Total Parental Nutrition as a Proportionate Means of Conserving Life

The cases of Nancy Cruzan and Terry Schiavo brought the discussion of assisted nutrition and hydration to the notice of the public. Many individuals inside and outside the medical community have weighed in on the matter of whether assisted nutrition is an obligation to provide to patients, especially those that have unresponsive wakefulness syndrome (previously referred to as persistent vegetative state), as well as whether this act should be considered medical in nature. While there have been a few disagreements between Catholic theologians, the Catholic moral tradition has generally provided an unwavering response to these questions stemming from the Church's emphasis on the inherent dignity of all human life from conception until natural death. As far back as the sixteenth century, Francisco de Vitoria, a commentator on the works of St Thomas Aquinas said:

If a sick man can take food or any form of nourishment, when there is a hope that he will live, he must do so, just as he would be required to give it to another sick person…If his depression is so great and his appetite so diminished that he can only take food with enormous effort, almost as though it were a form of torture, then a certain impossibility must surely be recognized and he is therefore excused, at least from mortal sin, particularly where there is little or no hope that he will live. (Giovanelli 2011, 385)

This theme is maintained in the most recent version of the ethical and religious directives for Catholic healthcare services when it states, “In principle, there is an obligation to provide patients with food and water, including medically assisted nutrition and hydration for those who cannot take food orally” (United States Conference of Catholic Bishops 2025, no. 58). Most of the discussions around medically assisted nutrition and hydration have focused on enteral nutrition. The present article aims to argue that the obligation to provide nutrition and hydration, in principle, extends to providing parenteral nutrition for patients who cannot take in food through their intestines so long as the intervention does not constitute a grave burden, does not entail excessive expense, and provides a reasonable hope of efficacy. I will discuss how total parenteral nutrition (TPN) is utilized as standard of care for certain medical conditions, and show how it is, in principle, a proportionate means of care, drawing comparisons to gastrostomy tube feeding.

John Paul II stated that, “The administration of water and food, even when provided by artificial means, always represents a natural means of preserving life, not a medical act” (John Paul II 2004, no. 4). The New Charter for Healthcare workers echoes this when it says, “Nutrition and hydration, even if administered artificially, are classified as basic care” (Zimowski 2017, 111). There are those who, while conceding that enteral feeding via a nasogastric or gastrostomy tube is natural, may argue that nutrition is unnatural when provided via a central venous line. I would counter first by reminding them that there are multiple instances in medicine in which there is no debate, where either- short- or long-term parenteral nutrition is the standard. Very premature babies, for example, will often require dextrose containing intravenous fluids as well as TPN for a variety of reasons to include gut immaturity, necrotizing enterocolitis, or during treatment with high dose vasopressors or extracorporeal membrane oxygenation (Griffin 2024). Mothers suffering from severe hyperemesis gravidarum will occasionally require TPN for up to several months. Occasionally, enteral feeding will not be an option for patients with superior mesenteric artery syndrome, and parenteral nutrition may be necessary. There are also several causes of intestinal failure where the patient is otherwise well, yet they are simply unable to assimilate foods in their intestines. In all these scenarios, artificial parenteral nutrition is the standard way to provide, in principle, a proportionate means of sustenance. Secondly, as Fr. Giovanelli eloquently stated:

What is not natural in medical terms may in fact be so in theological terms, and what is natural in theological terms may not be so in medical terms. In the theological sense, natural means everything that pertains to the nature of man understood in a holistic sense, even if it occurs through artificial means, because it allows man to achieve his ends, first among which is self-preservation and sustenance. (Giovanelli 2011, 395)

Using Giovanelli's language, TPN, while artificial, is a theologically natural method of providing nutrition and hydration that leads to the individual's sustenance. To say that it is theologically natural simply indicates that it is a proportionate means of providing basic care. That the natural route of receiving nutrition is being replaced by the parenteral route does not change the fact that the aim is to maintain the patient's comfort and preserve their dignity by providing necessary fluid and nutrition. TPN should not be viewed as a medical treatment aimed at a cure, but rather as a means of providing hydration and nourishment to maintain essential bodily functions.

Over the past few decades, society has prioritized heightened patient autonomy. The European Society for Clinical Nutrition and Metabolism, in their 2016 guidelines, said, “A competent patient has the right to refuse a treatment after adequate information even when this refusal would lead to his or her death…artificial nutrition and hydration are medical interventions and require a predefined achievable treatment goal and the informed consent of the competent patient” (Druml et al. 2016). Yet patients should be informed that there are certain elements of basic care, assuming they are not gravely burdensome, that they cannot refuse with a clean conscience. The inability to tolerate nutrition enterally should not be either a death sentence or a condonation of passive euthanasia via dehydration and starvation if death is not imminent. Fr. Tadeusz Pacholczyk, discussing the related topic of whether feeding tubes are required when oral feeding is no longer possible said, “Our death, in other words, should result from the progress of a pathological condition, not from a lack of food or water if it could have been readily and effectively offered to provide comfort and support to a patient” (Pacholczyk 2006). While several long-term complications can arise with TPN, including central-line-induced thromboses, central line infections, or TPN-induced liver injury or failure, for TPN-dependent patients secondary to intestinal failure the “overall survival probability was 88%, 74% and 64% at 1, 3 and 5 years respectively” (Joly et al. 2018). Proceeding with TPN as a method of assisted nutrition and hydration therefore has the potential to aid in the prolongation of life worth living, as well as preventing unnecessary death via dehydration and starvation.

Archbishop Cronin, in his doctoral dissertation, discussed ordinary versus extraordinary means of conserving life. In addition to providing some hope of benefit, ordinary means to Cronin are those means which are common, not too difficult, relatively simple, and in keeping with one's status (Cronin 2011, chap. 3). The process of transitioning from nutrition by mouth to either gastrostomy tube feeding, or TPN are very similar. They both require a surgical procedure that is generally considered to be safe. They both utilize a pump to deliver nutrition and hydration. While the complications differ, the surgical complication rate is similar. One report evaluating complications following percutaneous endoscopic gastrostomy tube placement, showed that “3 percent had major complications, including gastric perforation, gastric bleeding, and hematoma development” (DeLegge 2024). Similarly, a systematic review and meta-analysis “found that approximately 3% of central venous catheter placements were associated with major complications” (including arterial cannulation, pneumothorax, infection, or deep vein thrombosis) (Teja et al. 2024). Although gastrostomy tube feeding has more durable long-term success rates, given their similarities, it follows that the administration of TPN is also, in principle, proportionate care.

Most of the discussion from the magisterium has discussed the obligation in principle of providing “nutrition and hydration,” with some references to providing “food and water” to all patients. There has been very little direct reference to this nutrition and hydration needing to be provided enterally. The references with the most direct ties to enteral feeding are those regarding the assimilation of food and liquids. The congregation for the doctrine of the faith, responding to questions from the USCCB said, “Nor is the possibility excluded that, due to emerging complications, a patient may be unable to assimilate food and liquids, so that their provision becomes altogether useless” (Congregation Doctrine of Faith 2007a). Yet, in a different manner, TPN also needs to be assimilated. Parenteral nutrition “is associated with metabolic complications, including hyperglycemia, serum electrolyte alterations, macro- or micronutrient excess or deficiency… and hepatic dysfunction” (Seres 2024). The development of metabolic abnormalities, fluid overload, or other complications from TPN could indicate poor assimilation, which could render it disproportionate care. Ultimately the congregation for the doctrine of the faith has stated that, “The administration of food and water even by artificial means is, in principle, an ordinary and proportionate means of preserving life. It is therefore obligatory to the extent to which, and for as long as, it is shown to accomplish its proper finality, which is the hydration and nourishment of the patient. In this way suffering and death by starvation and dehydration are prevented” (Congregation Doctrine of Faith 2007b). Is not TPN simply an artificial means of administering food and water which prevents this suffering and death?

Artificial nutrition and hydration is, in principle, proportionate and obligatory care, but in some circumstances it may become disproportionate. Extraordinary and disproportionate means of preserving life, according to Archbishop Cronin, are those that either offer no hope of benefit, or are either impossible, require great effort or excessive hardship, involve excruciating or excessive pain, entail extraordinary expense, or lead to intense fear or repugnance (Cronin 2011). Yet “the act of nourishment and hydration, even if achieved through medical interventions, remains first and foremost a matter of ordinary care giving. It is not an intervention carried out in the context of illness and aimed at restoration of one's well-being” (Travaline and Berg 2011). As such, regarding artificial nutrition and hydration, one should consider not whether there is hope of benefit but rather hope of efficacy. The question is not whether this basic medical care helps to reverse the underlying pathology, but rather whether it is successfully performing its role of providing nutrition and hydration for one's sustenance. If enteral or parenteral nutrition can provide this function, they should be considered “morally obligatory, insofar as and until it is seen to have attained its proper finality, which in the present case consists in providing nourishment to the patient and alleviation of his suffering” (John Paul II 2004). The Congregation for the Doctrine of the Faith reemphasized this requirement in Samaritanus bonus when they said, “It is not lawful to suspend treatments that are required to maintain essential physiological functions, as long as the body can benefit from them (such as hydration, nutrition, thermoregulation, proportionate respiratory support, and the other types of assistance needed to maintain bodily homeostasis and manage systemic and organic pain)” (Congregation Doctrine of Faith 2020). As hope of benefit has no part in the discussion of basic healthcare, for artificial nutrition and hydration to be considered disproportionate it would have to entail no hope of efficacy, “entail an excessive burden or impose excessive expense on the patient, the family, or the community” (United States Conference of Catholic Bishops 2025, no. 56).

TPN should be considered proportionate and obligatory means of care in certain instances, such as when patients have isolated intestinal failure, or poor intestinal assimilation of food and liquids due to an underlying reversible illness. TPN would be disproportionate in these cases if it were excessively burdensome. This could include poor assimilation of TPN with difficult-to-manage metabolic complications, severe TPN-induced liver disease, recurrent central-line-associated bloodstream infections, or recurrent deep vein thromboses. The burden imposed on families may also stem from nonclinical concerns. TPN can be very expensive, with cost being prohibitive to certain families. In addition, many healthcare settings, especially in underserved national and international communities, will not have the resources to provide these services. Finally, intense fear, repugnance, or pain may lead to TPN being considered disproportionate for the individual.

TPN does not constitute proportionate care at the end of life when patients have multi-organ failure with intestinal failure. When patients are no longer able to assimilate food and liquids in their intestines in their final days of life, it would not be expected of them to trial parenteral nutrition. Instead, it would be prudent to acknowledge that they are not the owners, but rather the stewards of their life, and be reminded that they have “the right to die peacefully with human and Christian dignity” (Congregation Doctrine of Faith 1980).

Decisions regarding artificial nutrition and hydration should focus on the human rights inherent to all people that are rooted in the individual's ontological dignity. “But first we must speak of man's rights. Man has the right to live. He has the right to bodily integrity and to the means necessary for the proper development of life, particularly food, clothing, shelter, medical care, rest, and, finally, the necessary social services. In consequence, he has the right to be looked after in the event of ill-health” (John XXIII 1963). While a person does not have a duty to preserve one's life at all costs and in all circumstances, it would be wrong to trivialize life and cast it aside simply because of a poorly functioning gastrointestinal system. TPN is often used as the standard of care in medicine. It is a proportionate method of sustaining life by preventing unnecessary dehydration and starvation. While the long-term risks differ, TPN holds a similar rate of surgical complications, and has a comparable method of delivery when compared to gastrostomy tube feeding. As such, the obligation to provide food and water, in principle, extends to providing parenteral nutrition for patients who cannot take in food through their intestines so long as the intervention does not constitute either a grave burden or excessive expense, and provides a reasonable hope of efficacy. “After all, life on earth is not an ‘ultimate’ but a ‘penultimate’ reality; even so, it remains a sacred reality entrusted to us, to be preserved with a sense of responsibility” (John Paul II 1995).