The Prevention of Postoperative Delirium

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.

Management of Postoperative Pain in the Elderly Client

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.

Does the Risk of Surgery Increase with Age

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.

Gero-Anesthesia: Principles of Perioperative Care for the Elderly Surgical Patient

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.

The Fundamental Importance of Perioperative Care

Proportionately, the elderly are the major consumers of health care in our society. Surgery is similar to all other areas of medicine, in that the operating room lists are becoming dominated by senior citizens. Many of the high volume surgical procedures (most cancers, prostate resection, joint replacement, and coronary artery surgery) are performed predominantly on the elderly. A few years ago, an article was published in the Lancet about colon resection in octogenarians. By using minimally invasive surgery, nerve blocks to decrease narcotic use, and promoting early activity and feeding, the authors were able to discharge these patients on the third postoperative day. The message is simple. Even though new surgical techniques are crucial in decreasing morbidity, we lose much of their benefit if we do not modify our perioperative medical management.

Some of the most important interventions are relatively straight forward, and although most commonly required in the elderly, are similar at any age. These include anticoagulation for high-risk joint replacement and beta-blockers for those with coronary artery disease. Dr. Geerts and Dr. Shammash, respectively, discuss these topics in articles in this issue.

Postoperative pain relief is a major issue in the elderly, particularly in those who are frail or have pre-existing cognitive impairment. Pain must be relieved, but the health care team has to be vigilant in anticipating and preventing complications. Pam Larsen addresses these issues in her article.

Laurie Jacobs addresses the issue of perioperative evaluation and management, particularly when to start medications and, in his article, Dr. Muravchick reminds us about the intraoperative management of older patients.

In my practice, the most vexing perioperative problem is that of delirium. This is particularly a problem in elderly patients with fractured hips. Not only is it difficult to identify the contributing factors, the management requires much attention to behavioural issues--an area requiring special expertise. Even more problematic, some delirious patients never seem to regain their baseline cognitive function, no matter how careful the management of their acute confusional state. Dr. Little, a regular contributor, reviews the information on how to prevent postoperative delirium.

Our senior editor, Shabbir Alibhai, a noted expert in the field of cancer and aging, reviews the evidence concerning surgical risk and aging. You might be surprised by his conclusions, and you will certainly be impressed by his knowledge in the field.

As usual we have a large number of other articles on areas of interest in the elderly. There is an article by Sudeep Gill and Barbara Liu on avoiding dangerous prescribing habits in the elderly. I suspect that improved prescribing (avoiding both errors of omission and commission) is the single most important thing we can do to improve health care of the elderly.

Also included is the second part of our series on the treatment of cardiovascular disease in nursing homes--the remaining articles focus on acute coronary syndromes and pacemakers in the elderly. There are also articles on falls prevention strategies (Clare Robertson) and living wills in long-term care (Michael Gordon).

Enjoy this issue.

Perioperative Use of Beta-Blockers

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.

Perioperative Evaluation and Management in the Elderly

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.