Geriatrics and Anesthesia Practice PDF

54 Geriatrics and Anesthesia Practice SANDRA K. BORDI The number of people in the world who are 65 years and older has operative risk and overall physical status in relationship to type of increased by 300% over the last 50 years. It is projected that the United surgery and organ s...

54 Geriatrics and Anesthesia Practice SANDRA K. BORDI The number of people in the world who are 65 years and older has operative risk and overall physical status in relationship to type of increased by 300% over the last 50 years. It is projected that the United surgery and organ specific indices (i.e., cardiac, neurocognitive).3,4 Risk States will have approximately 73 million people aged 65 years and assessment and stratification is also important to assist in determining older by 2030 and 83 million by 2050, almost double its estimated a multidisciplinary team approach to perioperative management. population in 2012. By 2050 the surviving baby boomers will be the Moreover, patients and health care providers use this information as oldest old (85 years and older), which is estimated to triple in number part of their surgical and anesthesia informed consent. Depending on and place the United States as the largest population of oldest old the risk(s) deemed, a different surgical and/or anesthetic approach may among the developed countries. For the first time in history the number be necessary, or surgery may not be performed at all. Therefore identify- of individuals 60 years of age and older will exceed the number of ing perioperative risk is part of the preoperative assessment and is younger adults. During this time the population of older adults will preferably performed prior to the day of surgery. become more racially and ethnically diverse; the number of African In order to provide high quality care for the older adult surgical Americans over the age 65 years will double, and the number of Asian patient, a comprehensive and thorough preoperative evaluation is Americans and Hispanic Americans will triple.1 The aging population essential. The American College of Surgeons National Surgical Quality will also affect hospital utilization, surgical services and health care Improvement Program (ACS NSQIP) and the American Geriatrics costs. The National Hospital Discharge Survey reported that those over Society (AGS) developed Best Practice Guidelines for Optimal Preop- 65 years of age have higher rates of inpatient and outpatient surgical erative Assessment for the elderly surgical patient.5 Based on these and nonsurgical procedures as compared to other age groups, with the guidelines, in addition to conducting a complete and thorough history oldest old having significantly higher rates of hospitalization as com- and physical examination, there are specific assessment categories that pared to adults 84 years and younger.2 It is inevitable that surgical are highly recommended to provide guidance for perioperative manage- services and hospitalizations for older adults will increase as its popula- ment of this complex patient population (Table 54.1). These specific tion increases. Therefore the increased aging of the United States, and assessment categories will be discussed within the age-related physio- its diversity, will have significant implications for anesthesia practitio- logic body system changes of this chapter. ners and their approach to the anesthetic management of the geriatric patient. Age-Related Physiologic Changes in the Older Adult Definitions of aging are often subjective and place an arbitrary Aging is a time-related occurrence during the life cycle of an organism. marker on chronologic age; however, this section will operationally It can be defined as a time-dependent biologic continuum that begins define “older adults” or “elderly” as persons 65 years or older. Although with birth and persists with gradual impairments of organ subsystems, aging is not routinely associated with surgical risk, the challenges and ultimately causes an organism to become more susceptible to illness related to anatomic and physiologic changes that occur with aging and death. By the age of 30 years, most age-related physiologic func- impact every aspect of the perioperative course. tions in humans have peaked and gradually decline thereafter. Aging is The intent of this chapter is to provide a targeted review of the not synonymous with poor physiologic function. Because chronologic anatomic and physiologic changes that occur with aging and identify age (age in years since birth), which is often used in clinical practice, how these changes affect anesthesia. In addition, this information and biologic age (functional status) differ, chronologic age alone is no might offer the practitioner additional evidence to be considered in longer a reliable indicator of morbidity or of mortality. The degree of their current practice, thus providing a foundation for modifying the functional status that remains with increasing age varies. For example, current options to improve perioperative outcomes if required. a 75-year-old patient who bicycles 3 miles every day, has no evidence of coexisting diseases, and lives a healthy lifestyle is considered “physi- Preoperative Assessment ologically young.” Whereas a 75-year-old patient who is sedentary, has Preoperative evaluation is thoroughly discussed in Chapter 20; however, a history of hypertension and diabetes mellitus, and is a chronic smoker the preoperative assessment of the older adult warrants some special may be deemed as “physiologically old.” In addition, changes in organ considerations. Because the elderly population is growing significantly, function manifest as decreased margins of reserve. Aging patients may as are those who undergo surgical procedures, the identification and be able to maintain homeostasis, but become increasingly less able to avoidance of untoward complications is critical. tolerate changes or restore homeostasis when exposed to surgical stress, The older adult is prone to progressive decline of baseline functions, trauma, or diseases. age-related comorbid disease(s), and an increase in American Society of Anesthesiologists (ASA) physical status classification; these place Cardiovascular System older adults at greater risk for perioperative complications that are Age-related changes in the cardiovascular system involve structural and directly related to negative outcomes, including morbidity and mortal- functional changes in the heart, vessels, and autonomic nervous system. ity in the postoperative period and increased hospital cost. Most post- In the older adult, the heart and vascular system is less compliant, operative complications in the elderly are cardiac, pulmonary, and leading to a faster propagation of the pulse pressure waveform, increase neurologic complications.3,4 Factors that influence perioperative out- in afterload, and an increase in systolic blood pressure, leading to ven- comes in older adults include emergency surgery, the number of comor- tricular thickening (hypertrophy) and prolonged ejection times. The bidities, and the type of surgical procedure. There is an array of risk combination of ventricular hypertrophy and slower myocardial relax- assessment tools used in the clinical setting. These vary from assessing ation often results in late diastolic filling and diastolic dysfunction. 1136  CH A PTER 54 Geriatrics and Anesthesia Practice 1137 TAB LE 54. 1 Hypertension is a risk factor for perioperative complications, with the risk doubling for every 20-mm Hg systolic/10-mm Hg diastolic ACS NSQIP/ AGS Assessment Categories increase in blood pressure. With aging the pulse pressure widens because of a greater proportionate increase in systolic blood pressure Assessment Category Screening Tool compared with diastolic blood pressure. Decreased vein compliance can Cognitive Ability Capacity Mini-Cog 3 Item Recall and clock draw lead to decreased venous return and reduced atrial filling. Likewise, Decision Making Capacity Legally relevant criterion: there is decreased sensitivity of baroreceptors in the aortic arch and 1. Understanding carotid sinuses in response to blood pressure changes, which results in 2. Appreciation increased episodes of hypotension. Age-related changes in the cardio- 3. Reasoning vascular system of the older adult also include changes in the heart’s 4. Choice regulation of calcium, which causes the myocardium to generate force Depression Patient Health Questionnaire-2 (PHQ-2) over a longer period after excitation, and prolongs the systolic phase of Risk for postoperative delirium Review: the cardiac cycle.6 Cognitive and Behavioral Disorders The myocardium in the older adult has decreased sensitivity to Coexisting diseases/illnesses β-adrenergic modulation, physiologically evident as decreased heart Metabolic disturbances rate and lower cardiac dilation at the end of diastole and systole. In Functional impairments general, older adults may have higher blood pressures caused by Other: polypharmacy, history of UTI, constipation increased peripheral vascular resistance, decreased arterial elasticity, and or presence of Foley catheter cardiac workload; likewise, older adults may have decreased cardiac Alcohol and Substance abuse Modified CAGE output and stroke volume because of decreased conduction velocity and Cardiac ACC/AHA algorithm for patients undergoing reduction in venous blood flow. Age-related cardiovascular changes and noncardiac surgery; METs their anesthetic implications are noted in Table 54.2. The combined Pulmonary Review: effect of decreased cardiac reserve and decreased maximum heart rate Patient related risk factors adversely affects the compensatory mechanisms of the older adult under Surgical procedure risk factors the stress of anesthesia and surgery. Frailty Slowness The elderly are significantly more vulnerable to adverse periopera- Weight loss Grip weakness tive cardiac events. Myocardial infarction is the most common cardiac Exhaustion complication and the leading cause of death in the postoperative Decrease in physical activity period. Therefore a complete cardiac assessment of the cardiovascular Functional Status Proxy report system in the older adult undergoing noncardiac surgery is essential TUGT and should be based on guidelines according to the American College Nutritional Status BMI of Cardiology/American Heart Association (ACC/AHA) as discussed Serum Albumin in Chapter 20. Other risk stratification tools that are highly recom- Unintentional weight loss mended in the older adult by the ACS NSQIP/AGS include measuring Medications Review prescribed, herbal and OTC the patient’s functional capacity via metabolic equivalents (METs) and Beers Criteria addressed the perioperative cardiac risk calculator, an interactive web-based tool, Patient Counseling Perioperative goals which replaces the Revised Cardiac Risk Index. The interactive periop- Assistance needs erative cardiac risk calculator quantifies risk according to the type of Advanced Directives surgical procedure, functional status, creatinine level, ASA classifica- DNR status tion, and age.7,8 It provides a probability for perioperative cardiac events Social support (i.e., myocardial infarction, cardiac arrest), which can assist in guiding perioperative management and informed consent. ACC/AHA, American College of Cardiology/American Heart Association; BMI, Body Mass The most frequently associated cardiovascular coexisting diseases in Index; DNR, do-not-resuscitate; METs, Metabolic Equivalent of Tasks; OTC, over the counter; TUGT, The Timed Up and Go Test; UTI, urinary tract infection. the older adult are hypertension, hyperlipidemia, coronary artery disease (ischemic heart disease), and congestive heart disease (heart From Optimal Perioperative Management of the Geriatric Patient: Best Practices Guideline from ACS NSQIP® /American Geriatrics Society. American Colleges of Surgeons Website. failure) (Fig. 54.1). Accessed 2016 at https://www.facs.org/quality-programs/acs-nsqip/geriatric-periop -guideline. Respiratory System There are various age-related alterations of the respiratory system that have an impact on oxygenation in the elderly patient. Older patients When these changes occur, atrial contraction becomes important in the develop calcifications of the chest wall, intervertebral joints, and inter- maintenance of adequate ventricular filling. Even though the elderly costal joints. These factors, along with decreased intercostal muscle have higher amounts of circulating catecholamines, they exhibit mass, contributes to a decrease in chest wall compliance. In addition, decreased end-organ adrenergic responsiveness. Therefore the older there is a flattening of the diaphragm, a loss of intervertebral disc adult has a reduced capacity to increase heart rate in response to hypo- height, and changes in spinal lordosis, which may further diminish tension, hypovolemia, and hypoxia. Prolonged circulation time causes chest wall compliance. Changes also occur with the lung parenchyma. a faster induction time with inhalation agents but delays the onset of There is a generalized loss of elastic tissue recoil of the lung. Conse- intravenous drugs. There is calcification of the conducting system with quently there is reduced functional alveolar surface area available for loss of sinoatrial node cells, which predisposes the elderly to atrial gas exchange. In elderly patients, even in the absence of disease, an fibrillation, sick sinus syndrome, first- and second-degree heart blocks, increase in lung compliance impairs the matching of ventilation and and arrhythmias. Hence a higher proportion of this population may perfusion, increases physiologic shunt, and results in the reduction of have, or require permanent pacemakers and/or automatic internal defi- oxygen exchange at the alveolar level. Because lung elastic recoil is brillators. Calcification is not limited to the conducting system, but necessary for maintaining small airway caliber, an increased lung com- may be present in the valves (primarily aortic and mitral), predisposing pliance causes small airway diameter to narrow, and eventually increases elderly patients to valvular stenosis or regurgitation. the closing volume (i.e., lung volume at which small airways in the 1138 UNI T V Intraoperative Management T ABL E 54.2 Age-Related Cardiovascular Changes and Anesthetic Implications Age-Related Change Mechanism Consequences Anesthetic Implications Myocardial hypertrophy Apoptotic cells are not replaced and Increased ventricular stiffness; prolonged Failure to maintain preload leads to an exaggerated there is compensatory hypertrophy contraction; and delayed relaxation decrease in CO; excessive volume more easily of existing cells; reflected waves increases filling pressures to congestive failure during late systole create strain on levels; dependence on sinus rhythm and myocardium leading to hypertrophy low-normal HR Myocardial stiffening Increased interstitial fibrosis; amyloid Ventricular filling dependent on atrial — deposition pressure Reduced LV relaxation Impaired calcium homeostasis; reduced Diastolic dysfunction — β-receptor responsiveness; early reflected wave Reduced β-receptor Diminished coupling of β-receptor to Increased circulating catecholamines; Hypotension from anesthetic blunting of responsiveness intracellular adenylate cyclase limited increase in HR and contractility sympathetic tone; altered reactivity to activity; decreased density of in response to endogenous and vasoactive drugs; increased dependence on β-receptors exogenous catecholamines; impaired Frank-Starling mechanism to maintain CO; labile baroreflex control of BP BP, more hypotension Conduction system Apoptosis; fibrosis; fatty infiltration; Conduction block; sick sinus syndrome; Severe bradycardia with potent opioids; decreased abnormalities and calcification of pacemaker and AF; decreased contribution of atrial CO from decrease in end-diastolic volume His-bundle cells contraction to diastolic volume Stiff arteries Loss of elastin; increased collagen; Systolic hypertension Labile BP; diastolic dysfunction; sensitive to volume glycosylation cross-linking of Arrival of reflected pressure wave during status collagen end-ejection leads to myocardial hypertrophy and impaired diastolic relaxation Stiff veins Loss of elastin; increased collagen; Decreased buffering of changes in blood Changes in blood volume cause exaggerated glycosylation cross-linking of volume impairs ability to maintain changes in cardiac filling collagen atrial pressure BP, Blood pressure; CO, cardiac output; HR, heart rate; LV, left ventricular; AF, atrial fibrillation From Sanders D, et al. Diastolic dysfunction, cardiovascular aging, and the anesthesiologist. Anesthesiol Clin. 2009;27(3):497–517. Stroke 4% Asthma 5% Osteoporosis 7% Atrial fibrillation 8% Cancer 8% Alzheimer disease 11% COPD 12% Depression 14% Chronic kidney disease 15% Heart failure 16% Diabetes 28% Arthritis 29% Ischemic heart disease 31% High cholesterol 45% High blood pressure 58% FIGURE 54.1 Percentage of Medicare fee-for-service beneficiaries with 15 selected chronic conditions: 2010. COPD, Chronic obstructive pulmonary disease. (In Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. Vol. 1. 25th ed. Philadelphia, PA: Elsevier; 2016:100–121. From Centers for Medicare and Medicaid Services: Chronic conditions among Medicare beneficiaries, Chartbook: 2012 edition. Based on 2010 Centers for Medicare and Medicaid Services administra- tion claims data for 100% of Medicare beneficiaries enrolled in the fee-for-service program.) dependent parts of the lung begin to close). The closing volume exceeds because of its correlation with height. There is also a decrease in forced functional residual capacity (FRC) at approximately 65 years of age in expiratory maneuvers. The forced vital capacity (FVC) and the forced the erect position and at age 45 years in the supine position (Fig. 54.2). expiratory volume in 1 second (FEV1) are both decreased as a result of Other dynamic and static lung volume changes include a decrease in the loss of lung elastic recoil, decrease in small airway diameter, and vital capacity, an increase in residual volume, and an increase in FRC subsequent airway collapse with forced expiration (Fig. 54.3). Overall with decreases in inspiratory reserve volume and expiratory reserve the elderly have impaired efficiency of gas exchange. Impaired oxygen- volume. Total lung capacity remains unchanged or may slightly decrease ation is reflected by a decline in resting arterial oxygen tension (PaO2),  CH A PTER 54 Geriatrics and Anesthesia Practice 1139 which remains somewhat stable at approximately 83 mm Hg, after 75 which increases the risk for pulmonary aspiration. Age-related pulmo- years of age. This decline in PaO2 is attributed to the premature closing nary changes and their anesthetic implications are noted in Table 54.3. of small airways and the reduction in the alveolar surface area.9 Similar to other organ systems, pulmonary changes in the elderly The regulation of breathing is also affected with aging. The central are extremely variable among individuals. Regardless of these variations, (medulla) and peripheral (carotid and aortic bodies) chemoreceptors an in-depth assessment of the respiratory system and identification of affect ventilation with changes in pH, PaO2, and partial pressure of CO2 coexisting diseases that affect the pulmonary system is important in in arterial blood (PaCO2). In the elderly, the ventilatory response to order to optimize preoperative respiratory function. hypoxemia and hypercarbia is decreased, predisposing them to increased episodes of apnea. Another challenge associated with oxygenation is the progressive decrease in laryngeal and pharyngeal support that accom- panies aging, which can result in airway obstruction. In addition, protective airway reflexes (i.e., coughing and swallowing) are decreased, FRC upright 3 FRC supine Lung volume (litres) 2 y acit ng cap Closi 1 FIGURE 54.3 Schematic representation of lung volume changes associated 0 with aging. Note that with senescence, there is a decrease in the inspiratory 30 40 50 60 70 reserve volume (IRV’), the expiratory reserve volume (ERV’), and the vital Age (years) capacity (VC’). There is a corresponding increase in residual volume (RV’) FIGURE 54.2 Functional residual capacity (FRC) and closing capacity as a and functional residual capacity (FRC’) such that the total lung capacity function of age. (In Lumb AB. Nunn’s Applied Respiratory Physiology. 8th ed. remains approximately the same. TV’, Tidal volume. (In Maguire SL, Slater Philadelphia, PA: Elsevier; 2017:29. Data from Leblanc P, et al. Effects of age BMJ. Physiology of aging. Anaesthesia & Int Care Med. 2010;11(7):290–292. and body position on ‘airway closure’ in man. J Appl Physiol. 1970;28: From Chan ED, Welsh CH. Geriatric respiratory medicine. Chest 1998; 448–453.) 114(6):1704–1733.) TAB LE 54. 3 Age-Related Pulmonary Changes and Anesthetic Considerations Structural Changes Consequences Anesthetic Considerations Chest wall Impaired gas exchange Risk for respiratory failure Stiff/decreased compliance Increased WOB Careful use of NDMRs, opioids, and benzodiazepines Flattened diaphragm Lung parenchyma Impaired gas exchange Risk for respiratory failure Increased lung compliance Increased V̇ /Q̇ mismatch Avoid high pressure/large TV Increased small airway closure Increased anatomic dead space Consider alveolar recruitment maneuvers (PEEP) Decreased alveolar surface area Limit high inspired O2 Decreased PCBF Maintain PaCO2 near normal preoperative value Decreased PaO2 Consider regional/local with sedation Muscle strength Risk for respiratory failure Risk for aspiration Decreased Increased WOB Adequate hydration Decreased protective airway reflexes Consider RSI with GA Ensure fully reversed prior to extubation Consider postoperative CPAP or BiPAP Vigilant monitoring Encourage cough/deep breathing postoperatively Control of breathing Risk for respiratory failure Decreased central/peripheral chemoreceptor sensitivity Increased hypoventilation Consider postoperative CPAP or BiPAP Increased apnea Vigilant monitoring Decreased ventilator responses Encourage cough/deep breathing postoperatively Supplemental oxygen postoperatively BiPAP, Bilevel positive airway pressure; CPAP, continuous positive airway pressure; GA, general anesthesia; NDMRs, nondepolarizing muscle relaxants; Pao2, resting arterial oxygen tension; Paco2, partial pressure of CO2 in arterial blood; PCBP, pulmonary capillary blood flow; PEEP, positive end-expiratory pressure; RSI, rapid sequence induction; TV, tidal volume; V̇ /Q̇ , ventilation- perfusion; WOB, work of breathing. 1140 UNI T V Intraoperative Management Age alone and prevalence of co-existing pulmonary diseases, (i.e., and to the excretion of drugs and their metabolites, it is essential that chronic obstructive pulmonary disease [COPD] and asthma) increases great consideration is given to the renal function of the aged patient. the risk for postoperative pulmonary complications (PPCs) in the older The decrease in GFR and impairment of the diluting segment of the adult. PPCs include atelectasis, bronchospasm, exacerbation of an nephron can easily predispose the patient to fluid overload if overzeal- underlying chronic lung disease, pneumonia, prolonged mechanical ous intravenous fluid is administered. The production of renin and ventilation, and postoperative respiratory failure.10 Therefore preopera- aldosterone is decreased with age, causing impairment of sodium con- tively assessing the elderly for their risk of developing PPCs is strongly servation. Sodium conservation and hydrogen ion excretion are recommended by the ACS NSQIP/AGS. Additional risk factors for decreased, resulting in an impaired ability of the kidneys to respond to PPCs include patient-related and surgical-related factors (Box 54.1). changes in electrolyte concentrations, intravascular volume, and free Of the modifiable risk factors, strategies should be implemented to water.11 The kidneys do not respond to nonrenal loss of water and minimize risks and prevent PPCs. For example, smoking cessation at sodium, and as a result dehydration can commonly occur. The serum least 8 weeks prior to surgery, implementing inspiratory muscle training creatinine is often unchanged if there is no renal failure because of and lung expansion maneuvers via incentive spirometry, and medically decreased creatinine production from the overall declining skeletal optimizing patients with COPD and/or asthma. muscle mass associated with aging. Creatinine clearance is the best indicator of drug clearance. The Cockroft–Gault equation is a common Renal Function formula for estimating creatinine clearance, which in turn estimates Age-related changes in renal function are particularly significant because GFR (eGFR) in the healthy older adult.12 of the many roles of the kidneys. Older adults have a significant baseline decrement in renal function relative to their younger counterparts. (140 − age in yrs) × (weight in kg) eGFR (mL/min) = Changes in renal function in the older patient are characterized by a 72 × (serum creatinine in mg/dL) progressive atrophy of kidney parenchymal tissues, deterioration of (× 0.85 for female patients) renal vascular structures, decreased renal blood flow, and an overall decrease in renal mass. The cumulative effect is a decrease in the glo- When this formula is applied to the critically ill or to patients taking merular filtration rate (GFR) resulting in decreased renal drug clearance medications that directly affect renal function, caution must be and decreased renal blood flow from age 20 years to age 90 years employed as it overestimates creatinine clearance. Therefore older (approximately a 25%–50% decline). The combined effect is particu- patients with renal impairment may be at increased risk for (1) fluid larly apparent with diminished renal clearance of hydrophilic agents overload; (2) accumulation of metabolites and drugs that are excreted and hydrophilic metabolites of lipophilic agents. by the kidneys; (3) decreased drug elimination, which can prolong the Because of the vital role that the kidneys play in the maintenance effects of a wide range of anesthetic drugs and adjuncts; and (4) elec- of fluid and electrolyte balance, their contribution to acid-base balance, trolyte imbalances, which can lead to arrhythmias by affecting cardiac conduction.11,12 In addition, overhydration in a compromised heart with marginal reserves must be cautiously avoided because the physi- ologic changes in the kidneys of older adults decrease the ability to BOX 54.1 excrete a large-volume load.11 Risk Factors for Postoperative Pulmonary The elderly are at higher risk for chronic kidney disease (CKD) Complications because of the aforementioned physiologic and functional kidney changes, the prevalence of co-existing diseases that are associated with Patient-Related Factors CKD (i.e., COPD, hypertension, vascular disease) and with coinciding Age greater than 60 years frailty, complex medical regimens, and polypharmacy. All, or a combi- Chronic obstructive pulmonary disease nation thereof, may induce CKD in the presence of marginal renal ASA class II or greater function in the elderly patient. Therefore the preoperative evaluation Functional dependence is focused on current renal function as this will be variable among Congestive heart failure individuals, and preventing acute kidney injury perioperatively. Obstructive sleep apnea Pulmonary hypertension Hepatic Function Current cigarette use The aging adult liver decreases in mass by approximately 20% to 40 % Impaired sensorium and may be attributed to the decrease in its blood flow. Age related Preoperative sepsis functional hepatic changes primarily affect drug metabolism and Weight loss greater than 10% in 6 months protein binding. The age-related physiologic changes in hepatic func- Serum albumin level less than 3.5 mg/dL Blood urea nitrogen level greater than or equal to 7.5 mmol/L (≥ 21 mg/dL) tion may cause decreased metabolism, prolonged half-life, and either Serum creatinine level greater than 133 mol/L (> 1.5 mg/dL) increased or decreased distribution of medications. Generally, hepatic functioning is well preserved in the healthy older adult; it is the com- Surgery-Related Factors bination of coexisting diseases (i.e., hepatitis, drug-induced liver injury, Prolonged operation (> 3 hours) cirrhosis) and lifestyle habits (i.e., smoking, alcohol consumption, poor Surgical site nutrition) that affect liver function more so than the physiologic aging Emergency operation liver. Even so, as with other organ systems, there is a decrease in func- General anesthesia tional hepatic reserve in the elderly patient. Perioperative transfusion Phase1 drug metabolism in the liver is somewhat variable. The phase Residual neuromuscular blockade after an operation 1 reaction of a drug involves oxidation, reduction, and hydrolysis; it is primarily mediated by the cytochrome P450 system. Phase 2 drug ASA, American Society of Anesthesiologists. metabolism involves conjugation reactions, sulfonic acid, or acetyla- Adapted from Chow WB, et al. American College of Surgeons National Surgical Quality Improvement Program, American Geriatrics Society. Optimal preoperative assessment of the tion. Age has been identified as an insignificant factor during phase 2 geriatric surgical patient: a best practices guideline from the American College of Surgeons drug metabolism. National Surgical Quality Improvement Program and the American Geriatrics Society. J Am The liver produces key proteins such as albumin and α1-acid gly- Coll Surg. 2012;215(4):455. coprotein (AAG). In the elderly, serum albumin decreases and AAG  CH A PTER 54 Geriatrics and Anesthesia Practice 1141 increases. Serum albumin primarily binds acidic drugs (i.e., benzodi- Thermoregulation in the elderly patient is impaired. In the older azepines, opioids), and AAG binds basic drugs (i.e., local anesthetics). adult there is a decrease in the function of the hypothalamus. Hypo- The effects of these alterations depend on the type of protein the thermia is more pronounced and lasts longer because of a lower basal medication is bound to and the resultant concentration of the unbound metabolic rate, a high ratio of surface to body area mass, and less effec- drug. Theoretically this may result in adverse drug effects especially tive peripheral vasoconstriction in response to cold.19 It is particularly when malnutrition is present. However, protein binding changes with detrimental in the elderly patient because it slows anesthetic elimina- aging do not routinely require alterations in drug dosing as the protein tion, prolongs recovery from anesthesia, impairs coagulation, impairs binding on free plasma concentration is rapidly counteracted by clear- immune function, blunts the ventilatory response to CO2 and increases ance.13 In the presence of concomitant diseases that affect liver func- the chance that the patient will shiver.20 Shivering drastically increases tion, the dosing of drugs dependent on hepatic metabolism must be oxygen consumption, which leads to hypoxia, acidosis, and cardiac considered. compromise. It is known that inhaled anesthetics inhibit the tempera- ture regulating centers in the hypothalamus; thus, the aging adult has Endocrine System this added insult to an already inhibited hypothalamus. Thermoregula- The endocrine system also undergoes age-related changes that have tory vasoconstriction can cause significant peripheral vasoconstriction, widespread effects on other body systems and processes. Nevertheless, predisposing older adults to produce less heat per kilogram of body few of these changes affect anesthetic management. The most notable weight; therefore older adults may be unable to maintain their heat in endocrine organ to impact the aging adult patient and postoperative the cooler environment of the operating room. Moreover, once tem- morbidity is the pancreas. There is a decline in number and function perature decreases in the elderly patient, it is difficult to restore normal of the pancreatic islet beta cells that results in decreased insulin secre- body temperature. Methods to maintain normothermia in the older tion. Furthermore, insulin resistance occurs peripherally, which con- adult patient should involve prevention of heat loss and active warming tributes to increased hepatic production of glucose and impaired initiated in the preoperative area and continued perioperatively.20 breakdown of fats and proteins making the elderly glucose tolerant or Methods include the administration of all fluids and blood transfusions diabetic. Diabetes is a major risk factor for cardiovascular disease, which through a warming device, a thermal mattress or forced air warmer, increases the risk for perioperative and postoperative complications and an environmental humidity higher than 50%. (i.e., stroke, myocardial infarction, ketoacidosis, infection). Patients The elderly have a decrease in dermal and epidermal thick- with long-term diabetes often have compromise in one or more organ ness of the skin, which is caused by a loss of collagen and elastin. systems.14 Diabetes and its associated complications (i.e., microvascular Because there is a decrease in subcutaneous fat and thinness of the disease, cardiovascular disease, and hypertension) places the older adult skin, the aging adult is prone to skin tears and nerve injuries with patient with diabetes at increased risk for developing complications positioning. during the perioperative and postoperative period. There are also a number of diabetic complications that have plausible relationships with Central Nervous System the aging adult, which may have an impact on perioperative manage- Age-related physiologic changes of the central nervous system (CNS) ment. For example, diabetes has an effect on brain aging and is associ- are characterized by a progressive loss of neurons and neuronal sub- ated with playing a role in impaired cognition and Alzheimer’s stance, decrease in neurotransmitter activity, and decreased brain dementia.15,16 volume. These losses are most prominent in the cerebral cortex, par- Assessment of the older patient with diabetes includes identification ticularly the frontal lobes. The associated physiologic changes cause a of the type of diabetes, diabetes control (hemoglobin A1c), length of decrease in cerebrospinal fluid, a decrease in nerve conduction velocity, disease, and complications from diabetes. Patients with a history of and degeneration of peripheral nerve cells. In addition, there is a diabetes for greater than 10 years are particularly at increased risk for decreased number of myelinated nerve fibers. The regulation of brain complications.17 Perioperative assessment of the degree of endocrine function, including neuronal membranes, receptors, ion channels, neu- dysfunction is essential, along with ongoing monitoring and timely rotransmitters, cerebral blood flow, and metabolism, is affected by intervention when appropriate. general anesthetics at all levels. Consequently, there are changes in mood, memory, and motor function. In addition, cellular processes Body Composition and Thermoregulation that participate in neurotransmitter synthesis and release such as intra- Body composition and metabolism changes occur with the aging adult. neuronal signal transduction and the second messenger system, may be There is a decrease in the basal metabolic rate (BMR) as a result of altered.21 The CNS changes experienced by the older patient result in decreased physical activity and/or decreases in serum testosterone and an increased sensitivity to anesthetic agents; as a result, there may be growth hormone levels. The decreased BMR may have an effect on an increased risk for postoperative delirium (POD) or cognitive dys- muscle mass and thermoregulation. Skeletal muscle mass and strength function.22 Brain function monitoring (bispectral index monitoring) declines with aging with 50% of skeletal mass being lost by the age of may be beneficial in the elderly surgical patient. It may assist in guiding 80 years. The loss of skeletal muscle tissue (sarcopenia) is one of the the titration of medications and inhalation agent, thus speeding recov- causes of functional decline and independence in the elderly.18 There ery times and perhaps decreasing the incidence of POD and postopera- is also a significant loss in body protein because of a decrease in skeletal tive cognitive dysfunction (POCD).23–25 muscle mass and alterations in carrier proteins (e.g., albumin and The older patient may experience increased sensitivity to drugs AAG). At the same time body fat increases with the aging adult; it is because the number of receptors available are decreased. The blood distributed more so in the viscera, subcutaneous abdominal area, intra- brain barrier becomes more permeable, which may also contribute to muscular and intrahepatic areas. In addition to changes in lean mass the sensitivity of medications in addition to neurocognitive disorders and body fat, there are changes in total body water. The total body such as Alzheimer dementia and delirium.26,27 As a rule older patients water loss is mostly intracellular and somewhat in the extracellular frequently experience an exaggerated response to CNS-depressant compartment; blood volume decreases approximately 20% to 30 % by drugs with particular sensitivity to general anesthetics, hypnotics, age 75 years. As a result of decrease in total body water, older adults opioids, and benzodiazepines.22 The dose of induction agents should are more vulnerable to hypotension and have difficulty compensating be decreased by as much as 50% in older patients, arguing for very for positional changes. Overall, the body composition changes primar- meticulous titration. Benzodiazepines should be avoided in older ily affect the pharmacokinetics of medications in the elderly and is adults because they contribute to adverse events (i.e., falls, confusion, described later in this chapter. POD).28,29 1142 UNI T V Intraoperative Management CNS changes in the elderly also affect neuraxial anesthesia. Because the surgeon identifies the decision-making ability of the patient during the number of myelinated nerve fibers are decreased, this poses a risk the informed consent. However, it is also the anesthesia provider’s for neural damage with regional anesthetics. Anatomic changes in the responsibility to ensure that the patient is able to make sound decisions. aging patient such as decreased intervertebral disc height, narrowing of The four legally–relevant criterion for decision making capacity are: (1) the intervertebral foramina, decreased space between the posterior understanding his/her treatment options; (2) appreciating and acknowl- spinous processes, presence of calcifications, and changes in normal edging his/her medical condition and likely outcomes; (3) exhibiting lordosis, contribute to difficulties associated with patient positioning reasoning and engaging in a rational discussion of his/her surgical treat- and spinal or epidural needle placement. It is also postulated that the ment options; and (4) clearly choosing a preferred treatment option.5,8 dura is more permeable to local anesthetics and that the CSF specific gravity increases, whereas its volume decreases. All these alterations in Frailty the nervous system may produce a more enhanced spread of local Frailty is a perioperative risk factor for complications and mortality. anesthetics for subarachnoid blocks.30 Because elderly patients have an Frailty rates of 4.1% to 50.3% have been reported in surgical impaired baroreceptor response, severe hypotension refractory to patients.32,33 Frail older adults are more likely to have complications adrenergic stimulation may result from postspinal sympathectomy. This postoperatively, are at increased risk for longer length of hospital stay, could potentially be detrimental in the presence of impaired cardiac and are more likely be discharged to a skilled or assisted living function. There is also an enhanced spread of local anesthetics with facility.32,33 epidural blockade. In addition, the use of an epinephrine “test dose” There is no agreed upon definition of frailty. This may be related to for identification of intrathecal injection is less reliable in the elderly the complexity of the syndrome and the fact that frailty often overlaps because of the decreased end-organ adrenergic responsiveness.31 There- with other syndromes. However, most agree that frailty is a biologic fore, a decreased dose of local anesthetic is recommended for subarach- state associated with increased vulnerability to adverse outcomes that noid and epidural blockade. Overall, subarachnoid and epidural result from decreased resistance to stressors as a result of deterioration blockade are generally not contraindicated in the elderly patient. A plan in multiple physiologic systems. Frailty is classified as primary or sec- of anesthesia should be developed, based on patient history and surgical ondary. Primary frailty occurs as part of the intrinsic process of aging. procedure while considering the risks and benefits, in an effort to Secondary frailty is related to the end-stage of chronic illnesses and is decrease postoperative morbidity and mortality. caused by inflammation and wasting, for example heart failure, COPD, inflammation, and wasting associated with cancer. Because frailty serves Issues of Specific Importance in the Older Adult as an indicator for adverse outcomes and mortality in older adults, ACS Preoperative Assessment NSQIP/AGS guidelines recommend that elderly surgical patients be assessed for frailty via a validated screening tool. Whereas there are Cognitive Ability/Capability and Decision Making multiple frailty screening tools, Fried et al. created an operational frailty As there is an increasing rate of neurocognitive disorders in the older score based on the physiologic parameters of grip strength, weight loss, adult, it is highly recommended by the ACS NSQIP/AGS that their walking speed, as well as energy level and physical activity. The sum- cognitive ability, capacity for decision making, and risk factors for POD mation of scores are categorized as frail, intermediate/prefrail, or be assessed. A preoperative neuropsychiatric assessment establishes a robust.4,34 Unfortunately, this tool does not include mental health or clinical baseline if changes are observed postoperatively and guides psychosocial status, which can be a part of frailty. Frailty has also been perioperative management. The guidelines recommend that a screening operationalized as a frailty index.34 The frailty index defines frailty as tool be used. Several screening tools are available, but the Mini-Cog the proportion of accumulated deficits over time, including diseases, can be rapidly administered, is highly sensitive and specific for demen- disability, geriatric syndromes, psychosocial risk factors, and physio- tia, and is unbiased by variances in education or language. It consists logic and cognitive impairment. It is suggested that the frailty index of a three-item recall and a clock draw algorithm (Box 54.2 and may be more sensitive to the identification of adverse outcomes than Fig. 54.4).8 Fried’s frailty phenotype. Determining the older adult’s decision making capacity is important in order to provide informed surgical consent. It is recommended that Nutritional Status A nutritional assessment is imperative in the older adult surgical patient. There is no uniform definition for malnutrition in the older BOX 54.2 adult. Most definitions include specific laboratory indices, and body mass index (BMI). However, malnutrition in older adults is common, Cognitive Assessment frequently overlooked, and results in postoperative complications, increased hospital cost, and death. Malnutrition, and protein deficiency 1. Get the patient’s attention, then say: (PD) in particular, are key factors for sarcopenia, frailty, and osteopo- “I am going to say three words that I want you to remember now and later. rosis; all can result in disability, loss of independence, falls, fractures The words are: banana, sunrise, chair. Please say them for me now.” and death in the elderly population.35 Undernutrition and/or Give the patient three tries to repeat the words. If unable after three tries, go to the next item. 2. Say all the following phrases in the order indicated: “Please draw a clock in the space below. Start by drawing a large circle. Put all the numbers in the circle and set the hands to show 11 : 10 (10 past 11).” If the patient has not finished clock drawing in 3 minutes, discontinue and ask for recall items. 3. Say: “What were the three words I asked you to remember?” In Chow WB, et al, American College of Surgeons National Surgical Quality Improvement FIGURE 54.4 Mini-Cog scoring algorithm. (In Nakhaie M, Tsai A. Preopera- Program, American Geriatrics Society. Optimal preoperative assessment of the geriatric surgi- tive Assessment of Geriatric Patients. Anesthesiology Clinics 2015; cal patient: a best practices guideline from the American College of Surgeons National Surgi- 33(3):471–480. Adapted from Borson S, et al. The Mini-Cog: a cognitive cal Quality Improvement Program and the American Geriatrics Society. J Am Coll Surg. “vital signs” measure for dementia screening in multi-lingual elderly. Int J 2012;215(4):455. From Mini-Cog, copyright S. Borson [[email protected]]. Geriatr Psychiatry 2000;15(11):1024. With permission.)  CH A PTER 54 Geriatrics and Anesthesia Practice 1143 malnutrition is common in the elderly as a result of changes in taste, The Timed Up and Go Test (TUGT) can be implemented to establish smell, a reduced ability to purchase and/or prepare food, and decreased mobility and gait. This entails having the older adult patient rise from functional status.36 Other factors that may directly influence dietary a standard chair, walk approximately 10 feet, turn back, and return to intake changes include coexisting diseases, cognitive and physical the chair and sit down again. If it takes longer than 20 seconds to decline, emotional and social changes, and depressive symptoms. Aging complete the test, the patient is determined to be at risk for falls. Longer is associated with decreases in all the senses; thus it is speculated that TUGT times are associated with increased postoperative complications the decrease in smell and taste may cause foods to be less appetizing. and 1-year mortality among older adult surgical patients.38 Deficits in Practitioners must be vigilant because disease and aging cause decreased vision and hearing can also contribute to fall risk and should be lean body mass that may mimic or be confused with malnutrition. Even included in the mobility assessment. The most important goals in the so, malnutrition should not be discounted in the aging patient because perioperative care of older adults are the avoidance of functional it may contribute to decreased albumin levels that can affect protein decline, and maintenance of independence postoperatively. binding of medications and impair wound healing. For the older adult surgical patient, decreases in caloric intake combined with illness Review of Medications and Polypharmacy depletes body caloric reserves necessary to withstand the stress of anes- A thorough review of all medications (i.e., prescription, over-the-coun- thesia and surgery. Regrettably, no clearly beneficial preoperative medi- ter [OTC], dietary supplements, herbals) that the older adult is cur- cation has been identified that stimulates the appetite in older adults. rently taking is critical in identifying medications that should be Multiple validated screening tools exist for identifying risk factors for discontinued prior to surgery, those to consider starting prior to surgery, malnutrition. However, there is no consensus as to which tool should and those to avoid administering perioperatively. In a 2016 study, it be used for screening. Per the ACS NSQIP/AGS guidelines, if an older was determined that from 2010 to 2011, 15% of older adults were at adult surgical patient exhibits any one of the following criterion: (1) a risk for a potential major drug-drug interaction as compared to 2005 BMI less than 18.5 kg/m, (2) serum albumin less than 3.0 g/dL to 2006, which was approximately 8%.39 The use of prescription medi- without evidence of renal or hepatic dysfunction, or (3) unintentional cations, dietary supplements, and concurrent use of five or more medi- weight loss within the past 6 months of greater than 10% to 15%, he/ cations or supplements also increased in older adults.39 Polypharmacy, she is deemed to be at severe nutritional risk.5 Those at severe nutri- or multiple medication use, is common in older adults and is associated tional risk should undergo further in-depth nutritional screening by a with adverse drug reactions (ADRs) or unwanted side effects. ADR’s dietician with a plan for optimization. Postponement of the surgery may be caused by prescribing error (e.g., large dose prescribed without may be indicated until nutritional status has improved because malnu- taking into account decreased renal and/or hepatic clearance), or not trition and PD are associated with increased risk of postoperative taking into account CNS sensitivity. complications (i.e., surgical site infection, pneumonia), increased To help prevent prescribing errors, medication side effects, and length of hospital stay, and mortality. ADRs, the American Geriatric Society developed guidelines (Beer’s Criteria for Potentially Inappropriate Medication Use in Older Adults) for Functional Status safe prescribing of drugs to older adults. Beer’s Criteria includes a list The assessment of functional status identifies the older adult’s ability of medications that should be avoided or have their dose adjusted based to perform self-care tasks, or activities of daily living (i.e., bathing, on the older adult’s renal function and select drug-to-drug reactions.29 dressing, toileting), and instrumental activities of daily living (i.e., Per ACS NSQIP/AGS guidelines, the preoperative review of medica- preparing meals, handling finances, driving or using public transporta- tions should consist of: (1) discontinuing or substituting medications tion).4 A preoperative functional status assessment serves as a baseline that have potential drug reactions with anesthesia; (2) discontinuing in physical capacity and assists in determining reasonable and individu- nonessential medications that increase surgical risk; (3) identifying alized postoperative goals. Impaired preoperative functional status is a medications that should be discontinued based on Beer’s Criteria; (4) predictor for longer postoperative recovery time with poor postopera- continuing medications with withdrawal potential; (5) avoid starting tive outcome, increased risk for POD, and increased length of hospi- new benzodiazepines and reducing the dose prescribed to patients at talization.37 Functional status can be assessed through proxy report risk for POD; (6) avoid administering meperidine for analgesia; (7) (Box 54.3). In addition, assessing falls through inquiry, and visualizing using caution with antihistamines and medications with strong anti- gait and mobility, assists in identifying the older adults risk for falls. cholinergic effects; (8) consider starting medications that decrease peri- operative cardiovascular adverse events per ACC/AHA guidelines for β-blockers and statins; and (9) adjusting dosing of medications that undergo renal excretion based on estimated GFR.5 BOX 54.3 A medication history may be difficult to obtain or inaccurate if the older adult suffers from cognitive or hearing impairment. Medication Functional Status Assessment Proxy compliance and use of OTC, dietary and herbal supplements may be difficult to ascertain. The preferred approach to the preoperative medi- Questions to ask the older adult: cation review and perioperative management of the older adult is Can you… appreciation for individualized physiologic aging, pharmacokinetic and 1. Get out of bed or the chair by yourself?* pharmacodynamics changes with aging, presence of coexisting diseases, 2. Dress or bathe yourself?* and respect for decreased functional reserve. 3. Make your own meals?* 4. Do your own grocery shopping?* Age-Related Pharmacologic Implications in the If “no” is answered to any of the questions it warrants further in-depth screening and Older Adult appropriate referrals for perioperative interventions (i.e., physical therapy, social Exaggerated responses to anesthetic drugs and a prolonged duration of services). action are often seen in the elderly. These differences in drug response *The answer may not be reliable when neurocognitive disorders are present. are the result of both pharmacokinetic and pharmacodynamic changes From Optimal Perioperative Management of the Geriatric Patient: Best Practices Guideline associated with aging. Pharmacokinetic alterations occur in the volume from ACS NSQIP® / American Geriatrics Society. American Colleges of Surgeons Website. of distribution, renal and hepatic clearance rates, compartmental redis- Accessed 2016 at https://www.facs.org/quality-programs/acs-nsqip/geriatric-periop- tribution, and elimination half-lives. A decreased blood volume results guideline. in a decrease in initial volume of distribution, which produces a 1144 UNI T V Intraoperative Management higher-than-expected initial concentration of drug with an intravenous T AB LE 54.4 bolus injection. Changes in steady-state volumes of distribution (Vdss) vary. In aging patients who have an increase in body fat, decrease in Recommended Dosing for Perioperative Medications lean body mass, and a decreased total body water, there is an increased Vdss for lipophilic drugs and a decrease for hydrophilic drugs.22 Agent Anesthetic Considerations Dose Decreased plasma protein binding in the elderly theoretically results in Propofol Hypotension; prolonged recovery; ↓ bolus and infusion by an increase in the free plasma concentration for drugs that are highly increased brain sensitivity 50% (manufacturer protein bound. A decrease in renal function resulting from lower renal recommends blood flow, glomerular filtration, and tubular secretion leads to 1–1.5 mg/kg bolus increased serum concentration and prolonged effects of drugs depen- for induction) dent on renal elimination. The elimination of hepatic-dependent drugs Etomidate Increased brain sensitivity; ↓ bolus by 50% varies. Phase I metabolism may be reduced, but phase II metabolic greater hemodynamic stability pathways are not affected by age.13,22 Opioids Increased brain sensitivity; ↓ bolus by 50% Pharmacodynamics changes in the elderly include altered receptor profound physiologic effects; density and binding, changes in signal transduction, and impaired cel- slower onset and delayed lular responses. Drug-induced changes tend to be longer lasting and recovery; consider route of require a greater length of time for recovery to preanesthetic steady metabolism and metabolites; state. The minimal alveolar concentration (MAC) of inhalational agents avoid meperidine decreases roughly 6.7% per decade from the MAC value of 40-year-old Midazolam Increased brain sensitivity; avoid Avoid; ↓ dose by 75% adults.40,41 per Beers Criteria Neuromuscular blocking drugs are not affected by the pharmaco- Nondepolarizing Slower onset and delayed No significant changes dynamics changes of the older adult. However, the pharmacokinetics MRs recovery; consider route of with intubating metabolism and metabolites; dose; maintenance is significantly altered. For all neuromuscular blocking drugs, the onset avoid long-acting NDMRs dose per PNS twitch of action is usually prolonged.22 Most of the nondepolarizing neuro- response muscular blockers are metabolized by the liver and excreted via the Depolarizing Slower onset and delayed No dose adjustment kidney, and in the presence of coexisting hepatic or renal disease, there MR recovery may be a prolonged effect. This residual neuromuscular blockade, in combination with the loss of pharyngeal and muscular support that is ↓, Decreased; MRs, muscle relaxants; NDMRs, nondepolarizing muscle relaxants; required to protect the airway, increases the risk for postoperative PNS, peripheral nerve stimulator respiratory failure and/or aspiration. The neuromuscular blocking medication of choice for the older adult is cisatracurium because this undergoes Hoffman elimination and ester hydrolysis and is not organ BOX 54.4 dependent. Generally, all medications are given in a lower dose to the older Ethical Principles adult patient. Even though this is well known, the tendency for anes- thesia providers to underappreciate the elderly patients’ sensitivity to medications, the pharmacodynamic and pharmacokinetic changes, Autonomy: Patient’s right to self-determination Beneficence: An obligation or responsibility to help the patient; “to do good” may result in overmedication and potential overdosing. Currently there Nonmaleficence: To not intentionally harm the patient; “do no harm” are no specific medication dosing guidelines for anesthesia medica- Justice: To treat the patient fairly tions for the older adult patient. Suggested dosing adjustments for perioperative medications are found in Table 54.4. Postoperative pain control and analgesics in the elderly surgical patient are discussed in Chapter 56. not be limiting factors for surgical treatment. Compared with younger surgical patients, the older adult is at relatively increased risk for mor- Comorbidity in the Older Adult bidity and mortality postelective surgery, but are at 30% higher risk Definitions for comorbidity and multimorbidity are not clear in the for postoperative complications and mortality with emergency literature. Therefore this section will use comorbidity and multimorbid- surgery.47–49 Therefore, a multidisciplinary approach to individualized ity interchangeably, and is defined as two or more chronic medical preoperative care and optimization is essential with the goal of avoiding conditions within one person.42,43 In the United States, multimorbidity postoperative complications and returning the older adult patient to has increased with advanced age, even though mortality rates have their same presurgical state. declined. It is associated with an increased risk for death, disability, poor functional status, ADRs, and increased length of hospitalization Ethical Issues in the Treatment of the Older Adult and health care costs.44,45 Multimorbidity increases steeply with older The advances in medical treatment, the changes in the health care adults. The prevalence of multimorbidity in those 65 to 74 years of age system, and the aging of the United States has given rise to specific is approximately 62%, at ages 75 to 84 years it is 75%, and 81% in ethical dilemmas that anesthesia providers encounter in the older adult. those who are 85 years of age and older44,46 The most common multi- The older adult patient often has other complicating factors (i.e., coex- morbidities in the older adult include hypertension, hyperlipidemia, isting diseases, impaired cognition, impaired decision-making capacity, diabetes, and ischemic heart disease. Prevalence varies by sex; women insufficient social support), which adds to the complexity in ethical have more arthritis than men, and men have more heart disease than issues. Examples of ethical issues in the older adult surgical patient women. Prevalence also varies by race, with older adult Hispanics and include informed consent, advanced directives, and perioperative do- African Americans having higher rates of hypertension, diabetes, and not-resuscitate (DNR) orders. The basic principles in ethical decision metabolic syndrome as compared to Caucasians.4,46 making that apply to the older adult are the same as those that apply Multimorbity in the older adult is common and is strongly associ- to all patients. In health care the most common principles are (1) ated with frailty, which in turn is associated with poor postoperative autonomy, (2) beneficence, (3) nonmaleficence, and (4) justice. Ethical outcomes.43 Even so, older age and presence of multimorbidities should principles are defined in Box 54.4. Certified Registered Nurse  CH A PTER 54 Geriatrics and Anesthesia Practice 1145 Anesthetists (CRNAs) follow the American Nurses Association Nursing BOX 54.5 Code of Ethics in their daily practice and abide by the American Asso- ciation of Nurse Anesthetists (AANA) Code of Ethics in guiding ethical AANA Reconsideration of Advance Directives decision-making. As professionals we base our decisions on “ethics of obligation,” yet personally we base them on “ethics of the good.”50 Unfortunately, difficult and complex situations arise that challenge the Full suspension: All provisions of the advance directive are suspended during anesthesia providers. Personal values and biases must be recognized anesthesia and the procedure for a specified period. while acknowledging, appreciating, and upholding the patient’s desires Partial suspension or modification: Specific provisions of the advance directive are suspended or modified during anesthesia and the procedure for a specified and decisions regarding their health care. period. The informed consent is the cornerstone for upholding the practice No suspension: The provisions of the advance directive remain active during of autonomy. However, all the ethical principles are involved when a anesthesia and the procedure patient makes an informed decision regarding his/her health care. Older age alone is not an obstacle to practicing autonomy. An impor- AANA, American Association of Nurse Anesthetists. tant aspect of the informed consent is assessing and assuring that the From AANA website for Practice Guidelines Ads. Accessed 2016 at http://www.aana.com/ patient has the cognitive ability/capability for decision making. resources2/professionalpractice/Pages/Reconsideration-of-Advance-Directives.aspx. Informed consent is discussed in Chapter 20, and assessing cognitive capability/ability for decision making is discussed earlier in the preop- erative assessment portion of this chapter. Legally and ethically anes- procedures will be determined by the anesthesia provider and the thesia providers and other practitioners must disclose factual, truthful surgeon based on clinical judgment, while keeping in mind the patient’s information while being objective and free of personal bias. values and wishes.53,54 The AANA also developed practice guidelines Autonomy is also exercised through an advanced directive (AD). that address the reconsideration of ADs prior to surgery, which are This legal document enables a surrogate or agent to act on the patient’s similar to the ASA and are found in Box 54.5. Facility policy is also behalf when he/she is unable to make health care decisions. The patient used as a resource in guiding the practitioner in addressing DNR status has communicated his/her beliefs and values about health care decisions of a patient undergoing surgery. Each patient and accompanying surgi- and life-sustaining treatment and appoints a surrogate. In 1991, legisla- cal procedure should be addressed on a unique case-by-case matter. tion enacted the Patient Self-Determination Act (PSDA), which After an informed discussion, an agreement should be made on the requires hospitals and other health organizations that receive Medicare DNR status by the patient or surrogate, surgeon, and anesthesia pro- funds to provide information to patients regarding their right and vider. Lastly, the perioperative DNR status should be documented in refusal of care (i.e., ADs). Since its inception, older adults AD comple- the medical record to substantiate the agreement, and to inform all tion rates are at an all-time high of 72%.51 As ADs are legislated at the health care providers of the designated plan. state level, there may be differing standards and laws for each state. It is widely accepted that chronologic age is possibly an independent Unlike an AD, a living will (LW), or directive to physicians, are death risk factor for anesthesia and surgery; its specific role as a risk factor is with dignity declarations, which provide specific instructions to the difficult to ascertain. Thus each patient should be treated fairly, regard- attending physician(s) stating the patient’s desired treatment for care less of age. The ethical principle of social justice is not providing the when his/her decision making capacity is lost because of a terminal or greatest good for the greatest number of people; it is treating people end-stage illness. LWs primarily direct resuscitation and withdrawal of equally, regardless of their age, race, cultural beliefs, religion, disease life sustaining treatment.52 Unfortunately, this document is limited to processes, or resuscitation status.50 Every patient should be informed, delineated medical situations and does not take into account unfore- at a comparable level, of all the alternatives regarding resuscitation seen circumstances. Regardless of which legal document the patient when undergoing any surgical procedure. It is a matter of justice to has, a review of the document and a conversation should take place ensure adequate and equitable informed anesthesia consent to all surgi- between the practitioner(s) and patient concerning his/her health care cal patients. Therefore age, as an independent factor, should not be wishes/goals during the perioperative period.50 regarded as a reason to exclude an older adult for any procedure. Informed consent is not limited to surgical procedures and anes- thetic technique; it is also applicable to the perioperative DNR order. Postoperative Delirium Health care providers are taught that it is their duty to provide care POD and postoperative cognitive dysfunction (POCD) are the most that is beneficial to the patient. Hence, in the presence of a patient who frequently occurring neurologic phenomena in older adults. POD and is undergoing surgery with a DNR status, health care providers may POCD are distinct conditions, with age over 65 years being the pre- feel compelled to suspend the DNR in the event that heroic measures dominant risk factor for both. are needed. From the perspective of anesthesia providers, it is their POD is characterized by disruption of perception, thinking, responsibility to ensure that the patient has a positive anesthetic memory, psychomotor behavior, sleep-wake cycle, consciousness, and outcome. Even though anesthesia providers view that suspending the attention.55,56 Its clinical presentation varies with hypoactive symptoms DNR status will inevitably help the patient in the event that cardio- (e.g., decreased motor activity and depression), hyperactive symptoms pulmonary resuscitation is needed, the DNR suspension may not be (e.g., aggression and agitation), or a combination thereof. In some aligned with the patient’s view of beneficence or his desires. Therefore instances, hypoactive symptoms are unrecognizable, which results in anesthesia providers cannot assume what is best for the patient; the misdiagnosis of POD.5,57 Symptoms typically manifest acutely within patient or surrogate needs to have informed consent regarding the the first few days after surgery and can last for several days or weeks. alternatives of the DNR status while in the operating room in order to The exact cause of POD is not known but is likely multifactorial. Risk make an informed decision based on his wishes, values, and beliefs. factors that have been associated with the development of POD are Because of this circumstance, the ASA suggests that specific resuscita- older age, male gender, dementia, history of alcohol abuse, depression, tion alternatives during the surgical procedure be presented and dis- duration of anesthesia, poor functional status, abnormal electrolytes cussed with the patient. These three alternatives include (1) the full and glucose, Parkinson disease, cardiovascular disease, dehydration, suspension of the DNR status intraoperatively and postoperatively, (2) metabolic diseases (e.g., diabetes, hyperthyroidism), anticholinergic the acceptance or refusal of specific resuscitative interventions (i.e., drugs used intraoperatively, patients requiring admission to the inten- chest compressions, defibrillation, vasopressor administration) with full sive care unit, inadequate pain control, ASA greater than or equal to documentation of these in the medical record, and (3) resuscitation 3, low serum albumin, and type of surgery.58–62 Depending on the type 1146 UNI T V Intraoperative Management of procedure, the rate of POD ranges from 9% to 50% with a high BOX 54.6 incidence occurring in aortic and orthopedic procedures (femoral frac- tures).5,51 POD is associated with increased risk of postoperative adverse Risk Factors for Postoperative Cognitive Dysfunction reactions (i.e., pulmonary and cardiac), increased length of hospital stay, increased health care cost, poor functional and cognitive recovery, and death.62,63 Genetic disposition The treatment of POD begins with prevention. Preoperatively, Lower educational level health care providers should identify patients who are at high risk for High alcohol intake or alcohol abuse Increasing age POD, including age over 65 years, chronic cognitive decline or demen- High ASA status tia, poor hearing or vision, presence of infection, current hip fracture, Preexisting mild cognitive impairment or severe illness. In combination with the risk factors, the physiologic History of cerebrovascular accident stress of surgery, which is determined by the extent of the operation, Major operations, redo operations may cumulatively contribute to the development of POD. Once POD Cardiac surgery is diagnosed treatment is dependent on the identifying cause. After Longer duration of surgery and anesthesia treating the underlying cause, it is recommended that health care pro- Intraoperative cerebral desaturation viders use multicomponent nonpharmacologic interventions (i.e., fre- Postoperative delirium quent reorientation, calm environment, eliminating restraint use, and Postoperative infection ensuring the use of hearing aids/glasses). The use of pharmacologic interventions (i.e., haloperidol, lorazepam) should be reserved for those ASA, American Society of Anesthesiologists. who are highly agitated and are threatening harm to self and/or From Grape S, et al. Postoperative cognitive dysfunction. Trends Anaesth Crit Care. others.5,55 Other recommendations for anesthesia providers include: (1) 2012;2(3):98–103. administering regional anesthesia for postoperative pain control thereby potentially preventing delirium, (2) intraoperative electroencephalo- gram (EEG) monitoring during intravenous sedation or general anes- Presently there is no cure for POCD, and patients who suffer from thesia as EEG suppression has been identified as an independent risk it may or may not recover to their preoperative cognitive state. Because factor for POD, and (3) conducting a thorough review of medications POCD pathogenesis is multifactorial and unclear, strategies should preoperatively while avoiding medications per Beer’s Criteria.20,64 be aimed at prevention. Unfortunately, there are no proven effective strategies. However, based on the knowledge that the elderly have Postoperative Cognitive Dysfunction decreased nervous system function and decreased cognitive reserve, POCD is often reported as being part of the same continuum as POD. efforts should consist in identifying risk factors and tailoring anesthetic Even though they are both neurocognitive disorders that contribute to management to minimize them. Recommendations are aimed at main- increased hospital costs, morbidity, and mortality, there are differences. taining oxygenation and cerebral perfusion.66 Because it is speculated POCD is characterized by an array of cognitive impairments such as that POCD may be caused by general anesthesia and/or surgery, it is memory deficits, difficulty with concentration, impaired comprehen- only prudent that surgeries should be as short or as minimally invasive sion, and delayed psychomotor speed. Unlike POD, the onset of as possible. Overall, there is no consensus in the literature regard- POCD is subtle and neurocognitive deficits may not present themselves ing the most appropriate anesthetic technique for the elderly surgical until weeks to months after surgery. This ultimately results in the patient. inability to work, a decline in activities of daily living, and perhaps a need for assisted care.56 Summary Currently there are no universally accepted diagnostic criteria for The United States is on the cusp of a very racially and ethnically POCD, nor is there a standard definition. To diagnose POCD, a diverse aging population surge. Health care providers will face many battery of time-consuming and sophisticated neurocognitive tests must challenges in keeping pace with a more comprehensive preoperative be done preoperatively and postoperatively in identifying cognitive elderly assessment, which will identify perioperative risks, assist with decline after surgery and anesthesia. Establishing baseline cognitive optimizing the older adult, and improve postoperative outcomes. function is critical because preoperative cognitive impairment may be The goal of anesthesia for the older adult patient is the same as any present prior to surgery. However, preoperative test timing, specific other patient; however, the physiologic changes, multimorbidities, and test(s), and test interpretations remain inconsistent and debatable. Risk functional decline in all organ systems of the older adult affect every factors for POCD are also controversial, with advanced age being the aspect o