Weight prediction in children in the emergency department
Wells, Michael David John
Objectives: to establish the accuracy and reliability of a new device, the PAWPER tape (PT), for length-based weight estimation in children; to assess whether the addition of a measure of body habitus could improve the accuracy of weight estimation; and to compare the performance of the PT with that of the Broselow tape (BT). Design: prospective, cross-sectional, descriptive study. Setting: emergency departments (EDs) of two Johannesburg private hospitals. Patients: children aged from 1 month to 12 years who were not in need of emergent medical management. Methods: each child had their weight estimated by both the BT and the PT (which included a method for adjusting the predicted weight according to body habitus). These predicted weights were then compared against measured weight to determine the bias and precision of the estimation techniques. Main Results: the PT performed as well or better than the BT in every analysis performed. The mean percentage error (MPE) was -3.8% vs 0% and the absolute MPE was 9.1% vs 4.5% for the BT and PT respectively (p<0.0001). The BT predicted weight to within 10% of actual weight in 63.6% of children and the PT in 89.2% (p<0.0001). The difference between the performances of the BT and PT was most pronounced in children >20kg, and in children above or below average weight-for-length. Conclusions: The PT was a reliable weight estimation device that performed well in this population, often with a greater degree of accuracy than the BT. The inclusion of an appraisal of body habitus in the methodology considerably improved the accuracy of weight estimation.
MSc (Med), Emergency Medicine, Faculty of Health Sciences, University of the Witwatersrand, 2009