Efficacy and safety of thrombolytic therapy after initially unsuccessful cardiopulmonary resuscitation: a prospective clinical trial

Thrombolytics in Cardiac Arrest from Pulmonary Embolism: A Systematic Review and Meta Analysis

BACKGROUND

During cardiopulmonary resuscitation, intravenous thrombolytics are commonly used for patients whose underlying etiology of cardiac arrest is presumed to be related to pulmonary embolism (PE).

METHODS

We performed a systematic review and meta-analysis of the existing literature that focused on the use of thrombolytics for cardiac arrest due to presumed or confirmed PE. Outcomes of interest were return of spontaneous circulation (ROSC), survival to hospital discharge, neurologically-intact survival, and bleeding complications.

RESULTS

Thirteen studies with a total of 803 patients were included in this review. Most studies included were single-armed and retrospective. Thrombolytic agent and dose were heterogeneous between studies. Among those with control groups, intravenous thrombolysis was associated with higher rates of ROSC (OR 2.55, 95% CI = 1.50-4.34), but without a significant difference in survival to hospital discharge (OR 1.41, 95% CI = 0.79-2.41) or bleeding complications (OR 2.21, 0.95-5.17).

CONCLUSIONS

Use of intravenous thrombolytics in cardiac arrest due to confirmed or presumed PE is associated with increased ROSC but not survival to hospital discharge or change in bleeding complications. Larger randomized studies are needed. Currently, we recommend continuing to follow existing consensus guidelines which support use of thrombolytics for this indication.

Cardiac arrest in the perioperative period: a consensus guideline for identification, treatment, and prevention from the European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery

INTRODUCTION

Cardiac arrest in the operating room is a rare but potentially life-threatening event with mortality rates of more than 50%. Contributing factors are often known, and the event is recognised rapidly as patients are usually under full monitoring. This guideline covers the perioperative period and is complementary to the European Resuscitation Council guidelines.

MATERIAL AND METHODS

The European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery jointly nominated a panel of experts to develop guidelines for the recognition, treatment, and prevention of cardiac arrest in the perioperative period. A literature search was conducted in MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials. All searches were restricted to publications from 1980 to 2019 inclusive and to the English, French, Italian and Spanish languages. The authors also contributed individual, independent literature searches.

RESULTS

This guideline contains background information and recommendation for the treatment of cardiac arrest in the operating room environment, and addresses controversial topics such as open chest cardiac massage, resuscitative endovascular balloon occlusion and resuscitative thoracotomy, pericardiocentesis, needle decompression, and thoracostomy.

CONCLUSIONS

Successful prevention and management of cardiac arrest during anaesthesia and surgery requires anticipation, early recognition, and a clear treatment plan. The ready availability of expert staff and equipment must also be taken into consideration. Success not only depends on medical knowledge, technical skills and a well-organised team using crew resource management, but also on an institutional safety culture embedded in everyday practice through continuous education, training, and multidisciplinary co-operation.

Cardiac arrest in the perioperative period: a consensus guideline for identification, treatment, and prevention from the European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery

INTRODUCTION

Cardiac arrest in the operating room is a rare but potentially life-threatening event with mortality rates of more than 50%. Contributing factors are often known, and the event is recognised rapidly as patients are usually under full monitoring. This guideline covers the perioperative period and is complementary to the European Resuscitation Council (ERC) guidelines.

MATERIAL AND METHODS

The European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery jointly nominated a panel of experts to develop guidelines for the recognition, treatment and prevention of cardiac arrest in the perioperative period. A literature search was conducted in MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials. All searches were restricted to publications from 1980 to 2019 inclusive and to the English, French, Italian and Spanish languages. The authors also contributed individual, independent literature searches.

RESULTS

This guideline contains background information and recommendation for the treatment of cardiac arrest in the operating room environment, and addresses controversial topics such as open chest cardiac massage (OCCM), resuscitative endovascular balloon occlusion (REBOA) and resuscitative thoracotomy, pericardiocentesis, needle decompression and thoracostomy.

CONCLUSION

Successful prevention and management of cardiac arrest during anaesthesia and surgery requires anticipation, early recognition and a clear treatment plan. The ready availability of expert staff and equipment must also be taken into consideration. Success not only depends on medical knowledge, technical skills and a well organised team using crew resource management but also on an institutional safety culture embedded in everyday practice through continuous education, training and multidisciplinary co-operation.

Differential diagnosis and cause-specific treatment during out-of-hospital cardiac arrest: a retrospective descriptive study

BACKGROUND

The cardiopulmonary resuscitation (CPR) guidelines recommend identifying and correcting the underlying reversible causes of out-of-hospital cardiac arrest (OHCA). However, it is uncertain how often these causes can be identified and treated. Our aim was to estimate the frequency of point of care ultrasound examinations, blood sample analyses and cause-specific treatments during OHCA.

METHODS

We performed a retrospective study in a physician-staffed helicopter emergency medical service (HEMS) unit. Data on 549 non-traumatic OHCA patients who were undergoing CPR at the arrival of the HEMS unit from 2016 to 2019 were collected from the HEMS database and patient records. We also recorded the frequency of ultrasound examinations, blood sample analyses and specific therapies provided during OHCA, such as procedures or medications other than chest compressions, airway management, ventilation, defibrillation, adrenaline or amiodarone.

RESULTS

Of the 549 patients, ultrasound was used in 331 (60%) and blood sample analyses in 136 (24%) patients during CPR. A total of 85 (15%) patients received cause-specific treatment, the most common ones being transportation to extracorporeal CPR and percutaneous coronary intervention (PCI) (n = 30), thrombolysis (n = 23), sodium bicarbonate (n = 17), calcium gluconate administration (n = 11) and fluid resuscitation (n = 10).

CONCLUSION

In our study, HEMS physicians deployed ultrasound or blood sample analyses in 84% of the encountered OHCA cases. Cause-specific treatment was administered in 15% of the cases. Our study demonstrates the frequent use of differential diagnostic tools and relatively infrequent use of cause-specific treatment during OHCA. Effect on protocol for differential diagnostics should be evaluated for more efficient cause specific treatment during OHCA.

Role of adjunct anticoagulant or thrombolytic therapy in cardiac arrest without ST-segment-elevation or percutaneous coronary intervention: A systematic review and meta-analysis

This study sought to compare the impact of additional anticoagulation or thrombolytic therapy in patients with cardiac arrest without ST-segment-elevation on electrocardiography and not receiving percutaneous coronary intervention. Three studies (two randomized controlled studies and one observational study) were included, which demonstrated that use of anticoagulation or thrombolytic therapy was associated with higher risk of bleeding, without improvements in time to return of spontaneous circulation or in-hospital mortality.

Novel Ex-Vivo Thrombolytic Reconditioning of Kidneys Retrieved 4 to 5 Hours After Circulatory Death

BACKGROUND

Due to organ shortage, many patients do not receive donor organs. The present novel thrombolytic technique utilizes organs from donors with uncontrolled donation after circulatory deaths (uDCD), with up to 4-5 h warm ischemia, without advanced cardiopulmonary resuscitation (aCPR) or extracorporeal circulation (EC) after death.

METHODS

The study group of pigs (n = 21) underwent simulated circulatory death. After 2 h, an ice slush was inserted into the abdomen. Kidneys were retrieved 4.5 h after death. Lys-plasminogen, antithrombin-III (ATIII), and alteplase (tPA) were injected through the renal arteries on the back table. Subsequent ex vivo perfusion at 15 °C was continued for 3 h, followed by 3 h with red blood cells (RBCs) at 32 °C. Perfusion outcome and histology were compared between uDCD kidneys, receiving no thrombolytic treatment (n = 8), and live donor kidneys (n = 7). The study kidneys were then transplanted into pigs as autologous grafts with a single functioning autologous kidney as the only renal support. uDCD control pigs (n = 8), receiving no ex vivo perfusion, served as controls.

RESULTS

Vascular resistance decreased to <200 mmHg/mL/min ( P < 0.0023) and arterial flow increased to >100 mL/100 g/min ( P < 0.00019) compared to controls. In total 13/21 study pigs survived for >10 days, while all uDCD control pigs died. Histology was preserved after reconditioning, and the creatinine level after 10 days was next to normal.

CONCLUSIONS

Kidneys from extended uDCD, not receiving aCPR/EC, can be salvaged using thrombolytic treatment to remove fibrin thrombi while preserving histology and enabling transplantation with a clinically acceptable early function.

Thrombolysis after cardiopulmonary resuscitation in myocardial infarction with abdominal pain as the first presentation: A case report

RATIONALE

Thrombolysis after cardiopulmonary resuscitation in patients with acute ST-segment elevation myocardial infarction (STEMI) is controversial. This case report describes a successful thrombolysis after resuscitation in delayed-diagnosis STEMI.

PATIENT CONCERNS

A 58-year-old man presented with acute abdominal pain as the first symptom of a subsequent STEMI diagnosis. When he returned to the clinic after having been assisted with abdominal pain relief, he suffered a sudden cardiac arrest. Cardiopulmonary resuscitation was performed immediately, and thrombolysis was carried out for his anterior STEMI. He was successfully resuscitated in a short period of time.

DIAGNOSIS

The patient was diagnosed with acute and extensive anterior STEMI. The D-dimer level was normal, and pericardial effusion was ruled out.

INTERVENTIONS

After successful resuscitation, the patient received half-dose alteplase thrombolytic therapy. After a few days, the patient was transferred to a general ward. Coronary angiography revealed unobstructed flow in the left anterior descending artery.

OUTCOMES

The ST segment of the patient gradually declined after thrombolytic therapy, and the myocardial injury marker levels increased. A small amount of pleural fluid in the lungs and pulmonary infection were observed. With effective diuretic, anti-infective, and other treatments, the patient's condition gradually improved, the ventilator was removed, and vasoactive drugs were successfully discontinued. Coronary angiography revealed that the flow of the culprit artery was unobstructed, and a drug-coated balloon was implanted. No wall motion abnormalities were detected on echocardiography, and the patient recovered well.

CONCLUSIONS

In patients with abdominal pain as the first presentation, a simple initial electrocardiogram may help reduce the risk of missed STEMI diagnosis. Thrombolysis after successful resuscitation is an effective treatment for these patients. However, the effects of thrombolysis after resuscitation remain unclear. The point of dispute lies in the effectiveness and safety of thrombolysis (primarily for bleeding). Prompt thrombolysis would lead to a better prognosis if spontaneous circulation can be restored within 10 minutes.

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.

Usefulness of thrombolysis in cardiac arrest secondary to suspected or confirmed pulmonary embolism

Acute pulmonary embolism (PE) is a form of venous thromboembolism associated with significant morbidity and mortality. Massive PE, characterized by hemodynamic instability, has been reported as a common cause of cardiac arrest. Thrombolytic agents have therefore been identified as a potential rescue therapy to restore circulatory perfusion. This study describes use patterns of systemic thrombolysis in cardiac arrest and corresponding patient outcomes. A multicenter retrospective chart review was conducted to evaluate adult patients who received rescue thrombolysis during cardiac arrest for suspected or confirmed PE. A total of 27 patients were included. PE was confirmed in 4 patients (15%). Pulseless electrical activity was the initial rhythm in 21 patients (78%), with a median cardiac arrest duration of 23 minutes in patients with return of spontaneous circulation (ROSC) vs 42.5 minutes in patients without ROSC. Among the 11 patients (41%) with ROSC, two (7%) survived to hospital discharge. Notable characteristics of the two survivors included a confirmed PE, an initial presenting rhythm of pulseless electrical activity, and administration of alteplase within 5 minutes of cardiac arrest. We recommend early administration of rescue thrombolysis when there is a high clinical index of suspicion that PE is the cause of the arrest.

Emergency Thrombolysis During Cardiac Arrest Due to Pulmonary Thromboembolism: Our Experience Over 6 Years

Introduction

Cardiac arrest (CA) is one of the leading causes of death worldwide. Among patients with CA, pulmonary embolism (PE) accounts for approximately 10% of all cases.

Objective

To compare the outcomes after cardiopulmonary-cerebral resuscitation (CCPR) with and without thrombolytic therapy (TT) in patients with CA secondary to PE.

Methods

We included patients older than 17 years admitted to our hospital between 2013 and 2017 with a diagnosis of CA with confirmed or highly suspected PE who received CCPR with or without TT. Measures of central tendency were used to depict the data.

Results

The study comprised 16 patients, 8 of whom received CCPR and thrombolysis with alteplase, whereas the remaining patients received CCPR without TT. The most frequent rhythm of CA in both groups was pulseless electrical activity. Return of spontaneous circulation (ROSC) occurred in 100% of patients who received TT and in 88% of non-thrombolysed patients. The mortality rate of patients who received TT and non-thrombolysed patients at 24 hours was 25% and 50%, respectively. However, at the time of hospital discharge, the mortality was the same in both groups (62%). In patients who received TT, mortality was related to sepsis and hemorrhage whereas in non-thrombolysed patients, mortality was due to myocardial dysfunction.

Conclusion

Intra-arrest thrombolysis resulted in a higher likelihood of ROSC and a higher 24-hour survival in adults with CA secondary to acute PE. Overall, the survival at hospital discharge was the same in the two groups.

Neuroprotective Treatment of Postanoxic Encephalopathy: A Review of Clinical Evidence

Postanoxic encephalopathy is the key determinant of death or disability after successful cardiopulmonary resuscitation. Animal studies have provided proof-of-principle evidence of efficacy of divergent classes of neuroprotective treatments to promote brain recovery. However, apart from targeted temperature management (TTM), neuroprotective treatments are not included in current care of patients with postanoxic encephalopathy after cardiac arrest. We aimed to review the clinical evidence of efficacy of neuroprotective strategies to improve recovery of comatose patients after cardiac arrest and to propose future directions. We performed a systematic search of the literature to identify prospective, comparative clinical trials on interventions to improve neurological outcome of comatose patients after cardiac arrest. We included 53 studies on 21 interventions. None showed unequivocal benefit. TTM at 33 or 36°C and adrenaline (epinephrine) are studied most, followed by xenon, erythropoietin, and calcium antagonists. Lack of efficacy is associated with heterogeneity of patient groups and limited specificity of outcome measures. Ongoing and future trials will benefit from systematic collection of measures of baseline encephalopathy and sufficiently powered predefined subgroup analyses. Outcome measurement should include comprehensive neuropsychological follow-up, to show treatment effects that are not detectable by gross measures of functional recovery. To enhance translation from animal models to patients, studies under experimental conditions should adhere to strict methodological and publication guidelines.

Oxygen administration in patients recovering from cardiac arrest: a narrative review

High oxygen tension in blood and/or tissue affects clinical outcomes in several diseases. Thus, the optimal target PaO₂ for patients recovering from cardiac arrest (CA) has been extensively examined. Many patients develop hypoxic brain injury after the return of spontaneous circulation (ROSC); this supports the need for oxygen administration in patients after CA. Insufficient oxygen delivery due to decreased blood flow to cerebral tissue during CA results in hypoxic brain injury. By contrast, hyperoxia may increase dissolved oxygen in the blood and, subsequently, generate reactive oxygen species that are harmful to neuronal cells. This secondary brain injury is particularly concerning. Although several clinical studies demonstrated that hyperoxia during post-CA care was associated with poor neurological outcomes, considerable debate is ongoing because of inconsistent results. Potential reasons for the conflicting results include differences in the definition of hyperoxia, the timing of exposure to hyperoxia, and PaO₂ values used in analyses. Despite the conflicts, exposure to PaO₂ > 300 mmHg through administration of unnecessary oxygen should be avoided because no obvious benefit has been demonstrated. The feasibility of titrating oxygen administration by targeting SpO₂ at approximately 94% in patients recovering from CA has been demonstrated in pilot randomized controlled trials (RCTs). Such protocols should be further examined.

Systemic thrombolysis for refractory cardiac arrest due to presumed myocardial infarction

The empiric usage of systemic thrombolysis for refractory out of hospital cardiac arrest (OHCA) is considered for pulmonary embolism (PE), but not for undifferentiated cardiac etiology [1, 2]. We report a case of successful resuscitation after protracted OHCA with suspected non-PE cardiac etiology, with favorable neurological outcome after empiric administration of systemic thrombolysis. A 47-year-old male presented to the emergency department (ED) after a witnessed OHCA with no bystander cardiopulmonary resuscitation (CPR). His initial rhythm was ventricular fibrillation (VF) which had degenerated into pulseless electrical activity (PEA) by ED arrival. Fifty-seven minutes into his arrest, we gave systemic thrombolysis which obtained return of spontaneous circulation (ROSC). He was transferred to the coronary care unit (CCU) and underwent therapeutic hypothermia. On hospital day (HD) 4 he began following commands and was extubated on HD 5. Subsequent percutaneous coronary intervention (PCI) revealed non-obstructive stenosis in distal LAD. He was discharged home directly from the hospital, with one-month cerebral performance category (CPC) score of one. He was back to work three months post-arrest. Emergency physicians (EP) should be aware of this topic since we are front-line health care professionals for OHCA. Thrombolytics have the advantage of being widely available in ED and therefore offer an option on a case-by-case basis when intra-arrest PCI and ECPR are not available. This case report adds to the existing literature on systemic thrombolysis as salvage therapy for cardiac arrest from an undifferentiated cardiac etiology. The time is now for this treatment to be reevaluated.

Cardiopulmonary Resuscitation in Intensive Care Unit Patients With Coronavirus Disease 2019

Cardiopulmonary resuscitation (CPR) in patients with severe acute respiratory syndrome coronavirus-2–associated disease (coronavirus disease 2019) poses a unique challenge to health- care providers due to the risk of viral aerosolization and disease transmission. This has caused some centers to modify existing CPR procedures, limit the duration of CPR, or consider avoiding CPR altogether. In this review, the authors propose a procedure for CPR in the intensive care unit that minimizes the number of personnel in the immediate vicinity of the patient and conserves the use of scarce personal protective equipment. Highlighting the low likelihood of successful resuscitation in high-risk patients may prompt patients to decline CPR. The authors recommend the preemptive placement of central venous lines in high-risk patients with intravenous tubing extensions that allow for medication delivery from outside the patients’ rooms. During CPR, this practice can be used to deliver critical medications without delay. The use of a mechanical compression system for CPR further reduces the risk of infectious exposure to health- care providers. Extracorporeal membrane oxygenation should be reserved for patients with few comorbidities and a single failing organ system. Reliable teleconferencing tools are essential to facilitate communication between providers inside and outside the patients' rooms. General principles regarding the ethics and peri-resuscitative management of coronavirus 2019 patients also are discussed.

International Survey of Thrombolytic Use for Treatment of Cardiac Arrest Due to Massive Pulmonary Embolism

Objectives

This survey sought to characterize the national prescribing patterns and barriers to the use of thrombolytic agents in the treatment of pulmonary embolism, with a specific focus on treatment during actual or imminent cardiac arrest.

Design

A 19-question international, cross-sectional survey on thrombolytic use in pulmonary embolism was developed, validated, and administered. A multivariable logistic regression was conducted to determine factors predictive of utilization of thrombolytics in the setting of cardiac arrest secondary to pulmonary embolism.

Setting

International survey study.

Subjects

Physicians, pharmacists, nurses, and other healthcare professionals who were members of the Society of Critical Care Medicine.

Interventions

None.

Measurements and Main Results

Thrombolytic users were compared with nonusers. Respondents (n = 272) predominately were physicians (62.1%) or pharmacists (30.5%) practicing in an academic medical center (54.8%) or community teaching setting (24.6%). Thrombolytic users (n = 177; 66.8%) were compared with nonusers (n = 88; 33.2%) Thrombolytic users were more likely to work in pulmonary/critical care (80.2% thrombolytic use vs 59.8%; p < 0.01) and emergency medicine (6.8% vs 3.5%; p < 0.01). Users were more likely to have an institutional guideline or policy in place pertaining to the use of thrombolytics in cardiac arrest (27.8% vs 13.6%; p < 0.01) or have a pulmonary embolism response team (38.6% vs 19.3%; p < 0.01). Lack of evidence supporting use and the risk of adverse outcomes were barriers to thrombolytic use. Working in a pulmonary/critical care environment (odds ratio, 2.36; 95% CI, 1.24-4.52) and comfort level (odds ratio, 2.77; 95% CI, 1.7-4.53) were predictive of thrombolytic use in the multivariable analysis.

Conclusions

Most survey respondents used thrombolytics in the setting of cardiac arrest secondary to known or suspected pulmonary embolism. This survey study adds important data to the literature surrounding thrombolytics for pulmonary embolism as it describes thrombolytic user characteristic, barriers to use, and common prescribing practices internationally.

“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.

Can Systemic Thrombolysis Improve Prognosis of Cardiac Arrest Patients During Cardiopulmonary Resuscitation? A Systematic Review and Meta-Analysis

BACKGROUND

Cardiac arrests are caused in most cases by thromboembolic diseases, such as acute myocardial infarction (AMI) and pulmonary embolism (PE).

OBJECTIVE

We aimed to ascertain the associations of thrombolytic therapy with potential benefits among cardiac arrest patients during cardiopulmonary resuscitation (CPR).

METHODS

We searched PubMed, Embase, and Cochrane databases for studies that evaluated systemic thrombolysis in cardiac arrest patients. The primary outcome was survival to hospital discharge, and secondary outcomes included return of spontaneous circulation (ROSC), 24-h survival rate, hospital admission rate, and bleeding complications.

RESULTS

Nine studies with a total of 4384 cardiac arrest patients were pooled in the meta-analysis, including 1084 patients receiving systemic thrombolysis and 3300 patients receiving traditional treatments. Compared with conventional therapies, the use of systemic thrombolysis did not significantly improve survival to hospital discharge (13.5% vs. 10.8%; risk ratio [RR] 1.13; 95% confidence interval [CI] 0.92-1.39; p = 0.24, I² = 35%), ROSC (50.9% vs. 44.3%; RR 1.29; 95% CI 1.00-1.66; p = 0.05, I² = 73%), and 24-h survival (28.1% vs. 25.6%; RR 1.25; 95% CI 0.88-1.77; p = 0.22, I² = 63%). We observed higher hospital admission rates for patients receiving systemic thrombolysis (43.4% vs. 30.6%; RR 1.53; 95% CI 1.04-2.24; p = 0.03, I² = 87%). In addition, higher risk of bleeding was observed in the thrombolysis group (8.8% vs. 5.0%; RR 1.65; 95% CI 1.16-2.35; p = 0.005, I² = 7%).

CONCLUSIONS

Systemic thrombolysis during CPR did not improve hospital discharge rate, ROSC, and 24-h survival for cardiac arrest patients. Patients receiving thrombolytic therapy have a higher risk of bleeding. More high-quality studies are needed to confirm our results.

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.

Thrombolysis as a Therapeutic Modality in Cardiac Arrest

Introduction

In recent years, thrombolysis has emerged as a potentially promising treatment for cardiac arrest. Patients with cardiac arrests from myocardial infarction or pulmonary embolism, as well as out-of-hospital cardiac arrests, were reported to have improvement in both survival and neurologic outcome after being treated with thrombolysis. This paper aims to review the available literature on the use of thrombolysis in cardiac arrest.

Method

Study of papers from PubMed literature search for all articles with terms related to thrombolysis and cardiac arrest in title or abstract.

Results

Thrombolytics are thought to act by lysing both macroscopic clots and microthrombi, particularly in the cerebral microcirculation, thus alleviating or reversing post-arrest cerebral no-reflow. Their use in cardiac arrest has been restrained by concerns over their safety after cardiopulmonary resuscitation, in particular bleeding-related complications, although these concerns seem to have been misplaced.

Conclusions

Thrombolysis for cardiac arrest is likely to be most efficacious in a pre-hospital environment, and future research should be directed to this setting.

Coagulofibrinolytic Changes in Patients with Post-cardiac Arrest Syndrome

Whole-body ischemia and reperfusion due to cardiac arrest and subsequent return of spontaneous circulation constitute post-cardiac arrest syndrome (PCAS), which consists of four syndromes including systemic ischemia/reperfusion responses and post-cardiac arrest brain injury. The major pathophysiologies underlying systemic ischemia/reperfusion responses are systemic inflammatory response syndrome and increased coagulation, leading to disseminated intravascular coagulation (DIC), which clinically manifests as obstruction of microcirculation and multiple organ dysfunction. In particular, thrombotic occlusion in the brain due to DIC, referred to as the "no-reflow phenomenon," may be deeply involved in post-cardiac arrest brain injury, which is the leading cause of mortality in patients with PCAS. Coagulofibrinolytic changes in patients with PCAS are characterized by tissue factor-dependent coagulation, which is accelerated by impaired anticoagulant mechanisms, including antithrombin, protein C, thrombomodulin, and tissue factor pathway inhibitor. Damage-associated molecular patterns (DAMPs) accelerate not only tissue factor-dependent coagulation but also the factor XII- and factor XI-dependent activation of coagulation. Inflammatory cytokines are also involved in these changes via the expression of tissue factor on endothelial cells and monocytes, the inhibition of anticoagulant systems, and the release of neutrophil elastase from neutrophils activated by inflammatory cytokines. Hyperfibrinolysis in the early phase of PCAS is followed by inadequate endogenous fibrinolysis and fibrinolytic shutdown by plasminogen activator inhibitor-1. Moreover, cell-free DNA, which is also a DAMP, plays a pivotal role in the inhibition of fibrinolysis. DIC diagnosis criteria or fibrinolysis markers, including d-dimer and fibrin/fibrinogen degradation products, which are commonly tested in patients and easily accessible, can be used to predict the mortality or neurological outcome of PCAS patients with high accuracy. A number of studies have explored therapy for this unique pathophysiology since the first report on "no-reflow phenomenon" was published roughly 50 years ago. However, the optimum therapeutic strategy focusing on the coagulofibrinolytic changes in cardiac arrest or PCAS patients has not yet been established. The elucidation of more precise pathomechanisms of coagulofibrinolytic changes in PCAS may aid in the development of novel therapeutic targets, leading to an improvement in the outcomes of PCAS patients.

Outcome of out-of-hospital cardiac arrest after fibrinolysis with reteplase in comparison to the return of spontaneous circulation after cardiac arrest score in a geographic region without emergency coronary intervention

Coronary occlusion and pulmonary embolism are responsible for the majority of cases of out-of-hospital cardiac arrest (OHCA). Despite previous favourable results of pre-hospital fibrinolysis in cases of OHCA, the benefit could not be confirmed in a large controlled study using the fibrinolytic tenecteplase. For reteplase (r-PA), there are hardly any data regarding pre-hospital fibrinolysis during ongoing resuscitation. The present study reported results using r-PA therapy in a German physician-supported Emergency Medical Services system. The data of OHCA patients who received pre-hospital fibrinolytic treatment with r-PA after an individual risk/benefit assessment were retrospectively analysed. To assess the effectiveness of this approach, the rate of patients with a return of spontaneous circulation (ROSC) was compared with the corresponding figure that was calculated with the help of the RACA (ROSC after cardiac arrest) score. The RACA algorithm predicts the probability of ROSC based on data from the German Resuscitation Registry. Further outcome data comprised hospital discharge rate and neurologic status at discharge. From 2001 to 2009, 43 patients (mean age, 58.5 years; 65.1% male; 58.1% ventricular fibrillation) received r-PA. Of these, 20 patients (46.5%) achieved ROSC, compared to a probability of 49.8% according to the RACA score (P=0.58). A total of 8 patients (18.6%) were discharged alive, including 5 (11.2%) with a good neurological outcome. For the analysed small patient collective, pre-hospital r-PA did not offer any benefits with regard to the ROSC rate. Further analyses of larger patient numbers on a nationwide registry basis are recommended.

Clinical pathophysiology of hypoxic ischemic brain injury after cardiac arrest: a "two-hit" model

Hypoxic ischemic brain injury (HIBI) after cardiac arrest (CA) is a leading cause of mortality and long-term neurologic disability in survivors. The pathophysiology of HIBI encompasses a heterogeneous cascade that culminates in secondary brain injury and neuronal cell death. This begins with primary injury to the brain caused by the immediate cessation of cerebral blood flow following CA. Thereafter, the secondary injury of HIBI takes place in the hours and days following the initial CA and reperfusion. Among factors that may be implicated in this secondary injury include reperfusion injury, microcirculatory dysfunction, impaired cerebral autoregulation, hypoxemia, hyperoxia, hyperthermia, fluctuations in arterial carbon dioxide, and concomitant anemia.Clarifying the underlying pathophysiology of HIBI is imperative and has been the focus of considerable research to identify therapeutic targets. Most notably, targeted temperature management has been studied rigorously in preventing secondary injury after HIBI and is associated with improved outcome compared with hyperthermia. Recent advances point to important roles of anemia, carbon dioxide perturbations, hypoxemia, hyperoxia, and cerebral edema as contributing to secondary injury after HIBI and adverse outcomes. Furthermore, breakthroughs in the individualization of perfusion targets for patients with HIBI using cerebral autoregulation monitoring represent an attractive area of future work with therapeutic implications.We provide an in-depth review of the pathophysiology of HIBI to critically evaluate current approaches for the early treatment of HIBI secondary to CA. Potential therapeutic targets and future research directions are summarized.

Thrombolytic Therapy for Massive Pulmonary Embolism in a Patient With a Known Intracranial Tumor

The objective was to describe and review the use of thrombolytic therapy in a patient with an intracranial tumor and massive pulmonary embolism. This is the first reported case of a patient with a known glioblastoma multiforme and massive pulmonary embolism who was successfully treated with alteplase. Pulmonary embolism was demonstrated by a ventilation-perfusion scan and transthoracic echocardiogram with repeat studies demonstrating resolution of the thromboembolism and reperfusion of pulmonary vasculature. A review of the literature revealed that the incidence of intracranial hemorrhage with thrombolysis is <3% and compares favorably with the much higher mortality rate of 25% to ≥50% in patients with hemodynamically unstable pulmonary emboli. The benefit of thrombolysis may outweigh the risks of intracranial hemorrhage in these patients, and careful consideration for its use in these patients is warranted.

Double Bolus Thrombolysis for Suspected Massive Pulmonary Embolism during Cardiac Arrest

More than 70% of cardiac arrest cases are caused by acute myocardial infarction (AMI) or pulmonary embolism (PE). Although thrombolytic therapy is a recognised therapy for both AMI and PE, its indiscriminate use is not routinely recommended during cardiopulmonary resuscitation (CPR). We present a case describing the successful use of double dose thrombolysis during cardiac arrest caused by pulmonary embolism. Notwithstanding the relative lack of high-level evidence, this case suggests a scenario in which recombinant tissue Plasminogen Activator (rtPA) may be beneficial in cardiac arrest. In addition to the strong clinical suspicion of pulmonary embolism as the causative agent of the patient's cardiac arrest, the extremely low end-tidal CO2 suggested a massive PE. The absence of dilatation of the right heart on subxiphoid ultrasound argued against the diagnosis of PE, but not conclusively so. In the context of the circulatory collapse induced by cardiac arrest, this aspect was relegated in terms of importance. The second dose of rtPA utilised in this case resulted in return of spontaneous circulation (ROSC) and did not result in haemorrhage or an adverse effect.

Breakthrough in cardiac arrest: reports from the 4th Paris International Conference

Jean-Luc Diehl The French Intensive Care Society organized on 5th and 6th June 2014 its 4th "Paris International Conference in Intensive Care", whose principle is to bring together the best international experts on a hot topic in critical care medicine. The 2014 theme was "Breakthrough in cardiac arrest", with many high-quality updates on epidemiology, public health data, pre-hospital and in-ICU cares. The present review includes short summaries of the major presentations, classified into six main chapters: Epidemiology of CA Pre-hospital management Post-resuscitation management: targeted temperature management Post-resuscitation management: optimizing organ perfusion and metabolic parameters Neurological assessment of brain damages Public healthcare.

Neurologically normal survival after fibrinolysis during prolonged cardiac arrest: case report and discussion

Cardiac arrest secondary to pulmonary embolism is a devastating condition with a high mortality rate. It is currently unclear whether fibrinolysis (thrombolysis) is beneficial in this setting. We report the case of a 28-year-old woman with a pulmonary embolism who developed return of pulses following the administration of tissue plasminogen activator after 38 minutes of pulseless electrical activity cardiac arrest. She went on to make a full neurologic and cardiopulmonary recovery. This case is discussed with reference to the current literature on the subject.

[Clinical practice of systemic lysis in prehospital resuscitation. Success and complication rates]

BACKGROUND

Systemic thrombolysis was introduced as the sole prehospital treatment option in patients with cardiac arrest in the setting of acute myocardial ischemia or pulmonary embolism; however, it remains the subject of discussion.

PATIENTS AND METHODS

A total of 194 patients with sudden prehospital cardiac arrest were included in this retrospective case control study. Of these patients, 96 in whom circulatory arrest due to cardiac disease (pulmonary artery embolism or myocardial ischemia) was suspected underwent thrombolytic treatment and were compared to the remaining 98 patients that did not undergo thrombolytic therapy. In addition to the circumstances of circulatory arrest, the course and success of resuscitation, as well as in-hospital course (including bleeding complications), overall survival and neurological outcomes were compared.

RESULTS

There were no significant differences between patients with or without thrombolysis in terms of the circumstances of cardiac arrest. Patients that received thrombolytic treatment were significantly younger and were more frequently treated with anticoagulants, platelet aggregation inhibitors and amiodarone. They also received higher doses of epinephrine and arrived at hospital under ongoing resuscitation significantly more frequently. A trend toward more prehospital return of spontaneous circulation (ROSC) following thrombolytic treatment was seen in the entire cohort. However, patients pre-treated with acetylsalicylic acid and heparin did not show better prehospital ROSC rates as a result of additional thrombolytic therapy. Significant differences in terms of bleeding complications or the need for blood transfusion could not be seen due to the small number of patients.

DISCUSSION

The indication for systemic thrombolysis in the context of prehospital resuscitation should remain restricted to patients with clear symptoms of acute pulmonary embolism or recurrent episodes of ventricular fibrillation in the setting of acute myocardial infarction. Due to a lack of evidence, systemic thrombolysis should not be used as a treatment of last resort in younger patients with persistent ventricular fibrillation.

The significance of pre-arrest factors in out-of-hospital cardiac arrests witnessed by emergency medical services: a report from the Victorian Ambulance Cardiac Arrest Registry

BACKGROUND

The significance of pre-arrest factors in out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical services (EMS) is not well established. The purpose of this study was to assess the association between prodromal symptoms and pre-arrest clinical observations on the arresting rhythm and survival in EMS witnessed OHCA.

METHODS

Between 1st January 2003 and 31st December 2011, 1056 adult EMS witnessed arrests of a presumed cardiac aetiology were identified from the Victorian Ambulance Cardiac Arrest Registry. Pre-arrest prodromal features and clinical characteristics were extracted from the patient care record. Backward elimination logistic regression was used to identify pre-arrest factors associated with an initial shockable rhythm and survival to hospital discharge.

RESULTS

The median age was 73.0 years, 690 (65.3%) were male, and the rhythm of arrest was shockable in 465 (44.0%) cases. The most commonly reported prodromal symptoms prior to arrest were chest pain (48.8%), dyspnoea (41.8%) and altered consciousness (37.8%). An unrecordable systolic blood pressure was observed in 34.4%, a respiratory rate <13 or >24min(-1) was present in 43.1%, and 45.5% had a Glasgow coma score <15. In the multivariable analysis, the following pre-arrest factors were significantly associated with survival: age, public location, aged care facility, chest pain, arm or shoulder pain, dyspnoea, dizziness, vomiting, ventricular tachycardia, pulse rate, systolic blood pressure, respiratory rate, Glasgow coma score, aspirin and inotrope administration.

CONCLUSION

Pre-arrest factors are strongly associated with the arresting rhythm and survival following EMS witnessed OHCA. Potential opportunities to improve outcomes exist by way of early recognition and management of patients at risk of OHCA.

Evidence-based diagnosis and thrombolytic treatment of cardiac arrest or periarrest due to suspected pulmonary embolism

When a previously healthy adult experiences atraumatic cardiac arrest, providers must quickly identify the etiology and implement potentially lifesaving interventions such as advanced cardiac life support. A subset of these patients develop cardiac arrest or periarrest due to pulmonary embolism (PE). For these patients, an early, presumptive diagnosis of PE is critical in this patient population because administration of thrombolytic therapy may significantly improve outcomes. This article reviews thrombolysis as a potential treatment option for patients in cardiac arrest or periarrest due to presumed PE, identifies features associated with a high incidence of PE, evaluates thrombolytic agents, and systemically reviews trials evaluating thrombolytics in cardiac arrest or periarrest. Despite potentially improved outcomes with thrombolytic therapy, this intervention is not without risks. Patients exposed to thrombolytics may experience major bleeding events, with the most devastating complication usually being intracranial hemorrhage. To optimize the risk-benefit ratio of thrombolytics for treatment of cardiac arrest due to PE, the clinician must correctly identify patients with a high likelihood of PE and must also select an appropriate thrombolytic agent and dosing protocol.

A case of survival after cardiac arrest and 3½ hours of resuscitation

Although survival rates after cardiac arrest remain low, new techniques are improving patients' outcomes. We present the case of a 40-year-old man who survived a cardiac arrest that lasted approximately 3½ hours. Resuscitation was performed with strict adherence to American Heart Association/American College of Cardiology Advanced Cardiac Life Support guidelines until bedside extracorporeal membrane oxygenation could be placed. A hypothermia protocol was initiated immediately afterwards. The patient had a full neurologic recovery and was bridged from dual ventricular assist devices to a total artificial heart. On hospital day 160, he underwent orthotopic heart and cadaveric kidney transplantation. On day 179, he was discharged from the hospital in ambulatory condition. To our knowledge, this is the only reported case in which a patient survived with good neurologic outcomes after a resuscitation that lasted as long as 3½ hours. Documented cases of resuscitation with good recovery after prolonged arrest give hope for improved overall outcomes in the future.

Successful alteplase bolus administration for a presumed massive pulmonary embolism during cardiopulmonary resuscitation

OBJECTIVE

To describe the case of a patient successfully resuscitated with bolus alteplase for a presumed massive pulmonary embolism (PE) with associated cardiac arrest.

CASE SUMMARY

A 54-year-old man presented to the emergency department for evaluation of syncope following recent open reduction and internal fixation of his ankle. On arrival, his condition rapidly deteriorated and progressed to cardiopulmonary arrest. Because of noncompliance with postoperative thromboprophylaxis, there was high suspicion for PE. Following 40 minutes of advanced cardiac life support, empirical alteplase 50 mg was administered intravenously over 2 minutes with return of spontaneous circulation (ROSC) observed 6 minutes later. The diagnosis of PE using computed tomographic angiography was confirmed after fibrinolytic therapy. Although his hospital course was complicated by a gastrointestinal bleed requiring transfusion, he was discharged neurologically intact.

DISCUSSION

Clinical guidelines recommend fibrinolytic therapy for patients with PE and cardiac arrest. Data from retrospective analyses, case series, and case reports suggest that various fibrinolytic regimens may facilitate ROSC and improve neurologically intact survival without an increased risk of fatal hemorrhage.

CONCLUSION

The choice of fibrinolytic therapy should be based on hospital availability, with prompt initiation of treatment and incorporation of an intravenous bolus. A reasonable treatment regimen is alteplase 0.6 mg/kg (maximum of 50 mg) or fixed dose of alteplase 50 mg given over 2 to 15 minutes. Resuscitation should be continued for at least 30 minutes, or until ROSC, after fibrinolytic initiation to allow time for the medication to work.

Aortic intramural hematoma and hepatic artery pseudoaneurysm: unusual complication following resuscitation

We present a case of a 71-year-old woman with an unusual complication of aortic intramural hematoma and hepatic artery pseudoaneurysm following cardiopulmonary resuscitation and thrombolysis done for sudden cardiopulmonary arrest and pulmonary embolism. Patient was on Warfarin treatment for a prior history of pulmonary embolism and experienced recurrent cardiac arrests, which finally resolved after intravenous administration of thrombolytic agents. However, follow-up computed tomographic angiography revealed descending aortic intramural hematoma with intramural blood pool and concomitant liver laceration with hepatic artery pseudoaneurysm. The patient received transcatheter embolization for the hepatic injury with careful follow-up for the aortic injury and was later discharged in a stable condition. Follow-up with subsequent computed tomographic angiography at a regular interval over 1 month shows near complete resolution of the intramural hematoma. The purpose of this report is to describe the rare complication of cardiopulmonary resuscitation and thrombolysis in the form of concomitant injuries of the aorta and liver. Although the use of thrombolytic agents in patients with pulmonary embolism and cardiac arrest is still a matter of debate, this case report supports the concept that thrombolysis has a role in restoring cardiopulmonary circulation, especially in recurrent cardiac arrests resulting from pulmonary embolism. On the other hand, this case also highlights the increased association of the bleeding-related complication as a result of vigorous efforts of cardiopulmonary resuscitation. Aggressive management with interventional radiology for hepatic pseudoaneurysm and conservative management of the aortic intramural hematoma resulted in favorable outcome for our patient.

Expanding the role of percutaneous coronary intervention in patients resuscitated from cardiac arrest

Special attention to post-cardiac arrest management is important to long-term survival and favorable neurological outcome in patients resuscitated from cardiac arrest. The use of emergent percutaneous coronary intervention in resuscitated patients presenting with ST-segment elevation myocardial infarction has long been considered an appropriate approach for coronary revascularization. Recent evidence suggests that other subsets of patients, namely, post-cardiac arrest patients without ST-segment elevation myocardial infarction, may benefit from immediate percutaneous coronary intervention following resuscitation. These findings could eventually have important implications for the care of resuscitated patients, including transportation of resuscitated patients to appropriate cardiac interventional facilities, access to treatment modalities such as therapeutic hypothermia, and coordinated care with cardiac catheterization laboratories.

Sonographic diagnosis of pulmonary embolism with cardiac arrest without major dilation of the right ventricle or direct sign of lower limb venous thrombosis

Bedside focused echocardiography diagnosis of massive pulmonary embolism during cardiac arrest is mainly based on the detection of a dilated right ventricle, while the lack of compressibility of a deep vein of the lower limbs confirms diagnosis in doubtful cases. We describe a case of unusual sonographic signs in a young woman with cardiac arrest due to massive pulmonary embolism showing spontaneous blood echogenicity in the inferior vena cava ("sludge sign") and nonmodulated ("flat") Doppler waveform in the left lower limb veins, suggesting isolated iliac vein thrombosis.

Fate of patients with prehospital resuscitation for ST-elevation myocardial infarction and a high rate of early reperfusion therapy (results from the PREMIR [Prehospital Myocardial Infarction Registry])

Patients with acute ST-segment elevation myocardial infarction (STEMI) needing prehospital cardiopulmonary resuscitation (CPR) have a very high adverse-event rate. However, little is known about the fate of these patients and predictors of mortality in the era of early reperfusion therapy. From March 2003 through December 2004, 2,317 patients with prehospital diagnosed STEMI were enrolled in the Prehospital Myocardial Infarction Registry. One hundred ninety patients (8.2%) underwent prehospital CPR and were included in our analysis. Overall 90% of patients were treated with early reperfusion therapy, 56.3% received prehospital thrombolysis and 1/2 of these patients received early percutaneous coronary intervention after thrombolysis, 28.4% of patients were treated with primary percutaneous coronary intervention, and 5.3% received in-hospital thrombolysis. Total mortality was 40.0%. The highest mortality was seen in patients with asystole (63%) or pulseless electric activity (64%). Independent predictors of mortality were need for endotracheal intubation and older age, whereas ventricular fibrillation as initial heart rhythm was associated with survival. In conclusion, in this large registry with prehospital diagnosed STEMI, incidence of prehospital CPR was about 8%. Even with a very high rate of early reperfusion therapy, in-hospital mortality was high. Especially in elderly patients with asystole as initial heart rhythm and with need for endotracheal intubation, prognosis is poor despite aggressive reperfusion therapy.