Bolus thrombolytic infusions during CPR for patients with refractory arrest rhythms: outcome of a case series

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.

Frequency of Medical Reversal Among Published Randomized Controlled Trials Assessing Cardiopulmonary Resuscitation (CPR)

OBJECTIVE

To characterize what proportion of all randomized controlled trials (RCTs) among patients experiencing cardiac arrest find that an established practice is ineffective or harmful, that is, a medical reversal.

METHODS

We reviewed a database of all published RCTs of cardiac arrest patient populations between 1995 and 2014. Articles were classified on the basis of whether they tested a new or existing therapy and whether results were positive or negative. A reversal was defined as a negative RCT of an established practice. Further review and categorization were performed to confirm that reversals were supported by subsequent systematic review, as well as to identify the type of medical practice studied in each reversal. This study was conducted from October 2017 to June 17, 2019.

RESULTS

We reviewed 92 original articles, 76 of which could be conclusively categorized. Of these, 18 (24%) articles examined a new medical practice, whereas 58 (76%) tested an established practice. A total of 18 (24%) studies had positive findings, whereas 58 (76%) reached a negative conclusion. Of the 58 articles testing existing standard of care, 44 (76%) reversed that practice, whereas 14 (24%) reaffirmed it.

CONCLUSION

Reversal of cardiopulmonary resuscitation practices is widespread. This investigation sheds new light on low-value practices and patterns of medical research and suggests that novel resuscitation practices have low pretest probability and should be empirically tested with rigorous trials before implementation.

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.

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.

Current pharmacological advances in the treatment of cardiac arrest

Cardiac arrest is defined as the sudden cessation of spontaneous ventilation and circulation. Within 15 seconds of cardiac arrest, the patient loses consciousness, electroencephalogram becomes flat after 30 seconds, pupils dilate fully after 60 seconds, and cerebral damage takes place within 90–300 seconds. It is essential to act immediately as irreversible damage can occur in a short time. Cardiopulmonary resuscitation (CPR) is an attempt to restore spontaneous circulation through a broad range of interventions which are early defibrillation, high-quality and uninterrupted chest compressions, advanced airway interventions, and pharmacological interventions. Drugs should be considered only after initial shocks have been delivered (when indicated) and chest compressions and ventilation have been started. During cardiopulmonary resuscitation, no specific drug therapy has been shown to improve survival to hospital discharge after cardiac arrest, and only few drugs have a proven benefit for short-term survival. This paper reviews current pharmacological treatment of cardiac arrest. There are three groups of drugs relevant to the management of cardiac arrest: vasopressors, antiarrhythmics, and other drugs such as sodium bicarbonate, calcium, magnesium, atropine, fibrinolytic drugs, and corticosteroids.

Thrombolytics for Cardiac Arrest: Case Report and Systematic Review of Controlled Trials

Objective:

To describe a successful case involving the use of tenecteplase during cardiac arrest for presumed pulmonary embolism (PE) and to systematically review the evidence from controlled trials supporting the efficacy and safety of thrombolysis during cardiac arrest.

Case Summary:

A 48-year-old male presented to the emergency department with an acute onset of shortness of breath that began approximately 2 hours prior to presentation. Prior to undergoing a computed tomography (CT) scan to rule out PE, the patient went into cardiac arrest, with an initial rhythm of pulseless electrical activity at a rate of 140 beats/min. Cardiopulmonary resuscitation (CPR) was initiated and, due to suspected PE, a bolus dose of tenecteplase 50 mg was administered immediately following a single 1-mg dose of epinephrine. CPR was continued and 4 additional 1-mg doses of epinephrine and three 1-mg doses of atropine were given. After 13 minutes of CPR, return of spontaneous circulation (ROSC) was achieved, with a blood pressure of 144/50 mm Hg. After the patient was stabilized, a CT scan demonstrated extensive bilateral pulmonary emboli in most segmental arteries. He was admitted to the intensive care unit where he was sedated, paralyzed, and treated with induced hypothermia for 24 hours. He was discharged from the hospital 2 weeks later on warfarin, with no noted neurologic deficits.

Discussion:

A systematic search of MEDLINE (1950-August 2010), Embase (1980-August 2010), and Google Scholar (to August 2010) was conducted to identify prospective controlled trials that investigated the use of thrombolytic medications to treat cardiac arrest. Five trials involving 1544 undifferentiated cases of cardiac arrest were found. Overall, some trials reported an improved rate of ROSC following administration of thrombolytics, but there was no overall mortality reduction in any trial. There was, however, an increased risk of bleeding events following administration of a thrombolytic drug.

Conclusions:

Controlled trials demonstrate that there is a lack of benefit and potential harm in administering thrombolysis in an undifferentiated patient with cardiac arrest. However, the case we present provides evidence that fibrinolysis may benefit selected patients with cardiac arrest in whom PE is confirmed or in whom there is high index of suspicion of PE.

Venothromboembolism

This article focuses on the clinical presentation, diagnosis, and management of veno-thromboembolism, including deep venous thrombosis (DVT) and pulmonary embolism (PE), from the perspective of the emergency physician. The discussion is divided into two sections: DVT and PE. Because veno-thromboembolism is a continuum, certain aspects, such as background, incidence, the use of D dimer, and anticoagulation of both DVT and PE, are discussed together. Heavier emphasis is placed on topics germane to the emergency physician, and considerations for special populations are reviewed.

Bolus thrombolytic infusion during prolonged refractory cardiac arrest of undiagnosed cause

Acute myocardial infarction (AMI) and pulmonary embolism (PE) account for about 70% of cardiac arrest. Although thrombolytic therapy is an effective therapy for both AMI and PE, it is not routinely recommended during cardiopulmonary resuscitation (CPR) for fear of life threatening bleeding complications. Numerous case reports and retrospective studies have suggested a beneficial effect of thrombolytics in cardiac arrest secondary to AMI and PE; however, we present a case of successful use of bolus thrombolytics during CPR in a patient with undifferentiated cardiac arrest (undiagnosed cause) after prolonged conventional resuscitation without success.

Rapid cardiac ultrasound of inpatients suffering PEA arrest performed by nonexpert sonographers

Cardiac arrest presenting as pulseless electrical activity (PEA) currently has a very low survival rate. Many of the conditions underlying PEA (cardiac tamponade, hypovolemia, and pulmonary embolus) are associated with specific cardiac ultrasound findings. The aim of this study was to evaluate a rapid cardiac ultrasound assessment performed by trained nonexpert sonographers integrated into the ACLS response system at a major medical center.

METHODS

An emergency sonography system was created and deployed to each inpatient cardiac arrest occurring at Dartmouth Hitchcock Medical Center between November 1, 2003 and April 30, 2004. Thirteen internal medicine house officers received training to perform a limited subcostal cardiac ultrasound examination designed to diagnose cardiac tamponade, pulmonary embolus, severe hypovolemia, and lack of cardiac motion. Time from arrest alert to sonographic result, and correlation with over-reading by blinded echocardiography physicians were assessed.

RESULTS

A complete emergency ultrasound examination was performed in five PEA arrests. The average time from arrest alert to interpretation was 7.75 min. (95% CI 2.8-18.3 min). Three of these examinations (60%, 95% CI 14.7-94.7%) were adequate for interpretation. Agreement between the nonexpert sonographer and echocardiography physician occurred in four of five (kappa=0.706) cases.

CONCLUSION

Rapid cardiac sonography can be successfully integrated in the ACLS response. Nonexpert sonographers may be able to provide useful interpretive information when sufficiently trained.

Thrombolytic therapy during prolonged in-hospital cardiac arrest

We report a case of cardiac arrest secondary to acute myocardial infarction that was successfully resolved after thrombolytic therapy. This case suggests that thrombolysis can be used safely also during prolonged cardiopulmonary resuscitation for in-hospital cardiac arrest.

On-scene physician assessment of thromboembolic etiology in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OOHCA) treatment produces dismal recovery rates. Newer, directed therapies such as thrombolysis may be best considered if possible etiologies can be assessed immediately. We conducted a prospective, pilot, feasibility study of on-scene physician assessments in non-traumatic OOHCA. Physicians responded to the scene and reported likelihood of thromboembolic etiology based on detailed history and physical assessments. Included were 136/148 OOHCAs during the 6-month study period; median age was 69.5 years and 72% were men. Physicians judged 103/136 (76%) of arrests to be of thromboembolic etiology and would have recommended thrombolytic bolus in 83/136 (61%). Among 19 instances of physician-reported contraindications, 17 (90%) were not true contraindications. Median age was lower in the group recommended for thrombolysis. Thromboembolic etiology as judged by on-scene physicians was common and physicians recommended thrombolytic bolus commonly. Contraindications were highly overestimated. These data may be useful in the consideration of innovative, directed therapies such as thrombolysis in attempts to improve outcomes from OOHCA.

Safety of thrombolysis during cardiopulmonary resuscitation

The prognosis is generally poor for patients who experience a cardiac arrest. The most common causes of sudden cardiac arrest are massive pulmonary embolism (PE) and acute myocardial infarction (MI). While thrombolysis is a first-line treatment option in massive PE and acute MI, cardiopulmonary resuscitation (CPR) has been regarded as a relative contraindication for thrombolysis because of the anticipated bleeding risk caused by traumatic cardiocompressions. However, an increasing number of case reports and clinical studies on thrombolysis during and after CPR highlight an increased frequency of the return of spontaneous circulation and a better neurological outcome of surviving patients. These effects are mainly due to the thrombolysis of macroscopic blood clots and the amelioration of microcirculatory reperfusion. This article reviews case reports and clinical studies of thrombolysis during and shortly after CPR in order to estimate the risk of severe bleeding events caused by CPR in association with thrombolysis compared with CPR without thrombolysis. Although thrombolysis per se can cause severe and potentially fatal haemorrhage, there is no evidence that severe bleeding events occur more often when thrombolysis is combined with cardiocompressions. In addition, by far the majority of bleeding complications can be treated effectively. Thus, in many cases, the possible benefit of thrombolysis during CPR seems to outweigh the potential risks. However, there may be a publication bias in some case reports and studies towards reporting successful rather than unsuccessful CPRs. In addition, not enough controlled clinical trials have yet been conducted. Therefore, data from large randomised, multicentre studies are needed to definitely answer the question of the relationship between safety and efficacy of this promising treatment option. We conclude that the currently available data do not indicate that thrombolysis contributes to a significant increase in bleeding complications when administered during CPR.

Tissue plasminogen activator in cardiac arrest with pulseless electrical activity

BACKGROUND

Coronary thrombosis and pulmonary thromboembolism are common causes of cardiac arrest. We assessed whether the administration of tissue plasminogen activator (t-PA) during cardiopulmonary resuscitation would benefit patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause.

METHODS

Patients who were older than 16 years of age and who had more than one minute of pulseless electrical activity that was unresponsive to initial therapy outside the hospital or in the emergency department were eligible. Patients were randomly assigned to receive 100 mg of t-PA or placebo intravenously over a 15-minute period in a double-blind fashion. Standard resuscitation was then continued for at least 15 minutes. The primary outcome was survival to hospital discharge.

RESULTS

During the study period, 1583 patients with cardiac arrest were treated and 233 patients were enrolled (117 in the t-PA group and 116 in the placebo group). The characteristics of the patients in the two groups were similar. One patient in the t-PA group survived to hospital discharge, as compared with none in the placebo group (absolute difference between groups, 0.9; 95 percent confidence interval, -2.6 to 4.8; P=0.99). The proportion of patients with return of spontaneous circulation was 21.4 percent in the t-PA group and 23.3 percent in the placebo group (absolute difference between groups, -1.9; 95 percent confidence interval, -12.6 to 8.8; P=0.85).

CONCLUSIONS

We found no evidence of a beneficial effect of fibrinolysis in patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause. Our study had limited statistical power, and it remains unknown whether there is a small treatment effect or whether selected subgroups may benefit.

Out-of-hospital thrombolytic therapy during cardiopulmonary resuscitation in refractory cardiac arrest due to acute myocardial infarction

Out-of-hospital thrombolytic therapy was administrated to a 53-year-old woman with confirmed acute myocardial infarction and refractory cardiac arrest. Standard advanced cardiac life support measures were performed by an out-of-hospital critical care team but they were unsuccessful. Thrombolytic therapy was given as a rescue therapy after prolonged cardiopulmonary resuscitation. The patient recovered a sinus rhythm and circulation 20 minutes after a bolus infusion of tissue plasminogen activator and was fit to be transported to the hospital. Reversal of arterial occlusion was confirmed at the hospital. There was no sequelae related to thrombolytic therapy and the patient was finally discharged 21 days later. This is the first published report of out-of-hospital thrombolytic therapy during cardiopulmonary resuscitation for a patient with refractory cardiac arrest due to acute myocardial infarction.

Thrombolytic therapy during cardiopulmonary resuscitation and the role of coagulation activation after cardiac arrest

Thrombolysis is an effective causal therapy for patients suffering from massive pulmonary embolism or acute myocardial infarction. In more than 70% of patients with cardiac arrest, one of these two diseases is the underlying cause of deterioration. Nevertheless, because of the fear of severe bleeding complications, thrombolytic therapy during cardiopulmonary resuscitation (CPR) has been contraindicated. Increasing clinical experience and data from open studies now suggest that thrombolysis during CPR can contribute to hemodynamic stabilization and survival in patients with massive pulmonary embolism and acute myocardial infarction, after conventional CPR procedures have been performed unsuccessfully. After administration of thrombolytic agents, some patients have been stabilized even after more than 90 minutes of CPR. Besides the specific causal action of thrombolytic agents at the site of pulmonary emboli and coronary thrombosis, experimental data indicate that thrombolysis during CPR can improve microcirculatory reperfusion, which may be most important in the brain. In accordance with these data, marked activation of blood coagulation without adequate activation of endogenous fibrinolysis has been demonstrated during reperfusion after cardiac arrest. Massive coagulation activation with subsequent fibrin formation is responsible for microcirculatory reperfusion disorders, and thrombolytic therapy may be indicated. However, no controlled studies are available on this therapeutic concept. Because the risk of bleeding complications is potentially associated with the administration of thrombolytic agents, although this occurs far less than anticipated, thrombolysis during CPR is presently a treatment strategy that can be performed on an individual basis. Whether thrombolysis during CPR can improve survival rates and neurologic outcomes should be addressed in randomized, controlled trials.

Pulseless electrical activity with witnessed arrest as a predictor of sudden death from massive pulmonary embolism in outpatients

BACKGROUND

the objective was to determine clinical characteristics that can quickly distinguish sudden death from massive pulmonary embolism (MPE) from other causes of sudden death.

METHODS AND RESULTS

all medical examiner reports from Charlotte, NC from 1992 to 1999 (n=4926) were hand-searched for cases of sudden death which met the inclusion criteria: non-traumatic death, age 18-65 years, transported to an emergency department (ED), and autopsy performed. Supplemental data from ED and prehospital records were retrieved to complete documentation. Data were analyzed by univariate odds ratios (OR) followed by chi-square (chi(2)) recursive partitioning for decision tree construction. Three hundred eighty four cases met inclusion criteria; MPE was the second most frequent cause of cardiac arrest in this cohort (37/384, 9.6%). The mean age of subjects with MPE (40.2+/-11.1 years) was significantly lower compared with non-PE subjects (46.5+/-9.9 years). Pulseless electrical activity was observed as the initial arrest rhythm (primary PEA) in 52/384 (13.5%) subjects. Out of 52 subjects with primary PEA, 28 (53%) died from MPE. Odds ratio data indicated significant association of MPE with female gender, arrest witnessed by medical providers, presence of primary PEA, and return of spontaneous circulation. The most accurate decision rule to recognize MPE consisted of witnessed arrest+primary PEA. This rule generated sensitivity=67.6% and specificity=94.5% and yielded a posttest probability of MPE of 57%.

CONCLUSIONS

outpatients with witnessed cardiac arrest and primary PEA carry a high probability of MPE.

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

BACKGROUND

During cardiopulmonary resuscitation (CPR), thrombolysis can help to stabilise patients with pulmonary embolism and myocardial infarction. Moreover, thrombolysis during CPR has beneficial effects on cerebral reperfusion after cardiac arrest. We investigated this new therapeutic approach in patients in whom conventional CPR had been unsuccessful.

METHODS

We assessed, in a prospective study, patients undergoing CPR after out-of-hospital cardiac arrest for cardiological reasons in whom return of spontaneous circulation was not achieved within 15 min. According to the Ustein criteria, our control group consisted of patients who were assessed during 1 year. After this year patients were treated with a bolus of 5000 U of heparin and 50mg, over 2 min, of tissue-type plasminogen activator (rt-PA treated group). This intervention was repeated if return of spontaneous circulation was not achieved within the following 30 min. For controls only CPR was given.

FINDINGS

Overall, 90 patients were included; heparin and rt-PA were given to 40 patients. There were no bleeding complications related to the CPR procedures. Of the rt-PA group, 68% (27) had return of spontaneous circulation and 58% (23) were admitted to a cardiac intensive care unit, compared with 44% (22; p=0.026) and 30% (15; p=0.009) of the controls, respectively. At 24 h after cardiac arrest a larger proportion of the rt-PA group than of the controls was alive (35% [14] vs 22% [11], p=0.171), and 15% (six) of rt-PA-treated patients and 8% (four) of controls could be discharged from hospital.

INTERPRETATION

After initially unsuccessful out-of-hospital CPR, thrombolytic therapy combined with heparin is safe and might improve patient outcome. On the basis of our data a randomised controlled trial might be regarded as ethical.

Minimally invasive direct cardiac massage and defibrillation

Direct massage of the heart may be performed using a specifically designed device inserted via a limited thoracic incision. The technique is simple to perform and has been shown in experimental studies to be physiologically similar to formal open-chest cardiac massage. Preliminary human studies have been encouraging and pre-hospital and in-hospital studies are in progress. Modification of the device allows combined epicardial-transthoracic defibrillation. Energy requirements for successful defibrillation using this method are considerably lower than standard external defibrillation.