Trauma in our “elders”

The year 2030 marks a turning point for the US population. In 2030, all baby boomers (born 1946 to 1964) will be older than 65 years of age. One in every five Americans will be of retirement age ( Fig. 1 ). By 2034, older adults will outnumber children for the first time in US history. By 2060 there is projected to be almost 95 million older adults ( Fig. 2 ). The “oldest old,” those aged 85 or greater, comprise the most rapidly increasing elderly group. Between 1960 and 1994, their numbers rose 274% while the elderly population rose 100% and the entire U.S. population increased by 45%. The oldest old numbered 3 million in 1994, making them 10% of the elderly. U.S. Census Bureau estimates that the oldest old will increase to 19 million in 2050, which is 24% of elderly in America and 5% of all Americans ( Fig. 3 ). Improved quality medical care has contributed to longer life expectancy and an increase in the number of centenarians, people aged 100 or older. In 1980 there were 32,000 centenarians, which increased to 53,000 in 2010 and is projected to be more 600,000 by 2060.

Currently the elderly have fewer disabilities and have more active lifestyles than in previous generations, leading to increased risk of injury. With the surge in the elderly population, we can anticipate an increasing number of older trauma patients. All health care providers treating trauma patients need to be aware of common injuries and significant confounding comorbidities as well as age-related changes that place the elderly patient at increased risk of morbidity and mortality compared to younger patients following trauma.

There are many age-related studies in trauma patients with elderly defined anywhere from 55 to 75 years of age. In general, age 65 and older is defined as geriatric or older and are used interchangeably. This aligns with Medicare’s designation of “elderly” although this age lacks validation for its implementation in patient care processes. Recently Fakhry and colleagues reviewed over 255,000 trauma patients and found statistically increased mortality rates at age 55, 77, and 82 years compared to those less than 55 years of age. National Trauma Data Standard-defined comorbidities increased once age surpassed 55 years and the rate more than doubled for those over 77 years and those over 82 years. These data support the inclusion of 55- to 64-year-olds in the geriatric category. If the definition of geriatric was changed to include those 55 years or greater, the geriatric population increases from over 55 million to over 99 million people according to 2020 U.S. Census Bureau data. For the purposes of this chapter, “older adult,” “elderly,” and “geriatric” will refer to those age 65 years or greater, as this has been most commonly used. “Oldest old” will be used to refer to those age 85 years or greater.

Physiologic changes

Older patients are more susceptible to injury from minor mechanism and less able to compensate from any injury. This is due to physiologic changes of aging, presence of comorbidities, and the use of multiple medications, some of which may blunt their response to the physiologic stress of trauma. Geriatric trauma patients are at higher risk of disability and death when compared to younger trauma patients. Changes to all body systems occur with aging and are summarized in Table 1 .

TABLE 1

Physiologic Changes of Aging

Body System	Physiologic Change	Consequence
Neurologic	Deceased vision, sight, proprioception Poor balance, slower reflex response Dura adheres tightly to the skull and bridging veins are stretched Reduction in brain size Decreased cerebral autoregulation	Decreased ability to avoid injury Fall risk Risk of subdural hemorrhage Delayed symptoms of intracranial injury Increase risk of injury from decreased cerebral perfusion
Cardiac	Impaired sensitivity to catecholamines Decreased cardiac conduction Decreased maximal CO and maximal HR to activity Increased vascular stiffness	Absence of tachycardia in response to hypovolemia Decreased cardiac response to trauma and stress Systolic hypertension
Pulmonary	Weaker gag and cough reflexes Decreased pulmonary function (VC, FEV1) Impaired mucociliary bacteria clearance Reduction in lung compliance	Risk of aspiration Increased work of breathing Hypoventilation High risk of respiratory failure and need for mechanical ventilation
Gastrointestinal	Decreased gastric emptying Decreased hepatic clearance Decreased hepatic protein production	Risk of aspiration Decreased hepatic drug clearance Thrombocytopenia, coagulopathy
Renal	Decreased GFR and renal tubular function Decreased renal mass	Decreased ability to tolerate large-volume fluid resuscitation Risk for fluid and electrolyte imbalance Decreased drug clearance Risk of acute kidney injury
Endocrine	Decrease in thyroid hormone, GH, Vit D, DHEA, estrogen (in females) Increase glucocorticoid, PTH Glucose homeostasis disequilibrium	Decreased bone density Risk of fractures Increase adipose tissue Loss of appetite
Hematologic	Bone marrow mass decrease Red cell, platelet, WBC qualitative defects	Thrombocytopenia Anemia
Immunologic	Decreased immune response	Increased risk of infections Thrombocytopenia
Musculoskeletal	Decrease muscle mass Osteoporosis	Fall risk Risk of fractures
Integument	Decreased temperature control Loss of connective tissue Intrinsic and extrinsic skin changes	Risk of hypothermia Poor wound healing Skin prone to injury and burns

CO, Cardiac output; DHEA, dehydroepiandrosterone; FEV1, forced expiratory volume over 1 second; GFR, glomerular filtration rate; GH, growth hormone; HR, heart rate; PTH, parathyroid hormone; VC, vital capacity; Vit D, vitamin D; WBC, white blood cell count.

Neurologic changes

Advanced aging is associated with diminished vision and hearing, slower reflexes, and poorer balance contributing to an inability to avoid injury. This makes the older adult at higher risk for falls and trauma in general. Reduced sensation occurs with aging, which is exacerbated by neuropathy due to medical causes such as diabetes. These changes make the elderly more prone to falls, occult wounds, and infections. Underlying cerebral atherosclerotic and cerebrovascular disease may alter baseline neurologic function. Aging causes brain atrophy and loss of brain volume leading to stretching of the bridging dural veins increasing the risk for subdural hemorrhage with minor head trauma. A larger amount of hemorrhage is needed to cause mass effect and clinical symptoms of brain injury due to the loss of parenchymal brain volume. Because of this, the presenting Glasgow Coma Scale (GCS) in the elderly patient does not correspond to the degree of brain injury present. Symptoms of intracranial hemorrhage often present in a delayed fashion in the elderly. Additionally, cerebral autoregulation is decreased in the elderly, which may increase risk of additional secondary brain injury from decreased cerebral perfusion.

Cardiovascular changes

Aging causes structural changes in the myocardium, conduction system, and endocardium. There is progressive degeneration of cardiac structures resulting in loss of elasticity, fibrotic changes of heart valves, and amyloid infiltration. This results in decreased pumping capacity of the heart, decreased left ventricular compliance, and cardiac conduction problems. Age-related cardiovascular responses to exercise decline causing a decrease in maximal achievable heart rate (HR) with exercise and decrease in maximal cardiac output (CO) and aerobic capacity. This results in a blunted HR response to stress and hypovolemia often exacerbated with preinjury medications such as beta blockers. Decreased elasticity of arterial vessels with aging may result in chronic increases in vessel diameter and vessel wall rigidity. Arterial stiffening results in increased baseline arterial systolic and pulse pressure.

Pulmonary changes

Cough and gag reflexes weaken with age due to loss of muscle mass. This in combination with impaired ciliary clearance of bacteria leads to chronic colonization of airways. Chronic aspiration due to dysphagia is also more common in the elderly. Overall pulmonary function deteriorates with age. Vital capacity (VC) and forced expiratory volume over 1 second (FEV ₁ ) decrease leading to reduction in respiratory reserve. Loss of lean muscle mass leads to a decreased ability to recruit thoracic and accessory muscles of breathing leading to hypoventilation and atelectasis. As a result, small insults to chest wall mechanics, such as rib fractures, may result in respiratory failure in the elderly trauma patient.

Gastrointestinal

Loss of the ability to chew food due to poor dentition or dentures can lead to poor nutritional intake. Salivary gland atrophy leading to decreased saliva production make deglutition challenging and contribute to poor nutritional intake. Overall gastrointestinal motility slows with aging causing delays in gastric emptying and constipation. Hepatic parenchymal mass and total blood flow decrease with aging. This leads to decreased hepatic clearance of medications and toxins. Intrinsic protein production by the liver is decreased with less albumin, thrombopoietin, and vitamin K-dependent clotting factors leading to thrombocytopenia and coagulopathy.

Renal system changes

Neurohumoral desensitization of the bladder detrusor muscle leads to urinary incontinence and urinary retention. Urinary tract infection, prostatism, and medications may contribute to urinary retention. Kidney parenchymal loss and decrease in glomerular filtration rate lead to clearance problems with solute and reabsorption of water. This results in fluid and electrolyte problems. Creatinine clearance decreases with age and results in decreased clearance of many medications. Decreased drug dosing in the elderly is often required. The renin-angiotensin-aldosterone system is downregulated causing less responsiveness to hypovolemia and salt retention. With renal function decline, the kidney becomes less responsive to hypoxia and produces less erythropoietin leading to anemia. Vitamin D hydroxylation decreases leading to osteomalacia.

Endocrine changes

The secretory patterns of hormones produced by the hypothalamic-pituitary axis change as does the sensitivity of the axis to negative feedback by end hormones with aging. Overall, the thyroid hormone axis activity declines with age and is reflected by an increase in thyroid-stimulating hormone (TSH) and a decrease in triiodothyronine (T ₃ ) concentrations. These age-associated changes do not appear to be detrimental in the aging process and might be beneficial. A gradual and progressive decrease in growth hormone (GH) secretion, called somatopause, occurs with aging and is associated with increase in adipose tissue. Hormonal changes in ghrelin, leptin, and cholecystokinin result in decrease in appetite. Glucocorticoid generation, systemically and locally, and sensitivity of bone cells to glucocorticoids increase with age. This contributes to age-related decline in bone mineral density and bone strength and increased risk for fractures following minor trauma. Dehydroepiandrosterone (DHEA) concentrations decrease substantially with aging but few data show clinical significance of this decrease. Testosterone in men decreases gradually with aging. In women estradiol and testosterone decreases in the postmenopausal state. Drop in estrogen leads to more bone resorption than formation resulting in osteoporosis and increased risk of fractures following trauma. Vitamin D concentrations decrease with age and circulating parathyroid hormone (PTH) concentration increase with age. Melatonin levels decrease with aging, which may play a role in loss of normal sleep-wake cycles. Glucose homeostasis tends toward disequilibrium with increasing age. Although glucose metabolism disorders increase with age, it is not a necessary component of aging.

Hematologic changes

Bone marrow mass decreases with aging and the marrow is replaced by fat. This leads to reduction in hematopoiesis. Red cell, platelet, and white blood cell function decreases with qualitative defects observed. Anemia in the elderly is common. Macrocytic anemia is usually from folate and vitamin B ₁₂ deficiencies due to poor nutritional intake. Microcytic anemia is usually due to iron deficiency, although occult blood loss should be investigated.

Immunologic changes

Aging causes a slower immune response and can decrease immune function, which contribute to increase in infections, autoimmune disorders, and malignancies.

Soft tissue and skin changes

Body composition changes with advancing age with increases in body fat and modest loss of observed muscle mass. The average adult gains approximately 1 pound of fat every year between ages 30 to 60 and loses about one-half pound of muscle mass every year during this time frame. This shift in body composition is often masked by relatively stable overall body weight. These changes lead to loss of maximal strength and fitness, which contribute to weakness, loss of dependence, and falls. Age-related changes to the skin occur making thermoregulation more difficult due to thinning of the skin. Loss of connective tissue and skin elasticity leads to increased risk of skin tears and avulsions.

Preexisting medical conditions and medications

Preexisting medical conditions increase with advancing age and are associated with increased mortality in patients with minor injuries (Injury Severity Score [ISS] 1–15) or moderate injuries but not in those with more severe injury (ISS >25). However, all comorbidities do not affect mortality equally. Hypertension and heart disease are the most common preexisting conditions among older adult trauma patients. The greatest mortality risk in geriatric trauma patients is the presence of preinjury hepatic disease, followed by renal disease and congestive heart failure (CHF). Decompensated CHF increases odds of death particularly in patients taking anticoagulants, beta blockers, or both. The immunocompromised state increases odds of death in nonfall mechanisms while hematologic disease and cancer increase odds of death for fall mechanisms in the older adult.

Polypharmacy is common among the older adult due to the need to treat various comorbid diseases. As the number of medications used increases, the probability of drug-drug interaction increases. Many drugs may contribute to falls, confusion, and urinary incontinence. Thorough review and streamlining of medications should be performed to minimize adverse effects. The Beers Criteria for Potentially Inappropriate Medication Use in the Older Adults gives guidance regarding medications that should be avoided in older patients and is supported by the American Geriatrics Society (AGS).

Common drug classes associated with adverse drug reactions include anticoagulants, nonsteroidal anti-inflammatory agents, cardiovascular medications, diuretics, anticonvulsants, benzodiazepines, and hypoglycemic agents. Specific drugs that may interact in trauma patients negatively include antihypertensive medications, anticoagulants, antiplatelet agents, and chronic glucocorticoids.

Antihypertensive medications may exacerbate hypotension in the hypovolemic patient. Beta blockers, commonly used to treat hypertension, improve mortality in patients with CHF or myocardial infarction. However, preinjury beta blocker use is associated with increased mortality in older patients without head injuries (odds ratio 2.148). This may be due to blocking of the normal cardiac response to trauma leading to a period of suboptimal resuscitation or occult shock. Calcium channel blockers have negative chronotropic, dromotropic, and inotropic effect and block the normal cardiac response to trauma. In the United States, implantable pacemakers have been estimated to be present in 500,000 to 3 million individuals with over 70% of all pacemakers placed in patients over the age of 65 years. Pacemaker-dependent patients will not be able to mount a tachycardic response to hypovolemia or hemorrhage.

Atrial fibrillation is a major problem affecting 9% of people aged 65 years and older. In the United States, there are approximately 2.7 million to 6.1 million individuals with atrial fibrillation, and it is projected 12.1 million people will have atrial fibrillation in 2030. The use of oral anticoagulants in patients with atrial fibrillation has become standard of care to reduce stroke risk. In addition to warfarin, direct oral anticoagulants (DOACs) are widely used to treat atrial fibrillation and venous thromboembolism. Direct thrombin inhibitors and direct factor Xa inhibitors are now commonly used in place of warfarin. Advantages of DOACs are that they do not require frequent testing of levels and have fewer drug interactions. The downside is the lack of an objective and widely available method to detect its use and the lack or limited availability of reversal agents. Routine coagulation assays do not provide complete assessment of level of anticoagulation induced by DOACs, and thromboelastograms do not reliably detect DOACs. Expedited head computed tomography (CT) scan for rapid confirmation of intracranial hemorrhage with anticoagulation reversal is indicated in trauma patients with head trauma to decrease progression of intracranial hemorrhage. Patients with possible blunt torso trauma should have prompt CT scans of the chest, abdomen, and pelvis to rule out intrathoracic, intra-abdominal, and retroperitoneal hemorrhage.

Heart disease is the most frequent condition in older adults and the number one cause of death. Risk of myocardial infarction and stroke is decreased with the use of antiplatelet agents. In March 2019 the American Heart Association (AHA) and the American College of Cardiology (ACC) updated their guidelines and no longer recommend aspirin for primary cardiovascular prevention in adults aged 70 years or older or for those with a higher risk of bleeding. Despite this aspirin use is widespread in older adults. A survey published in 2015 of U.S. adults aged 45 to 75 years reported that 52% used aspirin regularly. Additionally, dual antiplatelet therapy (DAPT) is the basis of maintenance medication following elective percutaneous coronary intervention or acute coronary syndromes and following ischemic stroke. Use of antiplatelet agents are common in the elderly and may exacerbate hemorrhage in the trauma patient. Information of preinjury use of these agents is important and as with anticoagulants, prompt CT scanning is essential to determine presence of intracranial, intrathoracic, intra-abdominal, or retroperitoneal hemorrhage. Medication discontinuation and reversal are indicated when there are significant injuries with risk of bleeding.

Chronic glucocorticoids are used to treat Addison’s disease, asthma, acute exacerbation of chronic obstructive pulmonary disease (COPD), rheumatic diseases, and prevention of rejection in organ transplants. Glucocorticoids increase mortality in trauma. Abrupt cessation or rapid withdrawal of glucocorticoids may cause symptoms of adrenal insufficiency. Longtime use of glucocorticoids may require stress dose steroids following severe traumatic injuries or severe stress.

“geriatric giants”

The term “geriatric giants” was coined by Bernard Isaacs in 1965 to emphasize the principal chronic disabilities of old age that impact on the physical, mental, and social aspects of the older adult. In 1965 the five geriatric giants referred to immobility, instability, incontinence, and impaired memory. Modern geriatric giants have evolved to encompass the syndromes of frailty, sarcopenia, anorexia of aging, and cognitive impairment. These conditions are the harbingers of depression, delirium, falls, and hip fractures.

Frailty

Frailty is a multidimensional clinical syndrome characterized by decreased biologic reserves and lower resilience to adjust to external stressors. It is thought to be associated with increased inflammation (with increase interleukin-6 and tumor necrosis factor alpha) and decreased anabolic-endocrine response (decreased growth hormone and insulin-like growth factor (IGF)-1). The initial definition of frailty included weight loss, exhaustion, weakness (grip strength), walking speed, and low physical activity. Based on this schema, a simple 5-point questionnaire was developed by the International Association of Nutrition and Aging ( Table 2 ).

TABLE 2

Simple FRAIL Scale

Source: Morley JE, Malmstrom TK, Miller DK. A simple frailty questionnaire (FRAIL) predicts outcomes in middle aged African Americans. J Nutr Health Aging 16(7):601–608, 2012.

F: Fatigue	Does the patient fatigue or get exhausted easily?
R: Resistance	Does the patient have difficulty walking up one flight of stairs independently?
A: Ambulation	Does the patient have difficulty walking one block (several hundred yards)?
I: Illnesses	Does the patient have five or more illnesses (comorbidities including hypertension, diabetes, cancer [other than minor skin cancer], chronic lung disease, heart attack, congestive heart failure, angina, asthma, arthritis, stroke, kidney disease)?
L: Loss of weight	Has the patient loss weight (5%) over the last 6 months to 1 year?

Three or more “yes” answers = possible frailty; 1 or 2 “yes” answers = possible prefrailty.

Many frailty scales are available with most requiring subjective input from the patient or proxy. On review of 32 unique frailty assessment tools only 4 frailty assessment instruments are objective and feasible. This includes the Electronic Frailty Model, Patel Modified Frailty Index, fall history, and the National Surgical Quality Improvement Program (NSQIP) Frailty Index. One frailty assessment tool specifically developed to assess frailty in the trauma patient is the Trauma Specific Frailty Index (TSFI). It consists of 15 variables and is based on the Rockwood Canadian Study of Health and Aging (CSHA) Frailty Score. The TSFI includes comorbidities, daily activities, health attitude, physical function, and nutritional status. Prospective validation of the TSFI in a single institution demonstrated that TSFI was an independent predictor of adverse discharge disposition, adverse complications, failure to rescue, and mortality. Downsides of the TSFI is its reliance on personal judgment and exclusion of unresponsive patients without a proxy. Recent comparison of the TSFI, Modified Frailty Index (mFI), Rockwood Frailty Scale (RFS, and Frail Scale demonstrated the highest predictive power of outcomes with the TSFI and RFS. The TSFI is currently undergoing multicenter validation.

Frailty, rather than chronologic age, is the dominant predictor of adverse outcome. Frailty has been demonstrated to be associated with complications, failure to rescue, intensive care unit (ICU) admission, adverse discharge disposition, and mortality in geriatric surgical patients. A recent study in 819 trauma patients aged 60 years or older with ISS greater than 15 measured frailty by the mFI and found that high frailty was associated with a higher rate of serious complications following polytrauma including unplanned intubation, infection, and renal failure. Additionally, increasing frailty was associated with increased mortality at discharge and at 1 year post injury.

Early identification of frailty and practice care guidelines may be beneficial in the geriatric frail patient. One small study utilizing a standardized clinical pathway to manage frailty in older trauma patients has demonstrated reduction in delirium and 30-day readmission. The study’s clinical pathway included processes of care a geriatrician would typically recommend including early ambulation, bowel and pain regimens, nonpharmacologic delirium prevention, nutrition, physical therapy, and geriatric assessments. Standardized order sets for geriatric focused care and consultations, family meetings, and fall prevention education were also utilized.

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