Thrombolysis during cardiopulmonary resuscitation in fulminant pulmonary embolism: a review

Successful resuscitation with thrombolysis of a patient suffering fulminant pulmonary embolism after recent intracerebral haemorrhage

We report the life-saving administration of thrombolysis during cardiopulmonary resuscitation in a patient with recent intracerebral haemorrhage. A 53-year-old male with intracerebral haemorrhage was admitted to the intensive care unit. On the 24th day of treatment he suffered cardiac arrest with pulseless electrical activity. Transoesophageal echocardiography was performed during ongoing cardiopulmonary resuscitation. Thrombi in the right heart cavities with excessive right ventricular dysfunction confirmed the diagnosis of fulminant pulmonary embolism. Permanent restoration of a spontaneous rhythm was feasible only after administration of systemic thrombolysis with recombinant tissue plasminogen activator. Neurological examination and a computed tomogram of the brain did not show rebleeding. We conclude that under extreme circumstances absolute contraindications to thrombolysis should be weighed against the potential benefit.

When should we thrombolyse patients with pulmonary embolism? A systematic review of the literature

The early mortality in pulmonary embolism (PE) is largely predicted by the associated cardiovascular response, with progressive right ventricular failure, hypotension, shock, and circulatory arrest being associated with increasing mortality. Thrombolysis may improve the prognosis of PE associated with these varying degrees of circulatory collapse, but has no place in the treatment of small emboli with no cardiovascular compromise, as it carries a significant risk of haemorrhage. This review sets out to guide the emergency physician in deciding which patients with PE may benefit from thrombolysis.

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.

Update in the prevention and treatment of deep vein thrombosis and pulmonary embolism

PURPOSE OF REVIEW

Thromboembolic events have a major impact on outcome of surgical and medical patients. This review is focused on standards and recent advances in antithrombotic strategies for prevention and therapy of venous thromboembolism and pulmonary embolism.

RECENT FINDINGS

Alert programs improve prophylactic strategies to prevent venous thromboembolism. Evidenced-based guidelines are available on antithrombotic and thrombolytic therapy outweighing the benefits, risks, burdens and costs. Selective factor Xa and direct thrombin inhibitors are at least as effective as low-molecular-weight heparin in prevention of venous thromboembolism and treatment of pulmonary embolism, but have fewer side effects and will not need routine monitoring. In high-risk orthopaedic patients but not in general surgery patients fondaparinux is superior to low-molecular-weight heparin in the prevention of thromboembolic disease. Ximelagatran, the first oral direct thrombin inhibitor, is as effective and well tolerated as warfarin. Long-term treatment is uncertain, however, because of elevation in alanine transaminase levels. In high-risk patients with contraindication for anticoagulation, retrievable vena cava filters may be an option to prevent pulmonary embolism. Permanent cava filters do not improve long-term survival and are associated with relevant side effects. Thrombolytics should be reserved for deep venous thrombosis complicated by limb gangrene and for life threatening pulmonary embolism.

SUMMARY

There is currently sufficient information based on guidelines available on preventive and therapeutic strategies for venous thromboembolism and pulmonary embolism. Antithrombotics are the therapeutic backbone. In high-risk orthopedic surgery and venous thromboembolism the new antithrombotics fondaparinux, idraparinux and ximelagatran are superior to standard treatment. Temporary caval filters may be a therapeutic option in high-risk patients with contraindication for antithrombotics.

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.

A systematic review of currently available pharmacological neuroprotective agents as a sole intervention before anticipated or induced cardiac arrest

We conducted a Medline search for controlled studies evaluating currently available drugs for pharmacological neuroprotection. They had to be administered prior to transient global cerebral ischaemia without further non-pharmacological measures. We deliberately excluded focal ischaemia since its pathophysiology is substantially different from global ischaemia. A total of 45 articles conducted exclusively in laboratory animals met these criteria. The following classes of agents were evaluated: anaesthetics, GABAergic drugs, calcium-antagonists, anticonvulsives, sodium-channel blockers, potassium-channel activators, NMDA-receptor antagonists, hormones, vasodilators, dopamine- and alpha2-agonists, magnesium, xanthine oxidase- and cyclooxygenase inhibitors, a nootropic, a protease inhibitor, and immunosuppressants. Some of them were applied chronically and others administered via clinically impracticable routes. The available literature favours isoflurane, phenytoin, lamotrigine, magnesium, and potentially, nimodipine, and flunarizine. If factors like costs, toxicity, side effects, route and mode of application are considered, isoflurane and MgSO4 that have also been safely applied to patients with compromised left ventricular pump function are advantageous but their true role in human neuroprotection remains unclear.

Fehler und Gefahren der perioperativen Lysetherapie

Until recently, perioperative thrombolysis has always been thought to be a contraindication, because of the risk of bleeding complications. However, many case reports now show that thrombolytic drugs can be successfully used in the perioperative period. Possible indications for perioperative thrombolysis are massive pulmonary embolism and cardiopulmonary resuscitation which are also important causes of cardiac arrest. Thrombolysis can be the decisive therapeutical option, e.g. when normal cardiopulmonary resuscitation measures are not successful. Nevertheless, even against the background of many positive case reports the indication for perioperative thrombolysis should be a case-specific decision as the frequency of complications depends on the surgical intervention and must be weighed against the possible benefits of early thrombolysis. For perioperative thrombolysis there are no data available showing a beneficial effect of one particular therapeutic regimen. In the literature it is suggested that thrombolysis should be performed as quickly as possible, because the risk of bleeding complications depends more on the duration of thrombolysis than on the dosage or the thrombolytic drug itself.

[Prehospital thrombolysis of a pulmonary embolism with a severe shock]

The prehospital thrombolysis of a pulmonary embolism with high vital risk is not the subject of any recommendation. We report the case of a severe shock related to a suspicion of pulmonary embolism with favourable issue after the administration of a thrombolytic drug in prehospital conditions. The evolution's speed and the constraints of mobilization resulted in choosing an aggressive therapeutic strategy after evaluation of the benefit/risk ratio made only on the clinical data.

Tenecteplase and Return of Spontaneous Circulation After Refractory Cardiopulmonary Arrest

Even with the benefit of cardiopulmonary resuscitation, the prognosis of cardiac arrest remains poor. Multiple case series describe survival with the use of thrombolytic therapy for refractory cardiac arrest. Presumably thrombolysis treats that subset of cardiac arrest cases resulting from fulminant pulmonary embolism, or perhaps massive myocardial infarctions. Published reports to date have dealt exclusively with streptokinase, urokinase, reteplase, or recombinant tissue plasminogen activator. The authors report the first case of return of spontaneous circulation with the administration of tenecteplase. Tenecteplase is a recently developed reengineered isomer of tissue plasminogen activator that possesses many properties of the ideal cardiac arrest thrombolytic agent. It is bolus dosed, stable at room temperature before reconstitution, and is compatible with most other advanced cardiac life support medications. Because of clinical equivalency and its logistical advantages, tenecteplase should be evaluated as an alternative to other thrombolytics in future trials involving cardiac arrest.

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.

Tenecteplase for massive pulmonary embolus

The treatment of massive pulmonary embolus remains controversial. We describe the first report of the successful use of the thrombolytic agent, tenecteplase, in treating a hypotensive elderly patient with a saddle embolus. A brief review of the current literature concerning thrombolysis for massive pulmonary embolus is given.

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.