Pulseless electrical activity in pulmonary embolism treated with thrombolysis (from the "PEAPETT" study)

Diagnosis of acute pulmonary embolism by point-of-care ultrasound under continuous cardiopulmonary resuscitation: case series

INTRODUCTION AND IMPORTANCE

Acute pulmonary embolism, as one of the most common and dangerous diseases, sometimes can develop into cardiac arrest before receiving Computed Tomography Angiography (CTA) or other confirmatory workup. The success rate with merely Cardiopulmonary resuscitation (CPR) is extremely low, which raises the question whether it is appropriate to make medical decisions and treat patients empirically with systemic thrombolytic therapy based on point-of-care ultrasound.

CASE PRESENTATION

This case series reported three cases in which patients presented with cardiac arrest in the emergency department, given the cases were too emergent for CTA, pulmonary embolism was diagnosed based on point-of-care ultrasound given the emergency of the condition, the patient was given systemic thrombolytic therapy with continuous CPR, and achieved Return of Spontaneous Circulation (ROSC).

CLINICAL DISCUSSION

These cases discuss the importance of bedside ultrasound in the rapid identification of acute pulmonary embolism and the importance of intravenous thrombolysis in the context of continuous cardiopulmonary resuscitation.

CONCLUSION

Point of care ultrasound plays a crucial role in rapidly identifying acute pulmonary embolism in the emergency department. Systematic therapy with continuous CPR is an effective management for patients with cardiac arrest secondary to acute pulmonary embolism.

Fibrinolytic uses in the emergency department: a narrative review

INTRODUCTION

Several life-threatening conditions associated with thrombosis include acute ischemic stroke (AIS), acute myocardial infarction (AMI), and acute pulmonary embolism (PE). Fibrinolytics are among the treatment algorithms for these conditions.

OBJECTIVE

This narrative review provides emergency clinicians with an overview of fibrinolytics for AIS, AMI, and PE in the emergency department (ED) setting.

DISCUSSION

Pathologic thrombosis can result in vascular occlusion and embolism, ultimately leading to end-organ injury. Fibrinolytics are medications utilized to lyse a blood clot, improving vascular flow. One of the first agents utilized was streptokinase, though this is not as often used with the availability of fibrin-specific agents including alteplase (tPA), tenecteplase (TNK), and reteplase (rPA). These agents are integral components in the management of several conditions, including AIS, AMI, and PE. Patients with AIS who present within 3-4.5 h of measurable neurologic deficit with no evidence of intracerebral hemorrhage (ICH) or other contraindications may be eligible to receive tPA or TNK. In the absence of percutaneous coronary intervention (PCI), fibrinolytics should be considered in patients with AMI presenting with chest pain for at least 30 min but less than 12 h, though it may be considered up to 24 h. Unlike in AIS and PE, anticoagulation and antiplatelet medications should be administered in those with AMI receiving fibrinolytics. Following fibrinolytics, PCI is typically necessary. Fibrinolytics are recommended in patients with high-risk PE (hemodynamic instability), as they reduce the risk of mortality. The most significant complication following fibrinolytic administration includes major bleeding such as ICH, which occurs most frequently in those with AIS compared to AMI and PE. Thus, close patient monitoring is necessary following fibrinolytic administration.

CONCLUSIONS

An understanding of fibrinolytics in the ED setting is essential, including the indications, contraindications, and dosing.

Mortality Outcomes with Tenecteplase Versus Alteplase in the Treatment of Massive Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) leads to many emergency department visits annually. Thrombolytic agents, such as alteplase, are currently recommended for massive PE, but genetically modified tenecteplase (TNK) presents advantages. Limited comparative studies exist between TNK and alteplase in PE treatment.

OBJECTIVE

The aim of this study was to assess the safety and mortality of TNK compared with alteplase in patients with PE using real-world evidence obtained from a large multicenter registry. Primary outcomes included mortality, intracranial hemorrhage, and blood transfusions.

METHODS

This retrospective cohort study used the TriNetX Global Health Research Network. Patients aged 18 years or older with a PE diagnosis (International Classification of Diseases, 10th Revision, Clinical Modification code I26) were included. The following two cohorts were defined: TNK-treated (29 organizations, 266 cases) and alteplase-treated (22,864 cases). Propensity matching controlled for demographic characteristics, anticoagulant use, pre-existing conditions, and vital sign abnormalities associated with PE severity. Patients received TNK or alteplase within 7 days of diagnosis and outcomes were measured at 30 days post thrombolysis.

RESULTS

Two hundred eighty-three patients in each cohort were comparable in demographic characteristics and pre-existing conditions. Mortality rates at 30 days post thrombolysis were similar between TNK and alteplase cohorts (19.4% vs 19.8%; risk ratio 0.982; 95% CI 0.704-1.371). Rates of intracerebral hemorrhages and transfusion were too infrequent to analyze.

CONCLUSIONS

This study found TNK to exhibit a similar mortality rate to alteplase in the treatment of PE with hemodynamic instability. The results necessitate prospective evaluation. Given the cost-effectiveness and ease of administration of TNK, these findings contribute to the ongoing discussion about its adoption as a primary thrombolytic agent for stroke and PE.

Prehospital Ground and Helicopter-Based Extracorporeal Cardiopulmonary Resuscitation (ECPR) Reduce Barriers to ECPR: A GIS Model

INTRODUCTION

Evidence suggests that Extracorporeal Cardiopulmonary Resuscitation (ECPR) can improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). However, when ECPR is indicated over 50% of potential candidates are unable to qualify in the current hospital-based system due to geographic limitations. This study employs a Geographic Information System (GIS) model to estimate the number of ECPR eligible patients within the United States in the current hospital-based system, a prehospital ECPR ground-based system, and a prehospital ECPR Helicopter Emergency Medical Services (HEMS)-based system.

METHODS

We constructed a GIS model to estimate ground and helicopter transport times. Time-dependent rates of ECPR eligibility were derived from the Resuscitation Outcome Consortium (ROC) database, while the Cardiac Arrest Registry to Enhance Survival (CARES) registry determined the number of OHCA patients meeting ECPR criteria within designated transportation times. Emergency Medical Services (EMS) response time, ECPR candidacy determination time, and on-scene time were modeled based on data from the EROCA trial. The combined model was used to estimate the total ECPR eligibility in each system.

RESULTS

The CARES registry recorded 736,066 OHCA patients from 2013 to 2021. After applying clinical criteria, 24,661 (3.4%) ECPR-indicated OHCA were identified. When considering overall ECPR eligibility within 45 min from OHCA to initiation, only 11.76% of OHCA where ECPR was indicated were eligible in the current hospital-based system. The prehospital ECPR HEMS-based system exhibited a four-fold increase in ECPR eligibility (49.3%), while the prehospital ground-based system showed a more than two-fold increase (28.4%).

CONCLUSIONS

The study demonstrates a two-fold increase in ECPR eligibility for a prehospital ECPR ground-based system and a four-fold increase for a prehospital ECPR HEMS-based system compared to the current hospital-based ECPR system. This novel GIS model can inform future ECPR implementation strategies, optimizing systems of care.

The Pharmacologic Management of Cardiac Arrest

The effectiveness of pharmacologic management of cardiac arrest patients is widely debated; however, several studies published in the past 5 years have begun to clarify some of these issues. This article covers the current state of evidence for the effectiveness of the vasopressor epinephrine and the combination of vasopressin-steroids-epinephrine and antiarrhythmic medications amiodarone and lidocaine and reviews the role of other medications such as calcium, sodium bicarbonate, magnesium, and atropine in cardiac arrest care. We additionally review the role of β-blockers for refractory pulseless ventricular tachycardia/ventricular fibrillation and thrombolytics in undifferentiated cardiac arrest and suspected fatal pulmonary embolism.

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

Guidance for clinical practice using emergency and point-of-care ultrasonography

Owing to the miniaturization of diagnostic ultrasound scanners and their spread of their bedside use, ultrasonography has been actively utilized in emergency situations. Ultrasonography performed by medical personnel with focused approaches at the bedside for clinical decision-making and improving the quality of invasive procedures is now called point-of-care ultrasonography (POCUS). The concept of POCUS has spread worldwide; however, in Japan, formal clinical guidance concerning POCUS is lacking, except for the application of focused assessment with sonography for trauma (FAST) and ultrasound-guided central venous cannulation. The Committee for the Promotion of POCUS in the Japanese Association for Acute Medicine (JAAM) has often discussed improving the quality of acute care using POCUS, and the "Clinical Guidance for Emergency and Point-of-Care Ultrasonography" was finally established with the endorsement of JAAM. The background, targets for acute care physicians, rationale based on published articles, and integrated application were mentioned in this guidance. The core points include the fundamental principles of ultrasound, airway, chest, cardiac, abdominal, and deep venous ultrasound, ultrasound-guided procedures, and the usage of ultrasound based on symptoms. Additional points, which are currently being considered as potential core points in the future, have also been widely mentioned. This guidance describes the overview and future direction of ultrasonography for acute care physicians and can be utilized for emergency ultrasound education. We hope this guidance will contribute to the effective use of ultrasonography in acute care settings in Japan.

Outcomes in High-Risk Pulmonary Embolism Patients Undergoing FlowTriever Mechanical Thrombectomy or Other Contemporary Therapies: Results From the FLAME Study

BACKGROUND

Hemodynamically unstable high-risk, or massive, pulmonary embolism (PE) has a reported in-hospital mortality of over 25%. Systemic thrombolysis is the guideline-recommended treatment despite limited evidence. The FLAME study (FlowTriever for Acute Massive PE) was designed to generate evidence for interventional treatments in high-risk PE.

METHODS

The FLAME study was a prospective, multicenter, nonrandomized, parallel group, observational study of high-risk PE. Eligible patients were treated with FlowTriever mechanical thrombectomy (FlowTriever Arm) or with other contemporary therapies (Context Arm). The primary end point was an in-hospital composite of all-cause mortality, bailout to an alternate thrombus removal strategy, clinical deterioration, and major bleeding. This was compared in the FlowTriever Arm to a prespecified performance goal derived from a contemporary systematic review and meta-analysis.

RESULTS

A total of 53 patients were enrolled in the FlowTriever Arm and 61 in the Context Arm. Context Arm patients were primarily treated with systemic thrombolysis (68.9%) or anticoagulation alone (23.0%). The primary end point was reached in 9/53 (17.0%) FlowTriever Arm patients, significantly lower than the 32.0% performance goal (P<0.01). The primary end point was reached in 39/61 (63.9%) Context Arm patients. In-hospital mortality occurred in 1/53 (1.9%) patients in the FlowTriever Arm and in 18/61 (29.5%) patients in the Context Arm.

CONCLUSIONS

Among patients selected for mechanical thrombectomy with the FlowTriever System, a significantly lower associated rate of in-hospital adverse clinical outcomes was observed compared with a prespecified performance goal, primarily driven by low all-cause mortality of 1.9%.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04795167.

The Pharmacologic Management of Cardiac Arrest

The effectiveness of pharmacologic management of cardiac arrest patients is widely debated; however, several studies published in the past 5 years have begun to clarify some of these issues. This article covers the current state of evidence for the effectiveness of the vasopressor epinephrine and the combination of vasopressin-steroids-epinephrine and antiarrhythmic medications amiodarone and lidocaine and reviews the role of other medications such as calcium, sodium bicarbonate, magnesium, and atropine in cardiac arrest care. We additionally review the role of β-blockers for refractory pulseless ventricular tachycardia/ventricular fibrillation and thrombolytics in undifferentiated cardiac arrest and suspected fatal pulmonary embolism.

Percutaneous Management of High-Risk Pulmonary Embolism

Acute pulmonary embolism (PE) leads to an abrupt increase in pulmonary vascular resistance and right ventricular afterload, and when significant enough, can result in hemodynamic instability. High-risk PE is a dire cardiovascular emergency and portends a poor prognosis. Traditional therapeutic options to rapidly reduce thrombus burden like systemic thrombolysis and surgical pulmonary endarterectomy have limitations, both with regards to appropriate candidates and efficacy, and have limited data demonstrating their benefit in high-risk PE. There are growing percutaneous treatment options for acute PE that include both localized thrombolysis and mechanical embolectomy. Data for such therapies with high-risk PE are currently limited. However, given the limitations, there is an opportunity to improve outcomes, with percutaneous treatments options offering new mechanisms for clot reduction with a possible improved safety profile compared with systemic thrombolysis. Additionally, mechanical circulatory support options allow for complementary treatment for patients with persistent instability, allowing for a bridge to more definitive treatment options. As more data develop, a shift toward a percutaneous approach with mechanical circulatory support may become a preferred option for the management of high-risk PE at tertiary care centers.

Incidence of Mortality and Complications in High-Risk Pulmonary Embolism: A Systematic Review and Meta-Analysis

Background

The relationship between the early hemodynamic consequences of acute pulmonary embolism (PE) and short-term morbidity and mortality has long been recognized. The mortality incidence and other complications after high-risk (massive) PE, the most severe category of the disease, are summarized in this meta-analysis.

Methods

A systematic review and meta-analysis of studies reporting on patients with massive PE indexed by PubMed and the Cochrane Library over a 10-year period (2010-2020) was conducted. Studies with adequate information to specify a cohort of patients with high-risk PE defined by the American Heart Association and European Society of Cardiology criteria and their clinical outcomes were included. Incidences were calculated as weighted averages with 95% CIs.

Results

A total of 27 publications spanning 1517 patients were identified that met the search criteria for high-risk PE. In-hospital all-cause mortality averaged 28.3% (95% CI, 20.9%-37.0%) in patients at high risk, comparable to the 30-day all-cause mortality of 30.2% (95% CI, 22.3%-39.6%). In-hospital major bleeding was 13.8% (95% CI, 9.3%-20.0%), and intracranial hemorrhage was reported in 3.6% (95% CI, 2.2%-5.9%). The risk of bias in publications was graded as low-to-moderate, with substantial heterogeneity among the studies.

Conclusions

This systematic review and meta-analysis provided low-quality to moderate-quality evidence documenting mortality, major bleeding, and other complications in patients meeting the American Heart Association and European Society of Cardiology criteria for high-risk PE. This information was used to inform the design of the FLowTriever for Acute Massive Pulmonary Embolism (FLAME) study (NCT04795167), a study evaluating an advanced therapy for patients with high-risk PE.

Eligibility of out-of-hospital cardiac arrest patients for extracorporeal cardiopulmonary resuscitation in the United States: A geographic information system model

BACKGROUND

Recent evidence suggest that extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). Eligibility criteria for ECPR are often based on patient age, clinical variables, and facility capabilities. Expanding access to ECPR across the U.S. requires a better understanding of how these factors interact with transport time to ECPR centers.

METHODS

We constructed a Geographic Information System (GIS) model to estimate the number of ECPR candidates in the U.S. We utilized a Resuscitation Outcome Consortium (ROC) database to model time-dependent rates of ECPR eligibility and the Cardiac Arrest Registry to Enhance Survival (CARES) registry to determine the total number of OHCA patients who meet pre-specified ECPR criteria within designated transportation times. The combined model was used to estimate the total number of ECPR candidates.

RESULTS

There were 588,203 OHCA patients in the CARES registry from 2013 to 2020. After applying clinical eligibility criteria, 22,104 (3.76%) OHCA patients were deemed eligible for ECPR. The rate of ROSC increased with longer resuscitation time, which resulted in fewer ECPR candidates. The proportion of OHCA patients eligible for ECPR increased with older age cutoffs. Only 1.68% (9,889/588,203) of OHCA patients in the U.S. were eligible for ECPR based on a 45-minute transportation time to an ECMO-ready center model.

CONCLUSIONS

Less than 2% of OHCA patients are eligible for ECPR in the U.S. GIS models can identify the impact of clinical criteria, transportation time, and hospital capabilities on ECPR eligibility to inform future implementation strategies.

An Update on the Management of Acute High-Risk Pulmonary Embolism

Hemodynamic instability and right ventricular (RV) dysfunction are the key determinants of short-term prognosis in patients with acute pulmonary embolism (PE). High-risk PE encompasses a wide spectrum of clinical situations from sustained hypotension to cardiac arrest. Early recognition and treatment tailored to each individual are crucial. Systemic fibrinolysis is the first-line pulmonary reperfusion therapy to rapidly reverse RV overload and hemodynamic collapse, at the cost of a significant rate of bleeding. Catheter-directed pharmacological and mechanical techniques ensure swift recovery of echocardiographic parameters and may possess a better safety profile than systemic thrombolysis. Further clinical studies are mandatory to clarify which pulmonary reperfusion strategy may improve early clinical outcomes and fill existing gaps in the evidence.

Contemporary Practice Patterns and Outcomes of Systemic Thrombolysis in Acute Pulmonary Embolism

OBJECTIVE

While systemic thrombolysis (ST) is standard of care in treatment of high-risk pulmonary embolism, large variation in real world usage exists, including use in intermediate-risk pulmonary embolism. There is a paucity of data defining the outcomes, practice patterns of ST dose, duration, and treatment in presumed or imaging confirmed pulmonary embolism.

METHODS

We performed a multicenter retrospective study evaluating real world practice patterns of systemic thrombolysis use in the setting of acute pulmonary embolism (presumed versus imaging confirmed intermediate- and high-risk). Patients who received tissue plasminogen activator for pulmonary embolism between 2017 and 2019 were included. We compared baseline clinical characteristics, tissue plasminogen activator practice patterns, and outcomes in those with confirmed versus presumed pulmonary embolism.

RESULTS

104 patients received systemic thrombolysis for pulmonary embolism; 52 patients had confirmed pulmonary embolism and 52 patients had presumed pulmonary embolism. Significantly more patients treated for presumed pulmonary embolism experienced cardiac arrest (n=47, 90%) than those with confirmed pulmonary embolism (n=23, 44%, p<0.01). Survival to hospital discharge was 65% in patients with confirmed pulmonary embolism versus 6% for those with presumed pulmonary embolism (p<0.01). Systemic thrombolysis was contraindicated in 56% of patients with confirmed pulmonary embolism, with major bleeding in 26% but no intracranial hemorrhage.

CONCLUSIONS

The in-hospital mortality of confirmed acute pulmonary embolism remains high (35%) in contemporary practice in those treated with systemic thrombolysis. A large proportion of these patients had contraindications to systemic thrombolysis and major bleeding rates were significant. Confirmed pulmonary embolism had higher survival rate compared to presumed, including those with cardiac arrest. This observation suggests a limited role of empiric thrombolysis in cardiac arrest situations.

Acute Management of High-Risk and Intermediate-Risk Pulmonary Embolism in Children: A Review

Severe forms of pulmonary embolism (PE) in children, althought rare, cause significant morbidity and mortality. We review the pathophysiologic features of severe (high-risk and intermediate-risk) PE and suggest novel pediatric-specific risk stratifications and an acute treatment algorithm to expedite emergent decision-making. We defined pediatric high-risk PE as causing cardiopulmonary arrest, sustained hypotension, or normotension with signs or symptoms of shock. Rapid primary reperfusion should be pursued with either surgical embolectomy or systemic thrombolysis in conjunction with a heparin infusion and supportive care as appropriate. We defined pediatric intermediate-risk PE as a lack of systemic hypotension or compensated shock, but with evidence of right ventricular strain by imaging, myocardial necrosis by elevated cardiac troponin levels, or both. The decision to pursue primary reperfusion in this group is complex and should be reserved for patients with more severe disease; anticoagulation alone also may be appropriate in these patients. If primary reperfusion is pursued, catheter-based therapies may be beneficial. Acute management of severe PE in children may include systemic thrombolysis, surgical embolectomy, catheter-based therapies, or anticoagulation alone and may depend on patient and institutional factors. Pediatric emergency and intensive care physicians should be familiar with the risks and benefits of each therapy to expedite care. PE response teams also may have added benefit in streamlining care during these critical events.

Massive Pulmonary Embolism Causing Cardiac Arrest Managed with Systemic Thrombolytic Therapy: A Case Report

BACKGROUND Approximately 290 000 cases of in-hospital cardiac arrest occur annually, the majority of which are due to cardiac or respiratory causes. Cardiac arrest due to acute pulmonary embolism (PE) is associated with a 90% incidence of mortality and, if identified, it can be treated with systemic thrombolytics. Here, we describe a case in which the outcome for such an event was favorable. CASE REPORT A 66-year-old woman was admitted with multiple rib and left ankle fractures due to accidental trauma. Before undergoing orthopedic surgery, she experienced a cardiac arrest with pulseless electrical activity, which was witnessed. She had refractory hypoxia and hypotension following intubation and a brief initial return of spontaneous circulation (ROSC) before a second cardiac arrest. A 100-mg bolus dose of systemic thrombolytic therapy was promptly administered, with rapid achievement of sustained ROSC. The results of a subsequent electrocardiogram, echocardiogram, and computed tomography scan further supported the diagnosis of acute PE with right heart strain. Supportive care in the Intensive Care Unit resulted in full neurological recovery and she was discharged to a physical rehabilitation facility 12 days after her cardiac arrest. CONCLUSIONS Systemic thrombolytic therapy is beneficial for cardiac arrest due to acute PE.

Key articles and guidelines for the emergency medicine clinical pharmacist: 2011-2018 update

PURPOSE

To summarize recently published research reports and practice guidelines on emergency medicine (EM)-related pharmacotherapy.

SUMMARY

Our author group was composed of 14 EM pharmacists, who used a systematic process to determine main sections and topics for the update as well as pertinent literature for inclusion. Main sections and topics were determined using a modified Delphi method, author and peer reviewer groups were formed, and articles were selected based on a comprehensive literature review and several criteria for each author-reviewer pair. These criteria included the document "Oxford Centre for Evidence-based Medicine - Levels of Evidence (March 2009)" but also clinical implications, interest to reader, and belief that a publication was a "key article" for the practicing EM pharmacist. A total of 105 articles published from January 2011 through July 2018 were objectively selected for inclusion in this review. This was not intended as a complete representation of all available pertinent literature. The reviewed publications address the management of a wide variety of disease states and topic areas that are commonly found in the emergency department: analgesia and sedation, anticoagulation, cardiovascular emergencies, emergency preparedness, endocrine emergencies, infectious diseases, neurology, pharmacy services and patient safety, respiratory care, shock, substance abuse, toxicology, and trauma.

CONCLUSION

There are many important recent additions to the EM-related pharmacotherapy literature. As is evident with the surge of new studies, guidelines, and reviews in recent years, it is vital for the EM pharmacist to continue to stay current with advancing practice changes.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

Thrombolysis of a massive intracardiac thrombus during resuscitation: documentation by transoesophageal echocardiography

Acute pulmonary embolism is a frequent potentially reversible cause of sudden cardiac arrest. The early diagnosis is challenging but essential for further treatment. New therapeutic options in resuscitation, such as extracorporeal resuscitation, are leading to frequent transports of patients to emergency rooms with ongoing resuscitation. A transoesophageal echo performed during resuscitation can give hints for reversible causes for the cardiac arrest. We present a case of a 40-year-old female patient who was transferred to our department with ongoing resuscitation and received a transoesophageal echo immediately on arrival. The examination showed a massive intracardiac thrombus. The subsequent thrombolysis and following resuscitation were observed and documented via transoesophageal echo.

Successful Intraosseous Thrombolysis in the Management of a Massive Pulmonary Embolism With Cardiac Arrest

We describe the successful cardiopulmonary resuscitation of a patient with massive pulmonary embolism who received thrombolysis via the intraosseous route. This case also demonstrates survival without apparent long-term sequelae despite extreme metabolic acidosis. In the context of pulmonary embolism, this has not been widely reported in the existing literature. A 22-year-old woman suffered a prolonged cardiac arrest secondary to pulmonary embolism in a hospital corridor following short hospital admission for medical termination of pregnancy. A point-of-care echocardiogram showed a grossly dilated right ventricle indicative of pulmonary embolism. Due to severe peripheral vasoconstriction, intravenous access proved difficult, and the decision was made to deliver intraosseous thrombolysis. Initial blood gas analysis showed a profound acidosis due to alternating return of spontaneous circulation and further loss of output. Because of her prolonged "low-flow" state, she was deemed unsuitable for extracorporeal membrane oxygenation. Despite the poor prognosis, the decision was made to continue with resuscitation in light of a reversible pathology. She was successfully discharged from the hospital after a short intensive care stay with no long-term complications. This case demonstrates successful thrombolysis through an intraosseous route, with a good outcome despite poor prognostic factors. Early thrombolysis and continuous cardiopulmonary resuscitation in massive pulmonary embolism are imperative to survival in cardiac arrest.

Fibrinolytics for the treatment of pulmonary embolism

The use of fibrinolytic agents in acute pulmonary embolism (PE), first described over 50 years ago, hastens the resolution of RV stain, leading to earlier hemodynamic improvement. However, this benefit comes at the increased risk of bleeding. The strongest indication for fibrinolysis is in high-risk PE, or that characterized by sustained hypotension, while its use in patients with intermediate-risk PE remains controversial. Fibrinolysis is generally not recommended for routine use in intermediate-risk PE, although most guidelines advise that it may be considered in patients with signs of acute decompensation and an overall low bleeding risk. The efficacy of fibrinolysis often varies significantly between patients, which may be at least partially explained by several factors found to promote resistance to fibrinolysis. Ultimately, treatment decisions should carefully weigh the risks and benefits of the individual clinical scenario at hand, including the overall severity, the patient's bleeding risk, and the presence of factors known to promote resistance to fibrinolysis. This review aims to further explore the use of fibrinolytic agents in the treatment of PE including specific indications, outcomes, and special considerations.

Mid-term outcomes with the use of extracorporeal membrane oxygenation for cardiopulmonary failure secondary to massive pulmonary embolism

OBJECTIVES

There has been increasing interest in using extracorporeal membrane oxygenation (ECMO) to rescue patients with pulmonary embolism (PE) in the advanced stages of respiratory or haemodynamic decompensation. We examined mid-term outcomes and risk factors for in-hospital mortality.

METHODS

We conducted a retrospective study of 36 patients who required ECMO placement (32 veno-arterial ECMO, 4 veno-venous) following acute PE. Survival curves were estimated using the Kaplan-Meier method. Risk factors for in-hospital mortality were assessed by logistic regression analysis. Functional status and quality of life were assessed by phone questionnaire.

RESULTS

Overall survival to hospital discharge was 44.4% (16/36). Two-year survival conditional to discharge was 94% (15/16). Two-year survival after veno-arterial ECMO was 39% (13/32). In patients supported with veno-venous ECMO, survival to discharge was 50%, and both patients were alive at follow-up. In univariable analysis, a history of recent surgery (P = 0.064), low left ventricular ejection fraction (P = 0.029), right ventricular dysfunction ≥ moderate at weaning (P = 0.083), on-going cardiopulmonary resuscitation at ECMO placement (P = 0.053) and elevated lactate at weaning (P = 0.002) were risk factors for in-hospital mortality. In multivariable analysis, recent surgery (P = 0.018) and low left ventricular ejection fraction at weaning (P = 0.013) were independent factors associated with in-hospital mortality. At a median follow-up of 23 months, 10 patients responded to our phone survey; all had acceptable functional status and quality of life.

CONCLUSIONS

Massive acute PE requiring ECMO support is associated with high early mortality, but patients surviving to hospital discharge have excellent mid-term outcomes with acceptable functional status and quality of life. ECMO can provide a stable platform to administer other intervention with the potential to improve outcomes. Risk factors for in-hospital mortality after PE and veno-arterial ECMO support were identified.

“Real-World” Application of Thrombolysis in Cardiac Arrest

Background:

Current guidelines recommend consideration of thrombosis as a reversible cause of cardiac arrest. The use of thrombolytic therapy during cardiac arrest, however, is controversial.

Objective:

We sought to characterize the use of thrombolytic therapy during cardiac arrest and to evaluate the rate of return of spontaneous circulation (ROSC) in a “real-word” setting.

Methods:

A single-center, retrospective, cohort study of adult patients who received alteplase during cardiac arrest between 2010 and 2015 were performed at a tertiary academic medical center.

Results:

Twenty-six patients were identified. Patients were predominantly male (65%) and Caucasian (89%) and were a median age of 64 years. Five patients had a history of preexisting venous thromboembolism, and eight patients were receiving systemic anticoagulation. Pulmonary embolism was confirmed prior to the administration of alteplase in 5 patients. The median dose of alteplase administered was 100 mg. ROSC was achieved in 65% of patients, 2 of whom survived to hospital discharge. Both surviving patients experienced a bleeding event.

Conclusion:

In a single center’s experience, thrombolytic therapy is used infrequently for the management of cardiac arrest. Thrombolysis during cardiac arrest should be considered on a case-by-case basis and should be utilized only when there is a high suspicion for pulmonary embolism as the cause of arrest and when thrombolytic therapy is readily available.

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.

Tricuspid Annular Plane Systolic Excursion (TAPSE) for Risk Stratification and Prognostication of Patients with Pulmonary Embolism

BACKGROUND

The categorization of pulmonary embolism (PE) as non-massive, sub-massive, and massive helps guide acute management. The presence of right ventricular (RV) strain differentiates sub-massive from non-massive PEs. Unlike laboratory markers and electrocardiogram changes, the classic parameters used in the echocardiographic diagnosis of RV strain have a technical component that is operator-dependent.

OBJECTIVE

This narrative review will describe the physiologic effects of a PE on the RV and how this affects prognosis. It will summarize the literature evaluating the accuracy and prognostic ability of tricuspid annular plane systolic excursion (TAPSE) in the echocardiographic assessment of RVfunction. The review will describe the appeal of TAPSE for this purpose, provide cutoff measurements, and then illustrate how to perform the technique itself, while offering associated pearls and pitfalls in this bedside evaluation.

DISCUSSION

RV function and dynamics undergo acute changes in the setting of a PE. RV dysfunction predicts poor outcomes in both the short and long term. However, RV strain is difficult to capture on echocardiography due to the chamber's complex geometric shape and contraction. From the apical four-chamber window, TAPSE offers a quantitative measure that is more easily performed with high interobserver reliability for evaluating systolic RV contraction. This measurement carries prognostic value in patients diagnosed with PE.

CONCLUSIONS

Along with other more qualitative echocardiographic parameters, TAPSE can be used as a simple quantitative measure of RV dysfunction for differentiating sub-massive from non-massive PEs. This categorization helps guide acute management and disposition.

Pulmonary embolism critical care update: prognosis, treatment, and research gaps

PURPOSE OF REVIEW

We provide a timely update on treatment care issues facing clinicians and patients with acute pulmonary embolism accompanied by either right ventricular strain (sub-massive pulmonary embolism) or shock (massive pulmonary embolism).

RECENT FINDINGS

Care and research changes over the last several years have resulted in four important trends: more consensus and accuracy in the way acute pulmonary embolism severity is described and communicated among acute care clinicians and researchers, increased availability and use of risk prediction scoring systems, increased use of advanced invasive therapy in the setting of severe right ventricular dysfunction, and emergence of multidisciplinary pulmonary embolism response teams to guide standard care decision-making.

SUMMARY

Pulmonary embolism with shock should be treated with either systemic or catheter-based thrombolytic therapy in the absence of contraindications. Patients with sub-massive pulmonary embolism accompanied by right heart dysfunction who are treated with thrombolytic therapy likely will experience more rapid improvement in RV function and are less likely to progress to hemodynamic decompensation. This comes, however, with an increased risk of major bleeding. Our recommendation is to consider catheter-based or systemic fibrinolytic therapy in sub-massive pulmonary embolism cases where patients demonstrate high-risk features such as: severe RV strain on echo or CT, and importantly worsening over time trends in pulse, SBP, and oxygenation despite anticoagulation. Understanding the impact of advanced therapy beyond standard anticoagulation on patient-centered outcomes, such as functional status and quality of life represent a research knowledge gap.

Pediatric In-Hospital Cardiac Arrest Secondary to Acute Pulmonary Embolism

OBJECTIVES

Pulmonary embolism is a rarely reported and potentially treatable cause of cardiac arrest in children and adolescents. The objective of this case series is to describe the course of five adolescent patients with in-hospital cardiac arrest secondary to pulmonary embolism.

DESIGN

Case series.

SETTING

Single, large academic children's hospital.

PATIENTS

All patients under the age of 18 years (n = 5) who experienced an in-hospital cardiac arrest due to apparent pulmonary embolism from August 1, 2013, to July 31, 2017.

INTERVENTIONS

All five patients received systemic thrombolytic therapy (IV tissue plasminogen activator) during cardiac arrest or periarrest during ongoing resuscitation efforts.

MEASUREMENTS AND MAIN RESULTS

Five adolescent patients, 15-17 years old, were treated for pulmonary embolism-related cardiac arrests during the study period. These accounted for 6.3% of all children and 25% of adolescents (12-17 yr old) receiving at least 5 minutes of in-hospital cardiopulmonary resuscitation during the study period. All five had venous thromboembolism risk factors. Two patients had known, extensive venous thrombi at the time of cardiac arrest, and one was undergoing angiography at the time of arrest. The diagnoses of pulmonary embolism were based on clinical suspicion, bedside echocardiography (n = 4), and low end-tidal CO2 levels relative to arterial CO2 values (n = 5). IV tissue plasminogen activator was administered during cardiopulmonary resuscitation in three patients and after the return of spontaneous circulation, in the setting of severe hemodynamic instability, in the other two patients. Four of five patients were successfully resuscitated and survived to hospital discharge.

CONCLUSIONS

Pulmonary embolism was recognized as the etiology of multiple adolescent cardiac arrests in this single-center series and may be more common than previously reported. Recognition, high-quality cardiopulmonary resuscitation, and treatment with thrombolytic therapy resulted in survival in four of five patients.

Extracorporeal cardiopulmonary resuscitation in a patient with fulminant pulmonary embolism refractory to intraarrest thrombolysis

INTRODUCTION

A fulminant pulmonary embolism is a potentially reversible cause of cardiac arrest with a reported mortality rate of up to 95%. Therapeutic strategies for fulminant pulmonary embolism continue to evolve.

CASE REPORT

We present a case of a 38-year-old female who suffered an in-hospital cardiac arrest due to fulminant pulmonary embolism. Extracorporeal cardiopulmonary resuscitation (facilitated by the LUCAS^™ mechanical chest compression device) was successfully performed in this patient following failure of intraarrest thrombolysis.

DISCUSSION

For the management of fulminant pulmonary embolism, utilization of clot-directed therapies, especially intraarrest thrombolysis, has garnered increasing traction and interest. However, this therapeutic approach has its limitations. Fortuitously, the emergence of extracorporeal cardiopulmonary resuscitation has added a new dimension to the treatment of fulminant pulmonary embolism. A protocolized approach to treatment can improve outcomes in these patients.

CONCLUSION

Extracorporeal cardiopulmonary resuscitation can be used as a salvage therapy in patients with fulminant pulmonary embolism in whom intraarrest thrombolysis has failed.

Characterization of alteplase therapy for presumed or confirmed pulmonary embolism during cardiac arrest

PURPOSE

The dosing and administration of alteplase in cardiac arrest due to suspected or confirmed pulmonary embolism (PE) are characterized.

METHODS

This multicenter, retrospective, cohort study evaluated adult patients who received alteplase during PE-induced cardiac arrest at 16 medical centers. Outcomes analyzed included alteplase dosing characteristics, cardiopulmonary resuscitation survival, time to return of spontaneous circulation (ROSC), documented occurrence of major or minor bleeding, intensive care unit and hospital length of stay, and survival to discharge.

RESULTS

A total of 35 patients were included in the analysis. Forty-six percent of patients received alteplase by a bolus-only dosing strategy. The most common bolus-only alteplase dose was 50 mg. Patients in the bolus-only group had a significantly shorter mean time from cardiac arrest onset to alteplase administration (15.1 minutes) compared with both the infusion-only group (46.4 minutes) and the bolus-with-infusion group (48.0 minutes) (p = 0.006). The mean cumulative alteplase dose was significantly higher in patients who had ROSC than those who did not (90.6 and 69.4 mg, respectively; p = 0.03). Although there was a significant difference in the cardiac arrest survival between groups, there was no difference between dosing strategies and the attainment of ROSC, and survival to hospital discharge.

CONCLUSION

Among patients receiving alteplase for presumed or confirmed PE during cardiac arrest, the most common treatment was administration of a single 50-mg bolus of the thrombolytic agent. This treatment was received by all survivors of cardiac arrest.

Double Bolus Alteplase Therapy during Cardiopulmonary Resuscitation for Cardiac Arrest due to Massive Pulmonary Embolism Guided by Focused Bedside Echocardiography

Massive pulmonary embolism (PE) frequently leads to cardiac arrest (CA) which carries an extremely high mortality rate. Although available, randomized trials have not shown survival benefits from thrombolytic use. Thrombolytics however have been used successfully during resuscitation in clinical practice in multiple case reports and in retrospective studies. Recent resuscitation guidelines recommend using alteplase for PE related CA; however they do not offer a standardized treatment regimen. The most consistently applied approach is an intravenous bolus of 50 mg tissue plasminogen activator (t-PA) early during cardiopulmonary resuscitation (CPR). There is no consensus on the subsequent dosing. We present a case in which two 50 mg boluses of t-PA were administered 20 minutes apart during CPR due to persistent hemodynamic compromise guided by bedside echocardiogram. The patient had an excellent outcome with normalization of cardiac function and no neurologic sequela. This case demonstrates the benefit of utilizing bedside echocardiography to guide administration of a second bolus of alteplase when there is persistent hemodynamic compromise despite achieving return of spontaneous circulation after the initial bolus, and there is evidence of persistent right ventricle dysfunction. Future trials are warranted to help establish guidelines for thrombolytic use in cardiac arrest to maximize safety and efficacy.

Echocardiography in cardiac arrest: An emergency medicine review

INTRODUCTION

Cardiac arrest management primarily focuses on optimal chest compressions and early defibrillation for shockable cardiac rhythms. Non-shockable rhythms such as pulseless electrical activity (PEA) and asystole present challenges in management. Point-of-care ultrasound (POCUS) in cardiac arrest is promising.

OBJECTIVES

This review provides a focused assessment of POCUS in cardiac arrest, with an overview of transthoracic (TTE) and transesophageal echocardiogram (TEE), uses in arrest, and literature support.

DISCUSSION

Cardiac arrest can be distinguished between shockable and non-shockable rhythms, with management varying based on the rhythm. POCUS provides a diagnostic and prognostic tool in the emergency department (ED), which may improve accuracy in clinical decision-making. Several protocols incorporate POCUS based on different cardiac views. TTE includes parasternal long axis, parasternal short axis, apical 4-chamber, and subxiphoid views, which may be used in cardiac arrest for diagnosis of underlying cause and potential prognostication. TEE is conducted by inserting the probe into the esophagus of intubated patients, with several studies evaluating its use in cardiac arrest. It is associated with few adverse effects, while allowing continued compressions (and evaluation of those compressions) and not interrupting resuscitation efforts.

CONCLUSIONS

POCUS is a valuable diagnostic and prognostic tool in cardiac arrest, with recent literature supporting its diagnostic ability. TTE can guide resuscitation efforts dependent on the rhythm, though TTE should not interrupt other resuscitation measures. TEE can be useful during arrest, but further studies based in the ED are needed.

Interventional Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a serious and prevalent cause of vascular disease. Nevertheless, optimal treatment for many phenotypes of PE remains uncertain. Treating PE requires appropriate risk stratification as a first step. For the highest-risk PE, presenting as shock or arrest, emergent systemic thrombolysis or embolectomy is reasonable, while for low-risk PE, anticoagulation alone is often chosen. Normotensive patients with PE but with indicia of right heart dysfunction (by biomarkers or imaging) constitute an intermediate-risk group for whom there is controversy on therapeutic strategy. Some intermediate-risk patients with PE may require urgent stabilization, and ≈10% will decompensate hemodynamically and suffer high mortality, though identifying these specific patients remains challenging. Systemic thrombolysis is a consideration, but its risks of major and intracranial hemorrhages rival overall harms from intermediate PE. Multiple hybrid pharmacomechanical approaches have been devised to capture the benefits of thrombolysis while reducing its risks, but there is limited aggregate clinical experience with such novel interventional strategies. One method to counteract uncertainty and generate a consensus multidisciplinary prognostic and therapeutic plan is through a Pulmonary Embolism Response Team, which combines expertise from interventional cardiology, interventional radiology, cardiac surgery, cardiac imaging, and critical care. Such a team can help determine which intervention-catheter-directed fibrinolysis, ultrasound-assisted thrombolysis, percutaneous mechanical thrombus fragmentation, or percutaneous or surgical embolectomy-is best suited to a particular patient. This article reviews these various modalities and the background for each.

Pulmonary embolism with cardiac arrest: a STEMI patient's unexpected course

We describe the successful use and complications of bolus-dose alteplase to treat strongly suspected pulmonary embolism (PE) with cardiac arrest in a patient initially presenting as ST-elevation myocardial infarcation (MI). Case description is followed by a review of the indications, safety, and dosing of systemic thrombolytic therapy for high-risk PE in the emergency department (ED). Diagnostic and therapeutic approach to PE in critically ill patients is also considered, including the potential utility of point-of-care ultrasound (PoCUS) in the ED.