I work in an oncology unit. Recently, two of my patients had what I thought were clearly written advance directives. But their physicians disagreed with family members about how to interpret these patients' last wishes. Our hospital's ethics committee helped resolve the situations, but now I'm confused. Don't we always need to follow a patient's advance directive?-T.R., KAN.

Most states recognize two types of advance directives: the living will and the durable power of attorney for healthcare. The living will states what life- sustaining treatments a patient wants or doesn't want if she can't express her wishes. However, deciding what conditions meet these criteria can be open to interpretation. Would a severe stroke meet the criteria, for example? The durable power of attorney for healthcare allows a person named by the patient to make medical decisions in her best interests when she can no longer make her treatment wishes known.

Ideally, these two documents complement each other-but sometimes they conflict. Perhaps a spouse who's experiencing significant anticipatory grief simply refuses to stop treatment despite the patient's previously expressed wishes. Even though this decision contradicts the patient's living will, the spouse with durable power of attorney for healthcare may have the last word. When the patient's healthcare providers have a different interpretation of her wishes than the spouse, referring the case to the hospital ethics committee is appropriate.