Annals of Long Term Care

In her discussion on nursing home evaluations, Suzanne Bradley, MD, Associate Professor, University of Michigan and the Ann Arbor GRECC, presented symptoms and signs of infection in long-term care, an approach to diagnosis and management, useful diagnostic tests, common pathogens, and when to initiate antibiotics.

Most strategies for evaluating fever and infection have been derived from hospitals, where the entire institution is devoted to the diagnosis of acute illness (ie, physicians are present, all diagnostic laboratories are onsite). In contrast, nursing homes focus more on comfort care, physicians are rarely onsite, and many diagnostic tests are not available. “So, I think the bottom line is we need different criteria to diagnose infection in long-term care,” the speaker said.

Infection is common in the nursing home setting. There are also complications related to diagnosis because many patients fail to perceive symptoms, they are unable to communicate them, or the typical signs and symptoms of infection found in younger individuals may not be present in older adults because the inflammatory response may be lacking. Because physicians often rely on empiric antibiotic therapy, antibiotic resistance is common; when they fail to diagnose these processes, morbidity and mortality is also common.

In general, infection rates are expected to be highest in patients with the greatest functional disability, who require the most skilled care, and who have indwelling devices. Dr. Bradley noted that infection rates and attributable mortality are probably underestimated because very rarely do physicians make an absolute diagnosis of a clinical syndrome and patients are often treated empirically. Infection rates in nursing homes are virtually identical to those in hospitals (ie, approximately 4 infections per thousand patient-days).

Accounting for 90% of infections, the most common clinical syndromes are similar to those found in community-dwelling persons and those in hospital care: urinary tract and upper respiratory tract infections, and skin and soft tissue infections. Bloodstream and gastrointestinal infections are less common.

Diagnosing Infection
One method of diagnosing infection in the long-term care setting is the presence of an acute change in functional status (eg, increased confusion, inability to cooperate, new incontinence, falls, decreased mobility); infection most likely accounts for 77% of these symptoms. In addition, a fever of 99 degrees F or a change in baseline temperature may be very useful for detecting infection in this population. It is recommended that a lower threshold for detecting fevers be used (ie, lowering the cut-off from 101 degrees F to 99 degrees F); ability to detect infected persons increases over 80% if the threshold is lowered. Studies have demonstrated that the likelihood of having infection is greatest in nursing home patients with a temperature of 101degrees F or higher. In addition, because older adults do not mount an adequate febrile response, a temperature increase of 2.4 degrees F from baseline temperature is also a significant indication that infection is present. In addition, a respiratory rate of greater than 25 breaths per minute is a good indication that the patient is developing a lower respiratory tract infection. There is little data on other aspects of history and physical to report on. There is some variability on clinical presentation with clinical syndrome; however, if the typical signs and symptoms of infection found in hospitalized patients are present in long-term care patients, it is a good indication that the patients have the infection.

On the initial examination, other predisposing factors may assist in determining where the infection is occurring. An immobile patient should be examined for pressure sores, and skin and UTIs should be considered in a patient with diabetes.