Dean C. Norman

Fever in the Elderly

Fever in elderly persons is only one clinical presentation that can be used to assist the clinician at suspecting a serious disease, such as an infection. Infections, like all other illnesses in the geriatric patient, may occur with a variety of nonspecific, atypical, nonclassic, and unusual manifestations. The clinician caring for elderly patients should be aware of these nonclassical presentations of infections in this age group. Unexplained change in functional capacity, worsening of mental status, weight loss or failure to thrive, weakness and fatigue, falls, and generalized pain are only some of the clues that may aid the clinician in considering infection in elderly persons. Key concepts of fever in older adults are: Fever generally indicates presence of serious infection, most often caused by bacteria. Fever may be absent in 20%-30% of elderly patients harboring a serious infection. Criteria for fever in elderly patients should also include an elevation of body temperature of at least 2 degrees F from baseline values. FUO in elderly persons is caused by infections (30%-35%), CTD (25%-30%), and malignancies (15%-20%) in the majority of cases.

Fever Response in Elderly Nursing Home Residents: Are the Older Truly Colder?

Objective To test the hypothesis that many nursing home residents with an apparently blunted fever response (maximum temperature <101°F) may actually have a significant change in temperature (ΔT ≥ 2.4°F) which is not recognized because of a low baseline temperature.

FEVER IN THE ELDERLY

Infections in the elderly, similar to other acute illnesses in this age group, may present in atypical, nonclassical fashions. Fever, the cardinal sign of infection, may be absent or blunted 20%-30% of the time. An absent or blunted fever response may in turn contribute to diagnostic delays in this population, which is already at risk for increased morbidity and mortality due to infection. On the other hand, the presence of a fever in the geriatric patient is more likely to be associated with a serious viral or bacterial infection than is fever in a younger patient. Finally, a diagnosis can be made in the majority of cases of fever of unknown origin (FUO) in the elderly. FUO is often associated with treatable conditions in this age group.

Management of Complicated Urinary Tract Infection in Older Patients

Urinary tract infection (UTI) in older persons is a common medical problem that is seen in both the ambulatory and institutional settings. It affects older women and men with a gender prevalence ratio of 2:1, respectively. UTI in older persons can be a complex problem in terms of the approach to diagnosis, treatment, and prevention. In this report the discussion will begin with the unique aspects of UTI in older persons, particularly as they relate to UTI in the younger, general population. The remaining discussion will then focus on three complicated clinical circumstances and conditions of UTI in the geriatric population: non‐catheter recurrent UTI, asymptomatic bacteriuria, and catheter‐related bacteriuria and UTI.

Fever and Aging

The pathogenesis and clinical relevance of fever is reviewed. The interrelationship between fever and other biologic responses to infection is summarized. A blunted or absent fever response to infections observed in some elderly patients may be due to defects in thermoregulation. These abnormalities in thermoregulation may include impairment of both behavioral and physiologic responses. J Am Geriatr Soc 33:859, 1985

Correlation of Estimated Renal Function Parameters Versus 24-Hour Creatinine Clearance in Ambulatory Elderly

This study evaluates the correlation between estimated renal function parameters (ie, creatinine clearance by the Cockcroft‐Gault and Lott‐Hayton formulas, serum creatinine and blood urea nitrogen) and 24‐hour creatinine clearance in 15 young and 15 elderly subjects. Correlation coefficients (r) for the elderly group comparing Cockcroft‐Gault and Lott‐Hayton against 24‐hour creatinine clearance were 0.73 (P < .005) and 0.60 (P < .02) respectively, and r for the young subjects were 0.37 (P > .05) and 0.57 (P < .05), respectively. In 13 elderly subjects with creatinine clearance of 60 mL/minute or less, four (31%) had blood urea nitrogen of 20 mg/dL or less and 13 (100%) had serum creatinine between 1.0–1.5 mg/dL. We conclude that the formulas of Cockcroft‐Gault and Lott‐Hayton are valid in ambulatory elderly patients who are functionally independent without severe underlying disease, have normal body weight and are not on medication affecting renal function. Furthermore, in this select elderly population, an apparently normal serum creatinine (1.0–1.5 mg/dL) and blood urea nitrogen (20 mg/dL or less) may frequently represent a 24‐hour creatinine clearance of 60 mL/minute or less.

Platelet microbicidal protein enhances antibiotic-induced killing of and postantibiotic effect in Staphylococcus aureus.

The interaction of bacteria with platelets at the cardiac valve surface represents a critical event in the induction of infective endocarditis. Platelets are thought to modulate induction or propagation of endocarditis via secretion of alpha-granule-derived platelet microbicidal protein (PMP) (a low-molecular-mass, cationic, heat-stable protein distinct from lysozyme). We studied representative PMP-susceptible and PMP-resistant Staphylococcus aureus isolates to determine their in vitro bacteriostatic and bactericidal susceptibilities to combinations of PMP plus antistaphylococcal antibiotics. PMP plus oxacillin exerted a synergistic bactericidal effect, in contrast to either agent alone, regardless of the intrinsic PMP susceptibility of the isolate tested. Exposure of S. aureus to PMP alone resulted in residual postexposure growth-inhibitory effects lasting from 0.9 to 1.8 h. Sequential exposure of S. aureus isolates to PMP for 30 min followed by exposure to either oxacillin or vancomycin (each at 10x the MIC for 120 min) resulted in a significant extension of the postantibiotic-effect duration compared with antibiotic exposure alone (P less than or equal to 0.05). Collectively, these findings indicate that PMP both enhances antibiotic-induced killing of S. aureus and increases the postantibiotic-effect duration in S. aureus.

Approach to Fever and Infection in the Nursing Home

OBJECTIVE: To summarize current information on the scope, epidemiology, clinical manifestations, diagnostic approach, and general management of infectious diseases in nursing home residents, as well as the specific treatment of common infections occurring in the nursing home setting.

Evaluation of a Novel Medication Aid, the Calendar Blister‐Pak, and its Effect on Drug Compliance in a Geriatric Outpatient Clinic

A prospective, controlled, crossover study on drug compliance was initiated in 22 elderly patients from a geriatric clinic. Half of the patients received their pills from a commercially prepared calendar mealtime blister‐pak; the remaining patients received their medication from standard pill bottles. At the end of three months the two groups were crossed over. Pill count and issuance of a new drug supply were done monthly to assess compliance. It was found that the average noncompliance index was significantly decreased (9.17 to 2.04) with the blister‐pak packaging system. The relationship of age, Folstein mini‐mental status, over compliance, frequency of dosing interval, and living situation were also explored.

Clinically Inapparent (Asymptomatic) Bacteriuria in Ambulatory Elderly Men: Epidemiological, Clinical, and Microbiological Findings

In a prospective longitudinal study, ambulatory elderly men were followed from 1 to 4.5 years to gain insight into the prevalence rates, clinical characteristics, and patterns of clinically inapparent (asymptomatic) bacteriuria (CIB). The prevalence of CIB was 12% (29/238) and increases with age. Unlike the gram‐negative organisms that cause overt urinary tract infection in this age group, gram‐positive organisms dominated the CIB group. Both the CIB and abacteriuric patients have multiple chronic medical conditions and are indistinguishable on that basis. Twenty‐nine elderly men with bacteriuria and 105 abacteriuric subjects were followed with serial urine cultures. During the study period the bacteriuric subjects exhibited spontaneous temporary or permanent resolution (76%, 22/29), intermittency (21%, 6/29), and probable bacterial persistence (38%, 11/29). No consistent pattern of bacteriuria was evident. Therefore, antimicrobial therapy is not warranted in the treatment of asymptomatic or clinically inapparent bacteriuria in ambulatory elderly men.