Weight-Based Antibiotic Dosing in Osteomyelitis

Source: 

Investigators from multiple institutions conducted a retrospective study to compare outcomes in children with acute hematogenous osteomyelitis (AHO) who had healthy weights or were overweight or obese and evaluate antibiotic dosing variability by weight category. For the study, they abstracted data from the Cerner Health Facts database, which includes diagnostic and procedure codes, demographic information, inpatient medication orders, length of hospital stay (LOS), and anthropometric measurements on patient encounters from 684 health care facilities in the US. Study participants were children 2–17 years old with a primary diagnosis of AHO (based on ICD-9 and ICD-10 codes), hospitalized between 2010 and 2017. Children were categorized as healthy weight (BMI ≥5^th and <85^th percentile), overweight (BMI ≥85^th and <95^th percentile), or obese (≥95^th percentile). Primary study outcomes included AHO-related procedures and complications occurring within 6 months of the index hospitalization. Rates of these outcomes were compared for patients in different weight categories using chi-square tests. Secondary outcomes included LOS and AHO antibiotic dose, calculated as the mg/kg/day dose for commonly used drugs. Kruskal-Wallis tests were used to compare LOS and antibiotic dose in children in different weight groups.

There were 755 children enrolled. The mean age of study patients was 9.4 years, and 66% were male; 455 (60.3%) were classified as healthy weight, 117 (15.5%) were overweight, and 183 (24.2%) were categorized as obese. A total of 99 (13.1%) patients had an AHO-related procedure. The common procedures in all weight categories were surgical debridement and bone abscess drainage. The rates of procedures were higher in children who were obese or overweight than in healthy weight patients (16.9%, 18.8%, and 10.1%, respectively; P = 0.009). Complications occurred in 273 (36.2%) participants, including pyogenic arthritis in 139 (18.4%), myositis in 78 (10.3%), and sepsis in 43 (5.7%). There was no significant difference in rate of complications among children in different weight categories. LOS varied significantly by weight group (median LOS 4.9 days for healthy weight, 5.8 for overweight, and 5.7 for obese patients; P = 0.03). Among the study patients, 330 (50.3%) received clindamycin, 113 (17.2%) vancomycin, 83 (12.6%) cefazolin, and 26 (3.9%) ceftriaxone. Obese children received significantly lower doses by weight than healthy-weight patients for cefazolin (P <0.05), clindamycin (P <0.05), and ceftriaxone (P ≤0.01). There was no significant difference in dose of vancomycin between those who were obese or healthy weight and no significant difference in dose between those who were overweight vs healthy weight for any antibiotic assessed.

The authors conclude that obese and overweight children with AHO had longer LOS and more procedures than healthy-weight patients.

Dr Winer has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use...