The population is aging rapidly worldwide and as this occurs, the rate of surgical procedures in older people is increasing in conjunction with the required anesthesia services. Along with increased life expectancy, the disease burden is also expanding with advanced medical care. This chapter will explore the extent of worldwide aging demographics, the mechanics of aging, health care costs specific to geriatrics, and the significance of anesthetic considerations in a rapidly aging world.

The human body is a complex connection of various systems, each affected by the internal and external environment. Each system relies on the other and changes in one can result in variations in all other organ systems. As humans age, their physical appearance changes, but the aging process also occurs below the skin. Each organ system is impacted by time, and an individual’s lifestyle can greatly impact his/her organ system. Various anatomical and physiological alterations that occur to the major organ systems due to aging and are relevant to an anesthesiologist are discussed below.

In terms of different pharmacokinetic and pharmacodynamic interactions, geriatric patients exhibit greater sensitivity to anesthetics. Therefore, understanding the differences in body composition, hepatic and renal function, changes in protein binding, and minimal alveolar concentration are the key to titration of anesthetics in geriatric patients. In addition, polypharmacy, use of non-prescription medications and adverse medications related events warrant special considerations for the geriatric population, more so than in their younger counterparts. Lastly, careful titration of anesthetics may minimize the development of postoperative delirium and postoperative cognitive dysfunction, which are associated with higher morbidity, mortality, length of hospitalization, and overall cost.

Worldwide, life expectancy is increasing and people are living longer. Between 2015 and 2050, the proportion of the world’s population over the age of 60 years is expected to double from 12% to 22% [1]. As our elderly population grows, more elderly patients now require elective, urgent, and emergent surgery. Elderly patients are complex due to age-related changes and comorbidities. Anesthesia provides a critical line of defense for these patients, and this begins with a comprehensive pre-operative evaluation. Assessment begins with a history and physical exam and is supplemented with laboratory and clinical data. Special attention must be given to nutritional status, functional capacity, cardiovascular and pulmonary function, cognitive function, and emotional well-being. Understanding the physiologic changes of aging and common pathologies in the elderly helps predict the pharmacokinetics and pharmacodynamics of anesthetic agents. This understanding also helps plan for the hemodynamic, ventilatory, and cognitive impacts of anesthesia on the elderly. Perhaps equally important to determine a patient’s physical condition is establishing the individual’s goals of care, decision-making capacity, and surrogate decision-making for anesthesia and surgery.

 Geriatric patients have unique postoperative concerns that must be considered to safely guide their care. In this chapter, we discuss the commonly encountered complications in the post-anesthesia care unit with a focus on postoperative delirium, postoperative nausea, and vomiting, as well as issues relating to renal, respiratory, and cardiovascular systems with advancing age. Finally, we discuss opioid and nonopioid analgesic considerations unique to this vulnerable patient population.

As the world population ages, the number of older patients undergoing surgery will increase significantly. Postoperative cognitive dysfunction (POCD) and other perioperative neurocognitive disorders (PND) affecting patients after surgery have long been recognized in older patients and are considered some of the most common postoperative complications. POCD has been correlated with significant morbidity and mortality, and greater healthcare costs. Historically, the lack of standardized nomenclature used to describe cognitive change after surgery and anesthesia has made it challenging to conduct systematic reviews or analyze the results of similar studies to further understand the clinical implications of this disorder. This has led to minimal recognition of this disorder outside of the specialty of anesthesiology. Patient and surgery-related risk factors include old age, preexisting cognitive changes, and emergency surgery amongst others. Proposed etiologies include postsurgical neuroinflammation, impairment of neurotransmitter systems, and cerebral vascular events in the perioperative period. The medical literature offers little guidance to recommend a particular anesthetic to decrease the risk of POCD in the postoperative patient. Most studies found similar risks of POCD after general and regional anesthesia techniques. While there is no standardized test for diagnosing preoperative cognitive impairment, it is critical to identify high-risk patients so that timely interventions can be made to minimize POCD.

In the perioperative care of geriatric patient, it is common to have patients with heart failure and who have had previous cardiac surgery. In order to safely and successfully care for these patients it is imperative to understand the pathology and progression of the disease. Additionally, it is necessary to be able to recognize the signs and symptoms of heart failure so that it may be recognized in patients who have yet to be diagnosed in order to determine if further testing or optimization is required. Furthermore, it is necessary to know the special considerations necessary for the management of patients with heart failure or previous CABG. 

Geriatric patients are a significant proportion of the patients seen in the perioperative setting. Oftentimes, these patients are presenting for non-cardiac surgery after undergoing a cardiac procedure previously. Management of these patients starts with understanding the pathophysiology, surgical intervention, and anesthetic considerations. This management starts from risk assessment and perioperative management. In this chapter, risk assessment stemming from a patient’s co-morbid conditions is taken into account to form an overall risk profile. These conditions help the anesthesiologist establish a framework to model an anesthetic plan. Notably, a prior cardiac history, including a history of coronary artery disease (CAD), hypertension (HTN), and a history of valve disease and possible repair, is prudent. Also discussed is the need for appropriate intra-operative monitoring in specific situations as well as anticoagulation guidelines in the pre and post-operative settings.

Pulmonary hypertension is a common and life-threatening condition, characterized by elevated blood pressure in the pulmonary artery, which supplies blood to the lungs. This condition is typically classified into five groups based on etiology. The etiology of pulmonary hypertension in the elderly is complex and multifactorial. Some of the common causes of pulmonary hypertension in this population include leftsided heart disease, chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), and pulmonary embolism. The initial evaluation determines the cause, which guides the appropriate treatment. The most common causes in the elderly arise from left heart disease and the sequela of COPD. Long-standing disease can result in pulmonary hypertension leading to right heart failure and potentially catastrophic consequences in a patient population with decreased physiologic reserve. Anesthesia and surgery in patients with pulmonary hypertension pose a significant risk of complications including death. Acute right ventricular decompensation can result from various physiological changes induced by anesthesia and sedation. Adequate risk assessment and individualized care are essential components of care. Efforts to avoid increases in pulmonary vascular resistance are keys to anesthetic management. However, despite the increase of pulmonary hypertension in the geriatric population, limited studies are dedicated to this group.

As the number of patients and use of cardiovascular implantable electronic devices have increased, anesthesiologists must understand the different types of implanted devices and their management during the perioperative period. Caring for these patients requires knowledge of the standard nomenclature used to describe device function, the role of a magnet, and the differential responses a magnet can cause based on the device type.

Chronic pain is a major cause of physical disability, poor mental health, and decreased quality of life [1,2]. The burden of chronic pain is reflected in increased medical care utilization and consequently increased healthcare costs, which are estimated at an astounding $560 billion per year [3]. CDC estimates from 2019 reveal that while 20.4% of adults in the USA live with chronic pain, the prevalence increases with advancing age [4]. 30.8% of people aged 65 years and above had chronic pain while 11.8% of them had high-impact chronic pain, which is defined as pain that causes significant restriction of self-care, social and work-related activities [5]. The impact of chronic pain is more severe in the elderly; older adults report poorer physical health and disability in comparison to younger adults [6-8]. Chronic pain in the elderly is also associated with poorer sleep, cognitive decline, dementia, and death [9-13]. With the projected increase in the elderly population in the US every year, the burden of chronic pain is only expected to increase. This chapter outlines the physiologic and pharmacologic changes that happen with ageing, the major causes of chronic pain in the elderly, as well as the myriad of treatment options available with a focus on pharmacotherapy, behavioral and alternative therapies, and interventional pain therapies. The focus of treatment is not only targeted towards reducing pain but special considerations should be made to minimize the cognitive effects of polypharmacy in light of multiple comorbidities and promote mental well-being and functional independence [14].

Trauma is a leading cause of death for the geriatric population. Because of the acuity of the patient presenting in such circumstances, it is imperative to have a grasp of physiological changes that occur with time. As an anesthesia provider, understanding physiological changes can adjust the anesthetic plan, dosages, and uses of certain medications. It is also important to convey the risks and benefits of proceeding with major invasive surgery and recovery. Many patients now have living wills or advanced directives that may assist in decision-making.

With the advent of enhanced recovery programs, postoperative recovery has become more and more efficient with improved postoperative times to discharge, decreased hospitalizations, and improved patient satisfaction. Employing these same principles to a more vulnerable population in an ambulatory setting has proven effective in making outpatient day surgery possible and successful for the elderly population. This chapter will discuss the advancing age of the surgical population, the advancing numbers of surgeries being performed in an ambulatory setting, and the implications on the elderly population as they undergo ambulatory procedures. Further, the chapter will discuss how to optimize the elderly population to have a successful perioperative course by utilizing a team of professionals preoperatively and enhanced recovery programs peri-operatively. Finally, the chapter will conclude with certain potential complications that may occur with this populous and how to best avoid them.

Caring for and anesthetizing critically ill geriatric patients requires multiple special considerations. This chapter will explore the considerations that must be taken when anesthetizing this geriatric critically ill population. In addition, it will also describe in detail common critical care scenarios in the geriatric population such as airway and ventilation management, resuscitation, and sepsis. Finally, some critical care issues specifically related to the geriatric population such as frailty and end-of-life considerations will be discussed. 

Chronic neurological disorders encompass a broad range of challenges for the surgical and anesthesiology team in the perioperative setting. According to the World Population Prospects 2019, by 2050, 1 in 6 people will be over 65, from 1 in 11 in 2019 [1]. As our population continues to age, our understanding and ability to provide medical and surgical services must improve as well. Perioperative strokes are rare, but they can greatly impact a patient's recovery and function when they occur. Dementia strongly predicts postoperative complications, higher hospital costs, and 30- day mortality [2]. Patients with Parkinson’s disease are at a higher risk of perioperative medical and surgical complications not to mention specific medication regimens that need to be adjusted to avoid worsening symptomatology. Although rare, a patient presenting with Amyotrophic lateral sclerosis (ALS), can present with a broad range of neurologic symptoms, and cardiovascular and pulmonary dysfunction that can be daunting for any anesthesia provider. In this chapter, we will explore the comprehensive approach to managing chronic neurologic disorders, including multidisciplinary care, early identification of potential complications, specialized medication management, and intraoperative considerations.

There are several controversies when it comes to geriatric anesthesia including:

1. Determining the appropriate anesthesia technique: Geriatric patients may have decreased organ function and may be more susceptible to the adverse effects of anesthesia. There is ongoing debate about the best anesthesia technique for older adults, with some arguing for the use of regional anesthesia and others advocating for general anesthesia.

 2. Perioperative Beta-blockers: The use of perioperative beta-blockers continues to be debatable. On one hand, evidence suggests beta-blockers may reduce perioperative cardiac events in the elderly. On the other hand, there are concerns and potential risks, especially in this population.

3. Cognitive impairment: Older adults may be at increased risk of delirium and cognitive impairment after surgery. The use of certain medications, such as propofol or midazolam, may increase the risk of cognitive impairment. There is ongoing debate about the best way to minimize the risk of cognitive impairment in older adults.

4. Pain management and Frailty: Geriatric patients may have increased sensitivity to pain and may require higher doses of pain medication. However, older adults may also be at increased risk of adverse effects from pain medications, such as respiratory depression.

 5. Advance care planning and ethical considerations: Geriatric patients may have a higher risk of complications and death after surgery. Advance care planning, such as discussing the patient's goals of care and treatment preferences, can help ensure that the patient's wishes are respected in the event of an emergency. Geriatric patients may have a decreased ability to make decisions about their care due to cognitive impairment or other factors. There is ongoing debate about the best way to obtain informed consent from older adults and ensure that their wishes are respected.

6. Cardiac-related controversies including the use of Aminocaproic Acid in CABG surgeries. There are several studies that have shown reduced bleeding and the need for blood transfusions, while others have raised concerns about an increased risk of adverse events, such as renal failure and thromboembolic events. 

This chapter discusses the ethical and legal challenges faced by anesthesiologists in geriatric anesthesia due to medical, economic, and social issues. Anesthesiologists must exhibit patience, understanding, and compassion in order to overcome multiple challenges. It is also imperative that they stay up-to-date on the issues facing this particular population in order to adequately address them efficiently through collaborative communication and active involvement in patient care.

Men and women are created equal, but there are some biological differences between the two sexes that should be considered in the perioperative period to provide safe and equitable care. This chapter highlights specific anatomical differences between men and women and discusses conditions by system that are more prevalent among female geriatric patients. Plus, it briefly discusses particular sex differences in the pharmacokinetics of some drugs.

The COVID-19 pandemic resulted in a significant impact on healthcare across the world. The pandemic is caused by the coronavirus SARS-CoV-2 and is transmitted through respiratory secretions. The geriatric population comprised most morbidities and mortalities related to COVID-19. Common symptoms include fever, cough, dyspnea, myalgia, and culminating in acute hypoxic respiratory failure and acute myocardial injury. Geriatric patients with COVID-19 who require surgery are at a greater risk of postoperative complications. An assessment of the risks and benefits of surgical intervention relies on the degree of COVID-19 pathology and the type of surgery whether emergent or elective. The presence of COVID-19 does not warrant a change in the modality of anesthesia that would be performed for any given surgery in the absence of COVID-19.

Demographic studies show that life expectancy for people in the USA has been trending upwards for the past several decades. As the population ages, the number of geriatric patients who will require surgery has also increased. Information from the National Hospital Discharge Survey reported that in 2006, 35.3% of all inpatient procedures and 32.2% of all outpatient procedures were in patients aged 65 and older. Common elective surgeries in elderly patients include cataract and lens procedures, spinal fusions and laminectomies, and total or partial hip and knee replacements. Common urgent surgeries in this population include thoracic and abdominal cancer resections, breast and prostate cancer resections, and cholecystectomies. Finally, common emergency surgeries in the elderly population include hip fracture repairs and other geriatric traumas.