A43 The effect of hydrocortisone on the growth of preterm infants on prolonged mechanical ventilation

Abstract

Background and Aims: Heart rate is known to increase by approximately 10 beats per minute (bpm) per degree centigrade increase in body temperature in children. A higher heart rate than would be expected for a given level of fever may therefore be more suspicious for an infection compared to conventional heart rate cut-off values. Very few data exist on the relationship between temperature and heart rate in newborns. We aimed to evaluate the role of fever on heart rate in newborns during the first three days of life. Methods: We included all newborns hospitalised at our tertiary care teaching neonatal intensive care unit within the first three days of life during a four-year period. Temperature was measured every two to four hours and heart rate was recorded continuously. Results: Of 863 newborns included 69 (8%) had fever during the first three days of life (rectal temperature >38.5°C), 45 of them had culture proven and clinical early onset sepsis (65%). There was a positive correlation between temperature and heart rate (r = .314, p = .009) with an increment in heart rate by 17.5 bpm (CI 95% 4.6–30.4) with each 1°C increment in temperature. In the subgroup of sepsis positive newborns the increment in heart rate was higher compared to sepsis negative newborns (21.5 bpm (4.9–38.1) vs. 10.5 bpm (−11.7–32.6), respectively). Conclusions: Our results suggest a relationship between pulse rate and temperature in febrile newborns. Further studies might better explore the possible utility of a temperature dependent interpretation of heart rate in this age group.