Best practice & research. Clinical anaesthesiology
-
The elderly are an expanding population of patients presenting for anaesthesia. The pharmacokinetics of anaesthetic agents in the elderly deserves special attention because the normal ageing process and the effect of age-related diseases affect organ systems in a heterogeneous way with unpredictable consequences. The pharmacokinetics of each drug is also affected by these changes in a specific way and, together with the pharmacodynamic consequences, makes drug use and drug dosing challenging in this population. Although a decrease in bolus and infusion rates is a common theme, only pharmacokinetic modelling of drug disposition in the elderly will provide accurate dosing guidelines and increase the margin of safety.
-
Best Pract Res Clin Anaesthesiol · Jun 2003
ReviewCognitive function after anaesthesia in the elderly.
Despite advances in peri operative care, a significant percentage of elderly patients experience transient post operative delirium and/or long-term post-operative cognitive dysfunction (POCD). This chapter reviews the aetiology, clinical features, preventive strategies and treatment of these syndromes. Pre-operative, intra-operative, and post-operative risk factors for delirium and POCD following cardiac and non-cardiac surgery are discussed. ⋯ Currently there is no single therapy that can be recommended for treating post-operative cognitive deterioration. Primary prevention of delirium and POCD is probably the most effective treatment strategy. Several large clinical trials show the effectiveness of multicomponent intervention protocols that are designed to target well-documented risk factors in order to reduce the incidence of post-operative delirium and, possibly, POCD in the elderly.
-
An overview is given of the influence of age on the pharmacodynamics of drugs used during general and locoregional anaesthesia. For some groups of agents a distinct separation into age-related changes in the pharmacokinetics and pharmacodynamics is possible, whereas for others the literature indicates only that responses in the elderly are enhanced. I start with an overview of the influence of age on cardiovascular and neuroendocrine function and include a short account of the state-of-the-art in pharmacodynamic modelling. ⋯ For opioids and local anaesthetics applied for blockade of the central nervous system, the pharmacodynamic involvement is not always clear. For neuromuscular blocking agents, pharmacodynamic involvement appears to be nearly absent in the reduced dose requirements seen with age--so that the latter appear to be caused by altered pharmacokinetics. Future studies, using pharmacokinetic-pharmacodynamic (PK-PD) mixed-effects modelling, should further explore this area to obtain clinically applicable data for improving our insight into the delivery of anaesthetics to the elderly and improving the quality of anaesthesia in this fast-growing population.
-
Best Pract Res Clin Anaesthesiol · Jun 2003
ReviewThe ethics of end-of-life decisions in the elderly: deliberations from the ECOPE study.
Is age a factor underlying clinical decision-making? Should age be a criterion in the allocation of health care resources? Is it correct to criticize this approach as 'ageism'? What role does 'paternalism' play? These questions are the focus of this chapter which takes an interdisciplinary perspective of clinical ethics in order to provide an ethical evaluation of the situation of the elderly in health care. First, the text of the chapter is based on the descriptive level referring to (a) clinical ethics consultation, (b) the ECOPE study on 'Ethical Conditions of Passive Euthanasia' focusing on decision-making, and studies about age as a factor in clinical decisions, such as the American SUPPORT study. Second, at the normative level, ethical deliberations are discussed for and against age as a criterion for allocating health care resources. Finally, it is suggested that the differences in evidence to be found about the role of age as a factor in clinical decision-making may be due to the different national health policies as well as to the insufficient awareness of ethical principles violated by covert 'ageist' attitudes.
-
Best Pract Res Clin Anaesthesiol · Jun 2003
ReviewCo-medications, pre-medication and common diseases in the elderly.
Typically, old patients scheduled to undergo a surgical procedure take many medications for various disorders. The anaesthetist must consider the benefits and/or risks of continuation or withdrawal of such chronic medications. This chapter reviews these issues in respect of cardiovascular drugs (calcium channel blockers, beta adrenoreceptor antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists) and of psychotropic and antiparkinson medications and insulin. Focus is put on the few scientific studies available and on the recommendations given by experts in the field.