Jay A. Yelon
INTRODUCTION
According to U.S. census projections the elderly population, defined as age >65 years, is experiencing the largest growth in history. The post–World War II “baby boom” (75 million people born from 1946 to 1964) was 46–64 years old in 2010. By the year 2030, the elderly population will number 38 million and will usher in the gerentological explosion by 2050 in which 1 in 5 Americans will be elderly.1 The overwhelming evidence of this demographic imperative will result in an elderly population that is active and vital. The ever-increasing mobility and active lifestyles of today’s elderly place them at increased risk for serious injury. In fact, data from the National Trauma Data Bank (NTDB) for the year 2008 revealed that 30% of all patients in the registry were 55 years old or older.2 Injury is now the fifth leading cause of death in the elderly population.3
Older individuals sustaining injury respond differently than younger patients. The elderly have a higher morbidity and mortality, have more preexisting medical problems, and demonstrate a senescent physiologic response to injury when compared with younger individuals. Many of the reasons for the differing response are unknown. The literature, albeit plentiful, can be contradictory in places and there are few prospective randomized trials that focus specifically on the elderly. This is best demonstrated by a lack of consensus on the definition of what age constitutes elderly. Historically geriatric patients were considered to be patients over the age of 65 years. There are a variety of organ-specific injuries that demonstrate rising morbidity and mortality at chronological ages less than 65 years. As such, elderly should be viewed from the vantage of the physiologic response to an injury or injury complex rather than a specific age. Despite these limitations, this chapter will focus on an overview of care for the injured geriatric patient.
AGING
Declining cellular function is part of the aging process. Eventually, this will lead to organ failure. The aging process is characterized by impaired adaptive and homeostatic mechanisms, resulting in increased susceptibility to the stress of injury. This is commonly perceived as decreased physiologic reserve. Insults commonly tolerated by younger patients can lead to devastating results in the elderly patient. Differences in the metabolic response to injury were studied by Frankenfield and colleagues. In their study, they compared injured patients by dividing them into those older than 60 years and those who were younger. These investigators concluded that the metabolic response to injury is significantly attenuated in the elderly population. This was demonstrated by the older group having less fever, less oxygen consumption, more hyperglycemia, and more azotemia.4 This may be driven by the fact that there is evidence that immune function is significantly attenuated during the aging process and that cytokine response is impaired. This immune senescence is, in part, a function of reduced neutrophil function. Butcher et al. investigated a group of patients older than 65 years sustaining mild trauma (hip fracture). Neutrophil phagocytic function was assessed immediately after injury and patients were followed for 5 weeks for clinical infection. When compared with a younger cohort, the older patients had a significant reduction in neutrophil phagocytic function as measured by significantly depressed superoxide production.5 Additionally, nearly half of the elderly population suffered bacterial or fungal infection within the study period, compared with no infection in the younger patients. These authors suggest that the aging immune system may be a result of falling dehydroepiandrosterone (DHEA). In the presence of the physiologic stress of injury, patients have an obligatory rise in corticosterone levels, which is immune suppressive. The elderly patient, with a depressed DHEA level, produces a milieu of corticosterone excess contributing to neutrophil dysfunction.
ORGAN FUNCTION AND AGING
Cardiac
Cardiovascular comorbidities are most frequently seen in the elderly patient. Cardiac function declines by 50% between the ages of 20 and 80 years. The declining function is combined with a decreased sensitivity to catecholamines.6 The expected cardiovascular response to hypovolemia may not be apparent. This may be further complicated by a variety of medications, which includes β-blocker therapy.7 The cellular elements of the conductive system and the myocytes themselves are gradually replaced by fat and fibrous tissue. The resultant stiffer heart is more prone to dysfunction and to dysrythmias. Atherosclerotic changes to the arteries are common and valvular anatomy is changed by tissue thickening. The increased afterload causes an increase in systolic blood pressure and enlargement of the heart. The system is generally well compensated while at rest. However, in the event of hypovolemia, elderly patients generally are unable to compensate with tachycardia and an increase in cardiac output. The response is generally characterized by an increase in systemic vascular resistance. Traditional vital signs can be misleading. Despite “normal” blood pressure, many of these patients have evidence of tissue hypoperfusion.8
Pulmonary
There are significant anatomic and physiologic changes that occur in the respiratory system that are associated with aging. Grossly, with age-related loss in bone density, there is development of thoracic kyphosis. Rib calcification is associated with a decrease in transverse thoracic diameter. Muscle mass is reduced and the elastic recoil of the lung decreases with age. These anatomic changes result in a decreased compliance of the chest. Reduction in functional residual capacity and gas exchange is obligatory.9 The elderly commonly experience decreased cough reflex, decreased function of the mucociliary epithelium, decreased response to foreign antigen, and increased oropharyngeal colonization with microorganisms. These changes place the elderly patient at risk for hospital-acquired pneumonia.10
There is a decrease in alveolar surface area after the age of 30 years. This results in decreased alveolar surface tension that ultimately interferes with alveolar gas exchange. The alveoli are also noted to flatten and become shallow, thereby decreasing effective surface area for gas exchange. Diffusion capacity is decreased because of the decrease in effective surface area and an increase in alveolar–capillary membrane thickness.11
Renal System
Above the age of 50 years, renal mass is lost. Progressive sclerosis of the glomeruli occurs with normal aging. Between the ages of 50 and 80 years, there is a decrease in glomerular filtration rate (GFR) by about 45%.6 Generally, this is not detected by routine renal function testing, as it is accompanied by a decrease in total muscle mass and production of creatinine. The Cockroft–Gault formula can be used to estimate the degree of dysfunction. Furthermore, the endocrine response of the kidney to ADH and aldosterone is abnormal. This results in a decrease in the ability of the kidney to concentrate urine. Elderly patients may be able to maintain a deceptively adequate urine flow despite hypovolemia. As such, urine output should be used cautiously as a surrogate for renal perfusion.12,13
These age-related changes in renal function put the older patient at significant risk for acute kidney injury following trauma. Likewise, the elderly are at risk for developing untoward effects of aggressive volume resuscitation—such as hyperchloremic metabolic acidosis and volume overload. Care must be maintained when dosing renally excreted drugs to these patients.
Skin/Soft Tissue and Musculoskeletal System
Older people undergo an obligatory loss of lean body mass. This loss is estimated to be about 4% every 10 years after the age of 25. This loss then increases to approximately 10% after the age of 50. The loss of muscle is accompanied by a proportional increase in adipose tissue. From a skeletal aspect, osteoporosis is a common feature of aging. Over time, this loss can amount to 60% of trabecular bone and 35% of cortical bone.14 This makes the elderly individual at risk for fractures, especially those involving the vertebrae, hip, and distal forearm. There are age-associated changes of the joints and cartilages resulting in osteoarthritis and other degenerative features affecting nearly all joints. Degenerative changes to the cervical spine are particularly worrisome in the older population. Mobility is greatly affected putting this area at risk for injury. Additionally, oral intubation can be affected by this loss of mobility.15
Changes of the skin and soft tissue with loss of elastin and subcutaneous fat not only place the patient at risk for direct skin injury but may also complicate underlying fractures, such as pelvic fractures or open fractures.
Endocrine
There are age-related changes that affect endocrine function. The tissue responsiveness to thyroxin and its production is reduced.6 Secretion of cortisol does not seem to change with aging, but given decreases in DHEA production, this may predispose the physiologically stressed elderly patient to a hypercortisone state.
Functional Reserve
Maintaining homeostasis in the face of physiologic stress is a demonstration of good functional reserve. Declining functional reserve in the elderly may precipitate a decline in performance when the patient is exposed to chronic or acute illness. When faced with a physical insult, homeostasis may be poorly maintained (Table 44-1; Fig. 44-1).
TABLE 44-1 Organ System Changes with Aging
FIGURE 44-1 The functional reserve is the difference between basal function (red line) and maximal function (blue line). Even in healthy individuals, this functional reserve is reduced. (From Muravchick S. Geroanesthesia: Principles for Management of the Elderly Patient. St. Louis, MO: Mosby; 1997, with permission. Copyright © Elsevier).
The decline in functional reserve is heterogeneous. A variety of factors will impact on the magnitude of the loss of functional reserve. These include age-related disease and their treatments, genetics, lifestyle choices, and environmental factors. It is clear that older patients do not tolerate injury as well as younger patients. What is not clear is the reason for this discrepancy. The impact of preexisting medical problems,16–18 in combination with a declining functional reserve, results in poor outcome. This impact on outcome can be reduced by an aggressive management approach to the patient.
MANAGEMENT
Triage
Improper triage seems to contribute to the poor outcomes experienced by some elderly trauma patients. The effectiveness of triage can be evaluated by looking at the interaction between injury severity and complication rate, mortality, or requirement for intervention.19 Elderly patients with severe injury who are not treated with full trauma team activation (TTA) would be considered to be undertriaged. Multiple studies have shown a large incidence of undertriage as compared with younger patients.19–22 Undertriage can be viewed as a modifiable risk factor for poor outcome in the older patient. Lehmann et al. demonstrated that the classic physiologic criteria for TTA, that is, blood pressure and heart rate, failed to independently predict hospital mortality or the need for urgent interventions.20 These authors attribute the older patient’s “pseudostability” to declining functional reserve and the interaction of premorbid medications. Use of initial vital signs in the elderly population can be misleadingly normal. In a study from Los Angeles patients 70 years of age and older admitted to the trauma center were reviewed. Sixty-three percent of patients with an Injury Severity Score 
and 25% of patients with an 
did not meet the hypotension or tachycardia criteria for TTA. In this study, the overall mortality in “stable” patients not meeting any of the standard TTA criteria was 16%.19 The impact of apparently “minor” injury can have major impact on the older patient. Rib fractures and pulmonary contusions can lead to an abrupt decompensation and injuries such as intracranial hemorrhage are commonly underappreciated. It has been suggested that patient age of 70 or older be used as a criterion for TTA.19 The age at which triage and management issues become problematic is also controversial. The current recommendation of the ATLS program is 55 years of age.23 This is based on data from the Major Trauma Outcomes study that noted a significant increase in mortality between the 45- and 54-year-olds.24 TRISS uses a similar age cutoff, although a recent work examining TRISS methodology seems to indicate an older age is more accurate. Caterino et al., using the Ohio trauma registry, examined mortality trends. Regression analysis identified 70 years of age to be the most promising cutoff for predicting increased odds of mortality.21
Initial Assessment
Airway
The elderly airway poses specific challenges for providers. Given the fact that the elderly have significant loss of protective airway reflexes, timely decision making for establishing a definitive airway can be lifesaving. Patients may have dentures or be edentulous, the former making bag–mask ventilation easier. Arthritic changes may make mouth opening difficult. Choice of appropriately sized direct laryngoscopy equipment is mandatory. When performing rapid sequence intubation the doses of barbiturates, benzodiazepines, and etomidate should be reduced between 20% and 40% to minimize the risk of cardiovascular depression.25
Breathing
The anatomic and physiologic changes in the respiratory system associated with aging are reviewed above. Changes in the compliance of both the lungs and the chest wall result in an increased work of breathing with aging. These changes associated with the possibility of nutritional deficits and the supine position place the elderly trauma patient at high risk for respiratory failure. Given a suppressed heart rate response, as a result of aging, to hypoxia, respiratory failure may present in a more insidious fashion. Diagnosis can sometimes be difficult in interpreting clinical and laboratory information in the face of preexisting respiratory disease or nonpathologic changes in ventilation associated with age. Frequently, decisions to secure a patient’s airway and provide mechanical ventilation may be made prior to fully appreciating underlying premorbid respiratory conditions. This action may be lifesaving. However, intubation and mechanical ventilation in the elderly patient should not be taken lightly. The risk of ventilator-associated pneumonia and the possibility of prolonged ventilation are significant.25 The role for noninvasive mechanical ventilation in the acute resuscitative phases of trauma care seems to be very limited and is likely associated with significant risk to the patient.
Circulation
Age-related changes in the cardiovascular system place the elderly trauma patient at significant risk for mislabeling the patient as being “hemodynamically normal.” Since the elderly patient may have a fixed heart rate and cardiac output, response to hypovolemia will occur by increasing systemic vascular resistance. To further demonstrate the lack of classic symptoms as they relate to cardiovascular pathology, Chong and colleagues evaluated troponin I levels following emergency orthopedic surgery. One hundred and two patients over the age of 60 were evaluated, of which 52.9% of patients had elevated levels. The majority of patients with elevated troponin levels had no cardiac symptoms and had an increased mortality within 1 year of the event. Furthermore, since many elderly patients have preexisting hypertension, the seemingly “acceptable” blood pressure may truly reflect a relative hypotensive state. As such, identifying the patient who has significant tissue hypoperfusion is mandatory. Several methodologies have made, and continue to be used to make, this diagnosis. These include base deficit, serum lactate, age-adjusted Shock Index, and tissue-specific end points.8,26–28 Resuscitation of the geriatric hypoperfused patient is the same as all other patients and based on appropriate fluid and blood administration. The elderly trauma patient with evidence of circulatory failure should be assumed to be bleeding. However, given the incidence of elderly people with preexisting disease states, one should keep in mind that some physiologic event may have triggered the incident leading to injury. Ultimately an aggressive approach to resuscitation of the elderly patient with overt shock or a tissue-hypoperfused state will result in acceptable outcomes. Less aggressive measures based on the patient’s age are not acceptable.
Disability
Traumatic brain injury (TBI) is a problem of epidemic proportion in the elderly population.29 Older age is a known variable for poor outcome following brain injury. Aging will cause the dura to become more adherent to the skull. Additionally, older patients are more commonly prescribed anticoagulant and antiplatelet medications for preexisting medical conditions. These two factors place the elderly individual at high risk for intracranial hemorrhage. Atherosclerotic disease is common with aging and may contribute to primary or secondary brain injury. Moderate cerebral atrophy will permit intracranial pathology to initially present with a normal neurologic examination. Early identification and timely appropriate support including correction of therapeutic anticoagulation can improve outcomes.30
Exposure
Musculoskeletal changes associated with the aging process pose special concerns during this aspect of the initial assessment of the elderly trauma patient. Loss of subcutaneous fat, nutritional deficiencies, chronic medical conditions, and the associated medical therapies will place the elderly patient at risk for hypothermia and the risks associated with immobility (pressure ulcers, delirium). Rapid evaluation and, when possible, early mobilizations will prove to minimize the morbidities.
SPECIFIC INJURIES
Traumatic Brain Injury
In the elderly age group, TBI accounts for more than 80,000 emergency department visits each year of which a majority result in hospitalization. Falls are the leading cause of TBI for people over the age of 65 years (51%), followed by motor vehicle collisions (9%).29 Health care costs associated with the treatment of TBI in the elderly exceeded $2.2 billion in 2003.31 TBI is clearly a major health care problem in the elderly population. The current evidence-based approach to treating severe TBI in the adult is a “one size fits all” approach, neglecting specific issues of the older adult. Old age remains an independent predictor of worse outcome in TBI. An investigation using the New York State Trauma Registry compared mortality and functional outcome in elderly versus younger patients.32 In this study, Susman et al. demonstrated increased mortality in patients older than 65 years, but also showed that mortality increases as patients continue to age. These investigators also showed that a majority of elderly patients sustain TBI from falls and appear to have only mild TBI at admission and still had a much higher mortality as compared with younger patients. This same group then looked at the total effect of age on mortality after TBI.33 They concluded that mortality from TBI increases after 30 years, but has a sharp rise after 70 years. Given the anatomic changes associated with aging on the brain and the fact that a majority of elderly patients present with a GCS consistent with mild brain injury, a high index of suspicion must be maintained with the elderly patient presenting with any mechanism of head trauma. To address this, Mack et al. investigated the use of head computed tomography (CT) in elderly patients.34 This study specifically looked at mild head injury (GCS 13–15). In their study of 133 elderly patients, 14.3% had radiographic evidence of acute intracranial pathology. The authors also noted that there were no useful clinical predictors of intracranial injury and liberal use of head CT is recommended. Despite a higher mortality in general, patients surviving hospitalization will required aggressive rehabilitation. In a multi-institutional trial a group of elderly patients surviving their initial moderate to severe brain injury (head AIS = 3) were evaluated following discharge from acute care. In this cohort, there were few patients with low GCS who survived, and left patients with GCS of 13–15 to be evaluated. Functional outcome for these patients, as measured by the Glasgow Outcome Scale (GOS) and modified FIM, is good to excellent. Older patients required more inpatient rehabilitation and took longer to recover when compared with a younger patient cohort.35 Aggressive initial management and long-term rehabilitation in the elderly patient with TBI is required for acceptable outcomes.
Rib Fractures
Rib fractures in the elderly population pose a significant risk for morbidity and mortality when compared with younger patients, who, in general, suffer little morbidity. The morbidities include inadequate pain management, need for intubation, prolonged ventilatory support, and the development of pneumonia. Bulger et al. investigated the impact of rib fractures after blunt chest trauma in the elderly.36 This study showed a linear relationship between age, number of rib fractures, complications, and mortality. In a similar study, Holcomb et al. retrospectively evaluated 171 patients. These authors demonstrated an increase in negative outcomes based on increasing age and number of rib fractures. By grouping ages and number of rib fractures their data revealed that patients with more than four rib fractures who are older than 45 years exhibit increased morbidity (ICU length of stay [LOS], total LOS, ventilator days, and pulmonary complications). Given the impact of type of analgesia at reducing ventilator days and pulmonary complications, the authors attempted to determine the impact of epidural analgesia. Their data were unable to demonstrate a decreased incidence of morbidity and mortality. Given that this was only a portion of their entire population, it is possible that their results suffer from a type II statistical error. Analgesia is an important aspect of the care of the elderly trauma patient with rib fractures. The Eastern Association for the Surgery of Trauma has a Practice Management Guideline on chest trauma analgesia management.37 Readers are encouraged to refer to this document on evidence-based guidelines for analgesia. In an evaluation of data from the NTDB of the American College of Surgeons Committee on Trauma, Flagel et al. reviewed a large patient population.38 These investigators showed that the overall mortality rate for patients with rib fractures was 10%. This rate increased for each additional rib fracture independent of age. There was a similar trend of increasing pulmonary complication with additional rib fractures. The incidence of pneumonia in patients with up to five rib fractures was between 3% and 5.2%. This increased to 6.8–8.4% for patients with six or more rib fractures. These authors were unable to demonstrate that age is a risk factor for mortality in patients with rib fractures. Most recent data from a multicenter study of 1,621 patients were published by the Research Consortium of New England Centers for Trauma.39 These investigators evaluated patients over the age of 50 years with nearly isolated rib fractures. Thirty-five percent of the patients were admitted to the ICU with an average ICU LOS of 16.5 days and a total hospital LOS of 27.5 days. Intubation was required in 12% of patients and 4.3% went on to require tracheostomy. Univariate analysis of the data revealed risk factors for mortality were preexisting coronary artery disease or CHF, increasing age, ISS, number of ribs fractured, and increasing AIS for associated body regions. On multivariate analysis the strongest predictors of mortality were admission to a high-volume trauma center, preexisting CHF, intubation, and increasing age. Patient-controlled analgesia showed a trend toward improving survival but was not statistically significant. The only therapeutic maneuver that proved to be protective of survival was tracheostomy. Identification of the elderly patient with rib fractures and early recognition of respiratory failure with aggressive supportive maneuvers will potentially reduce morbidity and mortality of this lethal injury in the older patient.
Abdominal Injury
The nonoperative management of solid organ injury has generally become the preferred method of treatment for the hemodynamically normal patient. However, in the elderly trauma patient this approach must be used with caution. The classical physiologic response to hemorrhage that may be used as a criterion to attempt nonoperative care or as a marker for “failure” of nonoperative management may not be present. In a 6-year retrospective analysis of patients sustaining blunt splenic injury, Albrecht et al. evaluated the utility of nonoperative management of spleen injury in patients older than 55 years.40 In this small study of 37 patients meeting inclusion criteria, 13 patients went directly to the operating room; of the remaining 23 patients, nonoperative management was successful in 15 (62.5%) and failed in 8 (33.3%). Characteristics of the group that failed nonoperative management included higher AAST splenic injury grades and a greater likelihood of a large hemoperitoneum. In a larger retrospective study of 1,482 patients, 15% (n = 224) of who were 55 years or older, the mortality of the older population was significantly higher (43% vs. 23%) than the younger group. In this study 80% of patients over the age of 55 years were successfully managed nonoperatively, with 24 patients of the original 132 patients subsequently requiring exploration. Although not statistically significant, there was a trend toward increased failure rate with increasing grade of injury. When evaluated by grade of injury, grade I injuries had success rate for nonoperative management that was similar for younger and older patients. Success rates for older patients were lower for grade II (73% vs. 54%) and grade III (52% vs. 28%). All elderly patients with grade IV–V injuries required operation, either immediately or for failed nonoperative management.41 The data suggest that nonoperative management of splenic injury in the elderly patient should be undertaken with caution. Clear understanding of the grade of injury and assuring hemodynamic stability are absolute requirements. Elderly patients who fail nonoperative management may have a higher mortality as compared with younger patients.
Pelvic Fractures
Bone fractures are extremely common in the elderly population. Women are at particular risk because of osteoporosis. Relatively minor trauma can lead to significant bone injury. Pelvic fractures pose a significant risk for elderly patients, including the acute phase of fracture management, timing of operation, and functional outcome. The group from the R Adams Cowley Shock Trauma Center compared outcomes of patients sustaining pelvic fractures over a 2-year period.42 These investigators compared patients using age 55 years as a cutoff. Blood transfusion was required in 62% of older patients compared with 36% in the younger population 
. Further analysis revealed that patients who received transfusion were 2.8 times more likely to be over the age of 55. Mortality for the younger group was 6.2% compared with 20.5% for the older group 
, meaning the older group was four times more likely to die than the younger patients. Even after adjusting for ISS, death was four times more likely in the elderly patients. The authors suggest that every elderly patient with a pelvic fracture should be considered hemodynamically unstable until proven otherwise. Another consideration in the management of the elderly patient with orthopedic trauma is the timing of operation. The decision to proceed with orthopedic operation is made with the consideration of multiple variables that include extra-orthopedic injuries, physiologic status, and the magnitude of the operation planned. In a series of 367 elderly patients with hip fracture, a delay in operation for more than 2 days was associated with more than double the risk of death within the first postoperative year.43 Most believe that orthopedic operation to allow for mobilization from bed should occur as soon as possible when physiologic conditions have been optimized. Functional outcome is an additional consideration in caring for fractures in the elderly. Careful consideration by the orthopedic traumatologist is required when deciding between operative and nonoperative management as it relates to function. Osteopenic bones also need to be taken into consideration when dealing with periarticular fractures. Aggressive physical and occupational rehabilitation have been shown to improve outcomes as determined by patient satisfaction.
Burns
Burn injury in the elderly population is particularly devastating. The elderly burn patient has a higher mortality for a given size burn than younger patients. In fact, predictors of survival from burn injury continue to rely on age as a significantly weighted variable. Despite significant advances in the science and management of burn injury, the LD50 for burns in the 65 years or older population remains approximately 20% total body surface area (TBSA). Older individuals are at a significant risk for burn injury due to impaired mobility, diminished senses, and slower reaction time, all characteristics making it difficult to escape harm, ultimately leading to deeper and more extensive burns.
Predicting survival in older burn patients is important. It provides a framework for discussing realistic clinical expectations with patients and their families, and may allow for appropriate utilization of resources associated with the intensive care of burn patients. Wibbenmeyer et al. attempted to address this predictive model in relation to modern burn care.44 They reviewed 308 burn patients over the age of 60 years. A majority of these patients sustained flame burns of which 41.4% were sustained in household incidents. Sixty-four percent of the patients had at least one preexisting medical problem. The median TBSA size was 13%. The mortality for the cohort was 30.2%, with an LD50 of 30%. When this was further evaluated, the LD50 was age dependent. Specifically, for patients aged 60–69.9 it was 43.1%, for ages 70–79.9 it was 25.9%, and for those 80 years and older the LD50 was 13.1%. As expected, the presence of an inhalation injury significantly impacted survival negatively. These authors concluded that death was significantly related to age, TBSA burn, and presence of inhalation injury. Comorbidities did not impact on mortality. The Baux score is calculated as the sum of the age of the patient and the TBSA burn is an estimate of the percent mortality and is supported by data from this study. The abbreviated burn injury severity (ABSI) score, calculated as the weighted sum of age, gender, TBSA, percentage of full-thickness injury, and presence of inhalation injury, was also predictive of survival, but less so than the Baux score. The authors were unable to demonstrate an improvement in survival over the 20-year period of data collection. Another study from the Burnett Burn Center at Kansas University Medical Center retrospectively reviewed three decades of care for the elderly burn patient.45 Two hundred and one patients over the age of 75 years were evaluated. This group showed a 77% mortality rate in the 1970s, compared with a combined overall mortality of 41% during the 1980s and 1990s, suggesting a decrease in mortality with improved overall care of this population; however, the LD50 remained 20% TBSA.
Ho et al. reported outcome data from their regional burn center.46 They evaluated 94 patients over the age of 60 years. When compared with a younger population of burn patients, the older patients had a longer LOS, a mortality of 7.4%, and no differences in outcome based on early versus late excision. Timing of excision has yielded conflicting data. Deitch prospectively showed that early wound closure decreased LOS and number of septic complications and improved mortality.47 The studies by Ho and Wibbenmeyer did not show the benefits of early excision. Finally, gender seems to impact outcomes in elderly burn patients. Chang et al., from the University of Utah, demonstrated a higher mortality, longer LOS, and less likelihood of being discharged home in older female patient when compared with older men.48
Maintaining an aggressive approach to the older burn patient is warranted in the context of survivable injuries. Advanced age, larger burns, and the presence of inhalation injury are all negative predictors of survival in this population. Realistic therapeutic expectations are important for patients, their families, and the burn team when taking care of these very challenging patients.
Penetrating Trauma
With the growth in the proportion of elderly people there will be an obligatory rise in the number of elderly trauma patients. By far, blunt trauma is the predominant mechanism for injury; however, there are still a significant number of people over the age of 65 years who are victims of penetrating injury. It should be remembered that many of these patients may be victims of suicide attempt, a major cause of death in the geriatric population. In the original Major Trauma Outcome Study (MTOS), when examining patients over the age of 55 between the years 1982 and 1987, elderly patients had a higher mortality when compared with a younger cohort.49 Also, Finelli et al. reported a significantly higher mortality in the elderly (52%) compared with younger patients (20%) sustaining gunshot wounds.50 In contrast, Roth et al. from Los Angeles County and the University of Southern California retrospectively reviewed 79 patients over the age of 55 years suffering penetrating injuries. Their data showed no difference in mortality between elderly and younger patients (23% vs. 18%). Interestingly, 50% of the elderly patients who died presented with “normal” vital signs.51
Critical Care
In a large retrospective statewide trauma registry review of 22,571 blunt trauma patients of which 7,117 were elderly, ICU utilization was evaluated.52 The entire population had an ICU admission rate of 42.7% with a mean ICU LOS of 5.77 ± 8.86 days. The elderly patients, in contrast, had a lower ICU admission rate of 36.7% when compared with the younger population (45.5%). Interestingly, those elderly patients admitted to the ICU had a significantly longer ICU LOS. The lower utilization of ICU resources in the elderly may be explained by a higher early mortality and/or end-of-life (EOL) decisions that may have precluded admission to an ICU setting. Preventable complications in the elderly trauma patient significantly impact outcome. DeMaria et al. demonstrated an association of complications with death (32%) and an association of deaths from multisystem organ failure (62%).53 The relationship between senescence and infection deserves mention. Bochicchio et al. showed an increase risk of infection in elderly patients (39%) when compared with a younger population (17%) 
.54 Once infected, the elderly patients are at much higher risk for death (28%) than their younger counterparts (5%) 
. An aggressive approach to the older patient with infection is essential for improved outcomes. The aggressive management may include hemodynamic monitoring. Scalea et al. suggested that early invasive monitoring of the geriatric trauma patient can improve outcome.55 Noninvasive monitoring of elderly patients has been investigated in the critical care setting, but little has been concluded regarding the critically ill trauma patient.56 Because the elderly will fail to demonstrate the classic physiologic responses to shock, it is important to maintain an aggressive approach toward monitoring and resuscitation. The utility of invasive monitoring and aggressive critical care is demonstrated in a study on outcomes of elderly patients with acute respiratory distress syndrome (ARDS). In this study, Eachempati et al. evaluated a protocol approach to ARDS utilizing lung protective ventilator strategy and invasive hemodynamic monitoring. The investigators were able to demonstrate, in a group of 210 elderly patients with ARDS, a lower mortality when compared with historical controls despite higher illness severity.57
Delirium in the elderly trauma population is now being recognized as a significant risk factor for morbidity and mortality in the ICU. Delirium is characterized as a disturbance of consciousness associated with fluctuating mental status and disorganized thought. It complicates at least 20% of hospitalized patients over the age of 65 years, and increases hospitals costs by $2,500 per patient resulting in $6.9 billion of Medicare hospital expenditures.58 There is also a 3-fold higher mortality over 6 months following a single episode of delirium in the ICU.59 Understanding of the impact of delirium in the trauma patient has only recently been investigated. Pandharipande et al. undertook a prevalence study of delirium in their trauma and surgical ICUs. Using a validated screening tool, the CAM-ICU, these investigators found an overall prevalence of delirium of 70% (73% in surgical patients and 67% in trauma patients).60 The group from the trauma center at Denver General Health Science Center performed a 4-month study of 69 patients admitted to their trauma ICU following injury. They found a 59% incidence of delirium overall, and higher if the patient was mechanically ventilated. On univariate analysis, age proved to be a predictor for the development of delirium. However, on multivariate analysis the strongest predictors for transitioning into delirium were lower arrival GCS, higher packed red blood cell transfusion, and higher multiple organ failure (MOF) score.61 Most recently, a two-center study examining the impact of delirium on outcomes was performed. A total of 134 patients were evaluated, of which 63% progressed to delirium during their ICU stay. The patients with delirium had more ventilator days and longer ICU and hospital LOS. These investigators were unable to show a relationship between increasing age and the development of delirium.62 The association of advanced age and delirium is strong; in fact, delirium and dementia are highly interrelated; however, the nature of this interrelationship remains poorly examined.58 The association of delirium with opiod narcotics and benzodiazepines is well established and care must be taken in prescribing these medications to all patients, but especially the elderly. The issue of appropriate and goal-directed analgesia and sedation is commonly faced by the ICU staff. Finally, delirium represents one of the most common preventable adverse events among older persons during hospitalization.63 As such, the development of delirium in a patient may reflect processes of care in the hospital and therefore a reflection of the quality of care of that individual. Those caring for elderly injured patients must be aware of the development, diagnosis, prevention, and, if needed, appropriate treatment of delirium in order to provide the highest quality of care to this population.
OUTCOMES
Injured elderly patients admitted to the hospital consume significant health care resources. Average hospital lengths of stay are generally around 10 days and these patients usually stay in the ICU longer than younger patients (except for early deaths). Hospital-acquired complications are independent predictors of mortality in this age group. Richmond et al., in 2002, reported their 10-year retrospective statewide trauma registry review of geriatric trauma.64 They evaluated all patients 65 years or older who were included in the registry. Nearly 62% of the patients were injured as a result of a fall. This was followed by motor vehicle collisions in 22.6%. Operation was required in 28% of cases, and 37% of the cohort had a preexisting medical condition. Average LOS was 11.5 days and one third of the group required ICU admission. Ten percent of all patients died. These investigators found that as age increased the patients had higher mortality and more complications, and in those who survived, more patients required discharge to a facility other than home. The patients who died had a greater number of injuries with more body regions involved with a resultant higher ISS. Admission physiologic markers may predict those at risk for mortality. In a statewide trauma registry review from Pennsylvania, elderly patients who were hypotensive, had a GCS of 3, or had a respiratory rate of less than 10 had a significantly increased risk of death.52
Preexisting Conditions (PECs)
The interaction between injury and patient factors has been studied extensively. Data are conflicting regarding the impact of these factors on mortality. Despite this, there is a large body of evidence that PECs will impact morbidity and likely mortality. Morris et al. identified five PECs that appeared to influence outcomes.18 In that study of over 3,000 patients, one fourth of patients over the age of 65 years had one of the five PECs. These investigators identified cirrhosis, congenital coagulopathy, COPD, ischemic heart disease, and diabetes as PECs that influenced outcomes in trauma patients. Patients with one or more of these PECs were nearly two times more likely to die than those without PECs. These same authors then reported the interaction between injury and host factors, which included age, gender, and PECs.17Although injury severity was the primary determinant of mortality, host factors also played a significant role. These studies were later corroborated by a study by Grossman et al., in which an ISS >30 was considered the LD50, each additional year of age greater than 65 years carried a mortality increase of 6.8%, and PECs with the greatest impact on mortality were hepatic disease, renal disease, cancer, and congestive heart failure.16
Complications
There seems to be a relationship between PECs and the development of postinjury complications. The additional morbidity of a complication increases mortality. In a study by Taylor et al., reviewing a large statewide trauma registry, 6.2% of elderly patients developed pneumonia. Both preexisting pulmonary disease and increased ISS were risk factors for the development of pneumonia. Pneumonia predicted both an increased ICU and an increased hospital LOS. In this study, 5.9% of patients developed acute kidney injury that incurred a greater than 10-fold increase in mortality. Finally, the development of sepsis, which occurred in only 1.2% of patients, significantly increased mortality, ICU LOS, and hospital LOS. The only risk factor identified with the development of sepsis was increased ISS.65
Resource Utilization
The association between age as an independent predictor and outcome as documented by increased mortality and hospital LOS is well supported in the literature. Although hospital LOS is increased, ICU utilization is less than that by a younger population.52,65 This is due to an increased early mortality that is seen in the elderly, as well as decreased ICU admission resulting from advanced directives. Data from the Healthcare Financing Administration demonstrate that ICU use decreased with age and was least likely for age over 85 years.31 Young et al. looked at outcome in a cohort of elderly trauma patients.66 In this study, although the older group had a higher mortality rate, there were no differences in hospital or ICU LOS, or in ICU admission rate. In a study by Taylor et al., the elderly group had a lower ICU admission rate (36.7%) compared with younger trauma patients (45.5%). However, elderly patients, once admitted to the ICU, had a longer ICU LOS.52 The impact of withholding or withdrawal of care may influence ICU LOS. Plaisier et al. examined the practices of EOL care in a group of trauma patients. They divided their patients into elderly and younger groups that they cared for in their single institution. These investigators found there was no age bias in the elderly trauma patients admitted to the ICU.67
STRATEGIES FOR IMPROVING OUTCOMES
Triage
There are numerous studies suggesting that elderly trauma patients are undertriaged to trauma centers despite the proven mortality benefit of trauma center care. Statewide data from Maryland demonstrated that fewer elderly trauma patients were transported to trauma centers despite meeting physiologic criteria for trauma triage.68 In a similar study evaluating the Washington State trauma registry, Lehmann et al. demonstrated that patients over the age of 65 years despite having 
were less likely to have the prehospital trauma system activated, the trauma team activated, and a full trauma team response.20 The group of undertriaged elderly patients had a significantly higher mortality, discharge disability rate, and complication rate when compared with a group of younger patients. Meldon et al. demonstrated a significant survival benefit for severely injured elderly patients when treated in a trauma center (56%) versus a nontrauma center (8%).69 It is not clear why older patients are undertriaged; however, this group is less likely to demonstrate hypotension and tachycardia that are commonly seen in younger patients.
Medications
The increased awareness in medication reconciliation and its impact on patient safety is prominent in health care regulation. Medication-related problems are a significant health care problem. This is an important consideration in caring for the injured elderly patient. The acuteness of the hospital admission, and, at times, the initial underappreciation of significant anatomic injury, results in a potentially modifiable situation highlighting the importance of knowledge of a patient’s premorbid medications and the potential interaction of any newly prescribed medications. The Beers criteria are consensus criteria for safe medication use in elderly patients.70 Use of this system, along with expert input from geriatricians and pharmacists, may prove to reduce adverse drug reactions in older patients. There are a number of medications that deserve mention specifically relating to the trauma patient. β-Blockers are used in approximately 20% of elderly patients with coronary artery disease and 10% of patients with hypertension. The inherent physiologic blockade of the expectant response to hypovolemia may provide triage and treatment obstacles. Additionally, the impact of prolonged β-blockade on the progression and outcome of trauma and burn injury is not fully understood. Anticoagulation, in the form of both warfarin and antiplatelet therapy, poses significant problems for the bleeding patient. Warfarin therapy is used in a variety of commonly seen medical conditions in the older individual. The therapy itself carries a 1% per year risk of spontaneous intracranial hemorrhage. Assessment of the therapeutic level is important as many patients will be subtherapeutic or supratherapeutic. Many studies assessing the impact of warfarin on trauma, and specifically head injury, are limited in that they do not address the clinical level of anticoagulation. To address this limitation, a study of 3,242 trauma patients over the age of 50 years was performed. In this retrospective analysis international normalization ratio (INR) data were used as a surrogate for warfarin anticoagulation. These investigators demonstrated a mortality rate of 22.6% in the group with an 
compared with 8.2% for those with an 
. After adjusting for age and ISS the odds of death for each 1 U increase in INR were 30%.30 Patients with supratherapeutic anticoagulation fare even worse. In a study of 49 patients with severe TBI and an average INR of 6.5, the mortality rate was 87.8%.71 A more recent study comparing head and nonhead injury patients on anticoagulation with a matched control group showed no difference in mortality.72 A limitation in this study was that INR data were not included. Antiplatelet therapy is less well studied. This class of drugs includes aspirin (ASA) and clopidogrel, among others, is increasingly used for a wide variety of cardiovascular problems. In a registry review of patients over the age of 50 years sustaining TBI, patients taking ASA or clopidogrel were compared with those not receiving antiplatelet therapy. A statistically different mortality rate was observed for the two groups. The group receiving antiplatelet therapy had a mortality of 23% compared with 8.9% 
in the control group. Risk factors for death in this study included age >76 years and 
.73 Rapid reversal of anticoagulation with FFP transfusion is beneficial. Reversal of an elevated INR to normal within 2 hours reduced mortality from 48% to 10%.74 The role for factor VIIa is not completely clear; however, it seems to be effective in reversing anticoagulation in patients receiving warfarin.75
Specialists
The role for the geriatrician in the management of elderly trauma patients is logical. There are age-specific nuances in the care of these patients that make the geriatric specialist an invaluable member of the extended trauma team. Landefeld has shown that geriatric medical patients cared for in a special geriatric unit were less likely to require long-term care facilities than those cared for in standard medical wards.76 Fallon et al. had developed the idea of a “geriatric trauma team.”77 This involves the mandatory consultation from a group of interested and dedicated geriatricians. The consultants were able to address a variety of medical conditions in the study sites elderly trauma patients. These included pain management, rehabilitation, delirium, and advanced care planning, to name a few. Most notably, the group of patients seen in consultation had a lower mortality than a group of elderly trauma patients not seen by a geriatrician. There seem to be age-specific interventions that may improve outcome in this population. One of the first attempts to address this was work from Kings County trauma service. In this study, the authors were able to demonstrate an outcome benefit from early invasive monitoring and intervention.55 Recently, a study by Nathens et al. investigated the impact of an intensivist-model ICU on trauma-related mortality.78 In this large multicenter study, the authors concluded that an intensivist-model ICU when compared with an open-model ICU significantly reduced mortality. Furthermore, the greatest risk reduction was seen in the elderly population (RR, 0.55 [0.39–0.77]).
END OF LIFE
The ICU is an environment in which EOL decisions are made on a regular basis. In fact, in the United States, 38% of all hospitalized patients who died spent at least 10 days in the ICU.79 Older patients, having an understanding of their own wishes regarding health care, frequently utilize advanced directives and health care proxies. Many times, patients are educated regarding these legal entities through interaction with an astute family physician or by way of a previous elective hospital admission. Understanding the logistics of these documents is mandatory when caring for trauma patients. Given the acute onset of trauma, patients’ inability to predict future injury requires trauma practitioners to rely on a written document that may have been written years prior or by interactions with a health care proxy. The health care proxy is an individual who is appointed by a competent adult, who in the event that the individual is no longer able to make health care decisions would “speak” on behalf of the patient. There is evidence that physicians frequently have differing opinions regarding clinical outcome compared with the health care proxy, as well as personal beliefs that can influence EOL decisions.79 Withholding and withdrawing life support is commonly practiced in ICUs. Common reasons for this are futility, patient suffering, and the anticipation of a poor quality of life. In order to investigate the potential bias of age in withholding or withdrawing support, Plaisier et al. studied practice in their ICU. Despite a small patient population, this single-institution study was unable to show a difference between young and old regarding these EOL decisions.67 Futility is a concept with distinct ethical definition. Unfortunately, the term is applied frequently in situations that are strongly influenced by local environment and culture. What may be viewed as futile by one physician may not be seen in the same way by another. As such, utilization of ethics consultation will be important. The perception of suffering of elderly trauma patients is a cause of emotional distress for the ICU staff.80 The ubiquitous use of analgesics and sedatives in the ICU is necessary, but the science is imprecise. Most surgical ICU patients who survive indicate that they would repeat the experience again if necessary.81 EOL decisions based on this argument are not indicated. Using the argument of a poor quality of life is commonly based on the perceptions, beliefs, and personal interpretation of quality of life of the health care providers. Care must be taken to not interject one’s own beliefs when counseling families. When elderly ICU survivors were studied, most agreed that they have an acceptable quality of life and would undergo treatment again.82Quality of life following ICU treatment in trauma is not widely available. Limiting care in the elderly trauma patient in whom likely survival is nil is a necessary and ethical aspect of care provided by trauma practitioners. Utilizing standard ethical concepts and precise diagnoses will help facilitate discussions with families. Palliative care consultations have been used successfully with trauma patients, which can improve family and staff satisfaction with EOL care.83
CONCLUSION
The elderly population continues to grow at an exponential rate. Coupled with improved medical care and quality of life, the older individual is able to participate in a fulfilling and active lifestyle. As such, the elderly individual is at risk for injury. It is mandatory that trauma practitioners become familiar with the anatomic, physiologic, and philosophical needs of older people. Understanding these changes will allow appropriate delivery of high-quality trauma care to this population.
Falls and motor vehicle collision remain the primary mechanisms for injury. Preexisting medical problems, including depression, place these individuals at high risk for poor outcomes. Similarly, depression and chronic medical problems make suicide a true health care problem in this vulnerable population.
Early identification of the older patient with shock using nontraditional end points, coupled with an aggressive approach at resuscitation, monitoring, and treatment, will improve outcomes, ultimately returning the elderly patient to an acceptable quality of life.
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