Verapamil in the treatment of asystolic and pulseless idioventricular rhythm cardiopulmonary arrests: a preliminary report

Reporting approval by research ethics committees and subjects' consent in human resuscitation research

OBJECTIVE

To determine how frequently reports of research in human cardiopulmonary resuscitation mention approval by a research ethics committee and address subjects' consent.

METHODS

Retrospective review of published reports of interventional research in human cardiopulmonary resuscitation. Reports were retrieved from the MEDLINE database and selected according to pre-established criteria. Data were abstracted independently by the two authors with differences resolved by mutual agreement. Results were analyzed according to whether the research took place in the prehospital setting, the emergency department, or the hospital; whether it was conducted within or outside the United States; whether it received any funding from the US government; its randomization scheme; the year of publication; and whether the journal's instructions required mention of REC approval or subjects' consent.

RESULTS

Reports of 47 studies met our criteria for inclusion. Of these, 24 (51%) mentioned approval by a research ethics committee and 12 (26%) addressed subjects' consent. Significantly more studies reported ethics committee approval or addressed consent during more recent years. Authors were more likely to report consent, REC approval, or both when journal instructions required that REC approval be mentioned.

CONCLUSION

Reports of resuscitation research have not consistently mentioned approval from a research ethics committee or addressed subjects' consent for interventional studies using human subjects. However, they are doing so more frequently in recent years as journal requirements for reporting change. REC approval is now almost always being reported, but subjects' consent is often not addressed. Journal editors and reviewers should ensure that authors adhere to the journal's instructions about reporting ethical conduct of experiments.

Cardiopulmonary resuscitation. A current perspective

Cardiopulmonary resuscitation is effective if established early and coupled with specific therapeutic interventions. Most cardiopulmonary arrest is due to ventricular fibrillation and early defibrillation offers the highest probability of success. External cardiac compression alone is inadequate to provide adequate perfusion to vital organs and, therefore, cannot sustain life unless coupled with advanced therapeutic interventions. Many new techniques for increasing flow have been developed, but have not been established clinically. The American Heart Association guidelines for CPR are still valid and are the basis for our current CPR. A practical perspective is presented whereby the therapeutic interventions are pursued systematically in an expeditious and coordinated fashion so that the key interventions are made within the first 10 to 15 minutes of the arrest.

Controversies in resuscitation

Many controversies, only a few of which have been discussed here, are now raging in the field of resuscitation. Much is expected to change in the next five to ten years. The American Heart Association is now considering changes for its new advanced cardiac life support course, which should be ready this year. The course will not include some of the possible changes mentioned in this article, because too few studies have been done. Physicians and other rescuers should abide by the guidelines of the American Heart Association as a standard of practice because its recommendations are the result of the best possible consensus. Over the next several years, many exciting changes in resuscitation will occur and may lead to improved survival rates and quality.

Use of calcium blockers in electromechanical dissociation

Calcium antagonists have been shown to protect the myocardium against the deleterious effects of ischemia and reperfusion in both focal and global models. The mechanism of this protection is probably related to their ability to decrease the rapid and massive cytosolic and mitochondrial calcium overloading that occurs with reperfusion of severely ischemic myocardium. This calcium overloading uncouples oxidative phosphorylation, preventing repletion of ischemia-depleted ATP stores. The mode of action of calcium antagonists in protecting heart muscle is complex, and may ultimately depend on their ability to preserve sufficient energy to maintain intracellular ionic homeostasis. The cellular events that occur with prolonged cardiac ischemia have been well documented in animal studies, and are reflected in the clinical picture of electromechanical dissociation (EMD). ATP production is decreased during ischemia and quickly results in depleted energy stores. The electrical and mechanical activities of the heart are energy-consuming processes that gradually come to a halt in the presence of prolonged ischemia. In excised totally ischemic hearts, electrical activity persists for a time after contractions have ceased, resulting in the clinical picture of EMD. Eventually electrical activity stops as well, causing asystole. Calcium antagonists administered during resuscitation from EMD, as well as other terminal arrhythmias, may protect the myocardium from reperfusion injury and preserve the ATP stores necessary for normal cardiac function.