Rational desires and the limitation of life-sustaining treatment

It is accepted that treatment of previously competent, now incompetent patients can be limited if that is what the patient would desire, if she were now competent. Expressed past preferences or an advance directive are often taken to constitute sufficient evidence of what a patient would now desire. I distinguish between desires and rational desires. I argue that for a desire to be an expression of a person's autonomy, it must be or satisfy that person's rational desires. A person rationally desires a course of action if that person desires it while being in possession of all available relevant facts, without committing relevant error of logic, and "vividly imagining" what its consequences would be like for her. I argue that some competent, expressed desires obstruct autonomy. I show that several psychological mechanisms operate to prevent a person rationally evaluating what future life in a disabled state would be like. Rational evaluation is difficult. However, treatment limitation, if it is to respect autonomy, must be in accord with a patient's rational desires, and not merely her expressed desires. I illustrate the implications of these arguments for the use of advance directives and for the treatment of competent patients.     

Compelled organ donation

Along with ethical considerations, compelling an individual to donate organs, tissues, or bodily fluids brings several legal doctrines into conflict. The privacy of one's body is generally considered sacrosanct by American courts, which have upheld a competent adult's right to refuse medical procedures, even in cases when they are necessary to save the life of another. Although medical and legal communities stress “respect for the individual” as being paramount under American jurisprudential principles, the doctrine of “substituted judgment” permits a court to act (for example, by consenting to organ donation) on behalf of an incompetent individual or child. Parents also have the right to cause a child to “donate” an organ, and although a means exists by which the child can refuse, this may not be realistically feasible for young children. The revised Uniform Anatomical Gift Act of 2006, while clarifying issues of who may make organ donation decisions, does not resolve all the practical issues of compelled organ donation for minors.     

In the matter of Stephen Dawson: right v. duty of health care.

In cases like that of Stephen Dawson the ethics of proxy decision-making are at stake. As long as patients are persons they have rights, the incompetent ones no less than those who are competent. The only difference is that in the case of incompetent persons the rights must be exercised by proxy. The import of the Stephen Dawson case is that by this precedent Canadian law now radically alters the status of incompetent minors in such a way that their rights are curtailed in two fundamental ways. First, the parameter of qualitative considerations that is available to any other person is removed from the armory of the decision-making criteria of incompetent minors and can no longer be employed by the proxy decision-makers. Second, what are rights in the case of competent individuals--the right to life and the right to health care--become duties. Ethically this dénouement is deplorable. The medical profession now not only faces the pragmatically unenviable task of having to save or sustain all incompetent minors so long as medical science will permit but will have to do so even at the cost of quality of life. I shall pass over in silence the ethics of the resource-allocation problem that now arises. As a medical ethicist I can only hope that the medical profession will soon see fit to challenge this decision on a formal basis.     

Gender-dependence of substituted judgment on quality of life in patients with dementia

Background  

Substituted judgment asks the proxy to decide what the patient would have decided, had he or she been competent. It is unclear whether substituted judgment of the patient's quality of life can serve as a surrogate measure in patients with dementia.     

The role of deer in facilitating the spatial spread of the pathogen Borrelia burgdorferi

Borrelia burgdorferi is a vector-bourne zoonosis which propagates in wild populations of rodents and deer. The latter are incompetent for the pathogen but are required for the life cycle of hard-backed ticks which act as a vector for the pathogen. Increasing the diversity of hosts has previously suggested the presence of a ‘dilution effect’ in which such an increase reduces successful pathogen transmission as it increases the chance that a tick will encounter an incompetent host. This paper will produce a model which shows that whilst a dilution effect is possible for a system in which deer are the only incompetent host, this effect is not likely to be strong. Extending the population dynamics to include movement of deer into regions previously only inhabited by competent hosts, we find that, although ticks come in with the deer, there is a significant time lag before Borrelia appears.     

Anorexia Nervosa and Respecting a refusal of life-prolonging Therapy: A Limited Justification

People who suffer from eating disorders often have to be treated against their will, perhaps by being detained, perhaps by being forced to eat. In this paper it is argued that whilst forcing compliance is generally acceptable, there may be circumstances under which a sufferer's refusal of consent to treatment should be respected. This argument will hinge upon whether someone in the grip of an eating disorder can actually make competent decisions about their quality of life. If so, then the decision to refuse therapy may be on a par with other decisions to refuse life-prolonging therapy made by sufferers of debilitating chronic, or acute onset terminal illness. In such cases, palliation might justifiably replace aggressive therapy. The argument will also draw heavily on the distinction between competent refusal of therapy and passive euthanasia, and the distinction between incompetent and irrational decisions. Both distinctions will then be applied to decisions to refuse food. The extent to which sufferers from anorexia nervosa can be categorised as either incompetent or irrational will be examined. It is against this background that it will be argued that at least some of those who suffer from eating disorders should have their refusals respected, even if they may die as a result.     

A proposal for the use of advance directives in the treatment of incompetent mentally ill persons

[M]y question is how these patients while competent might be able to give their own informed consent to treatment, despite being both unwilling and incompetent to do so when treatment is to be begun, thereby reducing the need to relax the dangerousness criteria for involuntary commitment. It is uncontroversial that the dangerousness requirement would be too restrictive for all treatment of mental illness. When competent patients voluntarily seek and/or accept treatment for their mental illness, neither public policy nor medical practice restricts treatment to those patients judged to be dangerous. Instead, criteria should be and generally are comparable to those for the treatment of physical illness -- whether the patient is ill, in this case mentally ill, and likely to benefit from treatment. Through use of advance directives, it would be possible for mentally ill persons who are currently refusing treatment to give prior consent, while competent and with their disease in remission, to treatment at a later time when they are incompetent, have become noncompliant, and are refusing treatment. My proposal is certainly not entirely novel, since others have made similar proposals under the heading of Ulysses contracts and voluntary commitment contracts. Addressing briefly some of the criticisms of these earlier proposals will bring out one fundamental difference between them and my proposal here for a new use of advance directives -- whether the patient must then be incompetent when the contract or directive made earlier is later invoked -- a difference I shall argue strongly favors my proposal.     

A direct advance on advance directives

Advance directives (ADs), which are also sometimes referred to as 'living wills', are statements made by a person that indicate what treatment she should not be given in the event that she is not competent to consent or refuse at the future moment in question. As such, ADs provide a way for patients to make decisions in advance about what treatments they do not want to receive, without doctors having to find proxy decision-makers or having recourse to the doctrine of necessity. While patients can request particular treatments in an AD, only refusals are binding. This paper will examine whether ADs safeguard the autonomy and best interests of the incompetent patient, and whether legislating for the use of ADs is justified, using the specific context of the legal situation in the United Kingdom to illustrate the debate. The issue of whether the law should permit ADs is itself dependent on the issue of whether ADs are ethically justified; thus we must answer a normative question in order to answer the legislative one. It emerges that ADs suffer from two major problems, one related to autonomy and one to consent. First, ADs' emphasis on precedent autonomy effectively sentences some people who want to live to death. Second, many ADs might not meet the standard criteria for informed refusal of treatment, because they fail on the crucial criterion of sufficient information. Ultimately, it transpires that ADs are typically only appropriate for patients who temporarily lose physical or mental capacity.     

Centrosome phosphorylation and the developmental expression of meiotic competence in mouse oocytes.

Previous studies suggested that the transition from an incompetent to a competent meiotic state during the course of oogenesis in the mouse involved a G2/M-like cell cycle transition (Wickramasinghe et al, 1991. Dev. Biol. 143, 162). The present studies tested the hypothesis that centrosome phosphorylation, an event normally induced by MPF, is required for this developmental transition and the expression of meiotic competence in cultured growing mouse oocytes. Multiple fluorescence labeling techniques were used to evaluate centrosome number, phosphorylation status, and microtubule nucleating capacity in competent and incompetent oocytes. Experimental conditions were established for reversibly altering the phosphorylation status of the centrosomes and the effects of these treatments on meiotic resumption were examined. Phosphorylated centrosomes nucleating short microtubules were observed in competent oocytes, whereas nonphosphorylated centrosomes and interphase microtubule arrays were found in incompetent oocytes. Upon recovery from nocodazole-induced microtubule depolymerization, short microtubules formed from centrosomes in competent oocytes, whereas long microtubules reappear in the cytoplasm of incompetent oocytes. Perturbation of the phosphorylation state of oocytes with activators of protein kinase A or protein kinase C resulted in the formation of long interphase microtubules in competent oocytes while centrosome phosphorylation was maintained. Treatment of competent oocytes with the phosphorylation inhibitor 6-dimethylaminopurine also led to formation of long microtubules, although under these conditions centrosomes were dephosphorylated. When competent oocytes were treated simultaneously with puromycin and the phosphodiesterase inhibitor isobutyl methylxanthine (IBMX) for 6 hr, centrosomes became dephosphorylated; centrosomes were rephosphorylated when competent oocytes were further cultured in IBMX without puromycin. Conditions that induced centrosome dephosphorylation in competent oocytes resulted in the loss of the ability to express meiotic competence in culture, whereas maintenance of centrosome phosphorylation in these oocytes was correlated with the ability to resume meiosis. These results suggest that the G2/M transition that occurs when mouse oocytes progress from an incompetent to a competent state in vivo involves the phosphorylation of centrosomes and that the maintenance of centrosome phosphorylation is required for the in vitro expression of meiotic competence.     

Sperm morphology: Its relevance to compensable and uncompensable traits in semen

The nature of subfertility due to the male or inseminate is as complex as that of the female. Fertilization failure, and failure in embryogenesis, are both of seminal origin. Males also differ in the number of sperms required to reach their maximum fertilization rate. Males requiring more sperm are considered to have compensable seminal deficiencies. These include a number of known viability and morphology traits (including both abnormal heads and tails) and unknown factors (functional or molecular traits) precluding sperm access to the ovum or ability of the sperm to engage the ovum sufficiently to initiate fertilization and the block to polyspermy. Differences in fertility among males or inseminates independent of sperm dosage are considered uncompensable. These seminal deficiencies are associated with fertilizing sperm that are incompetent to maintain the fertilization process or subsequent embryogenesis (once initiated), with most failures occurring prior to maternal recognition of pregnancy; these sperm would pre-empt fertilization by competent sperm. Evidence now exists supporting the concept that the uncompensable effect is due to chromatin aberrations in morphologically normal or near-normal fertilizing sperm present in abnormal ejaculates (elevated content of abnormal sperm). Thus, sperm morphology may be our best indication for the presence of an uncompensable deficiency, although we have yet to identify the incompetent fertilizing sperm clinically.     

Sporulation competence in Aspergillus nidulans: a role for iron in development.

There is a difference in the response of DNA from mycelial extracts of Aspergillus nidulans to hot acid hydrolysis depending upon the state of sporulation competence. The DNA in incompetent culture mycelia is not hydrolyzable while the DNA in competent culture is hydrolyzable. The inhibition of DNA hydrolysis is due to the presence of iron. Although the concentration of iron decreases in mycelia during growth, there is sufficient iron present in competent mycelia to inhibit DNA hydrolysis. The change in DNA hydrolyzability may be the result of a change in intracellular iron distribution, or a change in an iron binding component. We suggest that these changes are related to the altered capacity for gene expression which occurs at the time of acquisition of sporulation competence.     

Making an advance directive.

The introduction in Britain of advance directives--which allow a person to state in advance of becoming incompetent that they wish to take part in treatment decisions when no longer mentally competent--has now been advocated by the medical and legal establishments. The practical application of directives relating to health care would be simplified by the adoption of a standard model document together with guidelines summarising the background clinical conditions and any subsequent acute events that may make it appropriate to trigger the use of a directive. As no specific legislation exists, good communication is needed at the various stages between the drafting and implementation of directives if the system of directives is to be successful.     

Seasonal population dynamics of ticks, and their influence on infection transmission: a semi-discrete approach

A semi-discrete model for tick population dynamics is presented, whereby tick feeding is assumed to occur only during summers of each year. Conditions for existence, uniqueness, and stability of a positive equilibrium were found; the system was then studied numerically using parameter estimates calibrated for the tick Ixodes ricinus in Trentino, Italy, and the sensitivity to parameters was examined. This model was then extended to consider tick-transmitted infection of one species of hosts, while other hosts are incompetent to the infection. Assuming, for simplicity, that the infection is not affecting the total number of either hosts or ticks, a threshold condition for infection persistence was obtained. The dependence of the equilibrium infection prevalence on parameters was studied numerically; in particular, we considered how infection prevalence depends on host densities. This analysis reveals that a dilution effect occurs both for competent and for incompetent hosts. This means that, besides a lower threshold for host densities for infection to persists, there also exists an upper threshold: if host densities were higher than the upper threshold, the infection would go to extinction. Numerically, it was found that the upper threshold was not much higher than observed densities for realistic parameter values.     

COUNTERFACTUAL REASONING IN SURROGATE DECISION MAKING – ANOTHER LOOK

Incompetent patients need to have someone else make decisions on their behalf. According to the Substituted Judgment Standard the surrogate decision maker ought to make the decision that the patient would have made, had he or she been competent. Objections have been raised against this traditional construal of the standard on the grounds that it involves flawed counterfactual reasoning, and amendments have been suggested within the framework of possible worlds semantics. The paper shows that while this approach may circumvent the alleged problem, the way it has so far been elaborated reflects insufficient understanding of the moral underpinnings of the idea of substituted judgment. Proper recognition of these moral underpinnings has potentially far‐reaching implications for our normative assumptions about accuracy and objectivity in surrogate decision making.     

Haemoprotein formation in yeast

Summary Catalase A and T activities were investigated in two standard strains and three catalase regulatory cgr mutants of yeast in respiratory competent and incompetent states, which were under various degrees of glucose repression.The formation of catalase A was very sensitive to glucose repression and was characterized by a long delay in derepression. Deprivation of the energy source in respiratory incompetent cells prevented the derepression of catalase A. The lack of catalase A in respiratory incompetent cells can be overcome by growing the cells in raffinose or by the prolongation of the fermentative phase of derepression.Catalase T is under control of different regulatory systems probably common with some other haemoproteins.     

Medicolegal considerations in the initiation and termination of resuscitation in Canada.

Medicolegal issues in cardiopulmonary resuscitation (CPR) and emergency cardiac care were considered in the United States by the National Conference on Cardiopulmonary Resuscitation in 1985. This paper discusses these issues in the Canadian context. Although there is little legislation or case precedent in Canada to guide providers of CPR in decision-making, there appears to be little risk of liability or prosecution for competently rendered care. Providers should be cautious in withholding or withdrawing resuscitative measures from incompetent patients when brain death has not occurred and cardiovascular unresponsiveness has not been demonstrated. However, resuscitation may be withheld when a competent patient refuses it or if there is another medically and legally valid reason to do so.     

Seasonal population dynamics of ticks,and its influence on infection transmission: A semi-discrete approach

In this paper, a simple semi-discrete (ticks’ feeding is assumed to occur only during the summers of each year) model for tick population dynamics is presented. Conditions for existence, uniqueness, and stability of a positive equilibrium are found; the system is then studied numerically using parameter estimates calibrated for the tick Ixodes ricinus in Trentino, Italy, and the sensitivity to parameters is examined. Then, this model is extended to consider a tick-transmitted infection of one species of hosts, while other hosts are incompetent to the infection. Assuming, for simplicity, that the infection is not affecting the total number either of hosts or ticks, a threshold condition for infection persistence is obtained. The dependence of the equilibrium infection prevalence on parameters is studied numerically; in particular, we considered how infection prevalence depends on host densities. This analysis reveals that a ‘dilution effect’ occurs both for competent and for incompetent hosts; this means that, besides a lower threshold for host densities for infection to persist, there exists also an upper threshold: if host densities were higher than the upper threshold, the infection would go to extinction. Numerically, it is found that, for realistic parameter values, the upper threshold is not much higher than observed densities.     

Cell surface-located deoxyribonucleic acid receptors in transformable pneumococci.

We studied deoxyribonucleic acid (DNA) binding in transformable pneumococci. The relevant findings are as follows. (i) At least half of the DNA Molecules adsorbed to competent cells in the growth medium are attached to sites on the protoplast membrane. (ii) Most of the DNA bound to live competent cells in the presence of glucose is not released by moderate shear or by autolysin treatment. In contrast, most of the DNA adsorbed to competent cells in the absence of glucose is shear and autolysin sensitive. (iii) The presence of binding sites resembling in properties the sites in live competent cells can be demonstrated in wall-membrane complexes. Most of these sites are lost during preparation of cell walls and protoplasts. It is suggested that the DNA-binding site is a membrane component (protein?) Stabilized by polysaccharide (cell Wall) material. (IV) Mechanical or enzymatic damage to the cell wall or change in the ionic conditions can induce DNA binding (and surface-nuclease activity) in the incompetent pneumococci. However, such cells still show neither genetic transformation nor extensive nuclease-resistant binding of DNA. It is suggested that both competent and incompetent cells contain a large number of sequestered DNA-binding sites that can be unmasked by several experimental conditions. Induction of the competent state by the competence activator protein may involve an endogenous unmasking process.     

Bioethics for clinicians: 11. Euthanasia and assisted suicide

Euthanasia and assisted suicide involve taking deliberate action to end or assist in ending the life of another person on compassionate grounds. There is considerable disagreement about the acceptability of these acts and about whether they are ethically distinct from decisions to forgo life-sustaining treatment. Euthanasia and assisted suicide are punishable offences under Canadian criminal law, despite increasing public pressure for a more permissive policy. Some Canadian physicians would be willing to practise euthanasia and assisted suicide if these acts were legal. In practice, physicians must differentiate between respecting competent decisions to forgo treatment, providing appropriate palliative care, and acceeding to a request for euthanasia or assisted suicide. Physicians who believe that euthanasia and assisted suicide should be legally accepted in Canada should pursue their convictions only through legal and democratic means.