Fever or not fever – that’s the question: A cohort study of simultaneously measured rectal and ear temperatures in febrile patients with suspected infection

Abstract

Objective: To study how ear and rectal body temperatures relate to each other over time in febrile patients. Methods: Descriptive cohort study with repeated measurements. The setting was a Unit for Infectious Diseases at a county hospital in Sweden. Patients, ≥ 18 years, admitted for suspected infection and with a rectal or ear temperature of ≥ 37.5• C were invited. 16 females and 24 men, 19 to 94 years were included. Ear and rectal temperature was measured simultaneously every two hours for one day.Results: Mean rectal temperature was higher, compared to both ear sites. Ninety-five percent of the differences between the rectal and ear sites were within 0.6 • C to 1.1 • C. Changes in rectal temperature were smaller and slower than in ear temperature, especially when patients were given temperature-lowering drugs. Conclusions: Adjustments from one temperature site to another is a risk of diagnostic error affecting clinical decision-making. Ear temperature reacts faster than the rectal site to body temperature changes and antipyretics, and is therefore more reliable in the assessment of the patient's condition. Traditional paradigm for temperature measurement and assessment needs to be replaced with evidence-based science to improve patient safety.

Interpretation of Body Temperature and Oxygen Saturation based on Individual Normal Ranges in Habitual Condition: A Step Forward for Applied Precision Medicine

“…Elevated temperature, assessed as fever, is an important sign often decisive for further action in case of suspected infectious disease [20][21][22] , and a legitimate reason for accessing the resources the healthcare system offers when the patient seeks care 23 . Since normal body temperature varies between individuals due to, among other things, sex, age, inflammatory processes and comorbidities, it is reasonable to assume that the temperature assessed as fever also varies between individuals [24][25][26] . Instead of starting from a predetermined limit value, a temperature rise at least 1°C increase from the individual's normal body temperature and a simultaneous malaise can be defined as fever 12,20 .…”

Use of temperature changes and pro-inflammatory biomarkers to diagnose bacterial infections in patients with severe cerebral trauma

“…This has been confirmed by Mackowiak and Worden [15], who showed that the thermometer used by Wunderlich measured 1.4°C to 2.2°C higher than modern digital devices. However, as the normal body temperature shows individual variation, a more logical approach is that the same should hold true for the febrile range [16][17][18]. We tested this hypothesis in a large multicenter study by measuring ear temperatures in 2006 apparently healthy individuals aged [2,4], and 10 to 89 years, of whom 1,700 also claimed that their temperature was assessed as fever by themselves and their children.…”