People older than 65 typically have one or more chronic diseases [32]. These diseases may require specific pharmacologic therapy or even surgery and may limit physical activity. The prevalence of chronic diseases that limit activity in geriatric patients is shown in Fig. 1.4. Note that all diseases increase with age, but problems with vision, hearing, and senility become more prevalent by age 85. Arthritis is a very common ailment that can progress even with appropriate therapy. About 50% of people over age 65 have arthritis with women affected more than men.

Geriatric patients can suffer from a number of chronic cardiovascular diseases. For example, coronary artery disease is very prominent and is more common in men. Ischemic heart disease can lead to increased risk of perioperative myocardial infarction which has a high morbidity and mortality. Valvular disease is also prevalent in the elderly and tends to affect the aortic and mitral valves. These valves may either be stenosed or incompetent. Altogether, 96 per 1000 people have cardiovascular disease that significantly impacts their activity [32]. This number increases to approximately 204 per 1000 over the age of 85 years, with women and men being equally affected. The process of atherosclerosis also affects other blood vessels in the body jeopardizing the integrity of the vessels themselves and the organs they supply. For example, stroke is the leading cause of severe long-term disability and affects older Americans more frequently. About 75% of strokes afflict people over 65 years old, and the risk doubles every 10 years after age 55 [33]. A prominent risk factor for stroke is hypertension . Hypertension affects about half of the population over 65, and it is slightly more prevalent in women. It should be treated aggressively to prevent heart disease and stroke as well as contribute to a stable hemodynamic perioperative course.

Common metabolic diseases that affect the geriatric population are diabetes and osteoporosis. Diabetes type 2 afflicts a large majority of older people, but surprisingly its diagnosis does not increase with age. Thus, diabetes is likely a chronic disease that develops before age 65 [32]. Careful management of diabetes is important as it is a precursor to a number of other serious diseases, including ischemic heart disease and stroke. Osteoporosis makes bones more brittle and prone to fracture, and women are more likely to develop this disease than men. The bones most affected by osteoporosis are the spine, hip, and wrist. Osteoporosis can also lead to fractures that require surgery. In fact, hip fractures are common and can lead to serious morbidity and mortality. Older people who have a hip fracture are three to four times more likely to die in 3 months than those who do not suffer a hip fracture [34, 35].

Half of the people diagnosed with cancer are 65 or older [32, 36]. This is a result of the increased longevity of people as well as an increase in some cancers in the elderly. The major significance of cancer to the anesthesiologist is that many patients have operations designed to cure or palliate. Prostate and breast cancers now have 5-year survival of ≥90%. This is in stark contrast to lung cancer with the low survival rate of 16%. The results of surgical treatment of cancer are about the same as younger patients in many types of cancer with slightly higher complication rates seen in the geriatric population [36]. Thus, it is reasonable to expect that as the population ages, there will be more surgical oncologic procedures.

Finally, the aging brain presents several potential challenges. Cognitive impairment is a term that includes the loss of higher mental functions that we associate with being human. Chief among the functions is memory, but there are others like planning, thinking, and performing mathematical skills. All functions tend to deteriorate as we age and each represents a challenge to the geriatric anesthesiologist (see Chaps. 10 and 30). There are two classifications of cognitive impairment, mild cognitive impairment and dementia. Mild cognitive impairment is common but can progress to more incapacitating dementias like Alzheimer’s disease that has an incidence of about 23 per 1000 in people over the age of 70 [32]. All loss of cognitive function is frustrating and when severe is incapacitating to the individual and catastrophic to the family.

Sight and hearing loss are also associated with aging and can lead to loss of activity (Fig. 1.4). Hearing loss is greater in men and advances with age, but as women get older, they tend to equal men in hearing impairment [37]. Visual impairment occurs more frequently in women but advances in both genders. Depression is the major mood disorder of the aging population. It is more common in women than men: the rate of diagnosed depression in women and men over 65 is reported to be 16% and 11%, respectively [32]. This is a relatively high incidence in both genders, and depression needs to be recognized early since it is associated with mortality from many causes in addition to suicide.

The burgeoning elderly population has some very specific implications for anesthesiologists and surgeons . Anesthesia and surgical knowledge and skills have increased over time, and there is a greater willingness to operate on older patients than ever before. Additionally, an older population can have more conditions that are amenable to surgery. The older population has an estimated higher percentage of surgery (58%) than younger, and it is estimated that between 2000 and 2020, there will be an increase in surgery ranging from 14% to 47% depending on the particular surgical specialty [30] (Fig. 1.5). In 2010, approximately 13% of the US population was 65 years or older, yet of all the hospital procedures, 37% were in people greater than 65 years of age. In other words, a disproportionate share of surgical procedures was performed in the elderly. For example, over half of the procedures done involving the cardiovascular system are performed on patients ≥65 years old. The only systems that are not more common in the elderly are ENT and those performed on women for genital and reproductive system . The rate of surgery falls once patients reach 85 even though medical hospitalizations increase for this age subset [38, 39]. However, it is probable that surgery will increase in ≥85 years old as this age group increases in size, and surgeons expand candidacy for surgery.

Generally, morbidity, mortality, and recovery times for elderly patients undergoing surgery are greater than those for younger patients [36, 40–43]. Ambulatory surgery is increasing in the elderly population in part because older patients are better oriented in familiar surroundings. Two recent reviews summarize many of the issues of ambulatory surgery in the elderly [44, 45]. There is also data showing that unanticipated hospital admission after ambulatory surgery is increased in elderly patients [46]. The mortality for elderly (≥65) in 227 surgical high-risk operations is about twice that of younger patients (6% vs 3%) meaning that older patients are less able to withstand the stress of already high-risk surgery [47]. Thus, there is abundant data that shows risk is influenced by age, though thorough risk modeling finds that comorbidities and other factors are stronger predictors than age alone [48]. In addition, the distinction between normal and successful aging highlights one of the principal phenomena in gerontology: that there is tremendous variability in aging between individuals of a given species. Although it is extremely convenient to categorize and even stereotype patients by age, chronological age is a poor predictor of physiologic aging. It therefore should not be used alone to predict risk for surgical procedures.

Since age alone does not necessarily confer added risk because each individual is different and some remain healthy with physiologic reserve in place while others may be weakened during aging by disease or the response to the stresses of life, one theory that explains the individual variability with age is the concept of homeostasis and physiologic reserve. A homeostatic system is an open biologic system that maintains its structure and functions by means of a multiplicity of dynamic equilibriums rigorously controlled by interdependent regulatory mechanisms [49]. Such a system reacts to change through a series of modifications of equal size and opposite direction to those that created the disturbance. The goal of these modifications is to maintain the internal balances. The term homeostenosis has been used to describe the progressive constriction of homeostatic reserve capacity. Another common means of expressing this idea is that aging results in a progressive decrease in reserve capacity. Diminishing reserve capacity can be identified at a cellular, organ, system, or whole-body level. As an example, glomerular filtration rate (GFR ) progressively decreases with aging, limiting the capacity to deal with any stress on this excretory mechanism, be that a fluid load or excretion of medications or other toxic substances. Once again, the variability associated with aging is a key modifier of the decrease in physiologic function. So, although in general GFR decreases 1 mL/year, 30% of participants in a large study that defined this change had no change in GFR, whereas others showed much greater decrements [50]. The concept of reserve has also been used in describing cognitive function [51]. Taffet has expanded the general interpretation of the decrease in physiologic reserve to emphasize that the reserve capacity is not an otherwise invisible organ capacity but the available organ function that will be used to maximal capacity by the elderly to maintain homeostasis. When the demands exceed the capacity of the organ or organism to respond, pathology and higher risks ensue (Fig. 1.6). This is ever more likely as aging decreases the capacity of any system to respond. It is likely that the stresses of surgery tip the balance of homeostasis to increased risk in the elderly at least in part because of exhausted physiologic reserves.

Comprehensive evidenced-based perioperative care of the elderly patient is rapidly evolving but far from complete. The preoperative evaluation has become critical in the care of the geriatric patient (see Chap. 4). At minimum, the anesthesiologist should determine the functional status, distinguish age-related organ system changes from disease, attempt to assess reserve capacity, and identify potential gaps in necessary workup prior to surgery. The preoperative visit is also an ideal time to equip the patient and family with realistic expectations and goals for the post-procedural recovery period. Finally, it is also an opportune time to document any advance directive wishes and health-care proxies the patient has designated. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and the American Geriatrics Society (AGS ) have outlined a formal process for routine preoperative evaluation of elderly patients [52, 53] (see Table 1.1 [52]). Acquiring information may be challenging and may involve discussions with the patient, their immediate caregivers, other family members, and reference to multiple previous medical records. A comprehensive approach to caring for the geriatric surgical patient may also assign preoperative tasks to multiple providers including a geriatrician, anesthesiologist, or surgeon which can present unique challenges for coordination of care.

In 2009, McGory et al. published over 90 validated perioperative quality indicators for patients older than 75 years of age [54]. Five intraoperative indicators have been validated for the geriatric population and are listed in Table 1.2 In addition, many of the measures described were deemed to be specific to the geriatric population, as care for the elderly in the perioperative period may be very different from that of the non-elderly surgical population (Table 1.3). Identifying process measures, especially those specific to the growing geriatric population, can potentially assist in improving quality of care as well as containing costs.