title: The Effect of Antipyretic Temperature Reduction on Heart Rate in Febrile Infants: a Pilot Study.
abstract: It is generally accepted that fever is associated with tachycardia and that the relationship, of an approximate increase of 10 beats/minute per °Celsius rise in temperature, is particularly pronounced in infants. It would be useful to determine how closely pulse and fever are associated during pharmacological temperature reduction, and whether it is influenced by the infectious status of the infant. Infants with fever presenting to the pediatric emergency department were prospectively enrolled in a study to determine temperature, heart rate, and the activity at initial assessment and 1 hour after antipyretic administration. Patients were also grouped into those with and without signs of serious bacterial infection for analysis. During pharmacological antipyresis, the relationship between pulse and fever deviated from the accepted norm, established during the febrile state: there was an average pulse rate reduction of 21.1 beats/minute/°Celsius decrement in fever (P = 0.0027; 95% CI, 14.05-28.15). Pulse reduction/°Celsius may also differ in infants with suspected serious bacterial infection. Our findings suggest caution in ascribing pulse changes to fever alone, especially in sick looking infants, and that this is especially true after the administration of antipyretics, which could be related to the mechanism of action of antipyretic drugs. Further research is needed to ascertain the clinical utility and importance of our observations.
authors.affiliation: 1Division of Pediatric Emergency Medicine, Department of Pediatrics, Dana-Dwek Children Hospital, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Division of Pediatric Emergency Medicine, Shaare Zedek Medical Center, Jerusalem, Israel; and 3Divisions of Pediatric Emergency Medicine and Clinical Pharmacology and Toxicology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Alexis
authors.initials: A
authors.lastname: Mitelpunkt
authors.forename: Shmuel
authors.initials: S
authors.lastname: Heitner
authors.forename: Dennis
authors.initials: D
authors.lastname: Scolnik
authors.forename: Ayelet
authors.initials: A
authors.lastname: Rimon
authors.forename: Francis B
authors.initials: FB
authors.lastname: Mimouni
authors.forename: Miguel
authors.initials: M
authors.lastname: Glatstein
mesh_terms: D058633:Antipyretics / Q000494:pharmacology / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy* / Q000503:physiopathology; D004636:Emergency Service, Hospital; D005260:Female; D005334:Fever / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D010865:Pilot Projects; D011446:Prospective Studies; D013610:Tachycardia / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D058633:Antipyretics