The accuracy of total body weight estimation in adults - A systematic review and meta-analysis.

BACKGROUND: Weight estimation is required in adult patients when weight-based medication must be administered during emergency care, as measuring weight is often impossible. Inaccurate estimations may lead to inaccurate drug doses, which may cause patient harm. Little is known about the relative accuracy of different methods of weight estimation that could be used during resuscitative care. The aim of this study was to evaluate the performance and suitability of existing weight estimation methods for use in adult emergency care. METHODS: A systematic literature search was performed for suitable articles that studied the accuracy of weight estimation systems in adults. The study characteristics, the quality of the studies, the weight estimation methods evaluated, the accuracy data, and any information on the ease-of-use of the method were extracted and evaluated. RESULTS: A total of 95 studies were included, in which 27 different methods of total body weight estimation were described, with 42 studies included in the meta-analysis. The most accurate methods, determined from the pooled estimates of accuracy (the percentage of estimates within 10% of true weight, with 95% confidence intervals) were 3-D camera estimates (88.8% (85.8 to 91.8%)), patient self-estimates (88.7% (87.7 to 89.7%)), the Lorenz method (77.5% (76.4 to 78.6%)) and family estimates (75.0% (71.5 to 78.6%)). However, no method was without significant potential limitations to use during emergency care. CONCLUSION: Patient self-estimations of weight were generally very accurate and should be the method of choice during emergency care, when possible. However, since alternative estimation methods must be available when confused, or otherwise incapacitated, patients are unable to provide an estimate, alternative strategies of weight estimation should also be available.

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.

Technically Adequate Images for Preparticipation Screening Echocardiography Can Be Obtained by Novices After a Single Day of Training.

OBJECTIVES: Echocardiography-naïve physicians were trained in a 1-day course to determine whether they could obtain images adequate for preparticipation screening in athletes. METHODS: Twenty-six physicians with no previous experience in echocardiography were trained to perform preparticipation screening echocardiography during a 6-hour course. Each image was rated for its technical quality on a diagnostic adequacy score. The time taken to perform the images was also evaluated. RESULTS: The images obtained a median score of 3 (interquartile range, 2-4), which was considered adequate for preparticipation screening. Video clips achieved a higher rating than the still images, with a median score of 4 (interquartile range, 3-4). The best-performing 50% of the participants obtained adequate images for screening 95% of the time after the initial training. Considering the group overall, 79.2% of all video clips were adequate. The median time to perform the scans was 39 seconds. The correlation between the time and adequacy score showed that the quickest novices were also able to obtain the best images. CONCLUSIONS: It is feasible to use novice sonographers to perform preparticipation screening echocardiography provided that the skill of the candidates is assessed after training, and competent individuals are selected. Video images should be used rather than still images.

Detection and Characterization of Renal Stones by Using Photon-Counting-based CT.

Purpose To compare a research photon-counting-detector (PCD) CT scanner to a dual-source, dual-energy CT scanner for the detection and characterization of renal stones in human participants with known stones. Materials and Methods Thirty study participants (median age, 61 years; 10 women) underwent a clinical renal stone characterization scan by using dual-energy CT and a subsequent research PCD CT scan by using the same radiation dose (as represented by volumetric CT dose index). Two radiologists were tasked with detection of stones, which were later characterized as uric acid or non-uric acid by using a commercial dual-energy CT analysis package. Stone size and contrast-to-noise ratio were additionally calculated. McNemar odds ratios and Cohen k were calculated separately for all stones and small stones (≤3 mm). Results One-hundred sixty renal stones (91 stones that were ≤ 3 mm in axial length) were visually detected. Compared with 1-mm-thick routine images from dual-energy CT, the odds of detecting a stone at PCD CT were 1.29 (95% confidence interval: 0.48, 3.45) for all stones. Stone segmentation and characterization were successful at PCD CT in 70.0% (112 of 160) of stones versus 54.4% (87 of 160) at dual-energy CT, and was superior for stones 3 mm or smaller at PCD CT (45 vs 25 stones, respectively; P = .002). Stone characterization agreement between scanners for stones of all sizes was substantial (k = 0.65). Conclusion Photon-counting-detector CT is similar to dual-energy CT for helping to detect renal stones and is better able to help characterize small renal stones. © RSNA, 2018.

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 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.

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.

Finding the mental foramen.

The mental foramen and mental nerve are clinically important landmarks for clinicians across various disciplines including dentists, oral maxillofacial surgeons, emergency physicians and plastic and reconstructive surgeons. To minimize complications related to procedures in the vicinity of the mental foramen and nerve, knowledge of its anatomy and anatomical variations is cardinal to concerned clinicians. In this review, basic anatomy, procedural complications, hard and soft tissue relations, variations between population groups, asymmetry, accessory mental foramina and the use of various radiological modalities to determine the position of the mental foramen are reviewed to provide a more thorough understanding of this important landmark.

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.

'It's a difficult situation to be an asylum seeker in the UK. It's not easy at all': An exploration of the social and psychological impact of seeking asylum in Wales.

Wales has been committed to receiving asylum seekers and resettling refugees in towns and cities, and these numbers are increasing on a yearly basis. However, many people seeking asylum feel disempowered by the disabling policies of the Home Office, leading to social and economic hardship for this population. This qualitative study aimed to capture the voices of this under-served group through in-depth, semi structured interviews to gain contextual understanding of the social and psychological challenges experienced by people seeking asylum in Wales. The findings suggest that many asylum seekers and refugees relied on their social support networks to compensate for the limited welfare offered to them by the asylum system. Changes to the asylum process and policies are needed for Wales to achieve its goal of ensuring that people seeking asylum are supported to rebuild their lives and make a full contribution to the Welsh society.

Educational concepts: A longitudinal interleaved curriculum for emergency medicine residency training.

Traditionally, emergency medicine (EM) residency programs teach non-adult emergency department activities (such as pediatric EM, point-of-care ultrasound [PoCUS], emergency medical services, and others) in a block format. In this way, a resident may have a 1-month pediatric EM rotation and then not have any further pediatric EM exposure until their next pediatric rotation 6‒9 months later. Furthermore, some rotations are only allotted for 1-month during the entire residency. A first-year EM resident may have their only formal PoCUS rotation early in the first year of training when their overall skills are developing, and their level of understanding and retention of information may not be optimal at that juncture of their residency training. This is far from ideal from an educational perspective. Learning scientists have now suggested that a longitudinal interleaved curriculum has substantial advantages over the traditional block format. This curriculum allows for a "spaced retrieval" practice that enhances retention of material and develops thinking processes that are important in clinical practice. The increased continuity of clinical experience has been shown to improve educational outcome and learner satisfaction. We developed a novel longitudinal interleaved curriculum for our EM resident trainees. This curriculum encompasses the entire 3 years of residency training and has the goals of increasing EM knowledge and clinical skills and being excellent preparation for board certification examinations. This concept has clear educational benefits. While adapting an existing medical training program would be challenging, a longitudinal curriculum could be phased in to replace a traditional EM curriculum.

The Florida Geriatric Head Trauma CT Clinical Decision Rule.

BACKGROUND: Several clinical decision rules have been devised to guide head computed tomography (CT) use in patients with minor head injuries, but none have been validated in patients 65 years or older. We aimed to derive and validate a head injury clinical decision rule for older adults. METHODS: We conducted a secondary analysis of an existing dataset of consecutive emergency department (ED) patients >65 years old with blunt head trauma. The main predictive outcomes were significant intracranial injury and Need for Neurosurgical Intervention on CT. The secondary outcomes also considered in the model development and validation were All Injuries and All Intracranial Injuries. Predictor variables were identified using multiple variable logistic regression, and clinical decision rule models were developed in a split-sample derivation cohort and then tested in an independent validation cohort. RESULTS: Of 5776 patients, 233 (4.0%) had significant intracranial injury and an additional 104 (1.8%) met CT criteria for Need for Neurosurgical Intervention. The best performing model, the Florida Geriatric Head Trauma CT Clinical Decision Rule, assigns points based on several clinical variables. If the points totaled 25 or more, a CT scan is indicated. The included predictors were arrival via Emergency Medical Services (+30 points), Glasgow Coma Scale (GCS) <15 (+20 points), GCS <14 (+50 points), antiplatelet medications (+17 points), loss of consciousness (+16 points), signs of basilar skull fracture (+50 points), and headache (+20 points). Utilizing this clinical decision rule in the validation cohort, a point total ≥25 had a sensitivity and specificity of 100.0% (95% CI: 96.0-100) and 12.3% (95% CI: 10.9-13.8), respectively, for significant intracranial injury and Need for Neurosurgical Intervention. CONCLUSIONS: The Florida Geriatric Head Trauma CT Clinical Decision Rule has the potential to reduce unnecessary CT scans in older adults, without compromising safe emergency medicine practice.

Is there evidence that length-based tapes with precalculated drug doses increase the accuracy of drug dose calculations in children? A systematic review.

Objective: The use of pediatric length-based weight estimation tapes with precalculated drug doses is advocated by major advanced life support organizations, but concerns have been raised on the accuracy of these systems. The objective of this systematic review was to collect, review, evaluate, and create a synthesis of the current literature to establish whether there is high-quality evidence for use of lengthbased tapes in accurate drug dose administration. A further objective was to determine how these tapes compare to other dosing aids. Methods: Eligible studies were identified and analyzed if they were peer reviewed, full text articles containing original data. Studies including any form of length-based precalculated drug dosing methodology in children aged 0 to 18 years were included. Results: Eighteen studies met the inclusion criteria. The most studied of the tapes was the Broselow tape in 16 studies (88.9%). When these tapes were used on their own without additional reference material, they produced a substantial number of potentially harmful dosing errors (>20% error). No tape was superior to another. Using the tapes was better than using no dosing aid but was inferior to using both comprehensive drug dosing guides and novel color-coded medication administration systems. Conclusion: There was no high-quality evidence that the use of length-based tapes with precalculated drug doses leads to accurate drug dosing. However, comprehensive drug dosing systems were more effective at reducing dosing errors than were length-based tapes on their own. The confounding effect of weight estimation accuracy on drug dosing accuracy has not been sufficiently studied.

Weight Estimation for Drug Dose Calculations in the Prehospital Setting - A Systematic Review.

BACKGROUND: Weight estimation is required to enable dose calculations for weight-based drugs administered during emergency care. The accuracy of the estimation will determine the accuracy of the administered dose. This is an important matter of patient safety. The objective of this systematic review was to collect, review, evaluate, and create a synthesis of the current literature focusing on the accuracy of weight estimation in the prehospital environment. METHODS: This systematic review followed the PRISMA guidelines. Studies were identified and included if they were peer reviewed, full length, published in English, and contained original data. Studies utilizing any form of weight estimation methodology in the prehospital setting (in children or adults) were included. Data on the quality of the studies and accuracy of the weight estimation systems were extracted. Common themes were also identified. RESULTS: Twenty-five studies met the inclusion criteria, with only nine studies (36.0%) containing useful weight estimation accuracy data. The overall quality of the studies was poor. The Broselow tape and paramedic estimates were the most studied methods of weight estimation, but there was insufficient evidence to support conclusions about accuracy. The major themes identified included the importance of accurate weight estimation and drug dosing as critical matters of patient safety, and the need for training to ensure these processes are performed accurately. CONCLUSIONS: There were limited robust data identified on the accuracy of different weight estimation methods used in the prehospital setting. Future high-quality clinical research in this area is of critical importance to ensure patient safety in the prehospital environment.

Estimating Lean Body Weight in Adults With the PAWPER XL-MAC Tape Using Actual Measured Weight as an Input Variable.

Introduction Accurate drug dose calculation in obese patients requires an estimation of lean body weight (LBW) for dosing hydrophilic medications. Inaccurate weight estimates during the management of critically ill obese adults may contribute to inaccurate drug doses and consequential poor outcomes. Existing methods of LBW estimation or measurement may be very difficult or impossible to use during emergency care. A point-of-care model that could provide rapid, accurate estimates of LBW would, therefore, be of significant clinical value. Methods A model was derived based using the adult version of the PAWPER XL-MAC tape. This derived model used recumbent length and measured total body weight (TBW) to estimate LBW. The derived model was used to generate LBW estimations in a random sample from National Health and Nutrition Examination Survey (NHANES) datasets (n=33,215). The benchmark outcome measure was to achieve >95% of LBW estimations within 20% of DXA-measured fat-free mass (P20>95%) and >70% of estimations within 10% of DXA-measured fat-free mass (P10>70%). Results The new model achieved a P20 of 99.7% and a P10 of 86.4% for LBW in the pooled sample and exceeded the minimum accuracy standards. This accuracy was maintained in both sexes, all ages, all ethnic groups, all lengths and in all habitus types. Conclusions The modified PAWPER XL-MAC model, using TBW as an input variable, proved to be an accurate method of LBW estimation. It could potentially have an important role in facilitating emergency drug dose calculations in critically ill or injured obese adult patients.

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.