Mike Wells

International Evidence-Based Recommendations for Focused Cardiac Ultrasound

BACKGROUND Focused cardiac ultrasound (FoCUS) is a simplified, clinician-performed application of echocardiography that is rapidly expanding in use, especially in emergency and critical care medicine. Performed by appropriately trained clinicians, typically not cardiologists, FoCUS ascertains the essential information needed in critical scenarios for time-sensitive clinical decision making. A need exists for quality evidence-based review and clinical recommendations on its use. METHODS The World Interactive Network Focused on Critical UltraSound conducted an international, multispecialty, evidence-based, methodologically rigorous consensus process on FoCUS. Thirty-three experts from 16 countries were involved. A systematic multiple-database, double-track literature search (January 1980 to September 2013) was performed. The Grading of Recommendation, Assessment, Development and Evaluation method was used to determine the quality of available evidence and subsequent development of the recommendations. Evidence-based panel judgment and consensus was collected and analyzed by means of the RAND appropriateness method. RESULTS During four conferences (in New Delhi, Milan, Boston, and Barcelona), 108 statements were elaborated and discussed. Face-to-face debates were held in two rounds using the modified Delphi technique. Disagreement occurred for 10 statements. Weak or conditional recommendations were made for two statements and strong or very strong recommendations for 96. These recommendations delineate the nature, applications, technique, potential benefits, clinical integration, education, and certification principles for FoCUS, both for adults and pediatric patients. CONCLUSIONS This document presents the results of the first International Conference on FoCUS. For the first time, evidence-based clinical recommendations comprehensively address this branch of point-of-care ultrasound, providing a framework for FoCUS to standardize its application in different clinical settings around the world.

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.

Early closure of colostomies in trauma patients—A prospective randomized trial

BACKGROUND Most traumatic colon injuries can be repaired primarily, but a colostomy may still be required for severe colonic or rectal injury. The current trend is to reverse the colostomy early, rather than to wait the traditional 3 months before closure. METHODS Forty-nine patients with colostomies after abdominal trauma were entered into the study. All patients had undergone a contrast enema in the second postoperative week to assess distal colon healing. Patients were excluded from early closure for nonhealing of the bowel injury, unresolving wound sepsis, or an unstable condition. We then compared the outcome of the remaining 38 (77.6%) patients allocated to either an early or a late colostomy group in a controlled, prospective, randomized trial. RESULTS We found no significant difference in morbidity between the two groups, with an overall complication rate of 26.3%. Technically the early closure of colostomies was far easier than late closure and required significantly less operating time (p = 0.036) and with less intraoperative blood loss (p = 0.020). The closure of end colostomies was more time consuming, both early (p < 0.001) and late (p < 0.001) and caused more bleeding (p < 0.001 and p < 0.001, respectively). Total hospitalization was marginally shorter overall for early closure, but late closure of end colostomies resulted in prolonged hospitalization (p = 0.023). CONCLUSIONS The early closure of colostomies and the use of loop colostomies whenever possible are recommended as both safe and beneficial for patients with colonic injury after trauma. Contraindications for early closure include nonhealing distal bowel, persistent wound sepsis, or persistent postoperative instability.

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.

The PAWPER tape and the Mercy method outperform other methods of weight estimation in children at a public hospital in South Africa.

BACKGROUND A rapid, accurate weight-estimation method is essential in paediatric emergency care, when it may not be possible to weigh a child, as drug dose calculations cannot be completed without weight. OBJECTIVES To determine and compare the performance of the Broselow tape, PAWPER (Paediatric Advanced Weight Prediction in the Emergency Room) tape, Mercy method, Wozniak method and three age-based formulae in estimating the weight of children. A secondary objective was to assess whether the addition of a figural rating scale to assess body habitus improved the performance of the PAWPER tape. METHODS We estimated the weights of children between the ages of 1 month and 12 years using the Broselow tape, PAWPER tape, Mercy method and Wozniak method. The performance of the four methods was evaluated, and they were compared with one another and with three aged-based formulae. RESULTS Three hundred children were enrolled in the study. The PAWPER tape and Mercy method performed the best, estimating weight within 10% of actual weight (PW10) in 88% and 80% of cases, respectively. The Broselow tape and Wozniak method fared significantly worse (PW10 54% for Broselow, 71% for the ulna length method and 63% for the tibia length method). The use of a figural rating scale to assess body habitus did not significantly improve the overall performance of the PAWPER tape. The age-based formulae performed poorly. CONCLUSIONS The PAWPER tape and Mercy method outperformed the Wozniak method and Broselow tape in estimating weight of children. The Broselow tape and the age-based formulae were very poor weight-estimation methods and should no longer be used, given the availability of better methods.

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.