Malignant cardiac neoplasms and associated malignancies over 16 years in the USA.

BACKGROUND: Malignant cardiac neoplasms (MCNs), both primary and metastatic, are rare with few epidemiologic studies. METHODS: This retrospective study used the Healthcare Utilization Project/Nationwide Inpatient Sample database from 2002 to 2018 to evaluate the co-occurrences with other malignancies, and mortality of MCNs in the USA. RESULTS: The data contained 7207 weighted discharges of MCN. Median patient age was 51.4 years, 52.29 % were male, in-hospital mortality was 10.51 %, mean cost of hospitalization was $34,280 USD. Lung, mediastinum, and airways were the most common primary cancers associated with metastatic MCN. CONCLUSIONS: MCN are rare in the USA, however they carry a high in-hospital mortality, high morbidity, and hospital cost.

An osteoinductive and biodegradable intramedullary implant accelerates bone healing and mitigates complications of bone transport in male rats.

Bone transport is a surgery-driven procedure for the treatment of large bone defects. However, challenging complications include prolonged consolidation, docking site nonunion and pin tract infection. Here, we develop an osteoinductive and biodegradable intramedullary implant by a hybrid tissue engineering construct technique to enable sustained delivery of bone morphogenetic protein-2 as an adjunctive therapy. In a male rat bone transport model, the eluting bone morphogenetic protein-2 from the implants accelerates bone formation and remodeling, leading to early bony fusion as shown by imaging, mechanical testing, histological analysis, and microarray assays. Moreover, no pin tract infection but tight osseointegration are observed. In contrast, conventional treatments show higher proportion of docking site nonunion and pin tract infection. The findings of this study demonstrate that the novel intramedullary implant holds great promise for advancing bone transport techniques by promoting bone regeneration and reducing complications in the treatment of bone defects.

Gait Analysis in Orthopaedic Surgery: History, Limitations, and Future Directions.

Gait analysis has expanding indications in orthopaedic surgery, both for clinical and research applications. Early work has been particularly helpful for understanding pathologic gait deviations in neuromuscular disorders and biomechanical imbalances that contribute to injury. Notable advances in image acquisition, health-related wearable devices, and computational capabilities for big data sets have led to a rapid expansion of gait analysis tools, enabling novel research in all orthopaedic subspecialties. Given the lower cost and increased accessibility, new gait analysis tools will surely affect the next generation of objective patient outcome data. This article reviews the basic principles of gait analysis, modern tools available to the common surgeon, and future directions in this space.

Value Analysis of Methods of Inguinal Hernia Repair.

OBJECTIVE: Value is defined as health outcomes important to patients relative to cost of achieving those outcomes: Value = Quality/Cost. For inguinal hernia repair, Level 1 evidence shows no differences in long-term functional status or recurrence rates when comparing surgical approaches. Differences in value reside within differences in cost. The aim of this study is to compare the value of different surgical approaches to inguinal hernia repair: Open (Open-IH), Laparoscopic (Lap-IH), and Robotic (R-TAPP). METHODS: Variable and fixed hospital costs were compared among consecutive Open-IH, Lap-IH, and R-TAPP repairs (100 each) performed in a university hospital. Variable costs (VC) including direct materials, labor, and variable overhead ($/min operating room [OR] time) were evaluated using Value Driven Outcomes, an internal activity-based costing methodology. Variable and fixed costs were allocated using full absorption costing to evaluate the impact of surgical approach on value. As cost data is proprietary, differences in cost were normalized to Open-IH cost. RESULTS: Compared to Open-IH, VC for Lap-IH were 1.02X higher (including a 0.81X reduction in cost for operating room [OR] time). For R-TAPP, VC were 2.11X higher (including 1.36X increased costs for OR time). With allocation of fixed cost, a Lap-IH was 1.03X more costly, whereas R-TAPP was 3.18X more costly than Open-IH. Using equivalent recurrence as the quality metric in the value equation, Lap-IH decreases value by 3% and R-TAPP by 69% compared to Open-IH. CONCLUSIONS: Use of higher cost technology to repair inguinal hernias reduces value. Incremental health benefits must be realized to justify increased costs. We expect payors and patients will incorporate value into payment decisions.

A Structured Review Instrument Improves the Quality of Orthopaedic Journal Club.

OBJECTIVE: We asked the following questions: 1. Does the use of an structured review instrument (SRI) at journal club increase presentation quality, as measured objectively by a standardized evaluation rubric? 2. Does SRI use increase the time required to prepare for journal club? 3. Does SRI use positively impact presenter perceptions about confidence while presenting, satisfaction, and journal club effectiveness, as measured by postparticipation surveys? DESIGN: A prospective study was designed in which a grading rubric was developed to evaluate journal club presentations. The rubric was applied to 24 presentations at journal clubs prior to introduction of the SRI. An SRI was developed and distributed to journal club participants, who were instructed to use it to prepare for journal club. The grading rubric was then used to assess 25 post-SRI presentations and scores were compared between the pre- and post-SRI groups. Presentations occurred at either trauma, pediatrics, or spine subspecialty journal clubs. Participants were also surveyed regarding time requirements for preparation, perceptions of confidence while presenting, satisfaction, and perceptions of overall club effectiveness. SETTING: A single academic center with an orthopaedic surgery residency program. PARTICIPANTS: Resident physicians in the department of orthopaedic surgery. RESULTS: Mean presentation scores increased from 14.0 ± 5.9 (mean ± standard deviation) to 24.4 ± 5.2 after introduction of the SRI (p < 0.001). Preparation time decreased from a mean of 47 minutes to 40 minutes after SRI introduction (p = 0.22). Perceptions of confidence, satisfaction, and club effectiveness among trainees trended toward more positive responses after SRI introduction (confidence: 63% positive responses pre-SRI vs 72% post-SRI, p = 0.73; satisfaction: 64% vs 91%, p = 0.18; effectiveness: 64% vs 91%, p = 0.19). CONCLUSIONS: The use of a structured review instrument to guide presentations at orthopaedic journal club increased presentation quality, and there was no difference in preparation time. There were trends toward improved presenter confidence, satisfaction, and perception of journal club effectiveness. SRI utilization at orthopaedic journal club may be an effective method for increasing the quality of journal club presentations. Future work should examine the relationship between presentation quality and overall club effectiveness.

Leishmania parasitophorous vacuole membranes display phosphoinositides that create conditions for continuous Akt activation and a target for miltefosine in Leishmania infections.

Miltefosine is an important drug for the treatment of leishmaniasis; however, its mechanism of action is still poorly understood. In these studies, we tested the hypothesis that like in cancer cells, miltefosine's efficacy in leishmaniasis is due to its inhibition of Akt activation in host cells. We show using pharmacologic agents that block Akt activation by different mechanisms and also using an inducible knockdown approach that miltefosine loses its efficacy when its access to Akt1 is limited. Interestingly, limitation of Akt activation results in clearance of established Leishmania infections. We then show, using fluorophore-tagged probes that bind to phosphoinositides, that Leishmania parasitophorous vacuole membranes (LPVMs) display the relevant phosphoinositides to which Akt can be recruited and activated continuously. Taken together, we propose that the acquisition of PI(4) P and the display of PI (3,4)P2 on LPVMs initiate the machinery that supports continuous Akt activation and sensitivity to miltefosine.

External validation in an intermediate unit of a respiratory decompensation model trained in an intensive care unit.

BACKGROUND: Preventing urgent intubation and upgrade in level of care in patients with subclinical deterioration could be of great utility in hospitalized patients. Early detection should result in decreased mortality, duration of stay, and/or resource use. The goal of this study was to externally validate a previously developed, vital sign-based, intensive care unit, respiratory instability model on a separate population, intermediate care patients. METHODS: From May 2014 to May 2016, the model calculated relative risk of adverse events every 15 minutes (n = 373,271 observations) for 2,050 patients in a surgical intermediate care unit. RESULTS: We identified 167 upgrades and 57 intubations. The performance of the model for predicting upgrades within 12 hours was highly significant with an area under the curve of 0.693 (95% confidence interval, 0.658-0.724). The model was well calibrated with relative risks in the highest and lowest deciles of 2.99 and 0.45, respectively (a 6.6-fold increase). The model was effective at predicting intubation, with a demonstrated area under the curve within 12 hours of the event of 0.748 (95% confidence interval, 0.685-0.800). The highest and lowest deciles of observed relative risk were 3.91 and 0.39, respectively (a 10.1-fold increase). Univariate analysis of vital signs showed that transfer upgrades were associated, in order of importance, with rising respiration rate, rising heart rate, and falling pulse-oxygen saturation level. CONCLUSION: The respiratory instability model developed previously is valid in intermediate care patients to predict both urgent intubations and requirements for upgrade in level of care to an intensive care unit.

Biomechanical and Clinical Correlates of Stance-Phase Knee Flexion in Persons With Spastic Cerebral Palsy.

OBJECTIVE: To identify biomechanical and clinical parameters that influence knee flexion (KF) angle at initial contact (IC) and during single limb stance phase of gait in children with spastic cerebral palsy (CP) who walk with flexed-knee gait. DESIGN: Retrospective analysis of gait kinematics and clinical data collected from 2010-2013. SETTING: Motion & Gait Analysis Laboratory at Lucile Packard Children's Hospital, Stanford, CA. PARTICIPANTS: Gait analysis data from persons with spastic CP (Gross Motor Function Classification System [GMFCS] I-III) who had no prior surgery were analyzed. Participants exhibiting KF ≥20° at IC were included; the more-involved limb was analyzed. METHODS: Outcome measures were analyzed with respect to clinical findings, including passive range of motion, Selective Motor Control Assessment for the Lower Extremity (SCALE), gait kinematics, and musculoskeletal models of muscle-tendon lengths during gait. MAIN OUTCOME MEASURES: KF at IC (KFIC) and minimum KF during single-limb support (KFSLS) were investigated. RESULTS: Thirty-four participants met the inclusion criteria, and their data were analyzed (20 males and 14 females, mean age 10.1 years, range 5-20 years). Mean KFIC was 34.4 ± 8.4 degrees and correlated with lower SCALE score (ρ = -0.530, P = .004), later peak KF during swing (ρ = 0.614, P < .001), and shorter maximal muscle length of the semimembranosus (ρ = -0.359, P = .037). Mean KFSLS was 18.7 ± 14.9 and correlated to KF contracture (ρ = 0.605, P < .001) and shorter maximal muscle length of the semimembranosus (ρ = -0.572, P < .001) and medial gastrocnemius (ρ = -0.386, P = .024). GMFCS correlated more strongly to KFIC (ρ = 0.502, P = .002) than to KFSLS (ρ = 0.371, P = .031). Linear regression found that both the SCALE score (P = .001) and delayed timing of peak KF during swing (P = .001) independently predicted KFIC. KF contracture (P = .026) and maximal length of the semimembranosus (P = .043) independently predicted KFSLS. CONCLUSION: Correlates of KFIC differed from those for KFSLS and suggest that impaired selective motor control and later timing of swing-phase KF influence knee position at IC, whereas KF contracture and muscle lengths influence minimal KF in single-limb support, findings with important treatment implications.

Caput valgum associated with developmental dysplasia of the hip: management by transphyseal screw fixation.

PURPOSE: A late finding of some hips treated for developmental dysplasia of the hip (DDH) is a growth disturbance of the lateral proximal femoral physis, which results in caput valgum and possibly osteoarthritis. Current treatment options include complete epiphysiodesis of the proximal femoral physis or a corrective proximal femoral osteotomy. Alternatively, a transphyseal screw through the inferomedial proximal femoral physis that preserves superolateral growth might improve this deformity. METHODS: This study evaluates the effect of such a transphyseal screw on both femoral and acetabular development in patients with caput valgum following open treatment of DDH. These patients were followed clinically and radiographically until skeletal maturity. Preoperative and postoperative radiographs were assessed, measuring the proximal femoral physeal orientation (PFPO), the head-shaft angle (HSA), Sharp's angle and the center edge angle of Wiberg (CE angle). RESULTS: Thirteen hips of 11 consecutive patients were followed prospectively. The age at the time of transphyseal screw placement was between 5 and 14 years. The mean improvement of the PFPO and HSA was 14° (p < 0.01) and 11° (p < 0.001), respectively. The mean improvement of Sharp's angle and CE angle was 4.7° (p < 0.01) and 5.8° (p < 0.02), respectively. Five patients underwent screw revision. CONCLUSIONS: A transphyseal screw across the proximal femoral physis improved the proximal femur and acetabular geometry.

Biomechanical and clinical correlates of swing-phase knee flexion in individuals with spastic cerebral palsy who walk with flexed-knee gait.

OBJECTIVE: To identify clinical and biomechanical parameters that influence swing-phase knee flexion and contribute to stiff-knee gait in individuals with spastic cerebral palsy (CP) and flexed-knee gait. DESIGN: Retrospective analysis of clinical data and gait kinematics collected from 2010 to 2013. SETTING: Motion and gait analysis laboratory at a children's hospital. PARTICIPANTS: Individuals with spastic CP (N=34; 20 boys, 14 girls; mean age ± SD, 10.1±4.1y [range, 5-20y]; Gross Motor Function Classification System I-III) who walked with flexed-knee gait ≥20° at initial contact and had no prior surgery were included; the more-involved limb was analyzed. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: The magnitude and timing of peak knee flexion (PKF) during swing were analyzed with respect to clinical data, including passive range of motion and Selective Control Assessment of the Lower Extremity, and biomechanical data, including joint kinematics and hamstring, rectus femoris, and gastrocnemius muscle-tendon length during gait. RESULTS: Data from participants demonstrated that achieving a higher magnitude of PKF during swing correlated with a higher maximum knee flexion velocity in swing (ρ=.582, P<0.001) and a longer maximum length of the rectus femoris (ρ=.491, P=.003). In contrast, attaining earlier timing of PKF during swing correlated with a higher knee flexion velocity at toe-off (ρ=-.576, P<.001), a longer maximum length of the gastrocnemius (ρ=-.355, P=.039), and a greater peak knee extension during single-limb support phase (ρ=-.354, P=.040). CONCLUSIONS: Results indicate that the magnitude and timing of PKF during swing were independent, and their biomechanical correlates differed, suggesting important treatment implications for both stiff-knee and flexed-knee gait.

The effect of dead-on-arrival and emergency department death classification on risk-adjusted performance in the American College of Surgeons Trauma Quality Improvement Program.

BACKGROUND: The American College of Surgeons' Trauma Quality Improvement Program is focused on identifying variations in outcomes across trauma centers for the purposes of performance improvement. In previous analyses, patients who died in the emergency department were excluded. We investigated the effect of inclusion and exclusion of emergency department (ED) deaths (dead on arrival [DOA] and died in ED [DIE]) on analyses of overall risk-adjusted trauma center performance. METHODS: Data for patients admitted to 65 Trauma Quality Improvement Program hospitals during the 2009 calendar year was used. A logistic regression model was developed to estimate risk-adjusted mortality. Trauma centers were then ranked based on their observed-to-expected (O/E) mortality ratio with 90% confidence intervals (CIs) and classified by outlier status: low outliers/high performers had a 90% CI for O/E mortality ratio of less than 1, and high outliers/low performers had a 90% CI for O/E mortality ratio of greater than 1. Changes in outlier status, rank, and quartile were examined with and without DOA and DIE patients included in the analyses to discern the impact of such exclusions on overall risk-adjusted center-specific performance. RESULTS: Thirty-one trauma centers (48%) reported no DOA patients in 2009, while 6 centers (9%) reported more than 10. Of 224 patients, 14 (6.2%) had a documented time of death of more than 30 minutes after ED arrival despite being recorded as DOA. Forty-one trauma centers (63%) changed rank by three positions or less. Ten trauma centers changed their quartile ranking by a single quartile, but no centers were found to change quartile rank more than one quartile. Changes in outlier status occurred for 6 trauma centers (9%). CONCLUSION: The relative frequency of patients classified as DOA varies greatly between trauma centers. Misclassification of patients as DOA occurs. Inclusion of ED deaths in risk-adjusted analysis of mortality results in a small but insignificant change in predicting the outcome results of a trauma center. This change is less than the rate of finding a center to be a high or low outlier by chance alone using the 90% CI. Inclusion of DOA and DIE patients in risk-adjusted analysis of mortality is appropriate and eliminates the bias introduced by exclusion of ED deaths owing to misuse of the DOA classification. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.

Severe traumatic head injury affects systemic cytokine expression.

BACKGROUND: The neuroimmunologic effect of traumatic head injury remains ill-defined. This study aimed to characterize systemic cytokine profiles among traumatically injured patients to assess the effect of traumatic head injury on the systemic inflammatory response. STUDY DESIGN: For 5 years, 1,022 patients were evaluated from a multi-institutional Trauma Immunomodulatory Database. Patients were stratified by presence of severe head injury (SHI; head Injury Severity Score ≥4, n = 335) vs nonsevere head injury (NHI; head Injury Severity Score ≤3, n = 687). Systemic cytokine expression was quantified by ELISA within 72 hours of admission. Patient factors, outcomes, and cytokine profiles were compared by univariate analyses. RESULTS: SHI patients were more severely injured with higher mortality, despite similar ICU infection and ventilator-associated pneumonia rates. Expression of early proinflammatory cytokines, interleukin-6 (p < 0.001) and tumor necrosis factor-α (p = 0.02), was higher among NHI patients, and expression of immunomodulatory cytokines, interferon-γ (p = 0.01) and interleukin-12 (p = 0.003), was higher in SHI patients. High tumor necrosis factor-α levels in NHI patients were associated with mortality (p = 0.01), increased mechanical ventilation (p = 0.02), and development of ventilator-associated pneumonia (p = 0.01). Alternatively, among SHI patients, high interleukin-2 levels were associated with survival, decreased mechanical ventilation, and absence of ventilator-associated pneumonia. CONCLUSIONS: The presence of severe traumatic head injury significantly alters systemic cytokine expression and exerts an immunomodulatory effect. Early recognition of these profiles can allow for targeted intervention to reduce patient morbidity and mortality.

Management of the knee in spastic diplegia: what is the dose?

This article discusses the sagittal gait patterns in children with spastic diplegia, with an emphasis on the knee, as well as the concept of the "dose" of surgery that is required to correct different gait pathologies. The authors list the various interventions in the order of their increasing dose. The concept of dose is useful in the consideration of the management of knee dysfunction.

What is the safety of nonemergent operative procedures performed at night? A study of 10,426 operations at an academic tertiary care hospital using the American College of Surgeons national surgical quality program improvement database.

BACKGROUND: Ever-increasing numbers of in-house acute care surgeons and competition for operating room time during normal daytime business hours have led to an increased frequency of nonemergent general and vascular surgery procedures occurring at night when there are fewer residents, consultants, nurses, and support staff available for assistance. This investigation tests the hypothesis that patients undergoing such procedures after hours are at increased risk for postoperative morbidity and mortality. METHODS: Clinical data for 10,426 operative procedures performed over a 5-year period at a single academic tertiary care hospital were obtained from the American College of Surgeons National Surgical Quality Improvement Program Database. The prevalence of preoperative comorbid conditions, postoperative length of stay, morbidity, and mortality was compared between two cohorts of patients: one who underwent nonemergent operative procedures at night and other who underwent similar procedures during the day. Subsequent statistical comparisons utilized chi tests for comparisons of categorical variables and F-tests for continuous variables. RESULTS: Patients undergoing procedures at night had a greater prevalence of serious preoperative comorbid conditions. Procedure complexity as measured by relative value unit did not differ between groups, but length of stay was longer after night procedures (7.8 days vs. 4.3 days, p < 0.0001). CONCLUSIONS: Patients undergoing nonemergent general and vascular surgery procedures at night in an academic medical center do not seem to be at increased risk for postoperative morbidity or mortality. Performing nonemergent procedures at night seems to be a safe solution for daytime overcrowding of operating rooms.

The use of "war games" to enhance high-risk clinical decision-making in students and residents.

BACKGROUND: Initial studies found that residents and students performed poorly in simple clinical scenarios. We hypothesized that repeated simulations in the "war games" format would improve performance. METHODS: Participants included medical students and residents on the trauma and surgical intensive care unit (SICU) services. Subjects were given a nursing report of an unstable patient and asked to verbalize management of the situation. Responses were transcribed and graded. RESULTS: Eighty subjects and 5 experts participated in 227 simulations. Naive medical students, postgraduate year (PGY)-1, and PGY-2+ subjects performed worse than experts (P <.05). After participation in >/=3 war games sessions, trainees' scores were similar to experts. Subjects with the least amount of clinical experience demonstrated the most improvement. DISCUSSION: We have designed an educational system that rapidly enhances the cognitive performance of students and residents. This may represent an important tool in assessing and enhancing the competencies of medical trainees in a safe environment.

Differences in early- and late-onset ventilator-associated pneumonia between surgical and trauma patients in a combined surgical or trauma intensive care unit.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is a leading cause of morbidity in the perioperative period. Based on differences in causes, VAP has been divided into early (96 hours of admission) onset. We sought to compare differences in patient characteristics and outcome between early- and late-onset VAP in trauma and nontrauma surgical patients. METHODS: A retrospective analysis of prospectively collected data were performed for all surgical and trauma patients admitted to the surgical or trauma intensive care unit of an academic medical center from December 1996 to March 2005 who developed VAP. Patients with early- and late-onset VAP were compared with regard to patient characteristics, cause, and outcome using bivariate and multivariate analyses. RESULTS: Three hundred thirty VAPs were identified in 233 trauma (71%) and 97 nontrauma surgery patients (29%). There was no statistically significant difference in recurrence, mortality, or length of stay between early- and late-onset VAP in trauma patients. Mortality for late- onset VAPs in nontrauma patients was 44% versus 23% for early-onset VAPs (p = 0.09). On a per case basis, trauma patients had significantly better mortality (11% vs. 41%) and length of stay (33.1 +/- 1.4 vs. 55.8 +/- 4.1 days) than nontrauma surgical patients with VAP (p < 0.0001), although the rate of VAP-related death favored the nontrauma patients (1.8 deaths of 100 intensive care unit trauma admissions vs. 1.1 deaths of 100 intensive care unit nontrauma admissions, p = 0.05). CONCLUSIONS: Although there is a trend toward worse outcome in nontrauma patients with late-onset VAP, trauma patients with late- and early-onset VAP behave similarly. On a per case basis, trauma patients have significantly better outcomes than nontrauma surgical patients with VAP when cared for within the same surgical or trauma intensive care unit.

Remodeling of birth fractures of the humeral diaphysis.

BACKGROUND: Birth fractures of the humeral diaphysis are encountered at most pediatric medical centers and pediatric orthopaedic practices. The treatment strategy of these fractures is uniformly nonoperative. However, we have not found sufficient studies in the literature demonstrating the extent to which remodeling is possible and therefore how much deformity is acceptable in the treatment of these fractures. METHODS: We reviewed the records of our institution's Orthopaedic Surgery Clinic and identified all children seen for birth fractures of the humerus from 2001 to 2005. The angulation and displacement at presentation and at follow-up were measured. RESULTS: All patients were treated nonoperatively, and most were managed by swaddling. In 9 patients with more than 4 months of radiographic follow-up, the mean initial angulation was 26 degrees in the coronal plane and 25 degrees in the sagittal plane. The mean angulation at final follow-up was 5 degrees in the coronal plane and 7 degrees in the sagittal plane. The maximum angulation at presentation was 66 degrees, which remodeled to 5 degrees at 7.3 months' follow-up. CONCLUSIONS: Our findings suggest that attempts to obtain an anatomical reduction or the use of more than the simplest immobilization methods are not necessary given the tremendous capacity for remodeling of these fractures in infants.

The use of "war games" to evaluate performance of students and residents in basic clinical scenarios: a disturbing analysis.

BACKGROUND: "Failure to Rescue" is a term applied to clinical issues that, if unrecognized or improperly treated, lead to adverse outcomes. We examined the cognitive components of rescue through the use of a "War Games" simulator format. Our hypothesis was that junior and senior medical students would be less able than interns and residents to detail the actions needed to assess, intervene, and stabilize patients. METHODS: Medical students and residents rotating on the trauma and surgical intensive care unit service participated. Twelve scenarios were created to focus on basic floor emergencies. Scores were assigned for clinical actions ordered. The scenarios were validated by two critical care attending physicians, and these scores were used as the expert group. Scores were assigned by two examiners, and the average of the grades in each area was used. The scores are a ratio of actual to possible correct responses in each section, and in the entire exercise. RESULTS: Subjects were divided into third-year medical students (MS3), fourth-year students (MS4), first-year residents (PGY1), residents beyond their first year (PGY2+), and experts. There were 20 subjects and 5 experts (n = 85) in each group for a total of 140 simulated cases examined. On initial evaluation, MS4 and PGY2+ performed significantly worse than expert, and MS3 and PGY1 performed similarly to experts. On secondary evaluation, all groups performed significantly worse than the expert group. In determining the diagnosis, only MS3 differed significantly from the experts. On follow-up, and in total score, all performed significantly worse than the experts. DISCUSSION: All groups had significant deficits in cognitive performance compared with experts in the areas of secondary evaluation, follow-up of the presenting problem, and total performance in simple clinical scenarios. We must design educational systems that rapidly enhance the cognitive performance of students and residents before they are left to independently diagnose and intervene in life-threatening clinical situations.