What happens just when we die and what happens afterwards represents one of life’s greatest mysteries. How does physical death actually occur? In one instant we are alive and the next we suddenly turn off? A new international study, the largest to date on the physiology of death, led by scientist Sonny Dhanani, has concluded that the death process is not sudden, but rather a slow and erratic transformation of our body towards total inactivity.
Their results, which are published in the New England Journal of Medicine, stemmed from close collaboration with the Canadian Donation and Transplant Research Program. The researchers asked more than 600 families to allow the vital signs of their loved ones to be monitored in the ICU during the dying process. Specifically, there were 631 patients in 20 adult intensive care units in the Czech Republic, Canada and the Netherlands.
Why is a study like this important?
In order to donate organs from a loved one who has passed away, the family must be able to be completely sure that the death is irreversible. There have been few cases of stories about people who have “come back to life” after a declaration of death, as there has always been little scientific evidence on the medical understanding of death. Hence the importance of this study, which is undoubtedly the largest of its kind to date.
Study conclusions
Clinical death is usually determined by the cessation of neuronal ( brain death) or circulatory activity, that is, when cardiac activity is reduced to zero.
In this study, the researchers examined the electrocardiogram and blood pressure records of all patients along with clinical observations. They expected imminent death after the withdrawal of life support in each and every case.
Thus, after the removal of the breathing tubes, medications and cardiac support, they examined all these data from that moment until 30 minutes after the declaration of death. The experts found that death did not happen suddenly, but was a complex, slow and quite erratic process , according to the patients.
14% of the patients experienced a “transient” resumption of cardiac activity after the flat line of death had appeared on the screen recording. That activity was subtle, barely 3.9 seconds on average, although there was one case that lasted up to 13 minutes. Experts clarify that this has nothing to do with Lazarus syndrome, based on the spontaneous recovery of the patient after a cardiac arrest.
Documenting the physiological process of death
Continuing this work will allow donation and transplant teams to predict how long it will take for patients to die after eliminating life support measures ; something that would be incredibly helpful in coordinating a donation and improving organ allocation to patients.
Referencia: Resumption of Cardiac Activity after Withdrawal of Life-Sustaining Measures. Sonny Dhanani, M.D. et al. N Engl J Med 2021; 384:345-352. DOI: 10.1056/NEJMoa2022713 New England Journal of Medicine 2021
