New York is one of the few states with a law that directly addresses resuscitation orders. In New York, even when a doctor believes that CPR would be medically futile, if the patient is incapable of indicating a preference for or against it and the patient's designated representative insists it be performed, the physician must ultimately go to court to prevail. Texas, which has a complex advance-directive law that includes checks and balances, ultimately sides with physicians, immunizing them from litigation.

Hawaii passed legislation this year giving great weight to a patient's "comfort care" document, which specifies the patient's preferences in dire medical situations. Nonetheless, if the patient has indicated no resuscitation but "the provider's own conscience" dictates otherwise, a medical professional may override the document.

"The black-and-white of the law has significant limitations in the emotional gray area of decision making around serious illness and dying," said William H. Colby, a lawyer who represented the family of Nancy Cruzan, a patient in a vegetative state whose parents won the right to refuse medical treatment for her. Colby is the author of "Unplugged: Reclaiming Our Right to Die in America."

One side effect of state legislation has been confusion. A 2004 survey of Oklahoma judges found that many felt uncomfortable and undereducated about their state's laws about resuscitation.

In recent years, many hospitals have quietly developed policies underscoring that doctors, not family members, should have the final authority to make these medical decisions.

But to pre-empt such clashes and elicit the patient's wishes, a simple document developed in Oregon about treatments like CPR is being increasingly used in at least 14 states. When elderly invalids are rushed to the hospital, usually in no condition to discuss resuscitation, the bright pink form called Physician Orders for Life-Sustaining Treatment, or POLST, travels with them and can stand in as a doctor's order.

Many physicians and patient advocates say that casting these end-of-life conversations as adversarial needlessly provokes tensions. Instead, they say, the focus should be on achieving a goal of end-stage care that both sides can agree on.

Typically, an order on a chart is a doctor's green light to staff: Give this medicine, do this therapy. A do not resuscitate, or DNR, order is a red light, an order not to do something. Such an order is needed because it is counterintuitive: The assumption in health care is that everyone who goes into cardiac arrest would want to be revived. Even though the success rate of CPR is poor and the likelihood great that its impact will be more burdensome than beneficial, health-care providers need explicit permission not to try it.