Chapter 44: The Geriatric Patient

INTRODUCTION

According to census projections, the elderly population in the United States, defined as age more than 65 years, is experiencing the largest growth in history. Members of the post-World War II “baby boom” (75 million people born from 1946 to 1964) were 46–64 years old in 2010. By the year 2030, the elderly population will number 38 million and, by 2050, 1 in 5 Americans will be elderly.¹

The ever-increasing mobility and active lifestyles of today’s elderly places them at increased risk for serious injury. In fact, data from the National Trauma Data Bank (NTDB) for the year 2014 revealed that 39% of all patients in the registry were 55 years old or older and the mortality for this group was 54% of all deaths reported to the NTDB.² Injury is now the fifth leading cause of death in the elderly population.³

The elderly have a higher morbidity and mortality, have more preexisting medical problems, and demonstrate a senescent physiologic response to injury when compared to younger individuals. The reasons for the differing response are unknown, the literature is 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 as noted above; however, there are a variety of organ specific injuries that demonstrate rising morbidity and mortality at chronological ages less than 65 years. As such, elderly patients should be assessed by the degree of frailty and viewed from the vantage of the physiologic response to an injury or injury complex rather than a specific age. Despite these limitations, this chapter focuses 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 an 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 et al.⁴ 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, as well. This immune senescence is, in part, is characterized by reduced neutrophil function. Butcher et al^...