Lara Nicole Goldstein

The PAWPER tape: A new concept tape-based device that increases the accuracy of weight estimation in children through the inclusion of a modifier based on body habitus.

AIMS Weight estimations in children, which are required when actual weight cannot be measured, are often very inaccurate because of variations in body habitus not accounted for in the estimating methodology. This study was conducted to evaluate the accuracy of the PAWPER tape, a new two-step weight-estimation tape device which employs a length-based habitus-modified weight estimation system. METHODS This was a prospective study in the Emergency Departments of two hospitals in Johannesburg, South Africa on a population of children aged from 1 month to 12 years. Each child had their weight estimated by both the Broselow tape and the PAWPER tape. These weight estimates were then compared against measured weight to determine the bias and precision of the estimation techniques. RESULTS The PAWPER tape performed well, and better than the Broselow tape in every analysis performed. The mean percentage error was -3.8% vs. 0% and the root mean squared percentage error was 9.1% vs. 4.5% for the Broselow tape and PAWPER tape, respectively (p<0.0001). The Broselow tape predicted weight to within 10% of actual weight in 63.6% of children and the PAWPER tape in 89.2% (p<0.0001). The difference between the performances of the Broselow tape and PAWPER tape was most pronounced in children >20 kg, and in children above or below average weight-for-length. CONCLUSIONS The PAWPER tape has been shown to be a simple and reliable method of weight estimation in children and infants. The inclusion of an appraisal of body habitus in the methodology considerably improved the accuracy of weight estimation.

The polony phantom: a cost-effective aid for teaching emergency ultrasound procedures

BackgroundCentral venous access and nerve blockade are essential skills in the practice of emergency medicine, and the utility of emergency ultrasound to guide these procedures has been well demonstrated.MethodsA phantom is a valuable tool to learn and develop the dexterity for ultrasound-guided techniques.ResultsTo date, the time and cost required to produce or purchase such models has somewhat limited their use.ConclusionA time- and cost-effective alternative using polony and common household items is presented.

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

AIM When childrens 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.

A validation study of the PAWPER XL tape: accurate estimation of both total and ideal body weight in children up to 16 years of age

Background: The PAWPER tape has proved to be one of the most accurate weight estimation systems available, but its reduced accuracy in obese children and relative shortness (153cm) limit its functioning. The PAWPER tape was redeveloped as the PAWPER XL tape, to provide additional capacity for estimating weight in obese children and taller children (for extra-length and extra-large children). The aim of this study was to evaluate the accuracy of the PAWPER XL tape in estimating total body weight (TBW) and ideal body weight (IBW) in a population with a high prevalence of underweight and obese children. Methods: Estimations of TBW and IBW were obtained using the Broselow tape, the Mercy method, the original PAWPER tape and the new PAWPER XL tape in a convenience sample of 332 Emergency Department children. These predicted weights were compared to actual weight and calculated IBW. Results: The percentage of TBW estimates within 10% of actual weight (PW10) for the PAWPER XL tape, the PAWPER tape, the Mercy method and the Broselow tape was 83.4%, 81.8%, 63.9% and 57.1% respectively. For IBW the PW10 for the PAWPER XL tape, the PAWPER tape and the Broselow tape was 87.9%, 86.7% and 80.0% respectively. Conclusions: The PAWPER XL tape estimated both TBW and IBW extremely accurately, significantly better than the other weight estimation systems. The increased length and number of habitus score categories of the PAWPER XL tape enabled it to outperform the PAWPER tape in children >153cm in length and in severely obese children. Correspondence to: Mike Wells, Division of Emergency Medicine, Faculty of Health Sciences, University of the Witwatersrand, 5 York Road, Parktown Johannesburg, South Africa, Tel: +27824910369; E-mail: mike.wells@emergencymedicine.co.za

Emergency department noise: mental activation or mental stress?

Background Healthcare professionals working in emergency medicine are often exposed to noisy environments. We determined if there is any difference in cognitive task performance required for clinical decision-making of healthcare professionals in a quiet compared with noisy environment and to assess the subjective experience of participants with regard to performance in a noisy environment. Methods This was a prospective cross-over study conducted at three academic hospitals in Johannesburg, South Africa. 41 doctors involved in the emergency management of patients were administered six matched and prevalidated medical questions over a 30-min period. Each doctor completed half of the questions with exposure to ambient noise (range 40–52 dB(A)) and the other half with exposure to pre-recorded background emergency department noise at 80–85 dB(A). The questions were completed in alternating quiet and noise: half of the physicians answered the odd questions in noise and half answered even numbered questions in noise. Each question was scored out of 10 and the time taken to complete each question was recorded. Results Overall median test scores in quiet and noise were 18.5/30 and 20/30 (p=0.2), respectively; time for test completion was longer in quiet (836 s in quiet and 819 s in noise (p=0.006)). While there was no statistically significant difference in task performance, 65% of the doctors found the noise distracting with 88% experiencing varying degrees of stress. Conclusions Performance of mental tasks is maintained during noise exposure but noise exposure is associated with significant degrees of self-reported distress.

High-tech adjuncts to emergency weight estimation: Point-of-care ultrasound and point-of-care bioelectrical impedance measurements can increase the accuracy of length-based weight estimation in children

Introduction: An accurate and reliable method of estimating weight in sick obese children, for purposes of drug dosing calculations, has proved to be elusive. Incorporating the use of high-tech, point-of-care technology into weight-estimation methodology has not been evaluated before. We aimed to determine if ultrasound and bioelectrical impedance measurements could be used in combination with the PAWPER XL tape (PTXL) to increase the accuracy of total body weight (TBW), ideal body weight (IBW) and fat-free mass (FFM) estimation. Methods: A convenience sample of 332 children attending an academic Emergency Department was enrolled. Each child had their weight estimated with the PAWPER XL tape and underwent anthropometric, point-of-care ultrasound (PoCUS) and bioelectrical impedance (BI) measurements of parameters useful for body composition assessment. Dual X-ray absorptiometry (DXA) was measured and used as a reference for body composition. Multiple regression techniques were used to identify variables and variable-combinations that were strongly associated with TBW, IBW and DXA-measured FFM. Low-tech combinations including anthropometric measurements only were compared with models including high-tech measurements. Results: The PTXL alone, with no lowor high-tech adjunct, provided the most accurate estimate of IBW. Estimates of TBW based on anthropometric measurements were significantly improved with the addition of poCUS or BI to the prediction models, especially in underweight and obese children. Similarly, high-tech models significantly outperformed the low-tech models for estimating FFM. Conclusions: The use of PoCUS and BI significantly improved the accuracy of TBW and FFM estimation in children when compared with anthropometric-based methods. Correspondence to: Mike Wells, Division of Emergency Medicine, Faculty of Health Sciences, University of the Witwatersrand, 5 York Road, Parktown Johannesburg, South Africa, Tel: +27824910369; E-mail: mike.wells@emergencymedicine.co.za

A systematic review and meta-analysis of the accuracy of weight estimation systems used in paediatric emergency care in developing countries

Introduction When weight cannot be measured during the management of medical emergencies in children, a convenient, quick and accurate method of weight estimation is required, as many drug doses and other interventions are based on body weight. Many weight estimation methodologies in current use have been shown to be inaccurate, especially in low- and middle-income countries with a high prevalence of underweight children. This meta-analysis evaluated the accuracy of weight estimation systems in children from studies from low- and middle-income countries. Methods Articles from low- and middle-income countries were screened for inclusion to evaluate and compare the accuracy of existing systems and the newer dual length- and habitus-based methods, using standard meta-analysis techniques. Results The 2D systems and parental estimates performed best overall. The PAWPER tape, parental estimates, the Wozniak method and the Mercy method were the most accurate systems with percentage of weight estimates within 10% of actual weight (PW10) accuracies of 86.9%, 80.4%, 72.1% and 71.4% respectively. The Broselow tape (PW10 47.1%) achieved a moderate accuracy and age-based estimates a very low accuracy (PW10 11.8–47.5%). Conclusions The PAWPER tape, the Wozniak method and the Mercy method achieved an acceptable level of accuracy in studies from low- and middle-income countries and should preferentially be used and further advanced for clinical emergency medicine practice. Parental estimates may be considered if the regular caregiver of the child is present and a recent measured weight is known. The Broselow tape and age-based formulas should be abandoned in low- and middle-income country populations as they are potentially dangerously inaccurate.

Accuracy of weight estimation by the Broselow tape is substantially improved by including a visual assessment of body habitus

BackgroundThe Broselow tape (BT) has been shown to estimate weight poorly primarily because of variations in body habitus. The manufacturers have suggested that a visual assessment of habitus may be used to increase its performance. This study evaluated the ability of habitus-modified models to improve the accuracy thereof.MethodsA post hoc analysis of prospectively collected data from four hospitals in Johannesburg, South Africa, on a population of 1,085 children. Sixteen a priori models generated a modified weight estimation or drug dose based on the BT weight and a gestalt assessment of habitus.ResultsThe habitus-modified method suggested by the manufacturer did not improve the accuracy of the BT. Five dosing and four weight-estimation models were identified that markedly improved dosing and weight estimation accuracy, respectively. The best dosing model improved dosing accuracy (doses within 10% of correct dose) from 52.0 to 69.6% and reduced critical dosing errors from 16.5 to 4.3%. The best weight-estimation model improved accuracy from 59.4 to 81.9% and reduced critical errors from 11.8 to 1.9%.ConclusionThe accuracy of the BT as a drug-dosing and weight-estimation device can be substantially improved by including an appraisal of body habitus in the methodology.

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 paediatric weight estimation during simulated emergencies: The effects of patient position, patient cooperation, and human errors

Introduction The effect of patient position and patient cooperation on the accuracy of emergency weight estimation systems has not been evaluated previously. The objective of this study was to evaluate weight estimation accuracy of the Broselow tape, the PAWPER XL tape, the Mercy method, and a custom-designed mobile phone App in a variety of realistic simulated paediatric emergencies. Methods This was a prospective study in which 32 emergency medicine volunteers participated in eight simulations of common paediatric emergency conditions, using children models. The participants used each of the four methods to estimate the children’s weight. The accuracy of and time taken for the weight estimations were evaluated for each method. A regression analysis determined the effects of patient position and cooperation on weight estimation accuracy. Evaluation of subgroups of best-performers and worst-performers among the participants provided information on the effects of human user-error on weight estimation accuracy. Results The Broselow tape, Mercy method, App and the PAWPER XL tape achieved percentages of weight estimation within 10% of actual weight in 47.7, 57.3, 68.1, and 73.0% of estimations, respectively. Patient position and cooperation strongly impacted the accuracy of the Broselow tape, had a minimal effect on the Mercy method and the App, and had no effect on the PAWPER XL tape. The best performing participants achieved very high accuracy with all methods except the Broselow tape. Discussion The Mercy method, the App, and the PAWPER XL tape achieved exceptionally high accuracy even in uncooperative and sub-optimally positioned children when used by the best-performing participants. Human error, from inexperience and inadequate training, had the most significant impact on accuracy. The Mercy method was the most subject to human error, and the PAWPER XL tape, the least. Adequate training in using weight estimation systems is essential for paediatric patient safety.