Roll up the tape? Laser and optical technologies improve paediatric weight estimation

Abstract

Background

A robust estimation method is needed to prevent medication dosing and equipment sizing errors and improve time to administration during paediatric resuscitation. An electronic measurement with computer interface may improve accuracy and alleviate cognitive burden. This study evaluates the accuracy of two electronic height measurement methods, a laser and an optical device, and compares them to the Broselow™ Pediatric Emergency Tape (BT) for weight estimation.

Methods

We enrolled children ages 0–14 years from the emergency department of a free-standing, academic children’s hospital. We obtained sex, body habitus, true weight, true height, BT colour, and experimental heights. We converted experimental height measurements into weight estimates using standardised growth charts. We calculated Pearson correlations between experimental and actual measurements and the percentages of weight estimates within 10% and 20% of true weights. We repeated analyses on a restricted cohort of children 0–11 years, the intended BT age range.

Results

We enrolled 198 children. The laser, optical device and BT weight estimates had strong positive correlations with the actual weight measurements with Pearson’s correlation coefficients of 0.946, p < 0.0001, 0.965, p < 0.0001, and 0.825, p < 0.0001 respectively. 47.8% of optical weight estimates fell within 10% of actual weight and 80.6% within 20%, compared to 40.5% and 75.4% of laser estimates and 39.8% and 65.1% of BT estimates.

Conclusion

Electronic-based weight estimates were more accurate than the BT. The accuracy of medication dosing and equipment sizing during paediatric resuscitation may be improved by integrating optical height-based weight estimates with electronic clinical decision support.

Introduction

Accurate weight estimation in paediatric resuscitation is a key component of increasing the patient’s chance of survival, as it dictates dosing of life-saving medication and medical equipment sizing. Previous studies showed that errors in weight estimation lead to differences between recommended dose and dose delivered, presenting a potential danger to children during resuscitation.1, 2, 3 Additionally, weight-based dosing calculations carry a significant cognitive burden that interferes with the critical thinking necessary to manage a critically ill child.⁴

With the intent of minimising cognitive load and improving treatment accuracy, weight estimation aids were developed. The Broselow™ Pediatric Emergency Tape (BT), which is the gold standard for resuscitation in children 0−11 years, is a laminated paper tape with nine coloured height ranges that each correspond to an estimated weight range and associated equipment sizes and medication doses. The BT has a maximum height of 145 cm with a corresponding maximum weight of 36 kg, rendering it ineffectual in approximately 40% of 10 year old patients and 70% of 11 year old patients.⁵ Though there have been multiple iterations of the BT since its patenting in 1998, the tape has become increasingly inaccurate in the American paediatric population due to the rising incidence of obesity.6, 7, 8, 9, 10 A 2015 study reported that the BT was only successful in predicting a weight that was within 10% of actual patient weight in 27% of cases.¹¹ In attempt to remedy this prevalent inaccuracy, various methods that incorporate both height and body habitus into weight estimation have demonstrated increased accuracy.12, 13, 14 The 2017 BT edition attempted to correct for an overweight body habitus by instructing to use one weight range higher than indicated. However, one study still reported that weight estimation inaccuracies still persist despite the proposed correction.¹⁵

The BT accuracy is restricted by a maximum height range limiting its use in older children, the use of weight ranges, and the inability to use readily available information such as true height and body habitus to generate a more accurate weight estimate. Furthermore, the BT tape and other current height-based weight estimation devices do not harness the capabilities of modern technology or electronic systems. The objectives of this study were to prove that we can use electronic height measurement methods to provide equal or superior height measurement and better weight estimations, which could be integrated into a mobile device application for paediatric resuscitation decision support.