Tympanic temperature measurements: are they reliable in the critically ill? A clinical study of measures of agreement.
OBJECTIVE
Accurate measurement of temperature is vital in the intensive care setting. A prospective trial was performed to compare the accuracy of tympanic, urinary, and axillary temperatures with that of pulmonary artery (PA) core temperature measurements.


METHODS
A total of 110 patients were enrolled in a prospective observational cohort study.


METHODS
Multidisciplinary intensive care unit of a university teaching hospital.


METHODS
The cohort was (mean +/- sd) 65 +/- 16 yrs of age, Acute Physiology and Chronic Health Evaluation (APACHE) II score was 25 +/- 9, 58% of the patients were men, and 76% were mechanically ventilated. The accuracy of tympanic (averaged over both ears), axillary (averaged over both sides), and urinary temperatures was referenced (as mean difference, Delta degrees centigrade) to PA temperatures as standard in 6,703 recordings. Lin concordance correlation (pc) and Bland-Altman 95% limits of agreement (degrees centigrade) described the relationship between paired measurements. Regression analysis (linear mixed model) assessed covariate confounding with respect to temperature modes and reliability formulated as an intraclass correlation coefficient.


RESULTS
Concordance of PA temperatures with tympanic, urinary, and axillary was 0.77, 0.92, and 0.83, respectively. Compared with PA temperatures, Delta (limits of agreement) were 0.36 degrees C (-0.56 degrees C, 1.28 degrees C), -0.05 degrees C (-0.69 degrees C, 0.59 degrees C), and 0.30 degrees C (-0.42 degrees C, 1.01 degrees C) for tympanic, urinary, and axillary temperatures, respectively. Temperature measurement mode effect, estimated via regression analysis, was consistent with concordance and Delta (PA vs. urinary, p = .98). Patient age (p = .03), sedation score (p = .0001), and dialysis (p = .0001) had modest negative relations with temperature; quadratic relationships were identified with adrenaline and dobutamine. No interactions with particular temperature modes were identified (p > or = .12 for all comparisons) and no relationship was identified with either mean arterial pressure or APACHE II score (p > or = .64). The average temperature mode intraclass correlation coefficient for test-retest reliability was 0.72.


CONCLUSIONS
Agreement of tympanic with pulmonary temperature was inferior to that of urinary temperature, which, on overall assessment, seemed more likely to reflect PA core temperature.
Moran
John L
JL
Department of Intensive Care Medicine, The Queen Elizabeth Hospital, Woodville, South Australia, Australia.
Peter
John Victor
JV
Solomon
Patricia J
PJ
Grealy
Bernadette
B
Smith
Tania
T
Ashforth
Wendy
W
Wake
Megan
M
Peake
Sandra L
SL
Peisach
Aaron R
AR
D018806:APACHE; D000368:Aged; D000704:Analysis of Variance; D001158:Arteries; D001365:Axilla; D015982:Bias; D001794:Blood Pressure; D001831:Body Temperature; D002407:Catheterization, Swan-Ganz; D003422:Critical Care / Q000379:methods; D016638:Critical Illness / Q000628:therapy; D005260:Female; D006785:Hospitals, University; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013021:South Australia; D013817:Thermography / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D014432:Tympanic Membrane; D014556:Urine