Medical or ethical justification of unrequested nutrition in a terminally ill patient is typically an emotional response to the clinical situation and has not been proved to be clinically beneficial. Winter reviewed the literature to determine the benefits and burdens of nutritional support in terminally ill patients.

The benefit of nutritional support in a terminally ill patient is measured by improvements in the patient's response to therapy, comfort or length of survival. Studies of terminally ill patients with cancer have uniformly shown that treatment with parenteral nutrition provides no survival benefit and does not improve response to chemotherapy. Parenteral nutrition was associated with a higher rate of infection related to the access catheter. Overall, studies—many of them randomized, controlled trials—have consistently failed to demonstrate a meaningful clinical benefit from the use from nutritional support in patients at or near the end of life.

There are many complications of nutritional support administered by an enteral or parenteral route (see accompanying table on page 153). Some of these complications are uncomfortable (nausea, vomiting, diarrhea and agitation) and some are life-threatening.

During a fasting state, fat replaces carbohydrates as the energy substrate, with amino acids as the primary source of energy for brain metabolism. As fasting continues beyond a week, the brain begins to use ketones for energy. Less use of amino acids reduces the urea load to the kidneys. Studies have also shown that fasting patients have less coughing, nausea, vomiting, diarrhea and respiratory secretions. Prolonged fasting, associated with higher ketone levels, causes reduced hunger. Studies of persons fasting for spiritual inspiration or weight loss have demonstrated a state of euphoria. A study of mentally aware and competent patients who were offered unlimited food and drink reported no hunger in 20 patients (63 percent) and mild hunger only at the beginning of the study in 11 patients (43 percent). There is no evidence that the patients had suffering caused by their self-chosen food refusal.

The 1983 President's Commission for the Study of Ethical Problems in Medicine and Biomedical Research (1983) held that physicians are not ethically required to provide futile treatments to patients. One definition of futile treatments is those that fail to provide “improvement in the patient's prognosis, comfort, well-being or general state of health.” Within the context of this definition and based on the available evidence, Winter states that nutritional support is futile in terminally ill patients and that physicians are not obligated to provide such treatment. Winter adds that unrequested nutritional support should not be considered an appropriate aspect of comfort care at the end of life.

In an accompanying editorial, Brody concurs that it is not ethically acceptable to offer patients a therapy that has no apparent benefit and may carry substantial risk. Artificial nutrition and hydration are “life-sustaining” treatments only if such therapy has a proven beneficial effect but, based on the available evidence, this does not seem to be the case.

editor's note: The information provided by Winter and Brody is helpful to physicians dealing with patients at or near the end of life. Using evidence to guide our treatment is wise, but we must avoid the "slippery slope" of providing no intervention for vulnerable patients. Determining that artificial nutritional support for a terminally ill patient is unbeneficial is one thing, but deciding, as some physicians do, that certain patients are not worthy of nutritional support (e.g., the advanced dementia patient, the patient in a persistent vegetative state or the severely retarded patient) is quite another. Few physicians would advocate employing a futile treatment, but the real issue seems to be determining which patients are indeed terminally ill. Legal definitions do not cover all of the situations physicians must deal with and maintaining feeding has symbolic and physiologic importance. In caring for vulnerable patients, we must decide whether feeding is our minimal obligation; if so, is artificial enteral or parenteral nutrition included, or does feeding include only attentive hand feeding? The evidence can only guide, not solve, the ethical dilemmas in medicine.—g.b.h.