Correspondence
Active Compression-Decompression Cardiopulmonary Resuscitation
N Engl J Med 1994; 330:1391May 12, 1994
- Article
To the Editor:
The recent study by Cohen et al. (Dec. 23 issue)1 demonstrates a common misconception about randomization in clinical trials. Assignment of patients to one of two treatment groups by means of medical-record numbers does not constitute true randomization, because an individual patient does not have an equal chance of being assigned to either group at the time of enrollment. The allocation of medical-record numbers themselves is often not strictly sequential and is obviously not random. Thus, it would be more accurate to describe the method of assigning patients to treatment groups in such studies as assignment according to protocol rather than random assignment. The use of medical-record numbers for assignment detracts from the reliability of the study results and should be discouraged.
1 ReferencesPeter G. Stone, M.R.C.P.
Beth Israel Hospital, Boston, MA 022151
Cohen TJ ,Goldner BG ,Maccaro PC , et al. A comparison of active compression-decompression cardiopulmonary resuscitation with standard cardiopulmonary resuscitation for cardiac arrests occurring in the hospital. N Engl J Med 1993;329:1918-1921
Full Text | Web of Science | Medline
To the Editor:
The article by Cohen et al. raises an ethical question. A total of 17 patients in their study had metastatic carcinoma or hematologic cancer, and 14 patients had end-stage congestive heart failure. The absence of a do-not-resuscitate order in the patient's chart dictated that the patient would be enrolled in the study “without informed consent.” I was unable to find any indication whether the absence of a do-not-resuscitate order reflected an earlier discussion between the patient and the attending physician concerning the patient's wishes for resuscitation or simply meant that the issue had never been discussed with the patient. The fact that attempts were made to resuscitate 31 patients with terminal disease is disturbing, and the statement that 39 percent of the patients who survived the initial resuscitation were subsequently given do-not-resuscitate status supports this concern.
I do not take issue with the desire to improve our performance in cardiac resuscitation. However, I believe that we must be careful to avoid performing any procedure that is not in the patient's best interest. The use of either standard or advanced methods to resuscitate patients with cardiac disease or cancer who are terminally ill would appear to be questionable, emphasizing the importance of discussing these matters with our patients in a timely fashion to avoid performing a resuscitation that is not in the patient's best interest.
Frederick L. Sachs, M.D.
Yale-New Haven Hospital, New Haven, CT 06504Author/Editor Response
Dr. Cohen replies:
To the Editor: Dr. Stone is correct that assignment by medical-record number alone is not always random. The reason is that medical-record numbers may not be assigned sequentially, and certain digits may have a specific meaning. The patients in our study were randomly assigned to a treatment group according to the last digit of their medical-record number. These numbers were assigned in order, and none of the digits had any inherent meaning. Therefore, the chance occurrence of a cardiac arrest and assignment of treatment in this fashion was a random event. In addition, we compared all known base-line characteristics in the two treatment groups and found no significant differences. Therefore, we believe that this approach to treatment assignment provides a rapid method of randomization.
Our investigators had the same concern as that expressed by Dr. Sachs. In the state of New York, the absence of a do-not-resuscitate order from a patient's chart is presumed to indicate that there has been an appropriate discussion between the attending physician and the patient or the patient's health care proxy and an explicit decision has been made that resuscitation is appropriate. In addition, we believed that exclusion of patients from the study on the basis of their medical status, other than a do-not-resuscitate order, might have resulted in a selection bias. Another randomized, prospective, in-hospital trial was initiated in the United States and completed at approximately the same time as ours1. Our patients were more severely ill, and as a result, although the technique of active compression-decompression improved resuscitation, 24-hour survival, and neurologic outcome, only two patients survived to be discharged (both randomly assigned to active compression-decompression). In the other trial, performed in a healthier cohort, 24 percent of the patients randomly assigned to active compression-decompression survived to be discharged, as compared with 11 percent of the patients receiving standard resuscitation1.
The testing of a new cardiopulmonary-resuscitation method without informed consent was discussed with a leading bioethicist before any trial involving humans was conducted, and the University of California's institutional review board granted approval2. Similarly, our recent trial was approved by the North Shore University Hospital's institutional research board on the basis of compassion. Other resuscitation trials have waived informed consent in a similar manner3.
3 ReferencesTodd J. Cohen, M.D.
North Shore University Hospital, Manhasset, NY 110301
Tucker KJ ,Galli F ,Savitt MA ,Kahsai D ,Bresnahan L ,Redberg RF . Active compression-decompression resuscitation: effects on resuscitation success after in-hospital arrest. Circulation 1993;88:Suppl I:I-10 abstract.
Web of Science2
Cohen TJ ,Tucker KJ ,Lurie KG , et al. Active compression-decompression: a new method of cardiopulmonary resuscitation. JAMA 1992;267:2916-2923
CrossRef | Web of Science | Medline3
Callaham M ,Barton CW ,Kayser S . Potential complications of high-dose epinephrine therapy in patients resuscitated from cardiac arrest. JAMA 1991;265:1117-1122
CrossRef | Web of Science | Medline
