Doctors Studied People’s Last Moments of Life to Figure Out When Death Begins

Doctors Studied People’s Last Moments of Life to Figure Out When Death Begins
Photo: Alex Wong, Getty Images

New research suggests that doctors are, thankfully, skilled at correctly identifying a person’s time of death — a crucial aspect of ensuring healthy organs for donation. At the same time, the body can sometimes show flitters of cardiac activity even after death has become truly irreversible, according to the study published in the New England of Medicine.

There’s no shortage of morbid curiosity surrounding death. But according to the researchers behind this project, known as the Death Prediction and Physiology after Removal of Therapy Study, or DePPaRT, there’s a lot we don’t know for sure about a person’s last minutes of life.

Since 2014, they’ve been collecting vital sign data from dying patients in Canada, the UK, and the Czech Republic as part of their work. Their main goal has been to document as much as possible about the process of dying, particularly in critically ill people who are taken off life support. They’ve also been studying how and why families decide to donate the organs of their loved ones soon before death and how the donation affects them. People in the study — around 600 in total — were only included after express consent from their families. The project received funding from the Canadian government as well as the Canadian Donation and Transplantation Research Program.

Though some organs, like the kidneys, can be kept viable for over a day before being transplanted, others, like the heart, have to be transplanted within hours. Any delay can be literally the difference between life and death for the organs recipients. But people are understandably sensitive about death, and many families and even doctors may hold out hope of a miraculous recovery even after a person is taken off life support.

“We recognise that there are stories about people coming back to life, even from members of the medical community. So we really wanted to provide scientific evidence about the process of dying, to dispel any potential myths for people,” lead researcher of the project Sonny Dhanani, a paediatrician at the CHEO Research Institute in Ontario, told Gizmodo by phone.

Nowadays, doctors in Canada are told to wait at least five minutes after blood circulation has stopped after the end of life support before officially calling a person’s time of death (in the U.S, two to five minutes is recommended). In the patients this team studied, there were no cases where doctors were wrong about their determination of death. That said, the movie-friendly sign of death — an immediate flatline on a EKG monitor — wasn’t completely right, either.

Sometimes, in about 14% of patients, there were on-and-off moments of cardiac activity. Importantly, though, these moments usually lasted for a few seconds and didn’t result in the heart fully restarting or in people suddenly waking back up. The longest time it took for a heart to fully stop was around four minutes, indicating that the five-minute rule is indeed a good amount of time to wait for the determination of death (should the heart restart during that period, doctors will then wait another five minutes before declaring the time of death).

“Doctors and families should be aware about this happening 14% of the time. But they also should be reassured that it doesn’t mean that the person will come back to life,” Dhanani said.

That reassurance is all too important for families, especially when it comes to decisions around organ donation. Of course, people can also offer that permission themselves by preemptively registering as an organ donor.

Dhanani and his team were surprised by how many families chose to participate in the project when asked (93%). And he hopes his team’s work will help people better recognise the benefits of organ donation, while putting their minds at ease about the process.

“Ultimately, we want our research to help open up the conservation around death, dying, and donation, which are topics that can be uncomfortable,” he said. “And we hope that this research can reassure people worried about the idea of being a donor, maybe because they fear their organs will be taken before they die. There’s a clear process to donation, and our research has shown people won’t be mistreated.”