The relationship between age and fever magnitude.

BACKGROUND: Infections are an important cause of morbidity and mortality in older people; however, they are often difficult to diagnose because the signs and symptoms of infection in older people are frequently atypical. Fever, one of the most important signs of infection, is a case in point. Preliminary evidence suggests that the febrile response in older persons is blunted, leading to the clinical maxim, "the older, the colder." The objective of this study was to assess the effect of age on the febrile response to moderate-to-severe pneumonia in hospitalized patients adjusted for the effect of anatomic site at which the temperature was measured. METHODS: This is a retrospective cohort study of 320 hospitalized patients with moderate-to-severe pneumonia. The study was designed to assess the effect of age on the febrile response to moderate-to-severe pneumonia in hospitalized patients, adjusting for the effect of the anatomic location of the temperature measurement. The highest temperature of each day and the anatomic sites at which temperatures were taken (axillary, oral, rectal, or other) on days 1 and 2 of infection and at hospital discharge. Baseline demographic information, including age, were obtained for each patient. RESULTS: There were 320 patients (median age, 64 years; range, 18-97 years). Using a linear regression model, significant inverse correlations were found between age and the temperature for patients on the first and second days of hospitalization (P < 0.001). For each decade increase in age, the average temperature on the first 3 days of infection was lower by 0.15 degrees C. Temperature at discharge, a surrogate for baseline temperature, also decreased at an equal rate with age. CONCLUSION: In this study, the febrile response to infections was reduced with increasing age and baseline temperatures were generally lower in older patients.

Effect of antipyretic therapy on the duration of illness in experimental influenza A, Shigella sonnei, and Rickettsia rickettsii infections.

STUDY OBJECTIVES: To determine whether antipyretic therapy prolongs the course of experimental influenza A, Shigella sonnei, and Rickettsia rickettsii infections. DESIGN: Retrospective observational study. SETTING: University Center for Vaccine Development. SUBJECTS: Fifty-four volunteers with experimentally induced influenza A, 45 with S. sonnei, and 21 with R. rickettsii infections participated. INTERVENTIONS: Subjects from the six influenza A studies were challenged intranasally. If they met certain criteria, they were offered aspirin or acetaminophen for symptomatic relief. Subjects from the three Shigella studies were challenged with the bacteria and then given trimethoprimsulfamethoxazole. Acetaminophen also could be administered. In the one R. rickettsii trial, subjects were inoculated intradermally and treated with tetracycline. Again, acetaminophen was administered for symptomatic relief. MEASUREMENTS AND MAIN RESULTS: Data, excerpted from subjects' study records, were evaluated using Wilcoxon tests, Spearman's correlation coefficients, and multiple regression analysis. Two-tailed hypotheses with a p value of 0.05 were used for all of the analyses. There was a striking correlation between antipyretic therapy and duration of illness in subjects infected with influenza A and S. sonnei, but not R. rickettsii. CONCLUSIONS: Multivariate analysis suggested that antipyretic therapy prolonged illness in subjects infected with influenza A, but its use was the result of prolonged illness in those infected with S. sonnei. The precise nature of these relationships requires a prospective, randomized, placebo-controlled trial.

Brief history of antipyretic therapy.

Both external cooling and pharmacotherapy have been used to treat fever since time immemorial. In the past century such treatments have proliferated at an astonishing rate. The COX-2 inhibitors are the most recent additions to the antipyretic pharmacopoeia. Additional research is needed to determine whether they represent an important new chapter in antipyretic therapy's long history or, for that matter, if the benefits of any currently available treatment for fever outweigh its cost.

Physiological rationale for suppression of fever.

Two critical assumptions are made when prescribing antipyretic therapy. One is that fever is, at least in part, noxious, and the other is that suppression of fever will reduce, if not eliminate, the noxious effects of fever. At present, neither assumption has been validated experimentally.

Diagnostic implications and clinical consequences of antipyretic therapy.

It has been suggested that the response to antipyretic therapy might differentiate between fevers due to serious illness and fevers caused by less severe disorders; that neoplastic fevers are more responsive to nonsteroidal anti-inflammatory drugs than are infectious fevers; that the metabolic costs of fever can exceeds its clinical benefits; that antipyretic therapy can prevent or reverse febrile seizures in children and fever-associated mental dysfunction in frail elderly patients. This article examines the data on which these assertions are based.

Antipyretic Therapy's future.

There is little doubt that clinicians will continue to seek new and, one hopes, more intelligent ways to suppress fever. In the process, new agents will be developed, new uses will be identified for existing antipyretic agents, new measures will be designed to maximize the benefits of antipyretic therapy while minimizing its adverse effects, and a concerted effort will be made to define more clearly and to promote appropriate indications for such therapy.

Antipyretic therapy: physiologic rationale, diagnostic implications, and clinical consequences.

Various treatments have been used to suppress fever since antiquity. Surprisingly, few studies have been performed to ascertain the physiologic consequences of antipyresis and validate the rationale behind such therapy. More importantly, it has not been established conclusively that the benefits of antipyretic therapy outweigh its risks. The present review considers these issues in light of currently available data and formulates guidelines for antipyretic therapy based on these data.

A resource-allocation model to enhance productivity of academic physicians.

The authors describe a resource-allocation model developed in the Medical Care Clinical Center at the Baltimore Veterans Affairs Medical Center (a part of the VA Maryland Health Care System) and implemented in 1989. This model is a computer-based system that tracks the workload of each of the clinical center's specialty sections (e.g., cardiology) and calculates each section's workload as a percentage of the total clinical center workload. As the basis of this calculation, six activities of each section are tracked by the model (e.g., inpatient attending physicians' rotations; inpatient consultations; etc.) to determine what percentage of each activity of the entire clinical center was provided by each section. Each of these percentages is then recalculated according to a weighted average based on the relative value of the activity to the department; these averages are revised periodically as needed. The model provides an incentive for the specialty sections to increase productivity by generating competition among sections for physician salary support. Communication among all concerned at the clinical center and its associated medical school and teaching hospital has been the key to success in implementing the model, which is periodically reviewed and has been revised several times after meetings with section chiefs and division heads. The authors are confident that the use of the model has been at least partly responsible for increased productivity of clinical center physicians, especially in the areas of visits per physician and funded VA research dollars per physician. Perhaps equally important is the future potential of the model. Because of its simplicity and because it is generally seen to be fair and effective, it will continue to be used to reward activities most important to the clinical center, especially now that the center operates under a fully capitated system, and in this way wil help ensure the financial viability of the center.

Concepts of fever.

If asked to define fever, most physicians would offer a thermal definition, such as "fever is a temperature greater than...." In offering their definition, many would ignore the importance of the anatomic site at which temperature measurements are taken, as well as the diurnal oscillations that characterize body temperature. If queried about the history of clinical thermometry, few physicians could identify the source or explain the pertinacity of the belief that 98.6 degrees F (37.0 degrees C) has special meaning vis-à-vis normal body temperature. Fewer still could cite the origin of the thermometer or trace the evolution of modern concepts of clinical thermometry. Although many would have some knowledge of the fundamentals of thermoregulation and the role played by exogenous and endogenous pyrogens in the induction of fever, few would have more than a superficial knowledge of the broad biological activities of pyrogenic cytokines or know of the existence of an equally complex and important system of endogenous cryogens. A distinct minority would appreciate the obvious paradoxes inherent in an enlarging body of data concerned with the question of fever's adaptive value. The present review considers many of these issues in the light of current data.

Effects of IFN-beta on human cerebral blood flow distribution.

The effect of interferon-beta1b (IFN-beta) on human cerebral blood flow distribution was examined in five multiple sclerosis patients using functional brain single-photon emission tomography (SPECT). Of nine regions of interest studied, only the basal ganglia exhibited a significant change (increase) in relative photon emission intensity (i.e., relative blood flow) when comparing SPECT scans obtained 6 h after s.c. IFN-beta injection with scans obtained at the same time of day (noon) 30 h after IFN-beta injection (IFN-beta-free day). The increase in relative blood flow to the basal ganglia following IFN-beta injection correlated positively with changes in mean arterial pressure (MAP). Additional studies will be required to determine the relevance of these observations for IFN-beta-induced central nervous system side effects.

Concepts of fever: recent advances and lingering dogma.

Fever has been a preoccupation of clinicians since medicine's beginning. One might therefore expect that basic concepts relating to this physiological response would be well delineated and that such concepts would be widely known. In fact, only in the past several decades has the febrile response been subjected to scientific scrutiny. As a result of recent scientific investigation, modern concepts have evolved from a perception of fever as nothing more than a rise in core temperature to one in which fever is recognized as a complex physiological response characterized by a cytokine-mediated rise in temperature, as well as by generation of acute-phase reactants and activation of a panoply of physiological, endocrinologic, and immunologic systems. The average clinician appears to have little more than a regrettably rudimentary knowledge of these modern concepts of fever. This symposium summary considers many such concepts that have immediate relevance to the practice of medicine.

The salary responsibility program for full-time faculty members in an academic clinical department.

The authors report a system developed in the Department of Medicine of the University of Maryland School of Medicine to encourage members of the full-time faculty to assume greater responsibility for their compensation. A member of the department's administrative staff individually interviews each faculty member and fills out, with the member, a "scorecard" that contains the number of hours per month and per year that the member reports were spent on his or her duties--such as teaching, attending, and consulting--that are assigned by the department or its divisions. This report also contains the record of unassigned time devoted to research (for investigators) or to personal practice (for clinicians). Assigned duties includes the time spent by clinicians performing procedures such as bronchoscopy cardiac catheterization, and endoscopy. The department pays for the otherwise unsupported costs of salary and benefits associated with assigned duties, and the faculty member is responsible for part of his or her compensation for time spent in research or practice. The program was developed and the data collected during the summer and fall of 1995. The salary reductions were applied on July 1, 1996. During the 1996-97 academic year the department projects a savings of $110,362 from compensation withheld from faculty members unable to fulfill their salary responsibilities and not paid to members who left the department, in part because of expected reductions in their incomes. The program has stimulated other faculty members to develop salary support with even greater vigor than that might otherwise have shown.