Robert Truog, who directs the Harvard Medical School Center for Bioethics, co-wrote the Massachusetts guidelines on rationing ventilators in April 2020. He and his colleagues considered giving the families of patients removed from ventilators the option to hand-ventilate their sick family member, as students had done with Blegdam’s patients nearly 70 years before. The ethicists decided not to offer families that option, says Truog, citing three issues: burdening family members unrealistically; medical complications that would likely result from the efforts of untrained human ‘ventilators’ and, finally, the likelihood that those patients wouldn’t survive anyway. ‘It would be cruel to the family to put them in the position of having to squeeze the bag, when in all likelihood the patient wouldn’t survive,’ he said.

Truog is referring to the concept of medical futility: moments when doctors decide not to offer certain interventions, because those interventions won’t help the patient enough to justify the harms. Futility is the most common ethical dilemma in the modern ICU. The question guiding care becomes not just how to save lives, but when to allow deaths. Not just animating machines, but deciding when to use them, and when not to.

Before physicians understood how people breathed, they couldn’t help people to continue breathing. They tried anyway – and all of their efforts, though well-intended, constituted futile care: interventions not reasonably likely to bring more good than harm. The term ‘futility’ didn’t exist not because the problem didn’t yet exist, but because the problem was too big to see. Scientifically sound ventilation methods changed that.

Now, doctors can prolong life – but not always in a condition that patients would choose to live with. We have to ask: what quality of life would we consider worth living? If the best possible medical care can’t give a patient a reasonable quality of life, patients and their physicians decide to withdraw or discontinue further treatment. We see it on medical shows – characters say: Don’t keep me on a machine. They often mean a ventilator. The more advanced and effective the ventilator has become, the more questions of futility arise.

How much can, or should, the ventilators of the future help doctors make decisions about when to turn off machines? The ‘ventilator’, once a caring human using arm muscles as proxy for patients’ paralysed diaphragms, is now a programmed device – and that programming could some day make decisions of life and death. The machines that have extended life might, in time, help to determine when it ends.

Read more or listen to the audio on Aeon.