Thrombolysis with recombinant tissue plasminogen activator during cardiopulmonary resuscitation in fulminant pulmonary embolism. A case series

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.

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.

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.

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.

Does Thrombolysis Have a Place in the Cardiopulmonary Resuscitation of Patients With Acute Pulmonary Embolism? A Case of Successful Thrombolysis During Pulmonary Embolism Induced Cardiopulmonary Arrest

OBJECTIVE

Pulmonary embolism often causes cardiac arrest. When this occurs, thrombolytic therapy is not routinely administered. There are multiple reasons for this, including difficulty with rapidly adequately diagnosing the embolus, the lack of good data supporting the use of thrombolytics during resuscitation, the belief that thrombolytic therapy is ineffective once a patient has already arrested, the difficulty of obtaining thrombolytics at the bedside rapidly enough to administer during a code, and the increased risks of bleeding, particularly with ongoing chest compressions. In this case report, we present a patient who was successfully treated with thrombolytic therapy during pulmonary embolism-induced cardiopulmonary arrest and discuss the role of thrombolytics in cardiopulmonary resuscitation.

DESIGN

Case report.

SETTING

Surgical ICU in a comprehensive cancer center.

PATIENT

A 56-year-old man who developed hypotension, dyspnea, hypoxia, and pulseless electrical activity 10 days after resection of a benign colon lesion with a right hemicolectomy and primary end-to-end anastomosis.

INTERVENTIONS

After a rapid bedside echocardiogram suggesting pulmonary embolus, thrombolytic therapy was administered during cardiopulmonary resuscitative efforts.

MEASUREMENTS AND MAIN RESULTS

The patient had a return of spontaneous circulation and showed improvement in repeat echocardiographic imaging. He had a prolonged course in the ICU and hospital, but eventually made an essentially complete clinical recovery.

CONCLUSION

As bedside echocardiographic technology becomes more rapidly and readily available, the rapid diagnosis of pulmonary embolism and use of thrombolytics during cardiopulmonary resuscitation may need to be more routinely considered a potential therapeutic adjunctive measure.

Massive Pulmonary Embolism Following Varicose Vein Surgery That Was Successfully Treated with Thrombolytic Therapy

The risk of massive pulmonary thromboembolism (PTE) secondary to varicose vein surgery is very low. There are only two cases which have been reported regarding massive PTE occurring after varicose vein surgery. We herein present the case of a woman who had suffered from chest pain. A short period following her admission to the emergency department, she had cardiac arrest and was subsequently diagnosed with massive PTE. Thrombolytic therapy was administered and her clinical status dramatically improved thereafter. Massive PTE may occur after minor surgical procedures, and thrombolytic therapy can safely be administered after cardiopulmonary resuscitation.

Successful thrombolytic therapy of post-operative massive pulmonary embolism after ultralong cardiopulmonary resuscitation: a case report and review of literature

BACKGROUND AND AIMS

Cardiac arrest caused by massive pulmonary embolism (PE) is highly refractory to conventional resuscitation. Thrombolytic therapy has been considered to be an effective way to massive PE.

METHODS

We reported a case of successful thrombolytic therapy of post-operative massive PE after 90-min cardiopulmonary resuscitation (CPR) and reviewed the relevant literature.

RESULTS

We presented the case of a 48-year-old woman with surgery of varicosis of great saphenous vein who suffered from a massive PE with circulatory arrest refractory to 90 min of aggressive CPR. Thrombolysis was given only as a single dose of 50 mg of recombinant tissue plasminogen activator. Rapid haemodynamic and clinical improvement followed the bolus dose. The patient was discharged later without neurological or other sequelae. An extensive literature search of the PubMed database only identified 11 cases of massive PE with cardiac arrest during the perioperative period with a survival rate was 88.9%. The time period of CPR before thrombolysis or anti-coagulation was 15-90 min.

CONCLUSIONS

Thrombolytic therapy is useful to achieve the return of spontaneous circulation in the resuscitation of patients with cardiac arrest secondary to massive PE during the perioperative period, even in the prolong resuscitation.

Thrombolytic treatment (alteplase; rt-Pa) in acute massive pulmonary embolism and cardiopulmonary arrest

Patients with pulmonary thromboembolism (PE) often decompensate suddenly, and once hemodynamic compromise has developed, mortality is extremely high. Currently, thrombolytic therapy for PE is still controversial. We retrospectively evaluated 34 patients with PE between January 2010 and December 2013 in the Department of Pulmonary Medicine, Medical Park Samsun Hospital, Samsun, Turkey. The demographic and disease characteristics of patients who received thrombolytic treatment were retrospectively analyzed. The female to male ratio was 19/15 and the mean age was 63.1±13.2 years. PE diagnosis was made using echocardiography (64.7%) or contrast-enhanced thorax computed tomography with echocardiography (32.4%). Twenty-two (64.7%) patients went into the cardiopulmonary arrest due to massive PE and 17 (50%) patients recovered without sequelae. Eleven (32.4%) patients were diagnosed with massive PE during cardiopulmonary arrest with clinical and echocardiographic findings. Alteplase (recombinant tissue plasminogen activator [rt-PA]) was administered during cardiopulmonary resuscitation (CPR) and four (36.3%) patients responded and survived without sequelae. The complications of rt-PA treatment were hemorrhage in five (14.7%) patients and allergic reactions in two (5.9%) patients. There was no mortality due to rt-PA treatment complications. In conclusion, mortality due to massive PE is much more than estimated and alteplase can be used safely in patients with massive PE. This thrombolytic treatment was not associated with any fatal hemorrhage complication. If there is any sign of acute PE, echocardiography should be used during cardiopulmonary arrest/instability. Alteplase should be given to patients with suspected massive PE.

Management dilemmas in acute pulmonary embolism

Background

Physicians treating acute pulmonary embolism (PE) are faced with difficult management decisions while specific guidance from recent guidelines may be absent.

Methods

Fourteen clinical dilemmas were identified by physicians and haematologists with specific interests in acute and chronic PE. Current evidence was reviewed and a practical approach suggested.

Results

Management dilemmas discussed include: sub-massive PE, PE following recent stroke or surgery, thrombolysis dosing and use in cardiac arrest, surgical or catheter-based therapy, failure to respond to initial thrombolysis, PE in pregnancy, right atrial thrombus, role of caval filter insertion, incidental and sub-segmental PE, differentiating acute from chronic PE, early discharge and novel oral anticoagulants.

Conclusion

The suggested approaches are based on a review of the available evidence and guidelines and on our clinical experience. Management in an individual patient requires clinical assessment of risks and benefits and also depends on local availability of therapeutic interventions.

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.

Giant right atrial thrombi treated with thrombolysis

The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery.

Outcomes of CPR in the presence of partial occlusion of left anterior descending coronary artery

OBJECTIVES

To develop a clinically relevant experimental model of cardiac arrest and CPR in which a partial occlusion of the left anterior descending coronary artery (LAD) is maintained during the resuscitation procedure and the initial post-resuscitation interval.

MATERIALS AND METHODS

Ventricular fibrillation (VF) was induced by LAD occlusion with a balloon tipped catheter in 16 domestic male pigs weighing 41+/-2kg. After a 7min interval of untreated VF, the LAD balloon occlusion was deflated and the catheter withdrawn in eight animals. The LAD balloon was deflated in the remaining eight animals but the catheter was kept in place in order to maintain a partial occlusion of the LAD, which was approximately 75% of the internal lumen. CPR, including chest compressions and ventilations with oxygen, was then performed for 2min before a defibrillation attempt. Thirty minutes following successful resuscitation the LAD catheter was withdrawn in the animals with partial occlusion of the LAD.

RESULTS

In the animals that had the LAD totally unoccluded before to starting CPR, each animal was resuscitated successfully and survived for more than 72h with better neurological recovery during the initial 24h post-resuscitation than did the partially occluded group. When a partial occlusion of the LAD was maintained during CPR, six of eight animals were resuscitated and only four of these survived for 72h. A significantly greater number of electrical shocks prior to ROSC were required when a partial occlusion of the LAD was maintained during CPR. Significantly greater severity of post-resuscitation myocardial dysfunction was observed in animals resuscitated with a partial occlusion of the LAD.

CONCLUSIONS

In this model of prolonged untreated cardiac arrest, maintaining a partial occlusion of the LAD during CPR and the initial post-resuscitation interval required a greater number of shocks before ROSC, increased severity of post-resuscitation myocardial dysfunction significantly and yielded less favourable outcomes.

Trombolisis en la parada cardíaca

Both acute myocardial infarction and pulmonary thromboembolism are responsible for a great number of cardiac arrests. Both present high rates of mortality. Thrombolysis has proved to be an effective treatment for acute myocardial infarction and pulmonary thromboembolism with shock. It would be worth considering whether thrombolysis could be effective and safe during or after cardiopulmonary resuscitation (CPR). Unfortunately, too few clinical studies presenting sufficient scientific data exist in order to respond adequately to this question. However, most studies they show that thrombolysis applied during and after CPR is a therapeutic option that is not associated with greater risk of serious hemorrhaging and could possibly have beneficial effects. On the other hand, experimental data exists which show that thrombolytics can attenuate neurological damage produced after CPR. Nevertheless, clinical trials would be necessary in order to adequately establish the effectiveness and safety of thrombolysis in patients who require CPR.

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.

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.

Pulmonary embolism

PE is one of the great challenges in medicine. It is a disease that carries with it a high mortality rate, yet no historical piece of information, physical examination finding, or diagnostic modality is perfect at excluding its possibility. Emergency physicians must be vigilant about considering PE in the differential diagnosis of a variety of presenting complaints and must use a variety of diagnostic and therapeutic options as they manage patients with suspected or confirmed PE. The diagnostic options range from bedside diagnostic tests to highly specialized imaging available at only specialized institutions. Knowing the advantages and disadvantages of each of the diagnostic modalities assists the physician in employing the best test. Therapeutic options also vary widely and include anticoagulation, vena caval interruption, systemic thrombolysis, embolectomy, and other therapeutic adjuncts, such as ECMO and inhaled nitric oxide. Similarly, awareness of the indications and contraindications to the varied therapeutic agents ensures appropriate therapy when the diagnosis is made.

Major bleeding complications in cardiopulmonary resuscitation: the place of thrombolytic therapy in cardiac arrest due to massive pulmonary embolism

OBJECTIVE

Thrombolytic therapy in patients with massive pulmonary embolism (MPE) and prolonged cardiopulmonary resuscitation (CPR) is subject to debate. This study was performed to determine whether (1) thrombolytic treatment increases the risk of bleeding complications, (2) if the risk of bleeding is influenced by the duration of CPR and if (3) thrombolytic therapy improves outcome.

DESIGN

Retrospective cohort study.

SETTING

Emergency department of a tertiary care university hospital.

PATIENTS AND METHODS

Sixty-six patients with cardiac arrest (CA) due to MPE admitted between July 1993 and December 2001. Thirty-six patients received thrombolysis (TL) and were compared with 30 patients without thrombolytic therapy. Bleeding complications were assessed by clinical evidence or autopsy.

RESULTS

Major bleeding complications appear to occur more frequently in patients treated with thrombolytics (9/36 (25%) vs. 3/30 (10%)) even though the difference was statistically not significant (P=0.15). It appears that CPR duration >10 min has no adverse impact on major bleeding complications. No difference in the rate of major bleeding complications between thrombolyzed patients who had a CPR duration of </=10 or >10 min could be observed (2/8 (25%) vs. 7/28 (25%), P=0.99). In thrombolyzed patients a return of spontaneous circulation could be achieved more frequently (24/36 (67%) vs.13/30 (43%) in controls, P=0.06) and survival after 24 h was higher (19/36 (53%) vs. 7/30 (23%), P=0.01). Survival to discharge was also higher in the TL group (7/36 (19%) vs. 2/30 (7%)), but not statistically significant (P=0.15).

CONCLUSION

Although severe bleeding complications tend to occur more frequently in patients undergoing TL, the benefit of this treatment might outweigh the risk of bleeding.

Plasminogen activators in inflammation and sepsis

Mortality of severe sepsis remains at 40% to 50%. Intensive efforts over the past two decades have only marginally improved outcome. Improving outcome in sepsis depends on understanding its pathophysiology, which involves triggers, responses of the organism, and dysfunction. Stress, injury, or infection trigger host responses, including local and systemic orchestrated mechanisms. Dysfunction and outcome depend on both trigger and response. Blood coagulation, inflammation, immunity, and fibrinolysis are critical components of the organism's responses. Understanding their role in sepsis pathophysiology is the key to effective treatment. Relevant studies were identified by a systematic literature search, complemented by manual search of individual citations. Using PubMed, 'sepsis' yields more than 62,000 references, 'plasminogen activators' more than 21,000. The selection of citations was guided by preference for reviews that expand important threads of argumentation. Single original studies were included when relevant to critical points. This analytical review describes the essential elements of pathophysiology and the current status of sepsis treatment. Based on this context, an emerging therapeutic option will be discussed: plasminogen activators.

Towards safer thrombolytic therapy

Plasminogen activators (PA) are unique agents that are currently applied as thrombolytic therapy to achieve rapid vascular reperfusion. Regimens of PA plus anticoagulants and antiplatelet drugs have attained a high degree of sophistication and predictable rates of positive clinical outcomes for acute myocardial infarction (MI), ischemic stroke, pulmonary embolism (PE), deep vein thrombosis (DVT), and thrombosed catheters. Included in the repertoire are newly approved mutants of tissue plasminogen activator (TPA), which have biochemical advantages that allow for bolus administration. Yet, despite tremendous effort devoted to enormous trials to establish the clinical efficacy of these agents in acute MI, mortality results are not superior to those with native TPA or streptokinase (SK). Furthermore, all PAs have the potential for hemorrhagic complication, most critically intracranial hemorrhage (ICH), occurring in 0.9% of patients treated with native or mutant TPA. It is possible that a limit of clinical effectiveness has been reached, beyond which more potent PAs do not achieve greater benefit without a serious increase in risk of bleeding. A breakthrough is possible, however, if the risk of ICH could be avoided. One solution is the application of the direct-acting thrombolytic enzyme, plasmin. While intravenous plasmin is not effective when administered systemically, regional infusion to a thrombus induces local thrombolysis. Unlike the PAs, plasmin treatment should not cause hemorrhage from vascular trauma sites, as it is neutralized by antiplasmin in the blood. Animal studies are fully consistent with this approach, which offers potential for achieving a truly regional thrombolytic treatment.

Advanced life support drugs: do they really work?

Basic life support and rapid defibrillation for ventricular fibrillation or pulseless ventricular tachycardia are the only two interventions that have been shown unequivocally to improve survival after cardiac arrest. Several drugs are advocated to treat cardiac arrest, but despite very encouraging animal data, no drug has been reliably proven to increase survival to hospital discharge after cardiac arrest. This review focuses on recent experimental and clinical data concerning the use of vasopressin, amiodarone, magnesium, and fibrinolytics during advanced life support (ALS). Animal data indicate that, in comparison with epinephrine (adrenaline), vasopressin produces better vital organ blood flow during cardiopulmonary resuscitation (CPR). These apparent advantages have yet to be converted into improved survival in large-scale trials of cardiac arrest in humans. Data from two prospective, randomized trials suggest that amiodarone may improve short-term survival after out-of-hospital ventricular fibrillation cardiac arrest. On the basis of anecdotal data, magnesium is recommended therapy for torsades de pointes and for shock-resistant ventricular fibrillation associated with hypomagnesemia. In the past, CPR has been a contraindication to giving fibrinolytics, but several studies have demonstrated the relative safety of fibrinolysis during and after CPR. Fibrinolytics are likely to be beneficial when cardiac arrest is associated with plaque rupture and fresh coronary thrombus or massive pulmonary embolism. Fibrinolysis may also improve cerebral microcirculatory perfusion once a spontaneous circulation has been restored. A planned, prospective, randomized trial may help to define the role of fibrinolysis during out-of-hospital CPR.