From the Journals

Cardiac activity not uncommon after lifesaving measures stop


 

Among critically ill patients pulseless after planned withdrawal of life-sustaining therapies, cardiac activity restarted in 14% of cases, research shows.

Reassuringly, most resumption of heart activity happened in the first 1-2 minutes and most lasted 1 or 2 seconds.

“The reason we wanted to look at death determination specifically is we know that the stories persist about people coming back to life following death, and that’s not just in the public, it’s in the medical community as well,” lead author Sonny Dhanani, MD, of Children’s Hospital of Eastern Ontario, Ottawa, said in an interview.

“We thought that if we provided scientific evidence of whether this happened or not, we might dispel some myths and misunderstanding, which would hopefully promote organ donation.”

About 70% of organ donations occur after brain death, but an increasing number follow circulatory determination of death, he noted. Most protocols recommend 5 minutes of apnea and pulselessness by arterial catheter monitor before declaring death. But practices vary from 10 minutes in some European countries to 75 seconds in infant heart donors at one Colorado hospital.

Reports of patients recovering 10 minutes after pulselessness have raised concerns about the Lazarus phenomenon, or autoresuscitation, but are based in patients after cardiopulmonary resuscitation was terminated.

The present study, known as Death Prediction and Physiology after Removal of Therapy (DePParRT), enrolled patients at 20 intensive care sites in Canada, the Czech Republic, and the Netherlands, only if surrogate decision-makers agreed on withdrawal of life-sustaining measures without CPR and imminent death was anticipated.

As reported Jan. 28 in the New England Journal of Medicine, physicians observed resumption of circulation or cardiac activity prospectively in 1% of 631 patients based on bedside ECG, arterial pressure catheter monitors, palpated arterial pulse, breaths, or physical movements.

A retrospective review of data from 480 patients with complete ECG and arterial waveforms and at least 5 minutes of continuous waveform monitoring after pulselessness showed resumption of cardiac activity in 14% of patients.

The longest period of pulselessness before the heart showed signs of activity again was 4 minutes and 20 seconds. “So that was a reassuring number, because that’s within our 5-minute window that we currently use,” Dr. Dhanani said.

Importantly, “nobody woke up, nobody ended up being resuscitated, and all of these individuals died. And I think that’s going to be very helpful in this context,” he added.

In all, there were 77 cessations and resumptions in 67 of the 480 patients. The median duration of resumed cardiac activity was 3.9 seconds but, notably, ranged from 1 second to 13 minutes and 14 seconds.

“Though surprising, I think maybe not unreasonable,” observed Dr. Dhanani. “The heart is a very robust organ, and we maybe should anticipate these things happening, where at the end of life the heart may restart for minutes.”

In this situation, it’s important to wait the 13 minutes for the heart to stop again and then “wait another 5 minutes to make sure it doesn’t restart before determining death,” he said. “I think that’s where this study is going to now inform policy makers and guidelines, especially in the context of donations.”

The findings will be taken as strong support for the 5-minute window, said Robert Truog, MD, director of the Harvard Medical School Center for Bioethics and the Frances Glessner Lee Professor of Medical Ethics, Anaesthesia, and Pediatrics, Boston.

“I think it’s a safe point, I think people will refer to it, and it will be used to support the 5-minute window, and that’s probably reasonable,” he told this news organization. “Certainly, if it’s read in Europe it will cut the time from 10 minutes to 5 minutes, and that’s a good thing because 10 minutes is a very long time to wait.”

He noted that the 5-minute window provides reasonable assurance to the public and, with new technologies, permits most organs to be usable for donation after cardiac death. That said, there’s nothing magical about the number.

“In some ways I see this paper as providing interesting data but not actually providing an answer, because from the patient’s perspective and from the recipient’s perspective, waiting until the heart has made its last squeeze may not be the most relevant ethical question,” Dr. Truog said. “It may be, once we know this patient is not going to have return of cardiorespiratory function, is not going to wake up, that’s the point at which we ought to focus on organ preservation and organ retrieval, and that can be much sooner than 5 minutes.”

Dr. Dhanani and colleagues note that the generalizability of the results might be limited because patients without arterial pressure catheters were excluded, and 24% of enrolled patients could not be included in the retrospective waveform analysis owing to incomplete data.

“Our study definition of cardiac activity used an arbitrary threshold of pulse pressure (less than 5 mm Hg) that does not imply meaningful circulation,” they add. “This conservative consensus definition may have been partially responsible for the ostensibly high incidence (14%) of transient resumptions of cardiac activity identified through waveform adjudication.”

The study was supported by the Canadian Institutes for Health Research as part of the Canadian Donation and Transplantation Research Program, CHEO Research Institute, and Karel Pavlík Foundation. Dr. Dhanani has consulted for Canadian Blood Services. Dr. Truog reports no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

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