An observational simulation-based study of the accuracy of intercostal drain placement and factors influencing placement.

Introduction: South Africa's significant burden of trauma and respiratory disease requires the regular need for intercostal drain (ICD) insertion. ICD misplacement is associated with significant complications. The aim of this study was to assess ICD insertion site accuracy and the factors affecting accuracy by Emergency Department doctors. Methods: This was a prospective, observational simulation-based study. Prior to participant admission, pertinent thoracic structures were marked on two simulated patients using an invisible marker which could only be seen using ultraviolet light. One by one, study participants were then asked to place a sticker on each side of each patient's chest to indicate where they would insert an ICD. Sticker placements were photographed under ultraviolet light. Placement sites were compared according to the most appropriate and accurate position for insertion (within the area superior to the 6th rib, posterior to pectoralis major and 1cm anterior to the mid-axillary line) as well as the British Thoracic Society's 'triangle of safety'. Comparisons of accuracy were made between participant rank (junior vs senior doctor), participant experience, simulated patient BMI category and placement side. Results: Insertion site was accurate in 47% of placements and within the 'triangle of safety' in 51% of placements. Improved accuracy was associated with greater participant experience (61% vs. 37%, p<0.01), and left-sided chest placement (54% vs 40%, p = 0.02). No difference was found when comparing simulated patient BMI category (low vs high, 43% vs 51%, p=0.18) or participant rank (junior vs senior, 41% vs 51%, p=0.10). Conclusion: Overall accuracy of ICD insertion site was low, and appropriate accuracy was only associated with greater participant experience and left sided placement. Further studies to determine methods to improve ICD placement accuracy are needed.

Development and Validation of a Length- and Habitus-Based Method of Ideal and Lean Body Weight Estimation for Adults Requiring Urgent Weight-Based Medical Intervention.

BACKGROUND AND OBJECTIVE: Accurate drug dosing in obese patients requires an estimation of ideal body weight (IBW) or lean body weight (LBW) for dosing hydrophilic medications. Erroneous weight estimates during the management of adults requiring weight-based treatment may contribute to poor outcomes. Existing methods of IBW and LBW estimation or measurement are very difficult to use during emergency care. A new point-of-care model would be useful to provide rapid estimates of IBW and LBW for this purpose. METHODS: A model was derived based on the PAWPER XL-MAC tape, a pediatric weight estimation system which uses recumbent length and mid-arm circumference to estimate IBW and LBW. The new adult model was used to generate IBW and LBW estimations for a derivation sample (n = 33155) and a validation sample (n = 5926) from National Health and Nutrition Examination Survey (NHANES) datasets. The model was developed in two steps, with calibration at each step, before being validated on an unused dataset. The outcome measure was to achieve >95% of IBW and LBW estimations within 20% of recognized reference standards (P20 > 95%) and >70% of estimations within 10% of these standards (P10 > 70%). RESULTS: The new model achieved a P20 of 100% and a P10 of 99.9% for IBW and a P20 of 98.3% and a P10 of 78.3% for LBW. This accuracy was maintained in both sexes, all ages, all ethnic groups, all lengths, and in all habitus types, except for the severely obese female subgroup. CONCLUSIONS: The modified PAWPER XL-MAC model proved to be an accurate method of IBW and LBW estimation. It could, therefore, have an important role in facilitating emergency drug dose calculations in obese adult patients.

Development and validation of a length- and habitus-based method of total body weight estimation in adults.

BACKGROUND: Erroneous weight estimation during the management of emergency presentations in adults may contribute to patient harm and poor outcomes. Patients can often not be weighed during emergencies and a weight estimation is required to facilitate weight-based therapies. Many existing methods of weight estimation are either unacceptably inaccurate or very difficult to use during the provision of emergency care. METHODS: The weight estimation system developed in this study was based on and modified from the PAWPER XL-MAC method, a pediatric weight estimation system that uses recumbent length and mid-arm circumference (MAC) to predict total body weight. This model was validated in the 2015-2018 National Health and Nutrition Examination Survey (NHANES) datasets. The primary outcome measure was to achieve >95% of estimations within 20% of measured weight (P20 > 95%). RESULTS: The modified PAWPER XL-MAC model achieved a P20 of 96.0% and a P10 of 71.3% in the validation dataset (N = 11,520). This accuracy (P20 > 95%) was maintained in both sexes, all ages, all ethnic groups, all lengths and in all habitus-types, except for the subgroup of severely obese individuals. CONCLUSIONS: The modified PAWPER XL-MAC model proved to be a very accurate method of weight estimation. It is more accurate than most other published reports of existing methods of weight estimation, except for patients' own estimations. It therefore could have a role in facilitating emergency drug dose calculations, if prospective studies bear out the accuracy found in this study.

The cost-effectiveness of upfront point-of-care testing in the emergency department: a secondary analysis of a randomised, controlled trial.

BACKGROUND: Time-saving is constantly sought after in the Emergency Department (ED), and Point-of-Care (POC) testing has been shown to be an effective time-saving intervention. However, when direct costs are compared, these tests commonly appear to be cost-prohibitive. Economic viability may become apparent when the time-saving is translated into financial benefits from staffing, time- and cost-saving. The purpose of this study was to evaluate the cost-effectiveness of diagnostic investigations utilised prior to medical contact for ED patients with common medical complaints. METHODS: This was a secondary analysis of data from a prospective, randomised, controlled trial in order to assess the cost-effectiveness of upfront, POC testing. Eleven combinations of POC equivalents of commonly-used special investigations (blood tests (i-STAT and complete blood count (CBC)), electrocardiograms (ECGs) and x-rays (LODOX® (Low Dose X-ray)) were evaluated compared to the standard ED pathway with traditional diagnostic tests. The economic viability of each permutation was assessed using the Incremental Cost Effectiveness Ratio and Cost-Effectiveness Acceptability Curves. Expenses related to the POC test implementation were compared to the control group while taking staffing costs and time-saving into account. RESULTS: There were 897 medical patients randomised to receive various combinations of POC tests. The most cost-effective combination was the i-STAT+CBC permutation which, based on the time saving, would ultimately save money if implemented. All LODOX®-containing permutations were costlier but still saved time. Non-LODOX® permutations were virtually 100% cost-effective if an additional cost of US$50 per patient was considered acceptable. Higher staffing costs would make using POC testing even more economical. CONCLUSIONS: In certain combinations, upfront, POC testing is more cost-effective than standard diagnostic testing for common ED undifferentiated medical presentations - the most economical POC test combination being the i-STAT + CBC. Upfront POC testing in the ED has the potential to not only save time but also to save money. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03102216.

The cost of time: A randomised, controlled trial to assess the economic impact of upfront, point-of-care blood tests in the Emergency Centre.

INTRODUCTION: Time and cost constraints abound in the Emergency Centre (EC). These resource-constraints are further magnified in low- and middle-income countries (LMIC). Almost half of all patients presenting to the EC require laboratory tests. Unfortunately, access to laboratory services in LMIC is commonly inadequate. Point-of-Care (POC) tests may assist to avert this shortcoming. The aims of this study were to evaluate the cost effectiveness of upfront POC blood tests performed prior to doctor assessment compared to the standard EC workflow. METHODS: A secondary analysis was performed on data from a prospective, randomised, controlled trial where patients with abdominal/chest symptoms or generalised body pain/weakness followed either the normal EC workflow pathway or one of two enhanced workflow pathways with POC tests (i-STAT with and without a complete blood count (CBC)) prior to doctor evaluation. The incremental cost effectiveness ratio (ICER) was used to perform the cost effectiveness analysis. RESULTS: There were 248 patients enrolled in the study. The use of the two upfront, POC test pathways significantly exceeded the primary outcome measure of a 20% reduction in treatment time. In the i-STAT + CBC group, the 31 min. time-saving translated into cost-saving of US$14.96 per patient (IECR 0.27) whereas the 21 min. time-saving in the i-STAT only group only had an additional net cost of US$3.11 per patient (IECR 0.90). CONCLUSION: Upfront, POC blood tests can be utilised in the resource-constrained EC to manage patients more efficiently by saving time. This time-saving can, in fact, be more cost effective than traditional EC workflow making it an economically viable option for implementation in LMIC.

The "PAWPER-on-a-page": Increasing global access to a low-cost weight estimation system.

BACKGROUND: The PAWPER tape is one of the most accurate weight estimation systems available today, but international access to the tape is limited because it has no commercial distribution. For this reason, the "PAWPER-on-a-page" concept was devised: downloadable image files that allow users to print and assemble their own tapes. However, the feasibility of this method is dependent on users being able to produce accurate tapes. This study was devised to determine whether untrained participants could print and assemble the "PAWPER-on-a-page" easily and accurately. METHODS: Doctor and nurse volunteers downloaded the "PAWPER-on-a-page" and "PAWPER XL-on-a-page" image files and printed copies on a home-printer and also at a commercial printer. One copy of each tape was then assembled according to instructions from an online video. The accuracy of printing and assembly, the time taken for assembly and the cost were then evaluated. RESULTS: There were 32 participants. The median time for assembly was 8 minutes 19 seconds and 7 minutes 31 seconds for the "PAWPER-on-a-page" and "PAWPER XL-on-a-page" respectively, with a median cost of USD 0.09 and USD 1.00 respectively. For the assembled tapes, 71.9% of the "PAWPER-on-a-page" tapes and 65.6% of the "PAWPER XL-on-a-page" achieved the required accuracy of 0.2%. Printing errors, related to scaling, were common, but easily detectable. CONCLUSION: The "PAWPER-on-a-page" system can be easily, quickly, affordably and accurately printed and assembled by end users. Stringent double checking of the printed and fully assembled tapes is essential to ensure accuracy.

Nervous breakdown! A registry of nerve blocks from a South African emergency centre.

INTRODUCTION: Nerve blocks are commonplace in the operating theatre and have recently made their way into emergency centres as a viable alternative to traditional methods of analgesia. Their use and safety has been documented for a variety of pathologies and it has been shown that they spare opioids and shorten time to discharge. No data exists on their use in South Africa. The purpose of this study was to analyse data from an existing nerve block registry from an emergency centre in South Africa. METHODS: The study was a retrospective, descriptive analysis of a nerve block registry from an academic emergency centre in Johannesburg, South Africa from May 2016 to September 2017. RESULTS: There were 168 nerve blocks performed by 36 different operators of varying experience. The most common indication was for fracture management and the most frequently performed blocks were femoral 3-in-1 (44.6%), pop-sciatic (16.7%) and forearm-ultrasound nerve blocks (16.7%). Ultrasound guidance was used in 88.6% of the blocks. The average time taken to perform a nerve block was 10 min. The success rate was 91.8%. None of the variables analysed (i.e., operator experience, type of nerve block performed, time taken to perform the nerve block, ultrasound guidance, amount of anaesthetic used and time taken to evaluate outcome) had any effect on the success rate. CONCLUSION: This study illustrates the use of nerve blocks as an effective, safe and timeous analgesic solution to a wide variety of musculoskeletal injuries in an academic emergency centre in South Africa.

The cost of time: A randomised, controlled trial to assess the economic impact of upfront, point-of-care blood tests in the Emergency Centre

Introduction Time and cost constraints abound in the Emergency Centre (EC). These resource-constraints are further magnified in low- and middle-income countries (LMIC). Almost half of all patients presenting to the EC require laboratory tests. Unfortunately, access to laboratory services in LMIC is commonly inadequate. Point-of-Care (POC) tests may assist to avert this shortcoming. The aims of this study were to evaluate the cost effectiveness of upfront POC blood tests performed prior to doctor assessment compared to the standard EC workflow.Methods A secondary analysis was performed on data from a prospective, randomised, controlled trial where patients with abdominal/chest symptoms or generalised body pain/weakness followed either the normal EC workflow pathway or one of two enhanced workflow pathways with POC tests (i-STAT with and without a complete blood count (CBC)) prior to doctor evaluation. The incremental cost effectiveness ratio (ICER) was used to perform the cost effectiveness analysis.Results :There were 248 patients enrolled in the study. The use of the two upfront, POC test pathways significantly exceeded the primary outcome measure of a 20% reduction in treatment time. In the i-STAT + CBC group, the 31 min. time-saving translated into cost-saving of US$14.96 per patient (IECR 0.27) whereas the 21 min. time-saving in the i-STAT only group only had an additional net cost of US$3.11 per patient (IECR 0.90).Conclusion Upfront, POC blood tests can be utilised in the resource-constrained EC to manage patients more efficiently by saving time. This time-saving can, in fact, be more cost effective than traditional EC workflow making it an economically viable option for implementation in LMIC

Doctors' perceptions of the impact of upfront point-of-care testing in the emergency department.

OBJECTIVES: Special investigations (e.g. blood tests, electrocardiograms, x-rays) play an integral role in patient management in the emergency department (ED). Having results immediately available prior to assessing a patient may lead to improved efficiency. This could be instituted by utilizing point-of-care (POC) testing with an alternative ED workflow, but the implementation would be dependent on acceptance by the end-users. The aim of this study was to assess doctors' perceptions of POC testing in the ED when the normal treatment pathway was modified to use upfront POC tests performed prior to doctor evaluation in an effort to decrease treatment times. METHODS: A prospective, randomized, controlled trial was performed in the ED where medical patients received either the normal ED workflow pathway or one of the enhanced workflow pathways with POC tests in various combinations prior to doctor evaluation. At the end of the study period, doctors were invited to participate in an anonymous survey to gauge their opinions on the implementation of the early POC testing. RESULTS: Overall, the doctors surveyed were very satisfied with use of upfront POC in the ED. One hundred per cent of the 28 doctors surveyed found it helpful to assess patients who already had test results available and would want it to be permanently available. Normalized satisfaction scores were more favorable for combinations of 3 or more tests (0.7-1.0) as opposed to combinations with 2 or less tests (0.3-0.7). There was a preference for combinations that included comprehensive blood results. CONCLUSION: The implementation of workflow changes to assist doctors in the ED can potentially make them more productive. End-user buy-in is essential in order for the change to be successful. Upfront, protocolised, POC testing is a low-input, high-yield intervention that decreased treatment time and satisfied doctors.

A one year audit of patients with venous thromboembolism presenting to a tertiary hospital in Johannesburg, South Africa.

INTRODUCTION: Given the growing burden of venous thromboembolism (VTE) worldwide and the paucity of data from the developing world, the aim of this study was to audit the characteristics, risk factors and length of hospital stay of patients with VTE presenting to a tertiary hospital emergency centre in Johannesburg, South Africa. METHODS: The study was a retrospective record review of all patients who presented with VTE to a tertiary academic emergency centre in Johannesburg, South Africa from 1 April 2012 to 30 March 2013. RESULTS: Venous thromboembolism was identified in 74 patients; 56 (75.7%) with isolated deep vein thrombosis, 13 (17.6%) with pulmonary embolism and five (6.8%) who had a concurrent deep vein thrombosis with pulmonary embolism. The median age of the patients was 40 years old (range 19-90). The female to male ratio was 2:1. HIV infection, tuberculosis and history of immobilisation were the most common risk factors. The median duration of hospital stay was 14 days (range 4-36). A therapeutic International Normalised Ratio at discharge was only reached in 36.5% of patients. CONCLUSION: Venous thromboembolism presentation to the emergency centre is not common, but the risks associated with the morbidity and mortality related to it makes it important despite its relative scarcity. The prevalence of HIV infection amongst patients with VTE is concerning - not only related to the frequency of the pathology but also due to HIV not being factored into the common VTE risk stratification scores.

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.

Ultrasound evaluation of the respiratory changes of the inferior vena cava and axillary vein diameter at rest and during positive pressure ventilation in spontaneously breathing healthy volunteers.

INTRODUCTION: Ultrasound assessment of the inferior vena cava (IVC) has gained favour in aiding fluid management decisions for controlled, mechanically ventilated patients as well as in non-mechanically ventilated, spontaneously breathing patients. Its utility in spontaneously breathing patients during positive pressure non-invasive ventilation has not yet been determined. The use of the axillary vein, as an alternative option to the IVC due to its ease of accessibility and independence from intra-abdominal pressure, has also not been evaluated. The aim of this study was to assess respiratory variation in IVC and axillary vein diameters in spontaneously breathing participants (Collapsibility Index) and with the application of increasing positive end-expiratory pressure (PEEP) via positive pressure non-invasive ventilation (Distensibility Index). METHODS: The IVC and axillary vein diameters of 28 healthy adult volunteers were measured, using ultrasound, at baseline and with increasing PEEP via non-invasive ventilation. The Collapsibility Index and Distensibility Index of these vessels were calculated and compared for each vessel. The association between increasing PEEP levels and the indices was evaluated. RESULTS: Positive pressure delivered via non-invasive ventilation produced a similar degree of diameter change in the IVC and the axillary vein, that is, the Distensibility Index was similar whether measured in the IVC or the axillary vein (P=0.21, 0.47 and 0.17 at baseline, 5 and 10 cmH2O PEEP, respectively). Individual study participants' IVC and axillary veins, however, had variable responses to PEEP; that is, there appeared to be no consistent relationship between PEEP and the diameter changes. CONCLUSION: While the axillary vein could potentially be used as an alternative vessel to the IVC to assess for volume responsiveness in controlled, mechanically ventilated patients as well as in non-mechanically ventilated, spontaneously breathing patients, neither vein should be used to guide fluid management decisions in spontaneously breathing patients during positive pressure non-invasive ventilation.

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

INTRODUCTION: During 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. METHODS: Relevant 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. RESULTS: There 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. CONCLUSION: Weight-estimation in obese children must be conducted appropriately to avoid medication errors. This algorithm provides a framework to achieve this.

Hypothermia in trauma patients arriving at an emergency department by ambulance in Johannesburg, South Africa: a prospective study.

INTRODUCTION: Normal body temperature is considered to be between 36 and 38°C. Temperatures that are too low may negatively affect physiological functions. In trauma cases, factors that promote the development of hypothermia include concomitant hypoxia, hypotension, decreased levels of consciousness, contact with cold surfaces, exposure to low ambient temperatures and the administration of cold fluids. Studies on emergency department related hypothermia in Africa are sparse. This study investigated instances of hypothermia in a sample of trauma cases arriving by ambulance to an emergency department in Johannesburg, South Africa. METHODS: Core body temperatures of 140 trauma cases were measured upon arrival and 30 minutes later. Ambient temperatures outside the hospital, inside the ED and in the resuscitation areas were also recorded. Additional information was gathered describing the equipment available to the ambulance crews for temperature, control and rewarming. RESULTS: Seventy-two (51%) of the cases were found to have core body temperatures less than 36°C upon arrival. Twenty-nine (21%) the cases were considered clinically hypothermic (core temperatures of less than <35°C). After 30 minutes, 79 (56%) of the participants had core body temperatures of less than 36°C and 39 (28%) remained lower than 35°C. Patients were not warming up in the ED as expected. Rather, some had become colder. The study also found that the ambient temperature in the triage area fluctuated and was recorded as less than the recommended 21°C in 95 (68%) of the cases. In addition, the majority of ambulances that transported these cases lacked appropriate equipment on board to properly facilitate temperature control and rewarming. CONCLUSION: Fifty-one percent of the trauma cases arriving by ambulance had core temperature <36°C. Many became even colder in the ED. Attention needs to be given to the early identification of hypothermia, the regulation of ambient temperatures inside the ED including the provision of appropriate heating and rewarming devices on ambulances.

The Use of Body Habitus Reference Images Improves the Ability of Novices to Accurately Estimate Children's Weight Using the PAWPER XL Tape System.

BACKGROUND: The original methodology of the PAWPER (Pediatric Advanced Weight Prediction in the Emergency Room) tape relies on a gestalt visual assessment of a child's body habitus to adjust a length-based weight estimation. This assessment is dependent on the user's subjective opinion, which may result in aberrations in accuracy between users and populations. With the development of the second-generation PAWPER XL tape, a more objective method of habitus evaluation was desired. OBJECTIVE: The aim of this study was to evaluate a new, more objective figural reference image system and a new checklist system for quantifying body habitus. METHODS: Volunteers were asked to assess the body habitus score of 90 children from a sequence of photographic images using the standard gestalt visual assessment system, a new checklist system, and a system using figural reference images. PAWPER XL tape weight estimations were generated from these scores, which were compared between the three test groups. Participants were also surveyed on their preferences for the different methodologies. RESULTS: There were 11,505 habitus score assessments from 138 doctor, nurse, and paramedic participants. The figural reference image system significantly outperformed the checklist system and the gestalt visual assessment system in terms of weight estimation accuracy, achieving 70.9%, 61.1%, and 60.9% of estimations within 10% of measured weight, respectively. The participants expressed a strong subjective preference for the image system because of speed of use, ease of use, perceived accuracy, objectivity, and low cognitive load. CONCLUSIONS: The figural reference image system was objectively much more accurate than, and subjectively preferable to, the original gestalt visual estimation 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 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.