Sudeep Gill, MD, FRCPC
Fellow, Division of Geriatric Medicine,
University of Toronto, Toronto, ON.

Barbara Liu, MD, FRCPC
Kunin-Lunenfeld Applied Research Unit,
Baycrest Centre for Geriatric Care,
Sunnybrook & Women's College Health Sciences Centre,
Assistant Professor of Medicine,
University of Toronto, Toronto, ON.

An adverse drug reaction (ADR) is defined as any noxious or unintended reaction to a drug that is administered in standard doses for the purpose of prophylaxis, diagnosis or treatment.¹ ADRs are common in the elderly--it is estimated that 10-17% of hospital admissions for older patients are directly related to ADRs. Furthermore, one in every 1,000 older inpatients dies as a result of complications of medication use. Many of these ADRs result from potentially inappropriate--and therefore avoidable--drug prescribing practices. In this article, we explore the following topics: pharmacokinetic changes that accompany aging; symptoms and signs that may lead to recognition of ADRs; risk factors that predispose to ADRs; and finally, an approach to appropriate drug prescribing in the elderly.

Drug Pharmacokinetics
Pharmacokinetics involves drug absorption, distribution, metabolism and excretion. With normal aging, there is no clinically significant decline in absorption.

D'Arcy Little, MD, CCFP
Director of Medical Education,
York Community Services, Toronto, ON.

Introduction
The nurses inform you that the elderly woman in Bed 140-B is agitated, and is complaining that a ghost-like man has been frightening her in her room at night. She is recovering from hip surgery that took place the day before yesterday. When you examine her in the morning, she is drowsy. Later that afternoon she is awake but has difficulty attending to your questions. You begin a work-up for postoperative delirium.

At one time or another, all physicians have faced the challenge of treating a delirious elderly patient in hospital. Delirium is a common, serious, yet potentially preventable cause of morbidity and mortality that primarily affects the elderly and is very common in the elderly post-surgical patient.^1-3 The condition is characterized by a disturbance of consciousness and a change in cognition that develops over a short period of time and tends to have a fluctuating course over the day. It is caused by the direct physiological consequences of a general medical condition (See Table 1).^2,4 The following article will review the epidemiology and etiology of delirium with a view to presenting an approach to the prevention of postoperative delirium in the elderly surgical patient.

When to Use a Pacemaker

Naushad Hirani, BSc, MD
Medical Writer,
Geriatrics & Aging.

For over four decades, permanent implantable pacemakers have been routinely used for the treatment of bradyarrhythmias. In that time, the sophistication, capabilities and potential usefulness of pacemakers for a wide variety of indications have grown tremendously. Most pacemaker recipients are elderly; it is estimated that, currently, more than 70% of pacemaker recipients are over the age of 70. The reasons for this preponderance include the changes in the conduction system associated with normal aging, as well as the increased prevalence of coronary artery disease and primary conduction system disease that is observed as age increases.

Approximately two billion beats are required from an average heart over a typical lifetime. Most of these are initiated in the sinus node. With increasing age, the "P" cells that are the main component of the sinus node are progressively replaced by collagen. In addition, the distal portions of the conduction system, the His bundle and the bundle branches show an age-related loss in conducting cells without a concomitant increase in collagen.

Diagnosis and Management of Acute Coronary Syndromes

Nariman Malik, BSc, MD
Medical Writer,
Geriatrics & Aging

Coronary heart disease (CHD) is one of the leading causes of death in individuals over the age of 65¹ and, through a variety of syndromes, is responsible for symptomatic and asymptomatic functional abnormalities. The prevalence of cardiovascular disease increases with age and is a major cause of death and disability in the elderly population.² CHD is the most prevalent cardiac illness in this population: it accounts for 85% of all deaths due to heart disease in persons over the age of 65.³ By age 70, 15% of men and 9% of women have coronary artery disease (CAD) and are at an increased risk of suffering an acute coronary syndrome (ACS).⁴ By age 80, the severity of lesions becomes nearly equal for men and women.⁴ An estimated 40% of all individuals over the age of 80 have symptomatic cardiac disease.²

Despite advances in cardiology, CHD is still the leading cause of death in older individuals, especially those aged over 75.¹ Nevertheless, there is wide variation in the severity of coronary illness and in the functional status of elderly patients.

Pamala D. Larsen, PhD, CRRN
Associate Dean for Academic Affairs,
College of Nursing and Health Professions,
The University of North Carolina at Charlotte, NC, USA.

Although the elderly compose a significant percentage of the surgical patient population, postoperative pain management for this population has received little attention.¹ According to 1990 data, more than 4,000 documents are published annually about pain, but fewer than 1% focus on pain in the older adult.² Lack of published information and research about geriatric pain results in most patients' pain being managed by trial and error.

Considerable evidence suggests that pain is undertreated in older patients. This may be due in part to the misconception that pain sensation diminishes with increasing age or that the elderly patient cannot tolerate narcotic analgesia.³ The perception that older adults have less pain sensitivity than do younger patients is influenced somewhat by the silent myocardial infarctions and emergent 'painless' intra-abdominal surgical events that frequently occur in older adults.⁴ The research involving pain perception in the elderly client provides mixed results. These conflicting results make it difficult to fully establish the relationship or connection between aging and the sensory pain component.

Shabbir M.H. Alibhai, MD, MSc, FRCP(C)
Staff Physician, University Health Network,
Instructor, University of Toronto,
Toronto, ON.

The last few decades have seen major advances in the surgical management of numerous illnesses. As the proportion of the elderly in the general population continues to increase, the prevalence of many chronic conditions also increases. Given the number of available surgical therapeutic options to cure or palliate these chronic conditions, more and more elderly patients are undergoing surgery. Conventional wisdom suggests that, compared to younger or middle-aged patients, older individuals have a higher risk of perioperative and postoperative complications, including death. This increased risk has been attributed to aging itself. This article will examine this relationship in greater detail.

Dozens of studies have suggested that advanced age leads to an increased risk of experiencing surgical complications. This includes an increased risk of postoperative complications such as deep venous thrombosis, infections (including wound, urinary tract, and lung), delirium and mortality.¹ In preoperative assessment clinics, internists and anesthetists utilize risk indices or algorithms to determine an individual patient's surgical risk and potentially modifiable risk factors.

Stanley Muravchick, MD, PhD
Professor of Anesthesia and Vice
Chair for Clinical Affairs,
Hospital of the University of Pennsylvania,
Philadelphia, PA, USA.

Introduction
Recent advances in our understanding of the perioperative implications of aging have been due in large part to the establishment of clear distinctions between processes of aging and age-related disease. The implications of disease are clear to physicians caring for surgical patients of any age. However, many gerontologists consider increased susceptibility to stress- and disease-induced organ system decompensation to be a defining characteristic of geriatric medicine.¹ Even for healthy and fit older surgical patients, maximal levels of organ function decline rapidly. In fact, the difference between maximal and basal function provides the concept of functional reserve. Therefore, normal aging typically produces a progressive loss of the organ-system functional reserve (Figure 1) that provides the "safety margin" available for the additional demands for cardiac output, carbon dioxide excretion, or protein synthesis imposed upon the patient by trauma, disease, surgery and convalescence.

Jonathan B. Shammash, MD
Assistant Professor of Medicine,
Director of General Medical Consultation Service,
Department of Medicine,
Weill Medical College of Cornell University,
New York, NY, USA.

Julie M. Gold, BA
Weill Medical College of Cornell University,
New York, NY, USA.

Overview
Cardiovascular complications are the leading cause of morbidity and mortality in patients undergoing major noncardiac surgeries. It is estimated that 20-40% of patients at risk for cardiac events will experience perioperative cardiac ischemia, conferring a nine-fold increase in risk of perioperative cardiac death, myocardial infarction or unstable angina. This is a serious concern in North America. In the United States, about 1.5 of the 30 million patients undergoing noncardiac surgery each year will experience cardiovascular morbidity.¹ Since many of these patients have identifiable risk factors for cardiac ischemia, research efforts have been channeled toward finding modifiable risk factors and introducing pharmacological interventions that may offer cardiovascular protection during the perioperative period. Several small clinical trials have examined the perioperative use of nitrates² and calcium channel blockers,³ but these did not show a significant reduction in the incidence of cardiac ischemic events.

M. Clare Robertson, PhD
Research fellow,
Department of Medical and Surgical Sciences,
University of Otago Medical School,
Dunedin, NZ.

A. John Campbell, MD, FRACP
Professor of Geriatric Medicine,
Department of Medical and Surgical Sciences,
Dean, Faculty of Medicine,
Dunedin, NZ.

Introduction
Falls are a common problem in older people and substantial healthcare resources are required for the treatment of injuries, for rehabilitation and for long-term care after a fall. For the older person and their family or caregivers, a fall can have serious consequences: trauma, pain, impaired function, loss of confidence in carrying out daily activities, loss of independence and autonomy, or even death.

Falls prevention strategies have been based on the multiple risk factors for falls and these are well defined in the literature.¹ There is now good evidence from randomized controlled trials that carefully designed, single or multiple interventions can reduce falls in older people living in the community.² There are fewer reports on the cost effectiveness of these strategies--useful information for making informed decisions on the allocation of scarce healthcare resources.

Figure 1 gives a list of the falls prevention strategies for community living older people that have been tested in randomized, controlled trials.

Laurie G. Jacobs, MD
Head, Unified Division of Geriatrics,
Albert Einstein College of Medicine & Montefiore Medical Center,
Bronx, NY, USA.

Introduction
Increasingly, older adults are undergoing invasive procedures and surgery. Surgery in the elderly has been associated with a greater morbidity and mortality than in younger patients due to the physiologic changes of aging, concurrent medical conditions and an increased rate of emergency procedures. Age alone is often a determining factor in whether a procedure or surgery should even be undertaken. Preoperative evaluation and perioperative care of the elderly patient requires evaluating the risk of complications, maximizing functional and physiologic parameters, instituting preventative measures, and focused management to assess potential risk and benefit for an individual patient.

Surgical Stress and Operative Risk
Noncardiac surgery in adults is associated with an incidence of postoperative myocardial infarction of 1-2%. Those with known heart disease, advanced age and serious comorbid conditions have a significantly greater risk for MI and other serious complications. Cardiovascular complications represent 50% of the causes of postoperative morbidity and mortality. In older adults, pulmonary, renal, infectious and cognitive adverse events are also extremely common.