It’s educational to think about the ethics of organ donation, and the underlying conflicts that sometimes arise:
This process requires the attending physician to begin switching loyalties from the patient to the organ recipient. As a result, required request procedures produce clinical conflicts of interest in both the identification and medical management of the patient/potential donor, as well as in caring for the potential donor’s family. These conflicts arise in relation to physical care, professional responsibility, and legal accountability.
Medical treatment of severely brain-injured persons, a major group of potential donorss, is difficult under the best of circumstances. For example, patients with extensive brain injury usually die from the effects of cerebral edema, which prevents circulation to the brain. Maintaining a slightly dehydrated fluid balance benefits the brain by lessening the edema, while overhydration tends to increase edema and reduce circulation to the brain, thus increasing the possibility of brain damage. Unfortunately, fluid management that is beneficial to the brain can be harmful to other organs. For example, limiting fluid intake in order to reduce cerebral pressure may injure the kidneys through reduction of urine output, especially when the brain injury causes concomitant release of antidiuretic hormones. Conversely, increasing fluids will counter antidiuresis and enhance kidney function, but may precipitate or hasten brain death through increased cerebral edema. 
More graphic and potentially costly conflicts arise with gunshot wounds to the head. In cases where the bullet had damaged the thalamus and hypothalamus, producing blood and air in the ventricles, the untreated lesion is inevitably fatal. However, treatment intended to preserve physiological equilibrium suitable for organ donation may result in preservation of the brain stem and persistent vegetative state for the patient.
While such conflicts of patient management are as old as medicine itself, introducing organ procurement into the decision process puts the conflicts in a different light, for the physician now experience pressures that have no relation to patient care. Institutionalizing the identification of potential organ donors appears to assume a shift in the physician’s clinical attitude so that willingness to diagnose or even hasten the diagnosis of brain death supersedes the incentive to fight for life.
Historically, the underlying ethic of medical practice had been to “do no harm.” In this tradition, “It is even more important to fight for life than to be willing to diagnose death,” which precludes considerations of organ donation by the physician until the time brain death is diagnosed.  Required request legislation subtly changes this traditional view and holds the clear possibility for pushing the point at which a decision is made to switch from “fight for life” to “potential donor” treatment modalities further and further back from the time of brain death diagnosis so that donor/recipient matching may begin as expeditiously as possible.
Clark, Leo, Susan Martyn, and Wright, Richard (Writer). “Required request for organ donation: moral, clinical, and legal problems.” The Hastings Center Report Apr.-May 1988: 27+.