August 1, 1995
Media Contact: John Cramer
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In older patients, fever alone often marks the need for hospitalization, even in the absence of any other abnormal signs, according to results of a Johns Hopkins study.
The study, published in the July issue of Annals of Emergency Medicine, involved 470 patients age 65 or older who came to the Johns Hopkins Bayview Medical Center emergency department with an oral temperature of 100 degrees or more. The study found that 76 percent of patients with a fever were seriously ill, that 49.6 percent had none of the standard indications of serious illness but were later found to be so, and that 13.8 percent of those discharged from the emergency department were later admitted to the hospital with serious ailments, mainly pneumonia, urinary tract infection or sepsis (bacterial infection of the blood).
"This is important in light of the rapid growth of older people in the population and the complexity of evaluating older patients," says Gabor Kelen, M.D., the study's senior author and director of emergency medicine at The Johns Hopkins Medical Institutions.
"The results suggest that the absence of abnormal findings does not reliably rule out a serious illness when there is fever, and the high proportion of serious illness in this study underscores the significance of fever in older people," says Catherine A. Marco, M.D., the study's lead author. The findings also suggest using short-stay units for fevered patients with no other indication of serious illness.
Fever in children and intravenous drug abusers often suggests serious illness, but Hopkins researchers wanted to see if fever was a similar marker in older patients, who often have weakened immune systems and other complications.
Indicators for "serious illness" used by the investigators were the presence of disease-causing microorganisms in the blood on the day of treatment; a related need for surgery or other inpatient treatment; prolonged use of intravenous antibiotics; prolonged hospitalization; an emergency department visit within the previous 72 hours; and, retrospectively, death within a month of an emergency department visit.
Hopkins researchers analyzed patients' temperature, age, heart rate, blood pressure, breathing rate, white blood cell count, urine, chest X-ray, residence (nursing home or home) and chronic disease history.
Those patients with no abnormal signs in the emergency department but who turned out to be seriously ill were more likely to have a temperature of 103 degrees or more, as well as a higher white blood cell count, higher respiration rate, higher pulse rate and bacterial infections, according to the results.
Emergency physicians routinely care for many geriatric patients, who make up 12 percent of the U.S. population and are the nation's fastest growing age group. These patients account for a disproportionate percentage of ambulance transports, emergency department hospital admissions and emergency department critical care unit admissions, according to researchers. Many emergency physicians consider evaluation and treatment of older patients to be more time consuming and difficult for several conditions, including fever, because they usually need more extensive evaluation of physical, immunological, social and psychological conditions, according to researchers. Kelen and Marco emphasized that fever in older people does not always indicate a serious illness, but recommended that they consult their family physicians.
The importance of body temperature as a sign of disease or health was established in 1868 and has since become as a routine part of physical examinations. Temperature regulation plays a key role in homeostasis, or the normal balance of biochemical mechanisms in the body. The highest acceptable normal temperature of 98.6 degrees has been reexamined in recent years and put at 99.9 degrees by a 1992 study in the Journal of the American Medical Association.
Other researchers were Charles N. Schoenfeld, M.D., Karen N. Hansen, M.D., David A. Hexter, M.D. and Dana A. Stearns, M.D.