Burns in older adults

Introduction

Burn injury in older adults is expected to have a greater impact on regional burn centers in the next several decades as the population in high-income countries is progressively aging. In the United States, adults aged ≥ 55 are projected to represent 30 % of the population by 2030 [1]. The appropriate age cut-off defining the older adult is debated, with a spectrum of age ≥ 45 to age ≥ 80 used in previous burn literature reports [2, 3]. Although this cut-off should ideally be based on biology, aging is a continuous process influenced by the individual’s health lifestyle and co-morbid conditions. In fact, the often quoted age ≥ 65 is primarily based on the age at which one can obtain full pension benefits, a reflection of societal constructs rather than biological truths. It is generally agreed, however, that aged patients are vulnerable to burn injury, and that injured older adults have far worse treatment outcomes compared to young adults [4]. Specifically, the American Burn Association reports that the lethal burn area associated with 50 % mortality (LA50) in a 50 year-old patient is 50 % TBSA [5]. In the United Kingdom, the reported LA50 for patients aged ≥ 65 is 21 % TBSA [6]. Furthermore, those who survive their injuries are at greater risk for long-term disability and loss of independence [7, 8]. It is thus imperative for all burn providers to become familiar with the injury epidemiology, pathophysiologic

Marc G. Jeschke et al. (eds.), Handbook of Burns

differences and acute management challenges in older patients.

Burn injury epidemiology

Flame exposure in household fires, brush burning, and smoking-related injuries account for approximately 65% of older patients requiring admission to US burn centers, followed by scalds (estimated at 15–30%), and contact injuries (5%) [2, 3, 9, 10]. Injury incidences and etiologies may vary with the region of interest. For instance, scalds may represent 31% of older adults admitted to a burn center in France, compared to 66% in Hong Kong [11, 12]. Interestingly, the higher incidence of burns in older adults in high-income countries has not yet been described in lowand middle-income countries, perhaps due to different population demographics and under-reporting [13]. Analysis of patients aged ≥ 55 in the US National Burn Repository (NBR) corroborates the epidemiologic and injury data reported by regional burn centers [14]. Most burns in adults ≥55 occur in the home (56%). The incidence of burns sustained in residential institutions is negligible in the youngest group (age 55–64), but rises to 5.5% in patients 75 and older. Mean burn severity is 9.6% TBSA with a 5.1% full-thickness component and does not significantly vary among age categories. Men comprise the majority of injuries (1.4:1 ratio),

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but the proportion of injured women increases with age. Women actually outnumber men in patients aged 75 and over. Older age remains an important risk factor for death after burn injury, as evidenced by commonly derived mortality prediction models (Table 1). Although several centers have reported improved outcomes in recent years, survival in older adults still lags far behind that in younger cohorts [10, 15, 16]. According to current US data, the adjusted odds ratios for death is 2.3 (95% CI 2.1–2.7) for the 65–74 age group, and 5.4 (95% CI 4.8–6.1) in the ≥ 75 group, compared to patients aged 55–64 [14].

There are multiple barriers to injury control in older adults. In the case of house fires, a low median income is associated with both a higher rate of fires and a higher rate of injuries once a fire has occurred. Certain types of homes (mobile homes, rental properties) and exposures (smoking, alcohol impairment) are strongly associated with burn injury. Individuals living in homes without a functioning smoke detector are more than eight times as likely to have

an injury related to a house fire. Fires by arson, however, may be less likely to cause injury [17, 18]. The practice of burning brush, trash and other debris occurs predominantly in rural communities for logistical, cost, and convenience reasons. Residential burning disproportionately injures older men who use fuel as an accelerant, where safety education and implementation of alternative waste management practices may help reduce the incidence of injuries [19–21]. Hot water scalds continue to occur despite multiple educational programs and legislative interventions to reduce home water temperatures. Agingrelated host factors predisposing to tap water scald injuries include not following recommendations, decreased mobility, impaired sensorium, and diabetic neuropathy, whereas environmental factors include lack of access to water temperature controls in some buildings, or living in buildings exempt from current law [22–26].

There are few available epidemiologic data on non-accidental burn injuries in aging adults, since