Influence of body mass index and antibiotic dose on the risk of surgical site infections in pediatric clean orthopedic surgery.

To evaluate body mass index (BMI) and antimicrobial dose as risk factors for surgical site infections in pediatric patients. Children between 2 and 19 years of age undergoing clean orthopedic procedures and receiving at least one dose of perioperative antibiotics (cefazolin, vancomycin, or clindamycin) were studied. The retrospective case-controlled study was conducted at the Alfred I. duPont Hospital for Children, a 180-bed tertiary-care academic pediatric hospital in Wilmington, DE. Data were collected from January 1, 2002, to December 31, 2005. Underweight children had a higher risk for SSIs than overweight and normal-weight children. American Society of Anesthesiologists classes II and greater were associated with a greater risk of SSI. Longer procedures were also associated with a higher risk of SSI, specifically, duration of surgery >2 h. Children weighing ≥70 kg who received a standard dose of cefazolin (maximum of 1 g) had a higher risk of SSI caused by methicillin-sensitive Staphylococcus aureus (MSSA). Being underweight and undergoing an operation lasting >2 h created significant risks for SSI. Children weighing ≥70 kg receiving a standard 1-g dose of cefazolin had a greater risk of MSSA SSIs than children weighing <70 kg who received an appropriate weight-based dose of this antibiotic.