Optimising emergency weight estimation in underweight and obese children: the accuracy of estimations of total body weight and ideal body weight.

OBJECTIVE: During medical emergencies, underweight and obese children are at a higher risk of weight-estimation errors than 'average' children, which may lead to poorer outcomes. In obese children, optimum drug dosing requires a measure of both total body weight (TBW) and ideal body weight (IBW) for appropriate scaling. We evaluated the ability of the Broselow tape, the Mercy method and the PAWPER XL tape to estimate TBW and IBW in obese and underweight children. PARTICIPANTS AND METHODS: Data for children aged 0-18 years were extracted and pooled from three previous weight-estimation studies. The accuracy of estimation of TBW and IBW by each method was evaluated using percentage of estimations within 10% of target weight (PW10) as the primary outcome measure.
RESULTS: The Broselow tape estimated TBW poorly in obese and underweight children (PW10: 3.9 and 41.4%), but estimated IBW extremely accurately (PW10: 90.6%). The Mercy method estimated TBW accurately in both obese and underweight children (PW10: 74.3 and 76.3%) but did not predict IBW accurately (PW10: 14.3%). The PAWPER XL tape predicted TBW well (PW10: 73.0% in obese children and 74.9% in underweight children) and predicted IBW extremely accurately (PW10: 100%).
CONCLUSION: The Broselow tape predicted IBW, but not TBW, accurately. The Mercy method estimated TBW very accurately, but not IBW. The PAWPER XL tape estimated both TBW and IBW accurately. The PAWPER XL tape should be considered when choosing a weight-estimation strategy for obese and underweight children.