Adam Gaffney is a Boston physician. In considering the Intensive Care Unit (ICU), designed specifically to colocate the people and technologies required to prolong life in the most seriously ill patients, Gaffney suggests that the ICU’s biggest contribution to medicine is simply to buy time for the body to complete the long and often arduous process of healing. But what happens when all the time in the world is not enough and the most tragic outcome is all but certain? At what point — morally, ethically, and realistically — does compassion mean withdrawing care?

In other words, the core purpose of an ICU—as Ibsen once conceived it, and as I do today—is to buy time. To buy enough time for the lungs to heal and the body to recover, so that the joys of life can resume. But that makes the ICU a gamble that does not always pay off: sometimes, time is not enough.

Perhaps more concerning, however, is the use of the ICU and invasive life support for patients too ill to benefit from their application. During their last six months of life, 40.3 percent of elderly American patients with cancer undergo one or more ICU stays, compared to only 8.2 percent of such patients in Germany and 15 percent in Canada. We are also far more likely to die in the ICU, even though it is a place where few people say they want to spend their final hours: while the ICU is the site of death for about one in twenty English patients, it is where nearly one in five of us Americans go to die.

Sometimes, however, the writing is on the wall, and doctors are put in a position of providing invasive care that they believe to be not merely fruitless but unethical.