Institutional and individual learning curves for focused abdominal ultrasound for trauma: cumulative sum analysis

Artificial intelligence evaluation of focused assessment with sonography in trauma

BACKGROUND

The focused assessment with sonography in trauma (FAST) is a widely used imaging modality to identify the location of life-threatening hemorrhage in a hemodynamically unstable trauma patient. This study evaluates the role of artificial intelligence in interpretation of the FAST examination abdominal views, as it pertains to adequacy of the view and accuracy of fluid survey positivity.

METHODS

Focused assessment with sonography for trauma examination images from 2015 to 2022, from trauma activations, were acquired from a quaternary care level 1 trauma center with more than 3,500 adult trauma evaluations, annually. Images pertaining to the right upper quadrant and left upper quadrant views were obtained and read by a surgeon or radiologist. Positivity was defined as fluid present in the hepatorenal or splenorenal fossa, while adequacy was defined by the presence of both the liver and kidney or the spleen and kidney for the right upper quadrant or left upper quadrant views, respectively. Four convolutional neural network architecture models (DenseNet121, InceptionV3, ResNet50, Vgg11bn) were evaluated.

RESULTS

A total of 6,608 images, representing 109 cases were included for analysis within the "adequate" and "positive" data sets. The models relayed 88.7% accuracy, 83.3% sensitivity, and 93.6% specificity for the adequate test cohort, while the positive cohort conferred 98.0% accuracy, 89.6% sensitivity, and 100.0% specificity against similar models. Augmentation improved the accuracy and sensitivity of the positive models to 95.1% accurate and 94.0% sensitive. DenseNet121 demonstrated the best accuracy across tasks.

CONCLUSION

Artificial intelligence can detect positivity and adequacy of FAST examinations with 94% and 97% accuracy, aiding in the standardization of care delivery with minimal expert clinician input. Artificial intelligence is a feasible modality to improve patient care imaging interpretation accuracy and should be pursued as a point-of-care clinical decision-making tool.

LEVEL OF EVIDENCE

Diagnostic Test/Criteria; Level III.

A method for identifying the learning curve for the surgical stabilization of rib fractures

BACKGROUND

Surgical stabilization of rib fractures (SSRF) is an accepted efficacious treatment modality for patients with severe chest wall injuries. Despite increased adoption of SSRF, surgical learning curves are unknown. We hypothesized intraoperative duration could define individual SSRF learning curves.

METHODS

Consecutive SSRF operations between January 2017 and December 2021 at a single institution were reviewed. Operative time, as measured from incision until skin closure, was evaluated by cumulative sum methodology using a range of acceptable "missteps" to determine the learning curves. Misstep was defined by extrapolation of accumulated operative time data.

RESULTS

Eighty-three patients underwent SSRF by three surgeons during this retrospective review. Average operative times ranged from 135 minutes for two plates to 247 minutes for seven plates. Using polynomial regression of average operative times, 75 minutes for general procedural requirements plus 35 minutes per plate were derived as the anticipated operative times per procedure. Cumulative sum analyses using 5%, 10%, 15%, and 20% incident rates for not meeting expected operative times, or "missteps" were used. An institutional learning curve between 15 and 55 SSRF operations was identified assuming a 90% performance rate. An individual learning curve of 15 to 20 operations assuming a 90% performance rate was observed. After this period, operative times stabilized or decreased for surgeons A, B, and C.

CONCLUSION

The institutional and individual surgeon learning curves for SSRF appears to steadily improve after 15 to 20 operations using operative time as a surrogate for performance. The implementation of SSRF programs by trauma/acute care surgeons is feasible with an attainable learning curve.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Head to toe ultrasound: a narrative review of experts' recommendations of methodological approaches

Critical care ultrasonography (US) is widely used by intensivists managing critically ill patients to accurately and rapidly assess different clinical scenarios, which include pneumothorax, pleural effusion, pulmonary edema, hydronephrosis, hemoperitoneum, and deep vein thrombosis. Basic and advanced critical care ultrasonographic skills are routinely used to supplement physical examination of critically ill patients, to determine the etiology of critical illness and to guide subsequent therapy. European guidelines now recommend the use of US for a number of practical procedures commonly performed in critical care. Full training and competence acquisition are essential before significant therapeutic decisions are made based on the US assessment. However, there are no universally accepted learning pathways and methodological standards for the acquisition of these skills.Therefore, in this review, we aim to provide a methodological approach of the head to toe ultrasonographic evaluation of critically ill patients considering different districts and clinical applications.

Results of single-incision distal biceps tendon repair for early-career upper-extremity surgeons

Background

The purpose of this investigation was to assess surgical outcomes after distal biceps tendon (DBT) repair for upper-extremity surgeons at the beginning of their careers, immediately following fellowship training. We aimed to determine if procedure times, complication rates, and clinical outcomes differed during the learning curve period for these early-career surgeons.

Methods

All cases of DBT repairs performed by 2 fellowship-trained surgeons from the start of their careers were included. Demographic data as well as operative times, complication rates, and patient reported outcomes were retrospectively collected. A cumulative sum chart (CUSUM) analysis was performed for the learning curve for both operative times and complication rate. This analysis continuously compares performance of an outcome to a predefined target level.

Results

A total of 78 DBT repairs performed by the two surgeons were included. In the CUSUM analysis of operative time for surgeon 1 and 2, both demonstrated a learning curve until case 4. In CUSUM analysis for complication rates, neither surgeon 1 nor surgeon 2 performed significantly worse than the target value and learning curve ranged from 14 to 21 cases. Mean Disabilities of Arm, Shoulder, and Hand score (QuickDASH) (10.65 ± 5.81) and the pain visual analog scale scores (1.13 ± 2.04) were comparable to previously reported literature.

Conclusions

These data suggest that a learning curve between 4 and 20 cases exists with respect to operative times and complication rates for DBT repairs for fellowship-trained upper-extremity surgeons at the start of clinical practice. Early-career surgeons appear to have acceptable clinical results and complications relative to previously published series irrespective of their learning stage.

Endoscopic transsphenoidal surgery for non-functioning pituitary adenoma: Learning curve and surgical results in a prospective series during initial experience

Background

To report the initial experience of surgery for non-functioning pituitary adenoma (NFPA) from a neurosurgeon in a dedicated residency training endoscopic transsphenoidal (ETS) program, and detail the surgical and clinical outcomes during this period.

Methods

A prospective series of all patients operated for NFPA, using an ETS approach, during the three first years of experience of a newly board-certified neurosurgeon was analysed. Clinical, radiological and peri-operative data were collected. Extent of resection (EOR) was determined by formal volumetric analysis. Impact of the learning curve and predictive factors of gross total resection (GTR) were determined.

Results

Fifty-three patients with NFPA were included in this prospective cohort which was divided in two periods of time (“First period”: 30 first cases, and “second period”: 23 following cases). Baseline characteristics of the patients in the two periods were similar. Overall occurrence of complication was 22% and was not significantly different in the two periods of time. No patient had severe neurological complication. Gross total resection was achieved in 70% of patients. Mean Extent of resection was 96%. In a multiple linear regression model, a higher EOR was positively correlated with experience (p = 0.018) and negatively correlated with Knosp Score equal to 4 (p < 0.001). Predictive factors for GTR were Higher Knosp grade (p = 0,01), higher pre-operative volume (p = 0.03), and second period of time (p = 0.01).

Conclusion

NFPA surgery can be safe and efficient during the learning period. Dedicated intensive learning, careful patient selection and multidisciplinary work are key to shorten the learning curve and achieve satisfactory results.

The use of evaluation tool for ultrasound skills development and education to assess the extent of point-of-care ultrasound adoption in lebanese emergency departments

Background:

Previously acknowledged as “bedside ultrasound”, point-of-care ultrasound (PoCUS) is gaining great recognition nowadays and more physicians are using it to effectively diagnose and adequately manage patients. To measure previous, present and potential adoption of PoCUS and barriers to its use in Canada, Woo et al established the questionnaire “Evaluation Tool for Ultrasound skills Development and Education” (ETUDE) in 2007. This questionnaire sorted respondents into innovators, early adopters, majority, and nonadopters.

Objectives:

In this article, we attempt to evaluate the prevalence of PoCUS and the barriers to its adoption in Lebanese EDs, using the ETUDE.

Materials and Methods:

The same questionnaire was again utilized in Lebanon to assess the extent of PoCUS adoption. Our target population is emergency physicians (EPs). To achieve a high response rate, hospitals all over Lebanon were contacted to obtain contact details of their EPs. Questionnaires with daily reminders were sent on daily basis.

Results:

The response rate was higher in our population (78.8%) compared to Woo et al's (36.4%), as the questionnaire was sent by email to each physician with subsequent daily reminders to fill it. In fact, out of the total number of the surveyed (85 physicians), respondents were 67, of which 76.1% were males and of a median age of 43. Using ETUDE, results came as nonadopters (47.8%), majority (28.3%), early adopters (16.4%), and innovators (7.5%). Respondents advocated using PoCUS currently and in the future in five main circumstances: focused assessment with sonography in trauma (FAST) (current 22.9%/future 62.9%), first-trimester pregnancy (current 17.1%/future 68.6%), suspected abdominal aortic aneurysm (current 5.7%/future 51.4%), basic cardiac indications (current 8.6%/future 57.1%), and central venous catheterization (current 22.9%/future 85.7%).

Conclusion:

This study is the first to tackle the extent of use and the hurdles to PoCUS adoption in Lebanese emergency medicine practice, using ETUDE. The findings from this study can be used in Lebanon to strengthen PoCUS use in the future.

Characterizing the learning curve of a virtual intracorporeal suturing simulator VBLaST-SS©

BACKGROUND

The virtual basic laparoscopic skill trainer suturing simulator (VBLaST-SS©) was developed to simulate the intracorporeal suturing task in the FLS program. The purpose of this study was to evaluate the training effectiveness and participants' learning curves on the VBLaST-SS© and to assess whether the skills were retained after 2 weeks without training.

METHODS

Fourteen medical students participated in the study. Participants were randomly assigned to two training groups (7 per group): VBLaST-SS© or FLS, based on the modality of training. Participants practiced on their assigned system for one session (30 min or up to ten repetitions) a day, 5 days a week for three consecutive weeks. Their baseline, post-test, and retention (after 2 weeks) performance were also analyzed. Participants' performance scores were calculated based on the original FLS scoring system. The cumulative summation (CUSUM) method was used to evaluate learning. Two-way mixed factorial ANOVA was used to compare the effects of group, time point (baseline, post-test, and retention), and their interaction on performance.

RESULTS

Six out of seven participants in each group reached the predefined proficiency level after 7 days of training. Participants' performance improved significantly (p < 0.001) after training within their assigned group. The CUSUM learning curve shows that one participant in each group achieved 5% failure rate by the end of the training period. Twelve out of fourteen participants' CUSUM curves showed a negative trend toward achieving the 5% failure rate after further training.

CONCLUSION

The VBLaST-SS© is effective in training laparoscopic suturing skill. Participants' performance of intracorporeal suturing was significantly improved after training on both systems and was retained after 2 weeks of no training.

Ultrasound Training in Surgical Critical Care Fellowship: A Survey of Program Directors

OBJECTIVE

Surgical critical care (SCC) fellows are expected to receive training in critical care ultrasound (CCUS) but training is sporadic and there is no standardized curriculum to guide educators. Previous studies show wide variation in CCUS training during fellowship across specialties but SCC has been underrepresented. This study was performed to assess SCC program directors' views regarding CCUS during fellowship training.

DESIGN

Adult SCC program directors were surveyed regarding the role of CCUS in fellowship training. This survey assessed how CCUS training was performed, perceived barriers to education, and importance of specific studies. Survey responses were measured using a Likert scale ranging from 5 (strongly agree) to 1 (strongly disagree).

SETTING

Web-based survey.

PARTICIPANTS

Adult Surgical Critical Care Fellowship Program Directors.

RESULTS

A total 67 of 108 (62%) SCC program directors responded to the survey. Over 75% felt that CCUS during training should be a priority. Fifteen (24.6%) programs required a specific number of ultrasounds to be performed. Five programs (7.5%) provided no CCUS training at all. Over 75% felt that training in FAST, transthoracic echocardiography, inferior vena cava assessment, and US for procedures (line placement, thoracentesis, and paracentesis) were either important or very important but experience in transesophageal echocardiography, assessment for deep vein thrombosis, and pulmonary US were not important. Lack of time (63.8%) and trained faculty (51.2%) were the most cited barriers to training.

CONCLUSIONS

There is a wide variation in how CCUS training is performed during SCC fellowship. SCC programs will need trained faculty, appropriate time allocation, and implementation of a standardized curriculum to provide consistent and high-quality CCUS education during fellowship.

Interobserver Agreement on Focused Assessment with Sonography for Trauma in Blunt Abdominal Injury

Introduction

Trauma constitutes a major public health problem. Ninty percent of world's fatalities on road occur in low and middle-income countries. Focused assessment with sonography in trauma (FAST) has a key role in trauma investigation, altering subsequent management in a significant number of patients. There is a rising trend of introducing FAST examination to non-radiologists and junior members of healthcare team to hasten triage of trauma patients.

Objective

To determine interobserver agreement on focused assessment with sonography for trauma in blunt abdominal injury between senior and junior residents.

Methods

This cross-sectional study was conducted at Aga Khan University Hospital. Three hundred patients with blunt abdominal trauma meeting inclusion criteria were enrolled. FAST was performed using standard curvilinear 3.5-5 MHz transducer. Agreement between junior and senior residents was measured and Kappa statistic was calculated.

Results

Mean age of the patients included in the study was 30.04 ± 18.09 years. Among these 237 (79%) were male and 63 (21%) were female. Sixteen (5.3%) were positive for intraperitoneal free fluid while the remaining 284 (94.7%) were negative. A total of 19 FAST examinations were reported positive by junior residents, of which 15 (78.9%) were confirmed by a senior resident to be correct, while four (21.05%) were falsely labeled positive by a junior resident. A total of 281 negative FAST examinations were reported by junior residents, of which 280 (99.6%) were confirmed by a senior resident, while only one (0.003%) was falsely labeled negative. Kappa statistic was calculated for inter-observer agreement on FAST examination findings, which showed a kappa value of 0.84 (very good agreement), with a p-value of <0.001.

Conclusion

Our study suggests very good interobserver agreement on FAST examination between senior and junior resident in patients with blunt trauma to the abdomen. Results suggest that FAST can be easily learnt with minimal radiology training and may have greater applicability in trauma.

Comparative Analysis of Simulated versus Live Patient-Based FAST (Focused Assessment With Sonography for Trauma) Training

OBJECTIVE

To investigate whether simulated patient (SP)-based training has comparable efficacy as live patient (LP)-based training in teaching Focused Abdominal Sonography for Trauma (FAST) knowledge and skill competencies to surgical residents.

DESIGN

A randomized pretest/intervention/posttest controlled study design was employed to compare the participants' performance in written and practical examinations regarding FAST examination after SP-based versus LP-based training.

SETTING

University-based general residency program at a single institution.

PARTICIPANTS

A total of 29 general surgery residents of various training levels and sonographic experience were recruited by convenience sampling.

RESULTS

There was no correlation between subjects' baseline training level or sonographic experience with either the posttest-pretest score difference or the percentage of subjects getting all 4 windows with adequate quality. There was no significant difference between the improvement in written posttest-pretest scores for SP and LP group, which were 33 ± 9.6 and 31 ± 6.8 (p = 0.40), respectively. With regard to performance-based learning efficacy, a statistically higher proportion of subjects were able to obtain all 4 windows with adequate quality among the LP than the SP group (6/8 vs 1/8, p = 0.01).

CONCLUSION

SP- and LP-based FAST training for surgical residents were associated with similar knowledge-based competency acquisition, but residents receiving LP-based training were better at acquiring adequate FAST windows on live patients. Simulation training appeared to be a valid adjunct to LP practice but cannot replace LP training. Future investigations on how to improve simulation fidelity and its training efficacy for skill-based competencies are warranted.

Validation of the VBLaST pattern cutting task: a learning curve study

BACKGROUND

Mastery of laparoscopic skills is essential in surgical practice and requires considerable time and effort to achieve. The Virtual Basic Laparoscopic Skill Trainer (VBLaST-PC^©) is a virtual simulator that was developed as a computerized version of the pattern cutting (PC) task in the Fundamentals of Laparoscopic Surgery (FLS) system. To establish convergent validity for the VBLaST-PC^©, we assessed trainees' learning curves using the cumulative summation (CUSUM) method and compared them with those on the FLS.

METHODS

Twenty-four medical students were randomly assigned to an FLS training group, a VBLaST training group, or a control group. Fifteen training sessions, 30 min in duration per session per day, were conducted over 3 weeks. All subjects completed pretest, posttest, and retention test (2 weeks after posttest) on both the FLS and VBLaST^© simulators. Performance data, including time, error, FLS score, learning rate, learning plateau, and CUSUM score, were analyzed.

RESULTS

The learning curve for all trained subjects demonstrated increasing performance and a performance plateau. CUSUM analyses showed that five of the seven subjects reached the intermediate proficiency level but none reached the expert proficiency level after 150 practice trials. Performance was significantly improved after simulation training, but only in the assigned simulator. No significant decay of skills after 2 weeks of disuse was observed. Control subjects did not show any learning on the FLS simulator, but improved continually in the VBLaST simulator.

CONCLUSIONS

Although VBLaST^©- and FLS-trained subjects demonstrated similar learning rates and plateaus, the majority of subjects required more than 150 trials to achieve proficiency. Trained subjects demonstrated improved performance in only the assigned simulator, indicating specificity of training. The virtual simulator may provide better opportunities for learning, especially with limited training exposure.

Pair Scanning: Integrating the Student Sonographer Without Impacting Patient Care

OBJECTIVES

Ultrasound departments in Canada frequently reduce patient bookings to support student training, which impacts not only patient care but also revenue generation. Therefore, physicians and employers are reluctant to host student sonographers, and educational programs struggle to find sufficient clinical placements for their students. Two research questions were investigated: (1) Can a pair scanning technique effectively integrate the student sonographer into the workplace without impacting patient volumes? (2) Does the pair scanning technique prepare the student sonographer for entry-level practice faster than traditional practice?

METHODS

This research project was divided into 2 phases. The first phase used action research to develop the pair scanning protocol at a single site with a single preceptor and student. The second phase used a mixed methods approach to test the transferability of the pair scanning protocol across multiple sites, preceptors, and students.

RESULTS

In phase 1, the student sonographer performed a greater number of total examinations than the rest of her cohort (who were at different placement sites), and the higher performance of independent examinations by the student sonographer under the pair scanning technique was statistically significant [H₍₄₎  = 36.297; P < .01]. In phase 2, the pair scanning group and the control group performed equally, with no statistically significant differences.

CONCLUSIONS

The pair scanning protocol is effective at integrating the student sonographer into the work flow without impacting patient care. It prepares the student sonographer for entry-level practice equally with traditional practice and may be most effective with the weak to average student.

Longitudinal Assessment of Examiner Experience and the Accuracy of Sonographic Fetal Weight Estimation at Term

OBJECTIVES

To evaluate the influence of examiner experience on the accuracy of sonographic weight estimation and to further analyze examiners' individual learning curves.

METHODS

In this multicenter study, 4613 sonographic weight estimations performed by 18 examiners at the beginning of their ultrasound training were included. To assess the effect of experience on the accuracy of weight estimation, a multivariable mixed regression model analysis was performed, with percentage error and absolute percentage error as outcome variables and the examiner, the examiner's experience (number of examinations), birth weight, gestational age, scan-to-delivery interval, and maternal body mass index as fixed effects and the perinatal center as random intercepts. To further analyze the individual learning curves of the examiners, the cumulative summation technique was used.

RESULTS

Regression analyses showed a significant influence of the number of examinations on the accuracy of sonographic weight estimation after adjustment for the above-mentioned parameters (P < .001). A typical learning curve with improving accuracy was found until approximately 200 examinations. Between 200 and 300 examinations, the diagnostic performance started to deteriorate again, with a continuous decrease until the end of the study period. Cumulative summation charts representing individual learning curves varied greatly between different examiners.

CONCLUSIONS

These findings indicate the great importance of continuous quality control systems in sonographic weight estimation.

Robotic major hepatectomy: Is there a learning curve?

BACKGROUND

Robotic hepatectomy has been suggested as a safe and effective management of liver disease. However, no large case series have documented the learning curve for robotic major hepatectomy.

METHOD

We conducted a retrospective study for robotic major hepatectomy performed by the same operative team between January 2012 and October 2015 and evaluated the learning curve for operation time using the cumulative sum method, presented as cumulative sum_{operation time}.

RESULTS

Overall, there were 183 robotic hepatectomies, 92 of which were performed in patients who underwent robotic major hepatectomy: left hemihepatectomy was performed in 32 (34.8%) patients, right hemihepatectomy in 41 (44.6%), left trisectionectomy in 3 (3.3%), right trisectionectomy in 6 (6.5%), and 8-5-4 trisegmentectomy in 10 (10.8%). The median duration of surgery was 434 minutes (142-805 minutes) and the median blood loss was 195 mL (50-2,000 mL). Fifty-nine percent of patients had malignancies, and those with advanced stages of cancer had more blood loss during an operation. The cumulative sum_{operation time} model of robotic major hepatectomy suggested that the learning curve comprised 3 characteristic phases: initial (phase 1, 15 patients), intermediate (phase 2, 25 patients), and mature (phase 3, 52 patients). The learning effects were underlined by shorter operation time and hospital stay after phase 1 and less blood loss after phase 2.

CONCLUSION

This is the largest series regarding robotic major hepatectomy. Our findings suggest that a solid training program based on the learning curve should be considered for beginners of robotic hepatectomy. Participants should evaluate the evolution of our minimally invasive hepatectomy before considering our robotic experience.

A unique method for estimating the reliability learning curve of optic nerve sheath diameter ultrasound measurement

Background

Optic nerve sheath diameter (ONSD) measurement using ultrasound has been proposed as a rapid, non-invasive, point of care technique to estimate intra-cranial pressure (ICP). Ultrasonic measurement of the optic nerve sheath can be quite challenging and there is limited literature surrounding learning curves for this technique. We attempted to develop a method to estimate the reliability learning curve for ONSD measurement utilizing a unique definition of reliability: a plateau in within-subject variability with unchanged between-subject variability.

Methods

As part of a previously published study, a single operator measured the ONSD in 120 healthy volunteers over a 6-month period. Utilizing the assumption that the four measurements made on each subject during this study should be equal, the relationship of within-subject variance was described using a quadratic-plateau model as assessed by segmental polynomial (knot) regression.

Results

Segmental polynomial (knot) regression revealed a plateau in within-subject variance after the 21st subject. However, there was no difference in overall mean values [3.69 vs 3.68 mm (p = 0.884)] or between-subject variance [14.49 vs 11.92 (p = 0.54)] above or below this cutoff.

Conclusions

This study suggests a significant finite learning curve associated with ONSD measurements. It also offers a unique method of calculating the learning curve associated with ONSD measurement.

Learning Curve for Intrapulmonary Artery Doppler in Fetuses with Congenital Diaphragmatic Hernia

Objective: To assess the learning curve for intrapulmonary artery Doppler in fetuses with congenital diaphragmatic hernia (CDH). Methods: Three fetal medicine fellows with the theoretic knowledge, but without prior experience, in the evaluation of intrapulmonary artery Doppler in CDH fetuses were selected. Each trainee and 1 experienced explorer assessed the intrapulmonary artery in the contralateral lung to the side of the hernia for calculation of 2 Doppler parameters - pulsatility index (PI) and peak early diastolic reversed flow (PEDRF) - in a cohort of 90 consecutive CDH fetuses. The average difference between the 3 trainees and the expert was calculated. A difference below 15% was considered as accurate measurement. The average learning curve was delineated using the cumulative sum analysis (CUSUM). Results: Among the total 270 intrapulmonary artery Doppler measurements performed by the 3 trainees, the number of failed examinations was 14 (15.6%) and 16 (17.8%) for PI and PEDRF, respectively. The CUSUM plots demonstrate that the learning curve was achieved by 53 and 63 tests performed for calculations of the intrapulmonary artery PI and PEDRF, respectively. Conclusion: Competence in Doppler evaluation of the intrapulmonary artery in CDH fetuses is achieved only after intensive continuous training.

Focused abdominal ultrasound for blunt trauma in an emergency department without advanced imaging or on-site surgical capability

Objectives:

To determine whether focused abdominal sonogram for trauma (FAST) in a rural hospital provides information that prompts immediate transfer to a tertiary care facility for patients with blunt abdominal trauma who would otherwise be discharged or held for observation.

Methods:

Prior to the study, participating emergency physicians underwent a minimum of 30 hours of ultrasound training. All patients who presented with blunt abdominal trauma to our rural hospital between Mar. 1, 2002, and Apr. 30, 2003, were eligible for study. Following a history and physical examination, the emergency physician documented his or her disposition decision. A FAST was then performed, and the disposition reconsidered in light of the FAST results.

Results:

Sixty-seven FAST exams were performed on 65 patients. Three examinations (4.5%) were true-positive (95% confidence interval [CI] 0.9%–12.5%); 60 (89.6%) were true-negative (95% CI 79.7%–95.7%), 4 (6%) were false-negative (95% CI 1.7%–14.6%) and none (0%) were false-positive (95% CI 0%–5.4%). These values reflect sensitivity, specificity, negative predictive value and positive predictive values of 43%, 100%, 94% and 100% respectively. FAST results did not alter the decision to transfer any patient (0%: 95% CI 0.0%–5.4%), although one positive FAST may have led to an expedited transfer. One of 38 patients who was discharged after a negative FAST study returned 24 hours later because of worsening symptoms, and was ultimately found to have splenic and pancreatic injuries.

Conclusions:

This study failed to demonstrate that FAST improves disposition decisions for patients with blunt abdominal trauma who are evaluated in a hospital without advanced imaging or on-site surgical capability. However, the study is not sufficiently powered to rule out a role for FAST in these circumstances, and our data suggest that up to 5.4% of transfer decisions could be influenced by FAST. Rural emergency physicians should not allow a negative FAST study to override a clinical indication for transfer to a trauma centre; however, positive FAST studies can be used to accelerate transfer for definitive treatment.

Focused Assessment with Sonography for Trauma in patients with confirmed liver lesions

BACKGROUND AND AIMS

The objective was to determine the sensitivity and specificity of Focused Assessment with Sonography for Trauma (FAST) in patients with confirmed liver lesions and also to compare results from surgeons trained in FAST with results from radiologists trained in general abdominal ultrasound as part of the specialist training. Explorative laparotomy or CT served as gold standard.

MATERIALS AND METHODS

This retrospective study included all patients admitted to our institution from 2003 to 2010 registered with the diagnosis "Injury of the liver or gallbladder". Of 405 patients, 135 patients were eligible for analysis. Seventy-two patients were examined by radiologists and 63 by surgeons.

RESULTS

We found FAST to have a sensitivity, specificity, PPV, and NPV of 79.6%, 100%, 100%, and 68.9%. There was no statistically significant difference between FAST performed by radiologists and surgeons trained in FAST.

CONCLUSION

FAST remains an important screening tool in abdominal trauma including liver lesions, and can be performed at a satisfactory level by surgeons trained in the FAST procedure only.

Focused Assessment Sonography for Trauma (FAST) training: a systematic review

BACKGROUND

The aim of this study was to systematically review the different methods for training Focused Assessment Sonography for Trauma (FAST), course design, and requirements for hospital credentialing.

METHODS

We searched MEDLINE/PubMed, EMBASE, and the Cochrane database and performed a manual search of selected papers. All papers and abstracts written in English that studied training and education of FAST were included. Papers were critically evaluated, looking into training methods and models of FAST, their advantages and disadvantages, number and type of training hours, practice exams in the course, and number of cases advised to achieve hospital credentialing.

RESULTS

A total of 52 studies were critically analyzed. The theoretical part of the courses lasted over a median (range) of 4 (1-16) h (n = 35 studies), while the practical part lasted over a median (range) of 4 (1-32) h (n = 34 studies). The participants performed a median (range) of 10 (3-20) FAST exams during the courses (n = 13 studies). The most commonly used model was the normal human model (65 %), followed by peritoneal dialysis patients (27 %). The least used models were animal (4 %) and cadaveric models (2 %). Each of these models had their advantages and disadvantages. The median number (range) of FAST exams needed for credentialing was 50 (10-200) (n = 19 studies).

CONCLUSION

Standardization of FAST training is important to improving the clinical impact of FAST. Different models used in FAST training are complementary; each has its own advantages and disadvantages. It is recommended that FAST courses be at least 2 days (16 h) long. The first day should include 4 h of theory and 4 h of training on normal human models. The second day should enforce learning using animal models, case scenarios including video clips, or simulators.

Comparison of the accuracy and reproducibility of focused abdominal sonography for trauma performed by emergency medicine and radiology residents

We compared the diagnostic accuracy of emergency medicine residents (EMRs) and radiology residents (RRs) in performing focused abdominal sonography for trauma (FAST). The cohort in this prospective study comprised 200 unstable patients (163 males and 37 females; mean ± standard deviation of age, 34.3 ± 16.4 y) who presented with trauma. These patients were evaluated using FAST, first by EMRs and subsequently by RRs. Patients with positive FAST results underwent further diagnostic procedures such as computed tomography, diagnostic peritoneal lavage and laparotomy. Those with negative FAST results underwent clinical follow-up for 72 h until their condition deteriorated or they were discharged. Sensitivity, specificity, positive and negative predictive values and accuracy in evaluating free intraperitoneal fluid were 80%, 95%, 57%, 98% and 94% when FAST was performed by EMRs and 86%, 95%, 59%, 98% and 94% when FAST was performed by RRs. The level of agreement between EMRs and RRs was moderate (κ = 0.525). FAST is a useful screening tool for initial assessment of free abdominal fluid in patients with trauma. Our results indicate that EMRs can perform sonography on trauma patients as successfully as RRs.

Implementation of a successful incentive-based ultrasound credentialing program for emergency physicians

Introducion:

With the rapid expansion of emergency ultrasound, resident education in ultrasound has become more clearly developed and broadly integrated. However, there still exists a lack of guidance in the training of physicians already in practice to become competent in this valuable skill. We sought to employ a step-wise, goal-directed, incentive-based credentialing program to educate emergency physicians in the use of emergency ultrasound. Successful completion of this program was the primary outcome.

Methods:

The goal was for the physicians to gain competency in 8 basic ultrasound examinations types: aorta, focused assessment with sonography in trauma, cardiac, renal, biliary, transabdominal pelvic, transvaginal pelvic, and deep venous thrombosis. We separated the 2.5 year training program into 4 distinct blocks, with each block focusing on 2 of the ultrasound examination types. Each block consisted of didactic and hands-on sessions with the goal of the physician completing 25 technically-adequate studies of each examination type. There was a financial incentive associated with completion of these requirements.

Results:

A total of 31 physicians participated in the training program. Only one physician, who retired prior to the end of the 2.5 year period, did not successfully complete the program. All have applied for and received hospital privileging in emergency ultrasound and incorporated it into their daily practice.

Conclusion:

We found that a step-wise, incentive-based ultrasound training program with a combination of didactics and ample hands-on teaching was successful in the training of physicians already in practice.

Characterizing the learning curve of the VBLaST-PT(©) (Virtual Basic Laparoscopic Skill Trainer)

BACKGROUND

Mastering laparoscopic surgical skills requires considerable time and effort. The Virtual Basic Laparoscopic Skill Trainer (VBLaST-PT(©)) is being developed as a computerized version of the peg transfer task of the Fundamentals of Laparoscopic Surgery (FLS) system using virtual reality technology. We assessed the learning curve of trainees on the VBLaST-PT(©) using the cumulative summation (CUSUM) method and compared them with those on the FLS to establish convergent validity for the VBLaST-PT(©).

METHODS

Eighteen medical students from were assigned randomly to one of three groups: control, VBLaST-training, and FLS-training. The VBLaST and the FLS groups performed a total of 150 trials of the peg-transfer task over a 3-week period, 5 days a week. Their CUSUM scores were computed based on predefined performance criteria (junior, intermediate, and senior levels).

RESULTS

Of the six subjects in the VBLaST-training group, five achieved at least the "junior" level, three achieved the "intermediate" level, and one achieved the "senior" level of performance criterion by the end of the 150 trials. In comparison, for the FLS group, three students achieved the "senior" criterion and all six students achieved the "intermediate" and "junior" criteria by the 150th trials. Both the VBLaST-PT(©) and the FLS systems showed significant skill improvement and retention, albeit with system specificity as measured by transfer of learning in the retention test: The VBLaST-trained group performed better on the VBLaST-PT(©) than on FLS (p = 0.003), whereas the FLS-trained group performed better on the FLS than on VBLaST-PT(©) (p = 0.002).

CONCLUSIONS

We characterized the learning curve for a virtual peg transfer task on the VBLaST-PT(©) and compared it with the FLS using CUSUM analysis. Subjects in both training groups showed significant improvement in skill performance, but the transfer of training between systems was not significant.

Laparoscopic splenectomy: learning curve comparison between benign and malignant disease

BACKGROUND

New surgical techniques should be formally evaluated for feasibility and safety. As a model for this evaluation, this study examines the authors' institution's experience with splenectomy for benign and malignant hematologic disease since the introduction of laparoscopic splenectomy (LS) in 1996. The authors present the evaluation of the recognized surgeon/institutional learning curve using CUSUM (cumulative sum) analysis.

METHODS

This is a single institution retrospective chart review of consecutive splenectomies for hematologic disease performed between 1996 and 2008. The primary outcome was conversion to open splenectomy. The learning curve for LS was evaluated using CUSUM analysis.

RESULTS

A total of 123 splenectomies were performed for benign (51.2%) or malignant (48.7%) hematologic disease. 58% of patients underwent planned LS, with a 21% conversion rate. The surgeon's overall learning curves for LS, as well as that for malignant disease, were maintained within acceptable conversion thresholds. However, the learning curve for benign disease did cross the unacceptable conversion threshold at case 29. With additional experience, the curve again approached the acceptable conversion threshold. Patients with malignant disease were significantly older (P = .0004), had larger spleens (P = .0004), were more likely to undergo open splenectomy (P = .001), and had longer lengths of stay (P = .01). However, there was no significant difference in operative time, transfusion requirements, morbidity rates, or mortality rates between patients with benign and malignant disease.

CONCLUSION

LS, for benign or for malignant hematologic disease, is associated with a significant learning curve. This evaluation model illustrates that careful patient selection and ongoing quality assessment is essential when introducing a new technique.

Learning curve for Doppler measurement of fetal modified myocardial performance index

OBJECTIVE

To assess the learning curve for measurement of the fetal modified myocardial performance index (MPI).

METHODS

Three trainees with the theoretical knowledge of but without prior experience in performing MPI measurement were selected. Each trainee and one experienced examiner measured MPI in a cohort of 90 consecutive fetuses. The average difference between the three trainees and the expert in the MPI measurements was calculated; a difference below 10% was considered to indicate an accurate measurement. Individual and averaged learning curves were delineated using cumulative sum analysis (CUSUM).

RESULTS

The gestational age at evaluation ranged from 20 + 4 to 41 + 4 (mean, 33 + 3) weeks. The CUSUM plots demonstrated that, on average, competence in performing fetal MPI measurement was achieved by 65 cases. The average number of attempts to achieve competence were 42, 77 and 83 for the ejection time, isovolumetric contraction time and isovolumetric relaxation time, respectively.

CONCLUSIONS

Evaluation of fetal MPI by an inexperienced trainee requires on average 65 measurements to achieve competence.

Assessment of a training curriculum for emergency ultrasound for pediatric soft tissue infections

OBJECTIVES

The objective was to evaluate a training protocol for pediatric emergency physicians (EPs) learning emergency ultrasound (EUS) for the evaluation of skin and soft tissue infections (SSTIs) by assessing technical ability and interrater reliability.

METHODS

Pediatric emergency medicine (EM) fellows and attending physicians completed a 1-day training course taught by an expert emergency sonologist. After the course, EPs performed proctored examinations on patients with SSTIs until they reached predefined performance criteria, after which they performed independent EUS examinations. All EUS examinations were recorded using still images and video clips that were reviewed and rated by the expert sonologist on four technical measures and combined into a composite score. The expert's opinion regarding the presence or absence of an abscess was also compared to the study sonologist's opinion and analyzed for interrater reliability.

RESULTS

Seven EPs performed 107 EUS examinations. The mean (±SD) composite score for the evaluation of technical ability for the first EUS was 3.3 ± 0.14 (on a 4-point scale), indicating a high level of quality following the training course. There was a small amount of improvement in the quality score (0.015, 95% confidence interval [CI] = 0.0003 to 0.03) with each consecutive EUS examination. The interrater reliability between the sonologist and the expert for the presence of an abscess as measured by the kappa statistic was 0.80 (95% CI = 0.63 to 0.97), indicating substantial agreement.

CONCLUSIONS

After a brief training program, pediatric EPs can perform technically successful emergency EUS examination of SSTIs, with excellent agreement with an expert sonologist.

Defining the learning curve in laparoscopic paraesophageal hernia repair: a CUSUM analysis

INTRODUCTION

There are numerous reports in the literature documenting high recurrence rates after laparoscopic paraesophageal hernia repair. The purpose of this study was to determine the learning curve for this procedure using the Cumulative Summation (CUSUM) technique.

METHODS

Forty-six consecutive patients with paraesophageal hernia were evaluated prospectively after laparoscopic paraesophageal hernia repair. Upper GI series was performed 3 months postoperatively to look for recurrence. Patients were stratified based on the surgeon's early (first 20 cases) and late experience (>20 cases). The CUSUM method was then used to further analyze the learning curve.

RESULTS

Nine patients (21%) had anatomic recurrence. There was a trend toward a higher recurrence rate during the first 20 cases, although this did not achieve statistical significance (33% vs. 13%, p = 0.10). However, using a CUSUM analysis to plot the learning curve, we found that the recurrence rate diminishes after 18 cases and reaches an acceptable rate after 26 cases.

CONCLUSIONS

Surgeon experience is an important predictor of recurrence after laparoscopic paraesophageal hernia repair. CUSUM analysis revealed there is a significant learning curve to become proficient at this procedure, with approximately 20 cases required before a consistent decrease in hernia recurrence rate is observed.

Risk factors for anastomotic leakage after laparoscopic rectal resection

PURPOSE

The anastomotic leakage rate after rectal resection has been reported to be approximately 2.5-21 percent, but most results were associated with open surgery. The aim of this study was to identify risk factors and their relationship to the experience of the surgeon for anastomotic leakage after laparoscopic rectal resection.

METHODS

Between March 2003 and December 2008, 156 patients underwent a laparoscopic rectal resection without a diverting ileostomy. The patients' characteristics, the details of treatment, the intraoperative results, and the postoperative results were recorded prospectively. Univariate and multivariate analyses were applied to identify risk factors for anastomotic leakage.

RESULTS

The majority of operations were performed for malignant disease (n = 150; 96.2%), and 96 patients (61.5%) were males. Conversion to open surgery occurred in 1 case (0.6%). The anastomotic leak rate was 10.3% (16/156), and there were no mortalities. In the univariate analysis, tumor location, anastomotic level, intraoperative events, and operation time were associated with increased anastomotic leakage rate. In the multivariate analysis, anastomotic level (odds ratio [OR], 6.855; 95% confidence interval [CI], 1.271 to 36.964) and operation time (OR, 8.115; 95% CI, 1.982 to 33.222) were significantly associated with anastomotic leakage.

CONCLUSION

The important risk factors for anastomotic leakage after laparoscopic rectal resection without a diverting ileostomy were low anastomosis and long operation time. An additional procedure, such as diverting stoma, may reduce the anastomotic leakage if it is selectively applied in cases with these risk factors.

Learning curve for lung area to head circumference ratio measurement in fetuses with congenital diaphragmatic hernia

OBJECTIVE

To assess the learning curve for the fetal lung area to head circumference ratio (LHR) calculation in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

Three trainees with the theoretical knowledge, but without prior experience in the LHR measurement, were selected. Each trainee and one experienced examiner measured the observed to expected (O/E)-LHR in the lung contralateral to the side of the hernia by two methods-manual tracing of lung borders and multiplication of the longest diameters-in a cohort of 95 consecutive CDH fetuses. The average difference between the three trainees and the expert in the O/E-LHR measurement was calculated. A difference below 10% was considered to indicate an accurate measurement. The average learning curve was delineated using cumulative sum analysis (CUSUM).

RESULTS

The CUSUM plots demonstrate that the learning curve was achieved by 77 and 72 tests performed for the area obtained by the manual-tracing and multiplication-of-the-longest-diameter methods, respectively.

CONCLUSION

The minimum number of scans required for an inexperienced trainee to become competent in examining the LHR is on average 70.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock

Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

[Training in emergency sonography for trauma. Concept of a 1-day course program]

In the last decade prehospital focused abdominal sonography for trauma (P-FAST) could be established as a valid on-site diagnostic tool for both air and ground rescue medical services in Germany. An appropriate use of P-FAST demands a standardized training concept. Therefore a 1-day training program was developed by the working group "emergency ultrasound" in Frankfurt/Main and was introduced in 2003. The training consists of lectures on general and specific aspects of emergency ultrasound techniques with demonstrations of numerous pathological findings, intensive hands-on training with patients and volunteers, as well as simulated on-site training. After completing the P-FAST course the participants gained competency to perform prehospital emergency ultrasound with high accuracy. Strict application of the exact technique as well as appropriate integration of the adjunct into the algorithm of prehospital care are the most important prerequisites for successful use of P-FAST. From February 2003 to March 2008 540 participants were trained in P-FAST in the 1-day course.

Evaluation and imaging of a thyroid nodule

The approach to the thyroid nodule has been incrementally modified over the past decade. The widespread adoption of fine needle aspiration in the 1980s, coupled with increased use of serial ultrasound monitoring, arguably led to the biggest changes in recommendations for surgical intervention during the past 50 years. For the office-based practitioner, thyroid nodule presentation patterns are changing with discoveries of more thyroid "incidentalomas" and with new risk assessment challenges associated with small (<1 cm) nodules. At the same time, improved primary evaluation techniques, most notably the increasing use of small, portable ultrasound imaging units, are making many clinicians more comfortable in recommending less invasive follow-up.

Learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer: single-institute, three-surgeon experience

BACKGROUND

Laparoscopic surgery demands mastery of a steep learning curve. Defining a learning curve in laparoscopic surgery is useful for planning training programs or clinical trials. This study aimed to define the learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer by evaluating early surgical outcome data from three colorectal surgeons.

METHODS

This study analyzed data from 138 consecutive patients undergoing laparoscopic sigmoidectomy for curable sigmoid colon cancer performed by three colorectal surgeons between May 2001 and November 2006. The learning curve for each surgeon were generated using the moving average method to assess changes in operation time and cumulative sum (CUSUM) analysis to assess changes in failure rates [(failure = conversion to open surgery, major perioperative complication, or failure to harvest an adequate number of lymph nodes (<12 nodes)].

RESULTS

Learning curves generated with the moving average method indicated that the operation time reached a steady state after 42 cases for surgeon A, 35 cases for surgeon B, and 30 cases for surgeon C. The overall open conversion rate was 2.9%. There was only one laparoscopy-related perioperative major complication (0.7%). An inadequate number of lymph nodes was harvested in 10 cases (7.2%): 6 (10.5%) for surgeon A, 1 (2.4%) for surgeon B, and 3 (7.7%) for surgeon C. Learning curves generated using CUSUM analysis based on a 90% success rate showed that adequate learning occurred after 10 cases for surgeon A, 17 cases for surgeon B, and 5 cases for surgeon C.

CONCLUSION

Pertinent learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer can be generated using the moving average method and CUSUM analysis. These results are likely to be useful in designing laparoscopic training programs and clinical trials aimed at investigating outcomes of laparoscopic colorectal cancer surgery.

Prehospital ultrasound detects pericardial tamponade in a pregnant victim of stabbing assault

The development of handheld, portable ultrasound devices has enabled the use of this diagnostic tool also in the out-of-hospital environment. We report on a pregnant teenager who was found haemodynamically unstable after a stab assault. When she suffered cardiac arrest shortly thereafter, diagnosis of cardiac tamponade was made by portable ultrasound, and immediate pericardiocentesis was performed by the emergency physician. While her baby died after emergency Caesarean section, the teenager survived after thoracotomy and prolonged resuscitation without neurological sequelae.

Toward an ultrasound curriculum for critical care medicine

Accurate assessment and rapid decision-making are essential to save lives and improve performance in critical care medicine. Real-time point-of-care ultrasound has become an invaluable adjunct to the clinical evaluation of critically ill and injured patients both for pre- and in-hospital situations. However, a high level of quality is necessary, guaranteed by appropriate education, experience, credentialing, quality control, continuing education, and professional development. Although educational recommendations have been proposed by a variety of nonimaging specialties, to date they are still scattered and limited examples of standards for critical and intensive care professionals. The challenge of providing adequate specialty-specific training, as encouraged by major medical societies, is made even more difficult by the diversity of critical care ultrasound utilization by various subspecialties in a variety of settings and numerous countries. In order to meet this educational challenge, a standard core curriculum is presented in this manuscript. The proposed curriculum is built on a competence, performance, and outcomes-based approach that is tailored to setting-specific training needs and prioritized according to critical problem-based pathways, rather than traditional organ-based systems. A multiple goal-oriented style fully addresses the specialty-specific approach of critical and intensive care professionals, who typically deal with disease states in complex scenarios rather than individual organ complaints. Because of the variation in the concept of what constitutes critical care worldwide, and the rate of change of information and technology, this manuscript attempts to present a learning system addressing a variety of needs for a rapidly changing world.

Focused ultrasound training for clinicians

Clinician use of diagnostic ultrasound, particularly at point of care and in emergency situations, is well established. The standard of training courses and of postcourse supervision and accreditation is variable, and international standards are required to maintain safety, accuracy, and credibility of the technique. The accuracy of the technique by trained personnel has been well documented. There is evidence that prereading, a course involving theoretical and practical training, and ongoing mentoring (proctoring) provides high standards of practice. Regular accreditation and continuous comparison with gold standards is required to maintain this level. Most areas of the body are now accessible to clinicians of varied specialties, even those previously thought impossible for ultrasound examination, such as the chest and bone. Training and supervision in rural, remote, and austere environments provides added challenges.

Cumulative sum (CUSUM) analysis in the assessment of trainee competence in fetal biometry measurement

OBJECTIVE

To determine the value of cumulative sum (CUSUM) analysis in assessing trainee proficiency in fetal biometry measurement.

METHODS

Three primary healthcare doctors with no prior ultrasound training were recruited. Each trainee measured the fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) on 100 consecutive pregnant women. The supervisor repeated the measurements. The CUSUM for each set of trainee measurements was calculated at a set failure rate of 10%. The point at which the graph fell below two consecutive boundary lines indicated the number of examinations required to achieve competence.

RESULTS

The CUSUM graphs showed that the rate of learning measurement skills varied among the three trainees. The graph for the CUSUM series for BPD and HC measurement for all trainees fell below two consecutive boundary lines and remained there, indicating competence. The CUSUM series for AC measurement for two of the trainees indicated that competence was achieved; however, for the third trainee, while the graph fell below two consecutive boundary lines, indicating competence, it rose again, crossing two consecutive boundary lines. This indicated a loss of competence and the need for further training. FL measurements for the same trainee never fell below two consecutive boundary lines, indicating failure to achieve competence; the other two achieved competence, but failed to maintain it.

CONCLUSIONS

CUSUM is a useful tool for identifying points of competence and for quantifying the duration of ultrasound training required for each trainee. It provides an early indication of performance, and highlights difficulties in individual performance.

Surgeon-Performed Ultrasound for Preoperative Localization of Abnormal Parathyroid Glands in Patients with Primary Hyperparathyroidism

BACKGROUND

The introduction of portable ultrasound equipment enables surgeons to perform ultrasound examinations in a clinic setting. This study was undertaken to evaluate surgeon-performed ultrasound (SP-US) in patients with primary hyperparathyroidism (PHPT).

METHODS

Between July 2003 and March 2004, 65 patients with PHPT were evaluated with SP-US and 48 of these patients underwent parathyroid surgery. Among this group of 48 evaluable patients, 47 had preoperative imaging with technetium-99m sestamibi scanning (MIBI), and 12 had an additional ultrasound examination at an external radiology department (RP-US).

RESULTS

All patients were cured of PHPT and the operative findings were used to determine the true status of the parathyroid glands of each patient. Twenty-four (50%) patients had concomitant thyroid nodules which were identified by SP-US, and 4 (8.3%) patients had simultaneous thyroid operations, 2 of which were for thyroid cancer. Considering data for all patients, SP-US had significantly higher sensitivity than MIBI or RP-US (60% vs. 46%, P = 0.013, and 60% vs. 11%, P = 0.004 respectively). Among the patients with a single adenoma, SP-US, MIBI, and RP-US had sensitivities of 83%, 63%, and 13% respectively. The specificities of all three imaging techniques were uniformly high and were not significantly different from each other.

CONCLUSIONS

Surgeon-performed ultrasound is an accurate modality for localizing abnormal parathyroid glands in patients with PHPT, with results that compare favorably with other parathyroid imaging modalities.

Prehospital ultrasound imaging improves management of abdominal trauma

BACKGROUND

Blunt abdominal trauma with intra-abdominal bleeding is often underdiagnosed or even overlooked at trauma scenes. The purpose of this prospective, multicentre study was to compare the accuracy of physical examination and prehospital focused abdominal sonography for trauma (PFAST) to detect abdominal bleeding.

METHODS

Six rescue centres took part in the study from December 2002 to December 2003, including 230 patients with suspected abdominal injury. The accuracy of physical examination at the scene and PFAST were compared. Later examinations in the emergency department (ultrasonography and/or computed tomography) were used as the reference standard.

RESULTS

The complete protocol and follow-up was obtained in 202 patients. The sensitivity, specificity and accuracy of PFAST were 93 per cent, 99 per cent and 99 per cent, respectively, compared with 93 per cent, 52 per cent and 57 per cent for physical examination at the scene. Scanning with PFAST occurred a mean(s.d.) 35(13) min earlier than ultrasound in the emergency department. Abdominal bleeding was detected in 14 per cent of patients. Using PFAST led to a change in either prehospital therapy or management in 30 per cent of patients, and a change to admitting hospital in 22 per cent.

CONCLUSION

In this study, PFAST was a useful and reliable diagnostic tool when used as part of surgical triage at the trauma scene.

Characterizing the learning curve for a basic laparoscopic drill

BACKGROUND

The psychomotor challenges inherent in laparoscopic surgery are evident by the steep procedural "learning curves" documented throughout the literature. Few methods have been described to evaluate learning curves. The cumulative summation (CUSUM) method is a criterion-based evaluation of the learning process. The purpose of this study is to describe the CUSUM learning curves for a simple task for individuals and for a group of novice laparoscopists.

METHODS

Sixteen medical students undertook four weekly sessions of 10 laparoscopic pegboard transfers in the MISTELS system. Their performance was scored and recorded for each trial. CUSUM learning curves were constructed based on the goal of achieving mean scores for senior, intermediate, or junior laparoscopists >or=95% of the time.

RESULTS

Based on senior criteria, one student achieved the goal by the 40th peg transfer trial. Based on intermediate criteria, three students achieved the goal by their 40th trial (trials 21 and 36), and for junior criteria, 10 students achieved the acceptable success rate by their 40th trial (range, 26-40).

CONCLUSION

CUSUM analysis suggests criterion-based practice is useful for novice laparoscopists. It allows educators to track the progress of an individual toward target criteria for each MISTELS task, to more logically allocate time for training and set attainable goals, to objectively evaluate trainee acquisition of basic laparoscopic skills, and to identify trainees who need remediation.

Establishing learning curves for surgical residents using Cumulative Summation (CUSUM) Analysis

BACKGROUND

The assessment of technical proficiency is of paramount importance in the training of surgical residents. The fact that technical proficiency is underrepresented in the context of the ACGME outcomes project is evidenced in that proficiency skills comprise less than 5% of all assessments that evaluate residents. In this study, we use Cumulative Summation Analysis (CUSUM) as a visual objective analytic tool to determine performance accuracy and establish learning curves for PGY-1s in surgery.

METHODS

From April 2001 to May 2002, 11 surgical residents completed a 1-month anesthesia rotation. Each resident was asked to complete a preoperative airway assessment followed by endotracheal intubation with induction of anesthesia. Airway assessment was performed independently by a resident and a licensed anesthesiologist or certified anesthetist with the modified Mallampati Score. Data were sequentially collected and plotted for summated successes and failures.

RESULTS

The average intern required approximately 19 intubation attempts to complete the learning curve experience. There was no learning curve for airway assessment.

CONCLUSIONS

The CUSUM analysis is an effective objective tool to define learning curves for technical skills. Vital information is provided for surgical programs that place residents in positions to manage airways, and limitless potential for defining the learning curves for technical skills is provided.