Tissue plasminogen activator in cardiac arrest with pulseless electrical activity

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.

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.

Vasopressin for cardiac arrest: meta-analysis of randomized controlled trials

BACKGROUND

Prior meta-analyses-reported results of randomised controlled trials (RCTs) published between 1997 and 2004 failed to show any vasopressin-related benefit in cardiac arrest. Based on new RCT-data and a hypothesis of a potentially increased vasoconstricting efficacy of vasopressin, we sought to determine whether the cumulative, current evidence supports or refutes an overall and/or selective benefit for vasopressin regarding sustained restoration of spontaneous circulation (ROSC), long-term survival, and neurological outcome.

METHODS

Two reviewers independently searched PubMed, EMBASE, and Cochrane Database for RCTs assigning adults with cardiac arrest to treatment with a vasopressin-containing regimen (vasopressin-group) vs adrenaline (epinephrine) alone (control-group) and reporting on long-term outcomes. Data from 4475 patients in 6 high-methodological quality RCTs were analyzed. Subgroup analyses were conducted according to initial cardiac rhythm and time from collapse to drug administration (T(DRUG))<20 min.

RESULTS

Vasopressin vs. control did not improve overall rates of sustained ROSC, long-term survival, or favourable neurological outcome. However, in asystole, vasopressin vs. control was associated with higher long-term survival {odds ratio (OR)=1.80, 95% confidence interval (CI)=1.04-3.12, P=0.04}. In asystolic patients of RCTs with average T(DRUG)<20 min, vasopressin vs. control increased the rates of sustained ROSC (data available from 2 RCTs; OR=1.70, 95% CI=1.17-2.47, P=0.005) and long-term survival (data available from 3 RCTs; OR=2.84, 95% CI=1.19-6.79, P=0.02).

CONCLUSIONS

Vasopressin use in the resuscitation of cardiac arrest patients is not associated with any overall benefit or harm. However, vasopressin may improve the long-term survival of asystolic patients, especially when average T(DRUG) is <20 min.

Empiric tenecteplase is associated with increased return of spontaneous circulation and short term survival in cardiac arrest patients unresponsive to standard interventions

BACKGROUND

Prospective and retrospective studies have shown that empiric use of fibrinolytic agents in sudden cardiac arrest is safe and may improve outcomes in sudden cardiac arrest. Use of fibrinolytic agents for this indication is increasing in response to these data.

METHODS

A prospective multicenter observational trial was performed in three emergency departments (EDs) to determine the proportion of patients that respond to empiric fibrinolysis with tenecteplase (TNK) after failing to respond to Advanced Cardiac Life Support (ACLS) measures. Cardiac arrest patients unresponsive to ACLS, who were given TNK by their treating physician, were enrolled in an outcome registry. Return of spontaneous circulation (ROSC), survival, complications, and neurological outcomes were recorded.

RESULTS

Fifty patients received TNK after a mean of 30min of cardiac arrest and eight doses of ACLS medications. One hundred and thirteen concurrent control patients received standard ACLS measures. ROSC occurred in 26% of TNK patients (95% confidence interval (CI) 16-40%) compared to 12.4% (95% CI 6.9-20%) among ACLS controls (p=.04); 12% (4.5-24%) of TNK patients survived to admission compared to none in the control group (p=.0007); 4% (0.5-14%) survived to 24h (p=NS); and 4% (0.5-14%) survived to hospital discharge (p=NS). All survivors had a good neurological outcome (Cerebral Performance Category (CPC) 1-2). One intracranial hemorrhage (ICH) occurred. No other significant bleeding complications were observed.

CONCLUSIONS

Empiric fibrinolysis with TNK in cardiac arrest is associated with increased ROSC and short term survival, and with survival to hospital discharge with good neurological function in patients who fail to respond to ACLS. Results may improve with earlier administration. Prospective controlled interventional trials are indicated to evaluate this promising new therapy.

Pre-randomization and de-randomization in emergency medical research: new names and rigorous criteria for old methods

Clinical trials are performed to determine if a therapy is effective in the treatment of a disease. The methods of randomization and blinding are used to assure that the only planned difference between the two groups is the therapy itself, and differences in outcome cannot be attributed to bias. Emergency medical conditions, and in particular therapies that must be administered in an emergency, present challenges to inclusion, exclusion, randomization, and blinding that are at times insurmountable in the context of available resources. Pre-randomization (that is, assigning the therapy to be used before the event occurs) and de-randomization (that is, removing randomized cases that do not meet established inclusion criteria) may address some of the challenges resulting from emergency enrollment but have the potential to create bias. We describe these techniques, and provide criteria that should be employed if pre-randomization and/or de-randomization are being considered. It is possible to use these techniques to successfully complete clinical trials that would not have been possible using only standard methodology and still ensure that results are without bias.

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.

Preconditioning and the oxidants of sudden death

Sudden cardiac death remains a daunting medical challenge. Rescuers have minutes to defibrillate the heart and prevent ischemic injury to critical organs. Cardiopulmonary resuscitation can extend the window for successful therapy but not for long. Complicating this further is the fact that few new therapies have been proven to protect against the postresuscitation phase of cardiac arrest, when as many as 90% of patients die despite successful defibrillation. Oxidants (both reactive oxygen and nitrogen) likely play critical roles during cardiac arrest, affecting defibrillation success by affecting cardiac gap junctions and after successful defibrillation causing multiorgan damage via direct and programmed cell death. Preconditioning is an intrinsic adaptive response to stress that targets this sequence of events and is highly protective against ischemia/reperfusion injury in the heart, brain, and other critical organs. Thus, how oxidants are affected by preconditioning could provide new insights and therapies for improving both defibrillation success and oxidant-mediated postresuscitation injury of sudden cardiac death.