Relationship of temperature pattern and serious bacterial infections in infants 4 to 8 weeks old 24 to 48 hours after antibiotic treatment

Study objective: A new management approach to selected febrile infants 4 to 8 weeks old evaluated for possible sepsis is outpatient ceftriaxone therapy, with subsequent re-evaluation 24 to 48 hours after presentation. This study assessed whether the temperature profile of such infants during the 24- to 48-hour period after treatment distinguished those with from those without serious bacterial infections (SBIs). Design: Prospective, descriptive clinical study. Participants: One hundred sixty-one febrile infants 4 to 8 weeks old. Setting: An urban pediatric emergency department and hospital. Measurements and main results: All infants underwent a sepsis evaluation (lumbar puncture, CBC/blood culture, and urinalysis/urine culture) and were hospitalized for at least 48 hours. Temperatures were measured on presentation and then every four hours during hospitalization. All infants received parenteral third-generation cephalosporin antibiotic therapy, and none received antipyretic medication unless fever was documented.. Fever (rectal temperature of more than 38.0 C) was documented during the 24- to 48-hour period after presentation in 28 infants (17.6%) - one of a total of 18 infants (5.6%) with SBI and 27 of a total of 143 infants (19%) without SBI (∞, more than .2; power, .30). All bacterial isolates in cases of SBI were susceptible to third-generation cephalosporin antibiotics. All repeat blood and urine cultures that were performed in infants with bacteremia or urinary tract infections, respectively, were negative 24 hours after presentation. Conclusion: Infants 4 to 8 weeks old who remain febrile during the 24 to 48-hour period after presentation and initiation of parenteral antibiotic therapy are less likely to have SBI. This study did not have sufficient power for this difference to be statistically significant.