hospital cardiac arrest and ongoing CPR were transported to the cardiac catheterization laboratory. ECMO, coronary angiography, and percutaneous coronary intervention were performed. Patients achieving an organized cardiac rhythm were admitted to the cardiac intensive care unit (CICU). All patients were considered eligible for necessary intervention/surgery until declaration of death.

RESULTS

Of 100 appropriately transported patients, 83 achieved CICU admission. 40/83 (48%) discharged functionally intact. Multi-system organ failure occurred in all patients. Cardiac, pulmonary, renal, and liver injury improved within 3-4 days. Neurologic injury caused death in 26/37 (70%) patients. Poor neurologic outcomes were associated with anoxic injury or cerebral edema on admission head CT, decline in cerebral oximetry over the first 48 h, and elevated neuron specific enolase on CICU admission. For survivors, mean time to ECMO decannulation was 3.5 ± 0.2 days, following commands at 5.7 ± 0.8 days, and hospital discharge at 21 ± 3.2 days. 41/83 (49%) patients developed infections. CPR caused traumatic injury requiring procedural/surgical intervention in 22/83 (27%) patients.

CONCLUSIONS

Multi-system organ failure is ubiquitous but treatable with adequate hemodynamic support. Neurologic recovery was prolonged requiring delayed prognostication. Immediate 24/7 availability of surgical and medical specialty expertise was required to achieve 48% functionally intact survival.