I commend Miles Edwards and Susan Tolle for their deeply personal account of disconnecting a conscious patient from a mechanical ventilator [1]. By way of recounting a related story, I would like to comment on the authors' insistence that they did not "kill" their patient.

Not long ago, I discontinued mechanical ventilation of a patient and longstanding friend, in accordance with her advance directive, after she had suffered for years because of disabling chronic obstructive lung disease. The woman did not die as anticipated; instead, she regained consciousness and lingered on, bedbound and continuously dyspneic at rest. At first, she fought to regain her strength with the hope of returning home, but there was no progress. After 3 weeks, she asked that we end her suffering with an overdose of medication.

Up until then, we had avoided all sedating medications for fear of respiratory depression. After discussions with family and staff, I administered 30 mg of morphine three times over 18 hours in a long-acting oral preparation. At first, no effect was discernible, but, after the third dose, she lapsed into unconsciousness and died.

Did I administer the morphine to relieve her dyspnea or to kill this woman at her request? We both knew that there was but one way out of her distress. Whatever my intention, the drug that I prescribed, that she swallowed, achieved both goals simultaneously, as we knew it would.

Ethicists have urged us to accept death in such instances as an anticipated but unintended secondary consequence of our efforts to relieve discomfort. However, when death is a near certain consequence, inseparable from any therapeutic response, the distinction between primary and secondary effects of treatment is lost.

Sometimes there is an inescapable gray zone between treating and killing, where actions cannot be rendered black or white simply by choosing the "right" words to justify them. In that gray zone, the doctor's anguish is especially acute. Sometimes all we can hope for is the conviction in retrospect, that we provided the best available care.