A5V4d

Feverish illness in children
The first study was a multi-centre, retrospective observational study (Davies et al., 2009) of 21,033
children which aimed to assess the effect of body temperature on heart rate in children attending a
paediatric emergency department.
The authors of the paper analysed the data using a quantile regression and a statistical model to
develop the following best fit equation:
114
Expected parameter value (heart rate) = (Temperature [ o C] x a) + (Age [months] x b) +
(Age 2 [months 2 ] x c) + constant
In the equation, the temperature multiplier a has a mean increase of 10.52 beats per minute (bpm)
through the centile, resulting in a heart rate increase of approximately 10 bpm with each 1 o C
increment in temperature. The results are shown in Table 5.48.
Table 5.48 Heart rate calculations for the 5 th , 25 th , 50 th , 75 th and 95 th centiles
Percentile a b c constant
5 th 9.468 -0.6543 0.001998 230.2
25 th 10.99 -0.7040 0.002198 270.1
50 th 11.44 -0.7393 0.002374 274.9
75 th 11.35 -0.7615 0.002474 258.8
95 th 9.397 -0.8494 0.002848 163.3
A number of limitations were identified including variation in how the measurements of pulse and
temperature were taken, and the study including children older than 5 years.
The second study was a cross-sectional prospective study (Thompson et al., 2008) of 1589 children
attending a paediatric emergency department that aimed to produce centile charts for heart rates in
febrile children.
Centile charts of heart rate plotted against temperature in febrile children were produced. The
incremental increases of heart rate for each increment of 1 o C in temperature are shown in Table 5.49.
Heart rate was negatively correlated with age (r = -0.62) and positively correlated with temperature
(r = 0.49).
Table 5.49 The incremental increases of heart rate for each increment of 1 o C in temperature
Population Mean increase in pulse rate per 1 o C (1.8 o F)
Increase in temperature (95% CI)
Combined group of 1589 children 13.7
Age 3–12 months 12.1
Age 1–2 years 9.9
Age 2–5 years 14.1
CI confidence interval
This study showed that, in the study population, the heart rate increases by 9.9 to 14.1 bpm with each
1 o C increment in temperature. The mean values of heart rate grouped by age at the 50 th , 75 th , 90 th
and 97 th centiles are displayed in Table 5.49.
A number of limitations were identified, including: the children recruited were not a representative
sample from primary care; and the study included children older than 5 years.
The third study was a prospective observational study (Hanna et al., 2004) which evaluated the effect
on heart rate of fever in a cohort of 490 children attending a paediatric emergency department.
2013 Update