David Doezema

Human simulation in emergency medicine training: a model curriculum.

The authors propose a three-year curriculum for emergency medicine residents using human simulation both to teach and to assess the Accreditation Council for Graduate Medical Education (ACGME) core competencies. Human simulation refers to a variety of technologies that allow residents to work through realistic patient problems so as to allow them to make mistakes, learn, and be evaluated without exposing a real patient to risk. This curriculum incorporates 15 simulated patient encounters with gradually increasing difficulty, complexity, and realism into a three-year emergency medicine residency. The core competencies are incorporated into each case, focusing on the areas of patient care, interpersonal skills and communication, professionalism, and practice based learning and improvement. Because of the limitations of current assessment tools, the demonstration of resident competence is used only for formative evaluations. Limitations of this proposal and difficulties in implementation are discussed, along with a description of the organization and initiation of the simulation program.

A Longitudinal Proton Magnetic Resonance Spectroscopy Study of Mild Traumatic Brain Injury

Despite the prevalence and impact of mild traumatic brain injury (mTBI), common clinical assessment methods for mTBI have insufficient sensitivity and specificity. Moreover, few researchers have attempted to document underlying changes in physiology as a function of recovery from mTBI. Proton magnetic resonance spectroscopy (¹H-MRS) was used to assess neurometabolite concentrations in a supraventricular tissue slab in 30 individuals with semi-acute mTBI, and 30 sex-, age-, and education-matched controls. No significant group differences were evident on traditional measures of attention, memory, working memory, processing speed, and executive skills, though the mTBI group reported significantly more somatic, cognitive, and emotional symptoms. At a mean of 13 days post-injury, white matter concentrations of creatine (Cre) and phosphocreatine (PCre) and the combined glutamate-glutamine signal (Glx) were elevated in the mTBI group, while gray matter concentrations of Glx were reduced. Partial normalization of these three neurometabolites and N-acetyl aspartate occurred in the early days post-injury, during the semi-acute period of recovery. In addition, 17 mTBI patients (57%) returned for a follow-up evaluation (mean = 120 days post-injury). A significant group × time interaction indicated recovery in the mTBI group for gray matter Glx, and trends toward recovery in white matter Cre and Glx. An estimate of premorbid intelligence predicted the magnitude of neurometabolite normalization over the follow-up interval for the mTBI group, indicating that biological factors underlying intelligence may also be associated with more rapid recovery.

Magnetic resonance imaging in minor head injury

STUDY OBJECTIVES To investigate the role of cranial magnetic resonance (MR) imaging in evaluating patients discharged from the emergency department after minor head injury. DESIGN A prospective blinded cohort study. SETTING University hospital ED. TYPE OF PARTICIPANTS Fifty-eight patients with minor head injury who were discharged from the ED with written head injury instructions. Patients admitted to the hospital were excluded. INTERVENTIONS Ultra-low-field cranial MR scans were performed on patients within 24 hours of discharge. Scans were read blindly by two radiologists. MEASUREMENTS AND MAIN RESULTS Fishers exact test was used to compare symptoms in patients with abnormal and normal MR scans. There was no significant difference in symptoms between patients with abnormal and those with normal scans (P greater than .10). The proportion of abnormal MR scans was analyzed using the binomial distribution. Six of the 58 patients (10.3%) had traumatic intracranial abnormalities (proportion, 0.103; SD, 0.04; 95% CI, 0.04-0.21). Three had cortical contusions, and three had small subdural hematomas. Two of the six patients with abnormal MR scans, both with small subdural hematomas, had normal computed tomography scans. CONCLUSION Ten percent of patients discharged from the ED after minor head injury had abnormal ultra-low-field cranial MR scans. Additional research is needed to establish the clinical importance of this unexpected observation.

Auditory Orienting and Inhibition of Return in Mild Traumatic Brain Injury: A FMRI Study

The semiacute phase of mild traumatic brain injury (mTBI) is associated with deficits in the cognitive domains of attention, memory, and executive function, which previous work suggests may be related to a specific deficit in disengaging attentional focus. However, to date, there have only been a few studies that have employed dynamic imaging techniques to investigate the potential neurological basis of these cognitive deficits during the semiacute stage of injury. Therefore, event‐related functional magnetic resonance imaging was used to investigate the neurological correlates of attentional dysfunction in a clinically homogeneous sample of 16 patients with mTBI during the semiacute phase of injury (<3 weeks). Behaviorally, patients with mTBI exhibited deficits in disengaging and reorienting auditory attention following invalid cues as well as a failure to inhibit attentional allocation to a cued spatial location compared to a group of matched controls. Accordingly, patients with mTBI also exhibited hypoactivation within thalamus, striatum, midbrain nuclei, and cerebellum across all trials as well as hypoactivation in the right posterior parietal cortex, presupplementary motor area, bilateral frontal eye fields, and right ventrolateral prefrontal cortex during attentional disengagement. Finally, the hemodynamic response within several regions of the attentional network predicted response times better for controls than for patients with mTBI. These objective neurological findings represent a potential biomarker for the behavioral deficits in spatial attention that characterize the initial recovery phase of mTBI. Hum Brain Mapp, 2009.

Does a physician visual assessment change triage

A prospective comparative trial was conducted to determine the effect of a physicians visual assessment of emergency patients on triage categorization and ability at triage to predict admission. The setting was a university, county, referral center and residency training site. Participants were a consecutive sample of emergency department patients presenting between the times of 0700 and 2300 hours for 5 weeks. All patients were assigned a triage category by an emergency nurse (RN) who saw the patient and by an emergency physician (EP) who had the option of performing a visual assessment. Triage categorization was compared for interobserver agreement (Kappa [kappa] statistic) and by ability to predict admission (MacNemars test). A total of 3,949 patients was entered. The patients that physicians visually assessed were triaged by nurses as more ill (P < .001). For triage categories visualized by the EP compared with RN categorization, interobserver agreement was 59.8%, kappa = .21. For triage categories not visualized by EP compared with RN categorization, interobserver agreement was 67.9%, kappa = .45 (P < .001). Sensitivity of EPs to predict admission is as follows: all RN triage, 41.3; not seen by EP, 54.9; seen by EP, 69.3. Specificity is as follows: all RN triage, 93.7; not seen by EP, 88.5, seen by EP, 83.9. When physician visual assessment was done, agreement between physicians and nurses decreased by more than half. Physicians who included visual assessment in patient triage were less likely to agree with RN categorization. A visual assessment by the physician improved the sensitivity for predicting admission with an only small cost in specificity.

An FMRI study of auditory orienting and inhibition of return in pediatric mild traumatic brain injury.

Studies in adult mild traumatic brain injury (mTBI) have shown that two key measures of attention, spatial reorienting and inhibition of return (IOR), are impaired during the first few weeks of injury. However, it is currently unknown whether similar deficits exist following pediatric mTBI. The current study used functional magnetic resonance imaging (fMRI) to investigate the effects of semi-acute mTBI (<3 weeks post-injury) on auditory orienting in 14 pediatric mTBI patients (age 13.50±1.83 years; education: 6.86±1.88 years), and 14 healthy controls (age 13.29±2.09 years; education: 7.21±2.08 years), matched for age and years of education. The results indicated that patients with mTBI showed subtle (i.e., moderate effect sizes) but non-significant deficits on formal neuropsychological testing and during IOR. In contrast, functional imaging results indicated that patients with mTBI demonstrated significantly decreased activation within the bilateral posterior cingulate gyrus, thalamus, basal ganglia, midbrain nuclei, and cerebellum. The spatial topography of hypoactivation was very similar to our previous study in adults, suggesting that subcortical structures may be particularly affected by the initial biomechanical forces in mTBI. Current results also suggest that fMRI may be a more sensitive tool for identifying semi-acute effects of mTBI than the procedures currently used in clinical practice, such as neuropsychological testing and structural scans. fMRI findings could potentially serve as a biomarker for measuring the subtle injury caused by mTBI, and documenting the course of recovery.

Anaphylaxis following administration of intravenous methylprednisolone sodium succinate

A 27-year-old man developed respiratory arrest following intravenous administration of methylprednisolone sodium succinate. Skin tests were positive to methylprednisolone sodium succinate but not to methylprednisolone acetate. Severe anaphylactic reactions to intravenous corticosteroid medications can occur and can require epinephrine administration or endotracheal intubation. Skin tests and drug challenge should be done to establish the safety of a particular corticosteroid drug.

Low Prevalence of Chlamydia trachomatis by Urinary Ligase Chain Reaction in Women Patients in the Emergency Department

UNLABELLED Recent studies suggest that women with acute urethral syndrome or abdominal pain, presenting to emergency departments (EDs), have a high prevalence of Chlamydia trachomatis. OBJECTIVES To estimate the prevalence of C. trachomatis in women presenting to an ED and to see whether those with dysuria or abdominal pain have a higher prevalence of C. trachomatis. METHODS The authors conducted a prospective cross-sectional study of C. trachomatis in the urine of women aged 18 to 50 years who had a urinalysis performed at a university/county ED from February through May 1998. Urine specimens were labeled for the presence of symptoms and analyzed for C. trachomatis by ligase chain reaction (LCR). Polymerase chain reaction (PCR) testing of cervical swabs for C. trachomatis was done for usual clinical indications. Difference in proportions of positive LCR tests among patients was tested with Fishers exact test. Agreement between PCR and LCR was measured using Cohens kappa statistic. RESULTS Of 397 women whose urine was tested, 280 had symptoms of dysuria, abdominal pain, or both, and 117 had no symptoms. The overall prevalence of C. trachomatis by LCR was 3.8% (95% CI = 2.1% to 6.2%); and the combined PCR-LCR prevalence was 4.3% (95% CI = 2.5% to 6.8%). The presence of symptoms was not associated with a positive LCR test for C. trachomatis (p = 0.26, power = 0.8, alpha = 0.05, difference 3% vs. 12%). In the 172 patients who had both a PCR cervical swab and urine LCR, agreement was excellent (kappa = 0.67, 95% CI = 0.45 to 0.90). CONCLUSIONS This ED had a surprisingly low prevalence of C. trachomatis. Women with symptoms were not more likely to test positive than those without.

The Effect of Local Anesthetics on Bacterial Proliferation: TAC Versus Lidocaine

We compared the effect of topical 0.5% tetracaine, 1:2,000 epinephrine, and 11.8% cocaine (TAC) with 1% lidocaine infiltration on bacterial proliferation in experimental lacerations. Forty-eight lacerations were made on the backs of Hampshire pigs, inoculated by injection with infectious doses of Staphylococcus aureus and randomly anesthetized with either topical TAC or lidocaine infiltration. Wounds were sutured, and quantitative cultures were obtained by excision after 48 hours. The mean log10 bacteria per gram of tissue for wounds anesthetized with TAC was 6.818 (95% confidence interval [CI], 6.07 to 7.54) compared with 6.820 (95% CI, 5.91 to 7.75) for those treated with lidocaine; this difference was not significant (P less than .05 by paired two-tailed t test). The probability of failing to detect an intergroup difference of 0.5 log10 bacteria per gram was less than .0001. TAC does not increase bacterial proliferation more than lidocaine infiltration in contaminated experimental porcine lacerations.

A New Approach to Teaching Prehospital Trauma Care to Paramedic Students

STUDY OBJECTIVE A modification of the standard Department of Transportation student paramedic curriculum encouraging individualized patient assessment decreases inappropriate on-scene procedures (OSPs) and scene time, measured on simulated patients. METHODS Scenario-based testing from 1991 through 1993 was videotaped for all students. A new trauma curriculum was introduced in 1992, individualizing patient assessment and prioritization of OSPs. Recorded OSPs included spinal immobilization, application of military antishock trousers, endotracheal intubation, cricothyrotomy, intravenous catheter insertion, and needle thoracostomy. Twenty videotaped random student performances of the 1991 class was compared with a similar sample of 20 from the 1993 class; scene times and the OSP numbers were measured. Two board-certified independent emergency physicians unfamiliar with the students or the new curriculum reviewed all 40 tests on a master videotape. Patient assessment appropriateness, scene time, OSPs, scenario difficulty, and number of inappropriate OSPs were evaluated using a linear analog scale. Data are presented as means with confidence intervals (CIs), analyzed by Students t test and the Mann-Whitney 2-sample test. RESULTS Scene time from 1991 to 1993 decreased overall with a mean of 4.3 minutes (95% CI 2.8 to 5.8 minutes), as did the number of OSPs: 3.1 versus 1.7 (mean difference, 1.45 OSPs per scenario; 95% CI.91 to 1.99). Physician reviewers noted improvements in the appropriateness of patient assessment, scene time, and OSPs from 1991 to 1993. There was no significant difference in scenario difficulty for 1991 compared with 1993. Inappropriate OSPs done on scene declined. Physician 1 indicated a mean of inappropriate procedures of 1.6 in 1991 versus.5 in 1993. Physician 2 indicated a mean of 1.4 in 1991 versus.3 in 1993. CONCLUSION This new paramedic curriculum decreased on-scene time and inappropriate use of procedures in stabilizing the condition of patients with simulated critical trauma.