PAWPER XL Research Articles

Weight estimation in two groups of Ghanaian children with chronic diseases using Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes.

The performance of various weight estimation methods in children with sickle cell disease (SCD) and heart disease (HD) has not been studied. We aimed to determine and compare the accuracies of the Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes in Ghanaian children with no known chronic diseases (controls), SCD and HD. We prospectively recruited 631 children (199 with HD, 209 SCD and 223 controls) from the Komfo Anokye Teaching Hospital (KATH). Their weights were estimated using the Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes. These estimated weights were compared to measured weight using mean percentage error (MPE), the proportion of weight estimates within ±10% (P10) and ±20% (P20) of measured weight. Bland-Altman limits of agreement (LOA) were determined to assess the precision of weight estimation and agreement with measured weight. The PAWPER XL, Mercy and PAWPER XL-MAC were the most accurate in all groups of children studied. All methods except the Broselow tape (BT), which performed best in the control group, had their best performance among children with SCD with negligible critical error rates (proportion of children with weight estimates > 20% of their actual weight). The P20 in the various groups of children using the BT were 88.36%, 80.21% and 51.10% respectively in the control, SCD and HD groups. The Mercy, PAWPER XL and PAWPER XL MAC tapes were generally above 90% in all groups. The Mercy, PAWPER XL and PAWPER XL-MAC tapes performed significantly better than the BT in all groups of children studied. These methods of weight estimation performed best in children with SCD with very little critical error.

A validation of newly developed weight estimating tape for Korean pediatric patients.

Pediatric drug dosages are based on body weight, so accurate measurement thereof is essential. However, this is not possible in emergencies. When using weight-estimating tapes, World Health Organization (WHO) growth charts serve as reference weights; however, local growth charts might be more accurate. This study developed a tape based on 2017 Korean National Growth Charts, which are more suitable for the Korean population than WHO growth charts, and evaluated its performance in a Korean pediatric population. This prospective cross-sectional study analyzed 792 pediatric patients who had visited the emergency department from June 2021 to December 2021. Weights were estimated using the Broselow tape (BT), Pediatric Advanced Weight Prediction in the Emergency Room XL (PAWPER XL), and Body Habitus-based Pediatric Emergency Tape (BHPET). The performance and measurement agreement of the tapes were analyzed. Among the tapes, the BHPET had the smallest mean absolute percentage error (MAPE), of 10.23%, and a root mean square percentage error (RMSPE) of 14.14%. Also, the percentage of weight estimations within 10% of the actual weight (PW10) was 59.6%, indicating better accuracy than the BT and PAWPER XL in all age groups. The intraclass correlation coefficients of the BT, PAWPER XL, and BHPET were 0.931, 0.977, and 0.985, respectively (p < 0.001). The performance and accuracy of the BHPET was similar or slightly superior to that of the other tapes. The body weight estimated using the BHPET for a local pediatric population was sufficiently correlated with the actual body weight.

Accuracy of Weight Estimation in Children Using the Broselow, PAWPER XL, PAWPER XL-MAC, and Mercy Tapes.

Quick and accurate estimate of a child's weight is often required for medical interventions like drug dose calculation when scale measured weights cannot be obtained safely. Length-based methods of weight estimation are more accurate than age-based methods, with the most accurate being the length-based, habitus-modified methods. This study sought to determine and compare the accuracies of the 2017 Broselow tape, Paediatric Advanced Weight Prediction in the Emergency Room Extra-Long (PAWPER XL) tape, Paediatric Advanced Weight Prediction in the Emergency Room Extra-Long Mid-Arm Circumference (PAWPER XL-MAC) tape, and the 2-dimensional (2D) Mercy tape in Ghanaian children. A cross-sectional study was conducted at the Tamale Teaching Hospital in Ghana. Eight hundred forty children between 2 months and 13 years had their weights estimated by the 2017 Broselow, PAWPER XL, PAWPER XL-MAC, and 2D Mercy tapes. Accuracy of the methods was determined by percentage of weight estimated to within 10% and 20% of actual weight. Mean percentage error and the Bland-Altman analysis were used to assess bias and precision. The proportion of weight estimates within 10% and 20% of actual weight for Broselow tape were 47.5% and 82.3%, for 2D Mercy tape were 73.1% and 96.3%, for PAWPER XL-MAC were 77.6% and 97.5%, and for PAWPER XL were 81.7% and 96.8%, respectively. The Broselow tape had the greatest bias and least precision among the 4 methods. The Mercy, PAWPER XL-MAC, and PAWPER XL tapes had similar performance, but all performed significantly better than the Broselow tape in pairwise comparison. The best weight estimation method overall was the PAWPER XL tape as it also had the least bias and greatest precision. The Mercy, PAWPER XL-MAC, and PAWPER XL tapes were more accurate than the 2017 Broselow tape and should be used in preference in Ghana and countries with similar population structure.

Human Factor Errors in the use of the PAWPER Tape Systems: An Analysis of Inter-Rater Reliability.

BackgroundInternational guidelines have promoted the use of length-based tapes for emergency weight estimation in children. This is primarily because of a perception that more modern methods might require more training than can practically be achieved. This study aimed to evaluate the inter-rater reliability of novice users of the PAWPER XL (paediatric advanced weight-prediction in the emergency room) tape as an indicator of the ability to use the device effectively with limited training.MethodsThis was a secondary analysis of unpublished data from three previous studies. Inter-rater reliability analyses were performed for each study for the accuracy of weight estimations and for the assignment of body habitus score. Inter-rater reliability was analysed using percentage agreement and Cohen’s Kappa for Study 1 and intraclass correlation (ICC) for Study 2 and Study 3. A value of <0.7 was considered to indicate inadequate agreement, 0.7 to 0.89 was considered to indicate good agreement and ≥0.9 was considered to indicate excellent agreement.Main ResultsA total of 7034 data points were available for analysis in the three studies. In Study 1, the percentage agreement of an accurate weight estimation in 50 children, with two raters, was 47/50 (94%) with a Cohen’s Kappa of 0.93 (0.81 - 1.0). In Study 2, the ICC for 6720 habitus score assessments, with 112 raters, was 0.73 (0.68 - 0.80). In Study 3, the ICC for 264 weight estimations (in terms of an accurate weight estimation, with 33 raters) was 0.88 (0.72 - 0.97).ConclusionsThere was good inter-rater reliability in the assessment of habitus and the accuracy of weight estimation for the PAWPER XL tape in this secondary analysis. The findings suggest that reasonable proficiency with the system can be achieved with minimal training. It is therefore unlikely that systems such as this require too much training to be practical in emergency care.

Pediatric weight estimation: validation of the PAWPER XL tape and the PAWPER XL tape mid-arm circumference method in a South African hospital.

ObjectiveThe primary aim of this study was to prospectively compare the performance of the Broselow tape, Mercy method, pediatric advanced weight prediction in the emergency room extra-long (PAWPER XL) tape, and PAWPER XL mid-arm circumference (MAC) method in estimating the weight of children from a low-income setting. The secondary aim was to analyze the time taken to perform each method.MethodsThis analyzed a convenience study sample of 300 children aged 0 to 18 years at the Baragwanath Hospital in South Africa. Weight estimations were obtained using each of the weight estimation systems on each child. These weight estimations were then compared against the actual weight to determine bias, precision, and accuracy of the estimation methods.ResultsThe PAWPER XL tape and PAWPER XL-MAC methods performed the best and provided estimated weights within 10% of the actual weight in 62.7% and 67.3% of cases, respectively, followed by the Mercy method (56.5%) and Broselow tape (43.9%). The use of MAC improved the accuracy of estimation, especially in heavier and taller children. The median times taken to perform measurements using the Broselow tape, Mercy method, PAWPER XL tape, and PAWPER XL-MAC method were 11.3 seconds, 34.7 seconds, 9.3 seconds, and 33.9 seconds respectively.ConclusionThe PAWPER XL tape and PAWPER XL-MAC methods were the most accurate methods of estimating weight in this group of children. These methods may be considered in preference to the Broselow tape or the Mercy method for emergency weight estimation in low socioeconomic status populations.

Using the Mercy Method to Estimate Ideal Body Weight in Children: A Description and Validation of a New Methodology.

BackgroundIn obese children, lipophilic medications should be dosed to total body weight (TBW) and hydrophilic medications to ideal body weight (IBW). During emergencies, these weights need to be estimated to ensure that urgent drug therapy is accurate and safe. The Mercy method is a well-established weight estimation system that has recently been adapted to provide estimations of body length in children. It was therefore conceivable that this could be further modified to provide estimations of IBW.MethodsA model was developed a priori using the Mercy method’s humeral length (HL) segments to predict IBW. The accuracy of this model was then tested in a sample of 13,134 children from the National Health and Nutrition Examination Survey (NHANES) datasets. The accuracy of IBW estimation was determined from the percentage of estimations falling within 10% (p10) and 20% (p20) of true IBW. The model was also tested to see the accuracy of the detection of obesity in the study sample.ResultsFrom the sample of 13,134 children, a subset of 1,318 obese children were identified. In this subset, the new Mercy method model achieved an IBW estimation accuracy p10 of 66.9% and a p20 of 95.1%. For the detection of the obese child, the model had a sensitivity of 88.6% and a specificity of 75.8%.ConclusionsThis study established that the Mercy method can be modified to provide a reasonably accurate estimation of IBW in obese children, with very few critical errors. The ability of the model to identify the obese child was also reasonably accurate, on a par with other such predictive methods. While other accurate methods of estimating both TBW and IBW exist, such as the Paediatric Advanced Weight Prediction in the Emergency Room eXtra-Long tape (PAWPER XL tape), the modified Mercy method is an acceptable alternative if such other devices are not available.

The utility of pediatric age-based weight estimation formulas for emergency drug dose calculations in obese children.

ObjectivesIn obese children, when drug therapy is required during emergency care, an estimation of ideal body weight is required for certain drug dose calculations. Some experts have previously speculated that age‐based weight estimation formulas could be used to predict ideal body weight. The objectives of this study were to evaluate how accurately age‐based formulas could predict ideal body weight and total body weight in obese children.MethodsThree age‐based weight estimation formulas were evaluated in a secondary analysis, using a pooled sample of children from 3 academic emergency departments in South Africa. The estimates produced by the 3 formulas (and the PAWPER XL tape as a control) were compared against measured total body weight and ideal body weight. The percentages of estimates falling within 10% of the standard weight were used as the primary outcome measure (PW10).ResultsThis study included 1026 children. For ideal body weight estimations in obese children, the old Advanced Life Support formula, the new Advanced Life Support formula, and the Best Guess formula achieved PW10s (with 95% confidence intervals [CIs]) of 29% (27.2%, 30.8%), 41.4% (38.9%, 43.9%), and 48.3% (45.3%, 51.3%), respectively. For total body weight estimations, the formulas achieved PW10s of 3.6% (3.4%, 3.8%), 5.2% (4.9%, 5.5%), and 19.0% (17.8%, 20.2%). The PAWPER XL tape achieved an accuracy of ideal body weight estimation of 100% (93.9%, 100%) and total body weight estimation of 49.7% (46.7%, 52.7%) in obese children.ConclusionsThe age‐based formulas were substantially less accurate at estimating total body weight and ideal body weight than existing length‐based methods such as the PAWPER XL tape, and should not be used for this purpose.

How and Why Paediatric Weight Estimation Systems Fail - A Body Composition Study.

BackgroundWeight estimation during medical emergencies in children is essential, but fraught with errors if the wrong techniques are used, which may result in critical drug dosing errors. Individualised weight estimation is required to allow for accurate dosing in underweight and obese children in particular. This study was designed to evaluate the associations between weight estimations from different systems and body composition in order to establish how and why they may perform well or poorly.MethodsA convenience sample of 332 children aged from one month to 16 years had weight estimations using four age-based formulas: the Broselow™ Pediatric Emergency Tape (Armstrong Medical Industries, Inc., Lincolnshire, IL), the Mercy Method, and the Pediatric Advanced Weight Prediction in the Emergency Room, Extra-large/Extra-long Tape (PAWPER XL) Tape. They also had an assessment of body composition using dual x-ray absorptiometry (DXA). The weight estimates were compared against total body weight (TBW), calculated ideal body weight (IBW), and DXA-measured fat-free mass (FFM). Analyses of associations between age, length, weight estimation outcomes, and body composition were performed.ResultsAge-based formulas were very inaccurate because of the erratic relationship between age and body composition. The Broselow tape estimated IBW well in obese children because of the strong relationship between length and fat-free mass. It predicted TBW poorly in underweight and obese children, however, because of the poor relationship between length and fat mass. The Mercy Method’s performance was unrelated to body composition, but estimated TBW reasonably well and could not predict IBW or FFM. The PAWPER XL Tape’s performance was the most closely associated with body composition and, therefore, achieved an acceptable accuracy for estimations of TBW, IBW, and FFM.ConclusionsOf the systems evaluated, the PAWPER XL Tape has the best association with body composition and the most accurate estimations of TBW, IBW, and FFM.

Drug dosing errors in simulated paediatric emergencies - Comprehensive dosing guides outperform length-based tapes with precalculated drug doses.

BackgroundThe accuracy of drug dosing calculations during medical emergencies in children has not been evaluated extensively. The objectives of this study were to evaluate the accuracy of drug dose calculations using the Broselow tape, the PAWPER XL tape plus its companion drug-dosing guide, a custom-designed mobile phone app and no drug-dosing aid (control group).MethodsThis 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 the three methods to estimate the children's weight and calculate drug doses. The accuracy of and time taken for the drug dose determinations were then evaluated for each of the methods.ResultsThe overall accuracy of drug dose determinations was extremely and potentially dangerously low in the control group in which no dosing guide was used as well as in the Broselow tape group (<20% of doses were correct). The accuracy was significantly higher with the PAWPER XL tape group and the mobile app group (47% and 31% respectively). The times taken to obtain the required information did not differ in a clinically meaningful magnitude.ConclusionsBoth an accurate weight estimation and a dosing guide with comprehensive information were necessary to produce an accurate prescription. The information on the Broselow tape was not sufficient for this purpose. The current guidelines recommending the use of tapes with limited information should be revised. The results from the comprehensive dosing guides were substantially better, but still had a lower proportion of accurate prescriptions than desirable. The role of training in every aspect of the emergency paediatric weight estimation and drug dosing procedure cannot be underestimated and should be routine in any environment where emergency care may be needed.

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

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. 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. 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%). 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.

A comparison of four weight estimation systems for paediatric resuscitation

One of the most important parameters that must be obtained when resuscitating a critically ill or injured paediatric patient is their weight. The best known paediatric weight estimation system is arguably the Broselow Tape, but the tape has been shown to be very inaccurate. The aim of this study was to determine and compare the accuracy of the Broselow tape, a modified Broselow tape system, the PAWPER XL tape and the hanging leg weight technique for potential utilisation in the paediatric resuscitation setting. A convenience sample of 200 children between the ages of 1 month and 16 years were enrolled. All the children's weights were estimated using the Broselow tape, a habitus-modified Broselow tape system, the PAWPER XL tape and the hanging leg weight technique. Overall accuracy was evaluated using the percentage of weight estimations falling within 10% of actual weight (PW10). The PAWPER XL tape performed the best, whilst the hanging leg weight technique performed the poorest with PW10s of 74% and 19.5%, respectively. The Broselow tape with and without habitus-modification only showed modest accuracy, with PW10s of 61.7% and 59.1% respectively. The PAWPER XL tape performed significantly better than other weight estimation systems and is most appropriate for use in South African paediatric emergencies. The habitus-modified Broselow system produced only modest improvement in overall weight estimation accuracy of the Broselow tape.

An algorithm to improve the accuracy of emergency weight estimation in obese children.

IntroductionDuring medical emergencies in children, accurate and appropriate weight estimations may ultimately influence the outcome by facilitating the delivery of safe and effective doses of medications. Children at the extremes of habitus, especially obese children, are more at risk of an inaccurate weight estimation and therefore may be more at risk of medication errors. The objective was therefore to develop an algorithm to guide accurate emergency weight estimation in obese children.MethodsRelevant medical evidence was reviewed regarding weight estimation and its role and timing in the resuscitation of obese children. This was used as the basis for a weight-estimation algorithm.ResultsThere was limited evidence regarding the way the weight-estimation systems should be used in obese children other than that the dual length- and habitus-based systems were the most accurate. The methods included in the algorithm were the Broselow tape, the Mercy method, parental estimates, the paediatric advanced weight prediction in the emergency room/ eXtra Length-eXtra Large (PAWPER XL) tape and the Traub-Johnson formula. The algorithm recognised several ways in which weight estimation could be tailored to the clinical scenario to estimate both ideal and total body weight.ConclusionWeight-estimation in obese children must be conducted appropriately to avoid medication errors. This algorithm provides a framework to achieve this.

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

IntroductionThe 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.MethodsThis 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.ResultsThe 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.DiscussionThe 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.

Estimating the weight of children in Nepal by Broselow, PAWPER XL and Mercy method.

Resuscitation of a critically-ill child requires an accurate weight for fluids and medication dosing; however, weighing children on a scale while critically ill is not always practical. The objective of this study is to determine the accuracy of three different weight estimation methods (Broselow, PAWPER XL and Mercy tape) of children presenting to Patan Hospital, Nepal. This was a prospective, cross-sectional study that included children presenting to the emergency department and under-fourteen outpatient clinic at Patan Hospital. Measured weight was compared to estimated weight of Broselow, PAWPER XL, and Mercy tapes. The mean percentage error and percentage of estimated weights that were within 10% (PW10) and 20% (PW20) of actual weight were calculated. Acceptable accuracy was determined as a PW10>70% and PW20>95%. A Bland-Altman analysis was done to determine agreement between each weight estimation method and actual weight. The study included 813 children. The mean age was 4.2 years (ranging from 4 days to 14 years) with 60% male. The mean percentage error (MPE) for Broselow, PAWPER XL and Mercy were -1.0% (SD 11.8), 0.7% (10.5) and 4.2% (11.9) respectively. The predicted weight within 10% was highest for the PAWPER XL (71.5%) followed by Broselow (63.2%) and Mercy (58.1%). The predicted weight within 20% of actual weight was 95.2%, 91.5% and 91.3% for PAWPER XL, Broselow and Mercy respectively. The PAWPER XL tape was the only method found to be accurate in estimating the weight of Nepalese children.

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

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