Infections in frail and vulnerable elderly patients

Frail and vulnerable elderly patients, recognized primarily by the presence of such disabilities as immobility, incontinence, and dementia, are at particularly high risk for the development of infectious diseases, which are the leading cause of hospitalization in this population. The infectious diseases most often observed in the debilitated elderly are pneumonias, urinary tract infections, skin infections, and gastroenteritis, with fever a common manifestation. Some of the factors identified as contributing to their increased susceptibility include diminishing physiologic functioning; compromised host-defense mechanisms; increased incidence of mechanical risk factors, such as pressure ulcers, indwelling or condom catheters, feeding tubes, and soft tissue injuries; and comorbidities such as soft tissue or pulmonary edema. In addition to the common infecting pathogens found in the general population, these unique compromising factors increase the risk of elderly patients for aerobic gram-negative bacillary infection. Further increasing the therapeutic dilemma are ethical considerations involved in prolonging treatment that might be considered medical intervention beyond what is routine and necessary. Although the decision to treat must be made on an individual basis, studies have not always shown treatment to provide benefits in terms of quality of life. Once it is decided to treat, however, appropriate therapy is crucial. One of the most important considerations is renal function, which impacts on effectiveness, toxicity, and cost of therapy and is likely to be diminished in elderly patients. A non-nephrotoxic agent, such as aztreonam, may be a more appropriate therapeutic choice than an aminoglycoside antibiotic in this patient population.