Emergency weight estimation in Aboriginal and Torres Strait Islander children in the Northern Territory: are the current methods accurate?

The accuracy of the Broselow tape as a weight estimation tool and a drug-dosing guide - A systematic review and meta-analysis

AIMS

The Broselow tape is widely used as a weight-estimation device and drug-dosing guide aid, but concerns about its accuracy and its efficacy have emerged in the last decade. The aim of this study was to systematically review the literature to analyse the accuracy of the Broselow tape as a weight estimation device and review evidence of its utility as a drug-dosing guide.

METHODS

This was a MOOSE-driven systematic review and meta-analysis, which focused on studies evaluating the accuracy of the Broselow tape and studies reviewing its use as a drug-dosing aid.

MAIN RESULTS

The tape has undergone substantial changes over the years, but there was no evidence to show that the changes have improved weight-estimation performance. The weight-estimation accuracy of the tape was suboptimal in all populations, with just over 50% of children receiving an estimation within 10% of their actual weight. The overestimation of weight in low- and middle-income countries was often extreme. This indicated a significant potential for potentially harmful medication errors. The limited available evidence on the value of the tape as a drug-dosing guide indicated that the tape was frequently used incorrectly and contained insufficient information to function without additional resources.

CONCLUSIONS

The Broselow tape lacked sufficient accuracy as a weight estimation and drug-dosing tool when compared to other available techniques. In addition, the Broselow tape contains insufficient drug-dosing information to function as a complete resuscitation aid without additional material. The frequent rate of incorrect usage of the tape indicated that appropriate training with the tape is mandatory to reduce errors.

The accuracy of emergency weight estimation systems in children-a systematic review and meta-analysis

The safe and effective administration of fluids and medications during the management of medical emergencies in children depends on an appropriately determined dose, based on body weight. Weight can often not be measured in these circumstances and a convenient, quick and accurate method of weight estimation is required. Most methods in current use are not accurate enough, but the newer length-based, habitus-modified (two-dimensional) systems have shown significantly higher accuracy. This meta-analysis evaluated the accuracy of weight estimation systems in children. Articles were screened for inclusion into two study arms: to determine an appropriate accuracy target for weight estimation systems; and to evaluate the accuracy of existing systems using standard meta-analysis techniques. There was no evidence found to support any specific goal of accuracy. Based on the findings of this study, a proposed minimum accuracy of 70% of estimations within 10% of actual weight (PW10 > 70%), and 95% within 20% of actual weight (PW20 > 95%) should be demonstrated by a weight estimation system before being considered to be accurate. In the meta-analysis, the two-dimensional systems performed best. The Mercy method (PW10 70.9%, PW20 95.3%), the PAWPER tape (PW10 78.0%, PW20 96.6%) and parental estimates (PW10 69.8%, PW20 87.1%) were the most accurate systems investigated, with the Broselow tape (PW10 55.6%, PW20 81.2%) achieving a lesser accuracy. Age-based estimates achieved a very low accuracy. Age- and length-based systems had a substantial difference in over- and underestimation of weight in high-income and low- and middle-income populations. A benchmark for minimum accuracy is recommended for weight estimation studies and a PW10 > 70% with PW20 > 95% is suggested. The Mercy method, the PAWPER tape and parental estimates were the most accurate weight estimation systems followed by length-based and age-based systems. The use of age-based formulas should be abandoned because of their poor accuracy.

New age-based weight estimation formulae for Japanese children

BACKGROUND

Although dosing and sizing of resuscitation drugs and equipment are mostly weight based, time is usually insufficient to weigh critically ill children. Many age-based weight estimation formulae for emergency use have been developed worldwide, but there is no specific formula for Japanese children. The aim of this study was therefore to develop and validate age-based formulae for estimating the bodyweight of children living in Japan.

METHODS

A total of 370 980 measurements of bodyweight were obtained from 39 547 participants aged 12-155 months. They participated in a national survey, called the Longitudinal Survey of Babies in the 21st Century, which started in 2001. We created the new original weight estimation formulae for children living in Japan, called the Japanese Pediatric Assessment of Normal weight (JAPAN) formulae, using 75% of measurements that were randomly selected from the total measurements. To check the validity of the formulae, we applied the JAPAN formulae, the Park et al. formula for Korean children, and the commonly used Nelson formula for the remaining 25% of measurements. The mean absolute error and the root mean square error (RMSE) were calculated for each scale.

RESULTS

The JAPAN formulae performed better than the two other formulae among Japanese children, with a mean absolute error and RMSE of 0.83 and 1.08 (kg), respectively. The performance of the Park et al. formulae for Korean children was poor for children living in Japan.

CONCLUSIONS

The newly developed JAPAN formulae for age-based weight estimation are appropriate for children living in Japan.

It is time to abandon age-based emergency weight estimation in children! A failed validation of 20 different age-based formulas

AIM

When children's weight cannot be measured during medical emergencies, it must be estimated, as weight is required for many interventions. Age-based formulas are the oldest weight estimation systems in children, but have been shown to be very inaccurate in many studies. This aim of this study was to evaluate the accuracy of age- and length-based formulas and to see if a measure of body habitus could be used to improve the performance of these formulas.

METHODS

This was an analysis of data from a sample of 1085 children aged from 1 month to 16 years, collected from four Emergency Departments in Johannesburg, South Africa. Basic demographic and anthropometric data was collected and each child had a visual assessment of body habitus, quantified as a habitus score. Weight estimates from 20 existing age-based formulas and two length-based formulas were then compared against measured weight to determine their accuracy. Age- and length-based, habitus-modified models were developed and similarly evaluated.

Estimating the weight of ethnically diverse children attending an Australian emergency department: a prospective, blinded, comparison of age-based and length-based tools including Mercy, PAWPER and Broselow

OBJECTIVE

To prospectively compare the actual weights of Australian children in an ethnically diverse metropolitan setting with the predicted weights using the Paediatric Advanced Weight Prediction in the Emergency Room (PAWPER) tape, Broselow tape, Mercy system and calculated weights using the updated Advanced Paediatric Life Support (APLS), Luscombe and Owens and Best Guess formulae.

METHODS

A prospective, cross-sectional, observational, blinded, convenience study conducted at the Children's Hospital at Westmead Paediatric Emergency Department in Sydney, Australia. Comparisons were made using Bland-Altman plots, mean difference, limits of agreement and estimated weight within 10% and 20% of actual weight.

RESULTS

199 patients were enrolled in the study with a mean actual weight of 27.2 kg (SD 17.2). Length-based tools, with or without body habitus adjustment, performed better than age-based formulae. When measuring estimated weight within 10% of actual weight, PAWPER performed best with 73%, followed by Mercy (69%), PAWPER with no adjustment (62%), Broselow (60%), Best Guess (47%), Luscombe and Owens (41%) and revised APLS (40%). Mean difference was similar across all methods ranging from 0.4 kg (0.0, 0.9) for Mercy to -2.2 kg (-3.5, -0.9) for revised APLS. Limits of agreement were narrower for the length-based tools (-5.9, 6.8 Mercy; -8.3, 5.6 Broselow; -9.0, 7.1 PAWPER adjusted; -12.1, 9.2 PAWPER unadjusted) than the age-based formulae (-18.6, 17.4 Best Guess; -19.4, 15.1 revised APLS, -21.8, 17.7 Luscombe and Owens).

CONCLUSION

In an ethnically diverse population, length-based methods with or without body habitus modification are superior to age-based methods for predicting actual body weight. Body habitus modifications increase the accuracy and precision slightly.

Comparison of the finger counting method, the Broselow tape and common weight estimation formulae in Filipino children after Typhoon Haiyan

OBJECTIVES

We sought to evaluate commonly used paediatric weight estimation techniques in a sample of children in the Philippines.

METHODS

We prospectively collected age, height and weight data for a sample of 207 children aged 1-9 years seen during a medical aid trip. Weights were estimated using the finger counting method, the Broselow method and four formulae. Bland-Altman analysis was performed to evaluate agreement with measured weight.

RESULTS

Mean difference and range of agreement in kilograms were as follows: 0.6 (95% CI 0.1-1.1) and 14.9 (95% CI 13.1-16.7) for the Broselow method; 1.1 (95% CI 0.5-1.7) and 17.3 (95% CI 15.2-19.3) for the traditional APLS formula; 3.1 (95% CI 2.4-3.7) and 18.6 (95% CI 16.4-20.8) for the finger counting method; 4.0 (95% CI 3.2-4.8) and 23.1 (95% CI 20.3-25.8) for the updated APLS method; 5.1 (95% CI 4.4-5.8) and 21.1 (95% CI 18.6-23.6) for the Luscombe formula; and 5.3 (95% CI 4.5-6.1) and 22.5 (95% CI 20-25.2) for the Best Guess formulae.

CONCLUSIONS

The Broselow tape and the traditional APLS formula performed best in our sample. The finger counting method also outperformed newer weight estimation formulae. 'Updated' age-based formulae created recently in developed countries should not be used in disaster relief efforts in the Philippines. Caution should be used when applying these formulae to other developing countries and in disaster response.