following inhalation injury [69]. Burn injury may also uncover comorbidities not diagnosed prior to the event. At autopsy, approximately 75% of patients aged ≥65 have evidence of ischemic heart disease [15]. Demling noted a 61% incidence of pre-existing protein energy malnutrition in hospitalized burn patients > 65 years old, associated with twice the hospital mortality rate compared to well-nourished patients [70]. Given their disparity, the impact of pre-existing conditions on burn outcomes is only beginning to be elucidated [71, 72]. Severe burn injuries are unlike elective surgery situations where preoperative optimization is possible, yet much work can be done to address co-morbidities in the intensive care unit, on the acute care ward, and at the time of hospital discharge. Preoperative optimization, however, is advisable with smaller size burns, for which the risks of the surgical procedure may outweigh the benefits of early wound closure. The contribution of geriatric specialists to the burn multidisciplinary care team model is another potential area for investigation, as it has already shown to benefit older patients with trauma and hip fractures [73, 74].

Acute management challenges

Fluid resuscitation

Recent publications on fluid administration highlight the phenomenon of excess fluid administration compared to prediction formulas, and describe the associated complications of elevated compartment pressures and acute lung injury [75–77]. Despite that, the incidence of acute kidney injury following resuscitation remains unacceptably high, and disproportionately affects aged patients [58, 78]. These data reinforce the adage that aged patients are less able to tolerate either overor under-resuscitation because of limited cardiopulmonary reserve. However, what constitutes a proper resuscitation remains unclear as there is lack of agreement among providers on the type and composition of fluids for aged burn patients [44, 79]. A recent multicenter observational study found that age was inversely related to volume of fluid administered, meaning that providers likely limited fluid infusion in aged patients [76]. A commonly cited rationale is the concern for excess

edema formation in the lung. Accumulation of extravascular lung water (EVLW) as a result of high volume resuscitation is often posited, yet has not been proven to occur following burns [80, 81]. There are two potential explanations for this finding: first, that central hydrostatic pressures do not become elevated despite high volume administration during burn resuscitation, and second, that EVLW accumulation is more closely associated with direct lung injury from inhalation, or secondary lung injury from shock and sepsis, rather than changes in Starling forces during resuscitation [82, 83]. In the absence of convincing data to guide proper resuscitation in aged adults, it is prudent to initiate resuscitation for all adults according to weight and burn size according to standard formulas, and subsequently adjust according to individual patient response.

Burn excision

Early excision has reduced mortality and decreased length of stay in pediatric and adult patients [84, 85]. Early excision in older adults, however remains controversial as multiple centers have indicated a lack of improvement in mortality, infection rates, and length of stay [11, 86–89]. Delayed wound healing and poor graft take are important limitations to wound closure in older patients. Despite harvesting thin grafts, it is often not possible to safely re-harvest from the same donor sites within several weeks. Interstices in expanded mesh grafts are slow to fill, and both grafted beds and donor sites are more prone to infection. In 1987, Herd et al. argued for a prospective randomized trial of early excision in older patients, given the lack of benefit at the authors’ institution [88]. In contrast, others have reported that older adults generally tolerate surgical excision well, and several centers have noted improved survival with an early excision approach [3, 6, 90–92]. The definition of early excision has also varied in the literature, with a range of 72 hours to 7 days post-injury. In 2010, this issue remains one of the major unanswered questions in modern burn care, where the results of a wellconducted prospective evaluation could potentially alter care paradigms throughout the world. Our current practice at the University of Washington Burn Center is to perform surgical excision following completion of fluid resuscitation, and before 7 days in

older patients with burns ≥ 20% TBSA. Our rationale for early excision is that older patients do not tolerate burn wound sepsis and that removal of the burn wound is essential for survival [33, 92].

Pain and sedation

Appropriate pain management in aging adults has been historically hampered by two contradictory, yet widely held beliefs: first, that pain perception decreases with age, and second, that chronic pain in geriatric patients is so prevalent that it is assumed to be part of “normal aging”. Pain research in older adults has proliferated over the past 20 years. It has helped characterize the complex and diverse causes of geriatric pain. Although older patients report decreased acute pain perception in certain circumstances, such as that associated with acute myocardial infarction, they are at increased risk of neuropathic pain with tissue injury, temporal summation and persistent hyperalgesia [93, 94]. Older patients are more likely to become disabled by pain than younger adults [95]. Pathways to adaptation to chronic pain perception may also differ middle age and older patient groups [96]. Thus pain does not simply increase or decrease with age. Rather different types of pain are affected differently by aging. The current framework conceptualizes geriatric pain as a disease associated with an underlying condition, rather than an unavoidable part of aging [97].

Pain assessment and treatment are both challenging in this population. Multiple studies have established that the standard visual analog scale (VAS) has limited value in older patients [98, 99]. Instead, pain experts currently recommend using numeric rating scales (NRS), verbal description scales (VDS), or the McGill Pain Questionnaire [97]. Observational scales become necessary when cognitive impairment or mechanical ventilation preclude self-re- porting. Numerous observational measurements have been specifically developed for older patients over the past 20 years [100]. Whether these tools can be validated for older burn patients or a new scale should be developed remains a topic for investigation. Burn providers are also appropriately cautious when using pharmacologic agents to relieve pain in older adults [101]. Common side-effects of non-ster- oidal inflammatory agents are GI bleeding and renal

toxicity. The initial opioid analgesic dose for acute pain should be 25–50% of that in younger adults and carefully titrated upwards to achieve comfort [102]. Titration is paramount as undertreated pain is a risk factor for acute delirium and postoperative cognitive dysfunction (POCD) [103]. Barbiturates, benzodiazepines, and tricyclic antidepressants are other classes of agents that require caution in older patients because of decreased clearance and side effects. Pharmacists and geriatricians’ expertise can contribute greatly to the multidisciplinary team in carefully titrating medications and minimizing of polypharmacy.

Acute delirium in the intensive care unit is an active area of research, with nearly 2,000 published manuscripts in the past 4 years. Criteria to diagnose acute delirium are 1) the acute onset of mental status change or fluctuating course, 2) inattention, and 3) disorganized thinking or altered level of consciousness [104]. Although providers easily recognize hyperactive delirium in agitated patients who pose a danger to themselves and their environment, hypoactive delirium is much more common and under-recognized. In this instance, the patient appears apathetic, withdrawn, and has decreased responsiveness. Acute delirium disproportionately affects older hospitalized patients because of pain, infection, inadequate sedation and intrinsic host factors such as mild dementia. Deeper sedation and higher severity of illness are other recognized risk factors for delirium. Data from surgical and mixedICU indicate that acute delirium is a risk factor for death and poor longterm outcomes [105, 106]. The benzodiazepine lorazepam has been implicated as an independent risk factor for delirium, whereas the newer sedation agent dexmedetomidine appears to decrease the incidence of delirium [107]. Until now, few pain and sedation studies have enrolled burn patients aged ≥ 65. However, we anticipate that future research will clarify the roles of traditional pharmacologic relief of pain, newer agents for sedation, and non-pharmacologic approaches to improve the care of older burn patients.

End of life decisions

Not infrequently in the burn intensive care unit, providers withhold or withdraw life-sustaining ther-