Comparison of 3 body size descriptors in critically ill obese children and adolescents: implications for medication...

Area of Science:

• Pediatric critical care medicine
• Clinical pharmacology
• Biostatistics

Background:

• Accurate weight determination is crucial for safe and effective medication dosing in pediatric patients, particularly those who are obese.
• Existing methods for estimating weight in obese children, such as lean body mass estimations and ideal body weight calculations, vary in complexity and feasibility.

Purpose of the Study:

• To compare three distinct methods for weight determination in medication dose calculations for obese children.
• To evaluate the feasibility of these methods for routine clinical application in a pediatric intensive care unit setting.

Main Methods:

• A patient safety and quality improvement study involving 176 obese and severely obese children (2-19 years) admitted to a pediatric intensive care unit.
• Comparison of lean body mass estimations (Peters and Foster methods) against ideal body weight estimates (BMI method).
• Statistical analysis included absolute differences, intraclass correlation (ICC), and Bland-Altman plots to assess agreement.

Main Results:

• All three methods demonstrated strong correlation (mean ICC = 0.968) and acceptable agreement in children weighing less than 50 kg.
• Systematic biases and increased variance were observed in children weighing above 50 kg, with sex influencing agreement.
• The Peters method yielded higher weight estimates compared to the Foster or BMI methods.

Conclusions:

• While all methods show good correlation, agreement varies with weight and sex, particularly above 50 kg.
• The Body Mass Index (BMI) method is the least complex and most feasible for routine medication dosing calculations in obese pediatric patients.
• Further refinement of weight estimation methods may be needed for children exceeding 50 kg to minimize systematic biases.