There are, however, situations in which nutrition can only be provided by artificial means. Like all other intervention, artificially provided hydration and nutrition may or may not be justified. It should be instituted or foregone only after a process of reasoned decision making focused upon estimates of benefits and burdens to the patient. For example, a neurological assessment of the patient completed by a physician is an important feature of estimating burdens and benefits. The burdens vary with the particulars of the patient, the substances to be delivered, the mode of delivery, and the anticipated outcome.
Ethical difficulties arise when it is unclear whether food and fluid are more beneficial or harmful.
Since they are essential for life, this uncertainty leads to questions about whether life, under certain circumstances, might be a greater harm than death. As in all other interventions, the anticipated benefits must outweigh the anticipated burdens for the intervention to be justified. Outcomes such as weight gain, increased caloric intake or changes in laboratory test results do not themselves serve as adequate justification for this intervention. Such changes in the absence of any relation to overall well-being of the patient as a person, are not persuasive reasons to begin or continue to provide artificial nutrition or hydration. Since competent, reflective adults are generally in the best position to evaluate various harms and benefits to themselves in the context of their own values, life projects, and tolerance of pain, their acceptance or refusal of food and fluid should be respected.