The Doctrine of Double Effect and end-of-life decisions

Introduction

‘If the first purpose of medicine, the restoration of health, can no longer be achieved there is still much for a doctor to do and he is entitled to do all that is proper and necessary to relieve pain and suffering even if the measures he takes may incidentally shorten life.’ ¹

Over the last century the need to make decisions about end-of-life patient care has become increasingly frequent. Today two-thirds of all deaths involve some kind of end-of-life decision and most clinicians will have played a part in making them. ² This increase has occurred because advances in modern medicine have brought about a shift in the cause of death; acute deaths due to infections have been replaced by a more protracted dying process from conditions which tend to affect us in old age such as cancer and cardiovascular disease. These changes have forced us to question our traditional approach to treating patients; we no longer think that the extension of life is always the appropriate goal of medicine, especially for those who are terminally ill. We have begun to accommodate different goals into our approach to end-of-life care. These include attempts to relieve a patient's pain and suffering, and to provide patients with a comfortable and dignified death. End-of-life decisions generally involve choosing: when a treatment has become futile (discussed in the Five-Minute Focus [FMF] on futility in Volume 1 ³ ); when to withhold or withdraw life-prolonging treatment such as nutrition, hydration and mechanical ventilation; and when to alleviate pain or suffering with drugs that may shorten the patient's life as a side-effect. End-of-life decisions, particularly those that might shorten a patient's life, can be both morally and legally difficult for physicians. The ‘Doctrine of Double Effect’ (DDE) (explained in the following paragraph) offers some guidance to physicians faced with complicated end-of-life decisions and the purpose of this FMF is to consider whether the advice the DDE gives is appropriate and useful.

Definition of the DDE

A single action can have more than one foreseen consequence: one consequence might be harmful, another good. In certain circumstances we are permitted to perform an action which may lead to harm provided it occurs as an unintended side-effect (or double effect) of the intended outcome which is good. The application of this principle which is described as the DDE is guided by four conditions that together are required to make an act morally permissible.

The nature of the act itself (regardless of its consequences) must be morally good or at least morally neutral;

History of the concept of double effect

In the 13th century Thomas Aquinas introduced the idea of actions having two effects. In the Summa Theologica he discusses how murder may be justified if a person is acting in self-defence because the bad effect (killing one's assailant) is not intended, and the good effect (to save one's own life) is not unlawful in itself. ⁴ In the 16th century Catholic theologians developed this idea and formulated the principle of a DDE. ⁵ An early example of its use in health care was to resolve challenges to the Church's prohibition of abortion in cases where continuation of pregnancy would place the mother's life at risk. The philosophical basis of the DDE rests on the idea that it is not just the consequences of an action that determine its moral worth, but also the state of mind (or intentions) of the agent performing the act. This idea allowed the theologians to assume, firstly, that there is a morally relevant difference between intending something and merely foreseeing that something will happen, and, secondly, that it is legitimate to decide whether an action with mixed consequences is morally permissible on the basis of whether the good effect is proportionate to the bad effect.

The clinical application of the DDE

The doctrine is usually invoked in health-care situations when the action of the health-care professional could be seen as contravening a moral duty, such as the duty not to kill or when the likelihood of the harmful foreseeable consequence is great. It is seen as being particularly useful to clinicians in caring for patients nearing the end of their life, where decisions about appropriate pain relief may need to be made.

When treating a patient with a terminal illness who is in severe pain there may come a point when the standard dose of analgesia is not sufficient to relieve their discomfort. Higher doses of these drugs may cause respiratory depression and shorten the patient's life. The proportion of deaths that are preceded by the administration of high doses of analgesia is thought to be as high as 26% in some European countries. ² DDE can provide a moral and legal justification for a clinician's decision to administer a potentially harmful dose of analgesia.

The legal position

This was first articulated in 1957 in the case of Dr B Adams who was accused of murder after a patient to whom he had given a large dose of opioids died. ⁶ He was the first person in the English courts to use the DDE in defence of his actions. He was acquitted because the jury did not believe he was motivated by a desire to kill, but rather, accepted that his intention was to alleviate the suffering of his patient. This position has been accepted in other legal cases since then. ⁷ However, the courts do not always accept that a health professional's intentions are to alleviate suffering rather than to end life. ⁸ Perhaps, the most high-profile example of this case being that of Harold Shipman who was found guilty of murdering 15 of his patients. One possible consequence of these cases is that doctors may be reluctant to use the high doses of opiates necessary to treat severe pain fearing that their intentions will be misconstrued. Critics of the DDE cite the ambiguity surrounding the interpretation of intention as a flaw but others see this as beneficial maintaining that it protects the proper image of medicine which holds that doctors heal and do not kill. ⁹ It is also suggested that the DDE prevents us from sliding down the slippery slope into a general acceptance of active euthanasia ^10,11 (for a discussion of euthanasia see the FMF in a previous issue of Clinical Ethics ¹² ).

Philosophical problems with the DDE

There are several philosophical challenges to the DDE. One is the question of why the intention behind an action is seen to have a different and more important moral significance from the foreseen consequences of that action. ¹³ Some philosophers argue that the distinction between foreseen and intended consequences is one of language determined by the way we describe our intentions. ^14,15 They maintain that we should include all the consequences that we know and believe may occur as a result of our actions into our concept of intention. This enlarged concept of intention, rejects the basic distinction between foreseen and intended consequences, but does not preclude the notion that we may desire some consequences more than others. It simply refuses to equate such desires with a morally significant distinction.

The proportionality condition in the DDE has also been challenged. ^16,17 For instance, it is not morally permissible to administer a potentially lethal dose of analgesia to a patient with kidney stones despite the fact that a doctor's intention in both the case where the patient has kidney stones and the case where the patient has a terminal illness may be the same – to alleviate suffering. Here, the proportionality condition judges that the alleviation of pain in a patient with kidney stones is not sufficiently good to outweigh the bad consequence of death.

The philosophical difficulty arises because it seems to suggests that we should weigh the good effects against the bad effects in a quantitative way. This proves to be particularly problematic in relation to end-of-life decisions where the bad effect is usually death, the ultimate harm, and therefore perhaps, beyond quantification.

Should we use the DDE as an ethical guide for clinicians?

The DDE is useful because it can reduce the occurrence of moral dilemmas for some clinicians. It does this by limiting the application of certain moral precepts. For instance, the precept that killing/harming is wrong does not apply in situations where a doctor is alleviating pain but unintentionally causes death. While the DDE can help to solve some moral dilemmas it makes certain requirements of a doctor that may give rise to other dilemmas. For doctors to justify their actions using the DDE they must make psychological distinctions between what they intend and what they do not intend. This is difficult and may be impossible. The intentions which motivate us to act are complex and inevitably involve more than one component. Doyal has argued that the DDE encourages doctors to think about the quality of their intentions, when they should be focusing on what is in their patient's best interest. ¹⁸ This may lead to increased patient suffering as doctors debate the true nature of their intentions. Even if they are clear about their intentions doctors still have to weigh their decisions on the scales of proportionality.

The need to develop a good system for resolving ethical and legal dilemmas which arise in end-of-life decisions is essential if we are committed to improving the quality of medical care for patients nearing the end of their life. This will become increasingly important with changing demographics and increases in the prevalence of chronic disease. Perhaps in response to these pressures several European countries have introduced or are debating legislation on physician-assisted suicide (PAS) and euthanasia. One argument in favour of legalizing PAS is that it removes the difficulties with construing intention, or distinguishing between different consequences of an action inherent in the DDE.

Conclusion

The DDE appears to offer some legal and ethical support for clinicians when making difficult decisions, although the principle rests on contested philosophical ground and the interpretation of ‘intention’ implied by the DDE is not universally accepted. When applied appropriately it allows a doctor fulfil both her duty to relieve her patient's suffering and her duty not to intentionally kill her patient. It is however open to abuse as the case of Harold Shipman demonstrated.

Summary points

The DDE states that sometimes we are only responsible for the intended consequences of an action and not those that are merely foreseen.