Managing Infectious Disease in the Critically Ill Elderly Patient

Infections and subsequent sepsis are an increasing cause of hospital admission and critical illness in the elderly population. The risk factors that predispose elderly patients to infections, such as comorbidities and frailty, also contribute to prolonged recovery times and subsequent mortality. Elderly patients may present with atypical symptoms such as delirium and remain afebrile thus delaying the diagnosis of infections. White blood cell count is not as useful in the diagnosis of infection as other biomarkers such as procalcitonin. Once an infection has begun, the elderly patient has less physiologic cardiac and respiratory reserve and develops end organ damage more rapidly. Frailty itself is strongly associated with high rates of first time sepsis. Mortality risk from sepsis clearly increases with age. Appropriate antibiotics and source control are necessary components of sepsis management as is early fluid resuscitation. Fluid resuscitation must be performed judiciously with appropriate endpoints utilizing bedside cardiac ultrasound and IVC collapsibility to avoid fluid overload. Acute kidney injury (AKI) occurs in 1/3–2/3 of elderly septic patients and increases mortality. AKI is potentially preventable with appropriate and timely fluid resuscitation and avoiding nephrotoxic medications including loading doses of vancomycin, limiting aminoglycoside exposure to < 3 days, and minimizing colistin use. Source control within 12 h when appropriate improves outcome. Specific infections, including Clostridium difficile, community-acquired pneumonia, and urinary tract infection, pose unique challenges in the elderly. Early goals-of-care discussions emphasizing potential complications and undesirable outcomes must be discussed when caring for critically ill elderly patients. Early recognition of sepsis via identification of atypical signs and symptoms in elderly patients is critical. This allows for timely and appropriate therapy to decrease the incidence of end organ damage and mortality in high-risk elderly patients.