Maximal benefit from CPCR will be achievable: a by minimizing response times; and b by extending reversible arrest times--the topic of this symposium. For reperfusion, closed chest CPR is more readily available than, but physiologically inferior to, open chest CPR and emergency cardiopulmonary bypass. To optimize outcome, four components of the postresuscitation syndrome are being investigated: a perfusion failure; b reoxygenation injury cascades; c self-intoxication; and d blood derangements.
Results from animal outcome studies so far suggest significant but still inconsistent benefit from several special postarrest treatments. After her heart was restarted, she was put on a helicopter where a doctor cooled her down using the frozen food she had just bought at the supermarket.
This was yet more luck - Nolan co-wrote best practice guidelines for the UK Resuscitation Council, which he chairs. By this time, Carol was in a coma. As the next few days passed, none of the signs were good - seizures and ominous EEG scans indicated that she might be brain dead. It looked like she had survived the earthquake but been left devastated by the tsunami. On the Monday following Carol's collapse, Nolan advised David and his daughter Maxine that the kindest thing might be to allow Carol to die.
They agreed. But when Maxine visited the hospital again three days later she found her mother awake and looking around. Cooling therapy is changing everything. Whereas Carol's seizures and low brain activity would once have been seen as unambiguously bad signs, such symptoms may be compatible with a good recovery.
Parnia says the guidelines already in circulation are not routinely enforced by hospitals. Nolan stops short of saying that Carol was brought back from the dead. Hospitals do not declare death, he says, until they have ruled out all processes that can be reversed. However, he agrees with Parnia that our concept of death needs updating.
But actually, we know that the dying process at the cellular level goes on for a period of time. The increasingly blurred line between life and death is prompting metaphysical questions as well as medical ones. These descriptions include travelling down tunnels towards bright lights, meeting angelic figures, recalling past events and in rare cases, floating above the surgeons in the operating theatre.
Parnia is currently working with a number of hospitals on a project to investigate out of body experiences. A fundamental principle of organ donation is the dead donor rule : donors must be dead prior to recovery of organs, and organ recovery must not be the cause of death. A lack of evidence about how long to wait before declaring death creates a tension: if doctors wait too long after the heart stops, the quality of organs begins to decline.
On the other hand, not waiting long enough introduces the risk of going ahead with organ recovery before death has actually occurred. Our interdisciplinary team of doctors, bio-engineers and experienced clinical researchers has spent the past decade studying what happens when a person dies after their heart stops.
We focused on patients in the intensive care unit who died after life support was withdrawn, since these patients may also be eligible for organ donation. In particular, we were interested in understanding whether it is possible for the heart to restart on its own , without any interventions like cardiopulmonary resuscitation CPR or medication. Our recent study, published in the New England Journal of Medicine , presents observations of the dying process of patients across Canada, the Czech Republic and the Netherlands who died in an intensive care unit.
In addition to collecting medical information about each patient, we built a computer program to capture and review heart rate, blood pressure, blood oxygenation level and respiratory patterns directly from bedside monitors.
As a result, we were able to analyze end-of-life flatline patterns for out of patients — including looking at whether and when any circulation or heart activity returned after stopping for at least one minute. As it turns out, the classic flatline of death is not so straightforward. We found that human heart activity often stops and restarts a number of times during a normal dying process.
The longest that the heart stopped before restarting on its own was four minutes and 20 seconds. The longest time that heart activity continued after restarting was 27 minutes, but most restarts lasted just one to two seconds.
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