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Limbo Lines:
Dead Here, Alive There

Brain death’s role in the uncertainties of death.

I. Dead and/or alive

Four years ago, Jahi McMath was declared brain dead, and therefore dead, by federal standards. Today, as she breathes with the assistance of a ventilator, Jahi is still considered alive by New Jersey state law. So long as her heart keeps beating, legally, Jahi is both dead and alive. The idea that different places have varying criteria for death introduces a “death limbo”, in which the status of someone’s death depends very much on where they geographically are. This “death limbo” persists across the world; in theory, a brain dead person could be officially dead in Hungary, wheeled across the border into Slovakia, and declared alive again.

These sorts of “limbo lines” exist in several other places. The following map shows in blue and green where countries have laws and guidelines regarding declaring brain death. In black stripes, we see countries that report no such rules. Wherever two differently colored countries touch, we’ve got a visible limbo line. Someone brain dead in Russia can be ambiguously alive in China; they can be pronounced dead in Mexico and legally revived in Guatemala.

Useful definitions: Confirmatory tests are often considered a triple-check for brain death, involving, for example, electric reactivity tests. More specifically, they can take place as cerebral angiography, electroencephalography, transcranial Doppler ultrasonography, and cerebral scintigraphy.

Note that these laws indicate only the presence of laws regarding brain death, not the equivalence of brain death to death. For example, until 2009, Japanese law did not accept brain death as death without individual written consent or for patients under 15 years old. Also, note that “limbo lines” may technically also exist between countries of the same color; each country may have different specific metrics for brain death. This will be discussed further later in this article.

II. What made death limbo possible: the gist of brain death

Until the 1950s, death generally meant that a person’s heart had stopped - no pulse, no life. However, with new intensive care unit technology, it has been possible to sustain patients’ hearts, livers, and other organs for days, weeks, and in Jahi’s case, years. That is, someone’s heart can beat independently as long as it has oxygen (for example, from a ventilator), even if the brain is damaged, without oxygen or blood, and stops functioning in any capacity. This is called brain death.

According to American guidelines, brain death has become one of two permanent and irreversible markers for human death (the other is cardiopulmonary - where the heart and lungs fail); yet, less than 1% of deaths in the United States are brain deaths (around 15,000 - 20,000 people per year). These are often people who suffer from strokes, head trauma, or anoxia.

III. Why it’s important to escape limbo: defining brain death

Although such a small share of people in the US are declared dead due to brain death, brain-dead donors provide more than 90% of donated organs in the United States. This is because while the brain ceases functioning, it is still possible for the heart to pump blood and a ventilator to provide oxygen to organs, keeping them viable after death. For a few days, hearts, livers, and other organs can still be donated to another patient in need. However, the longer organs spend being artificially sustained by blood pressure augmentation and hormones, the more likely tissues are to become infected.

Let's take a look at the typical and maximum times that organs remain viable for transplant after death.

As we can see, time is of the essence; every hour matters. The time after someone is declared brain dead - and therefore, legally dead - is critical for an organ transplant receiver. A clear definition is also useful in communicating an unambiguous status of someone’s life to their loved ones. For physicians and hospitals, time spent trying to recover a patient with no chance of recuperation could be costly.

At the same time, we also want to be really sure that someone is actually brain dead. For this reason, countries have set up double and triple checks, such as observation periods, apnea tests (exams that prove the absence of breathing mechanisms that a dead brain stem would not be able to facilitate), and the words of one or more physicians. Once again, we find wildly different criteria across countries.

When looking at specific laws and guidelines within various countries, we find even more fine-tuned “limbo lines”. Below, we compare countries that require at least one of two checks: the word of some number of physicians and some hours of observation before declaring brain death. Each country is also colored by nature of its apnea test stipulations.

Useful definitions: There are two major components in apnea tests - 1) examining patients after disconnecting their ventilator (their oxygen supply), and 2) then sometimes, more reliably, measuring levels of PCO2 (partial pressure of carbon dioxide) in a patient’s blood. A sharp rise in PCO2 after disconnection would indicate brain death.

Effectively, this means that a Swedish physician could declare a patient’s death and immediately begin an organ transplantation process, while across its east border in Norway, that same person would have to be observed for another day. Within that time period, every organ could lose its viability for donation.

With 20 people dying each day waiting for an organ transplant, practically speaking, the existing medical guideline of accepting brain death as death is useful. In terms of public policy, we see an abundance of “limbo lines”, clear divergences in how cultures evaluate and declare that metric. The widespread lack of consensus on brain death shows that there is still a margin of debate over the boundaries between life and death. In the meantime, more people are being added to organ transplant waiting lists while more potential donors are caught in limbo.

Data and Resources

Data about organ donations after death from University of Michigan Transplant Center. Data about brain death laws from Dr. Eelco Wijdicks’ “Brain death worldwide accepted fact but no global consensus in diagnostic criteria” published in Neurology Vol. 58. Other written statistics and facts come from Organ Procurement and Transplant Network’s national data reports, the University of Miami Miller School of Medicine’s website, and Professor Masahiro Morioka’s writings. Finally, thanks to Dr. Rumit Singh Kakar for reviewing this piece and his extensive collection of knowledge and resources.