NEJM: Some people’s heartbeat will recover several times until it stops completely During death

NEJM: Some people’s heartbeat will recover several times until it stops completely During death.   Clinically, organ donation is vital to the development of medical science. However, in the actual operation of organ donation, a very important issue cannot be ignored, and that is how to judge the “real” donor.

Clinically, organ donation is vital to the development of medical science. However, in the actual operation of organ donation, a very important issue cannot be ignored, that is
How to judge the “real” death of the donor?

The traditional criteria for determining a person’s death are permanent cardiac arrest, respiratory arrest and the disappearance of pupils’ light reflection. After the heartbeat and breathing stop, the tissues and organs in other parts of the body will lose their function due to the lack of oxygen and nutrients.

However, recently, a study led by the CHEO Research Institute of Canada and the Canadian Donation Transplant Research Project conducted a 30-minute post-mortem ECG monitoring on 631 dying patients, and found that human deaths It is not as simple as the classic “flat line” in TV series.

Specifically, the researchers found that although the human body’s heartbeat stops during death, some patients will automatically resume their beating several times after the heartbeat stops during death, and finally stop completely. However, no patient regained consciousness during this process. At the same time, the researchers found that the longest time interval between a patient’s heart stop and self-recovery was 4 minutes 20 seconds.

Related research papers entitled “Resumption of Cardiac Activity after Withdrawal of Life-Sustaining Measures” were published in the New England Journal of Medicine (NEJM).

How to tell when the organ donor died?

The principle of organ donation is that the death of the donor must have been declared before organ harvesting. Clinically, the most common method for determining death before organ donation is to make a neurological determination based on brain death criteria, but sometimes death is also determined based on circulatory system criteria.

Although, in recent years, life-sustaining measures have been removed clinically, and more and more cases of organ donation after death based on circulatory system standards have been determined, but the standards for determining circulatory system death are not uniform.

The current standard believes that the circulatory system standard determines that the organ donation program after death should be observed for 5 minutes without breathing and pulse (applying an arterial catheter monitor). After this period of time, if there is no attempt to restart the blood circulation, and the blood circulation has not been restored spontaneously, it can be considered that the blood circulation has been permanently lost and organ harvesting can begin. However, in clinical practice, the observation time ranges from 2 minutes to 10 minutes.

Previously, there have been reports that the baby was harvested only 75 seconds after the pulse disappeared, causing huge ethical controversy. Therefore, in order to ensure that blood circulation has been permanently lost, one must determine the shortest observation time after the heartbeat stops.

The heart will resume beating spontaneously after it stops

Limited prospective evidence suggests that after the removal of life-support measures and death based on the circulatory system criteria, there is less recovery of cardiac activity. At the same time, in an observational study of patients who died after the removal of life support measures, some researchers found that the circulation or cardiac activity recovered briefly after a few seconds to a few minutes without a pulse, but no patients recovered consciousness or were discharged alive. Report.

In order to further determine the recovery of cardiac activity and the time interval of cardiac recovery after the patient died according to the circulatory system criteria, researchers from Canada carried out a prospective, retrospective, and observational study: DePPaRT (prediction of death after withdrawal of treatment And physiology) research aimed at exploring the recovery rate and recovery time of cardiac electrical activity and pulse activity in critically ill adult patients who died after the removal of life support measures.

The researchers conducted the study in 20 intensive care units in three countries. The study plans to monitor the patient for 30 minutes after the death is determined, and the bedside clinician will prospectively report the recovery of cardiac activity. In addition, the researchers also recorded and retrospectively evaluated continuous blood pressure and electrocardiogram (ECG) waveforms to confirm the results of bedside observations and determine whether there is more recovery of heart activity.

During the experiment, a total of 1,999 patients were screened, and 631 were included in the study. In 5 patients (1%), the clinically reported recovery of cardiac activity, breathing exercise, or both were confirmed by the waveform analysis results.

A retrospective analysis of the ECG and blood pressure waveforms of 480 patients found that 67 patients (14%) recovered their heart activity after a period of pulse-free, including 5 patients reported by bedside clinicians. The longest interval from no pulse to recovery of heart activity is 4 minutes and 20 seconds. In 19% of patients, the last QRS complex coincided with the last arterial beat.

According to the results of the retrospective analysis of the waveforms, after removing the patient’s life-support measures, 14% of the patients briefly recovered at least one cycle of cardiac activity after being pulse-free; bedside assessments found only 1% of them. Within 4 minutes and 20 seconds after the pulse.

The results of this study show that death is not always as simple as the well-known “flattening” of the monitoring signal curve. In the process of death, some patients’ heart activity will recover several times until it finally stops completely-but no one restores blood circulation or regains consciousness during this process.

However, during the experiment, only 1% of patients were found by bedside doctors that their cardiac activity had recovered briefly, and nearly 14% of patients’ cardiac activity recovery was found in a retrospective waveform review. At the same time, the longest pulseless duration before heart activity resumes is 4 minutes and 20 seconds. This also means that clinicians should strictly follow the 5-minute standard to judge whether organ donation patients are really dead.

(source:internet, reference only)

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