title: An aid to drug dosing safety in obese children: development of a new nomogram and comparison with existing methods for estimation of ideal body weight and lean body mass.
abstract: The risk of accidental over-dosing of obese children poses challenges to anaesthetists during dose calculations for drugs with serious side-effects, such as analgesics. For many drugs, dosing scalars such as ideal body weight and lean body mass are recommended instead of total body weight during weight-based dose calculations. However, the complex current methods of obtaining these dosing scalars are impractical in the peri-operative setting. Arbitrary dose adjustments and guesswork are, unfortunately, tempting solutions for the time-pressured anaesthetist. The study's aim was to develop and validate an accurate, convenient alternative. A nomogram was created and its performance compared with the standard calculation method by volunteers using measurements from 108 obese children. The nomogram was as accurate (bias 0.12 kg vs -0.41 kg, respectively, p = 0.4), faster (mean (SD) time taken 2.8 (1.0) min (vs 3.3 (0.9) min respectively, p = 0.003) and less likely to result in mistakes (significant errors 3% vs 19%, respectively, p = 0.001). We present a system that simplifies estimation of ideal body weight and lean body mass in obese children, providing foundations for safer drug dose calculation.
authors.affiliation: Department of Anaesthesia, Alder Hey Children's Hospital, Liverpool, UK.
authors.forename: L C
authors.initials: LC
authors.lastname: Callaghan
authors.forename: J D
authors.initials: JD
authors.lastname: Walker
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000378:metabolism; D000777:Anesthetics / Q000008:administration & dosage / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D004305:Dose-Response Relationship, Drug; D054796:Drug Dosage Calculations; D062787:Drug Overdose / Q000517:prevention & control; D005260:Female; D006801:Humans; D056865:Ideal Body Weight; D008297:Male; D049451:Nomograms; D061214:Patient Safety / Q000706:statistics & numerical data*; D063766:Pediatric Obesity / Q000378:metabolism*; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D000700:Analgesics; D000777:Anesthetics