Research Forum Abstracts

the top of the T1 vertebrae) was assessed by 2 physician investigators blinded to height,weight and BMI. Correlation of height, weight, and BMI to the number of visiblevertebrae was determined using Spearman correlation coefficients.

Results: Of 20 subjects analyzed, only three (15%) had adequate films to T1, an additionalten (50%) had films revealing the spine down to C7, and none had a fracture. No subject withBMI�24, weight�70.5kg, or height�172cm had adequate plain films. The Spearmancorrelation coefficient for number of visible vertebrae was �0.43 as a function of BMI(p�.05), �0.29 for height (p�0.20), and �0.44 for weight (p�0.05).

Conclusion: Weight, and to a lesser degree, BMI, correlate best with theadequacy of cervical spine radiographs in trauma patients. A screen employingBMI�24 would have identified 14/17 subjects in our series (82%) with inadequateplain radiographs who could have been referred directly for CT, saving them the cost,time, and radiation exposure of two radiographic studies. Using weight�70.5kg aloneas a screen would have identified 11/17 subjects (65%). Prospective validation of thisscreening tool is needed.

268 The Epidemiology of Patellar Dislocations

Porter Jr PS, Salo D, Allegra JR/Morristown Hospital, Morristown, NJ

Study Objectives: It is generally reported in emergency medicine textbooks thatpatellar dislocations occur predominantly in women. Many dislocations are related toathletic injuries. As the participation of women in competitive sports has increasedfollowing Title IX of the Education Amendments of 1972, we hypothesized thatthere would be a marked female predominance of patellar dislocations. We found noemergency department (ED) studies examining the epidemiology of patellardislocations. Our goal was to examine sex and also age differences in the occurrenceof patellar dislocations in a large ED database.

Methods: Design: Retrospective cohort. Setting: 19 hospital EDs in urban,suburban and rural areas in New Jersey and New York with annual visits (20,000-75,000). Population: Consecutive visits from Jan 1, 1999 to Sept 30, 2007. Protocol:We extracted from the database all visits with ICD-9 codes of patella dislocation. Weanalyzed the data using SPSS version 10.0. Descriptive statistics and comparisonsbetween females and males are reported. The Student’s t-test was used to calculate95% confidence intervals (CIs).

Results: Of the 4,736,759 visits in the database, 1,053 visits (0.022%) had thediagnosis of patella dislocation. Females comprised 52% (95% CI 49%-55%). Themedian age for all patients was 19 with an inter quartile range of 15 to 31 years. Themedian for females and males was 20 and 19 and the year of peak incidence forfemales and males was 15 with 17 years respectively. There were no patelladislocations under the age of 5 and there were only 6 seen under the age of 9. Forages greater than 75 there were only 10 dislocations.

Conclusion: We found no significant difference in percent of patellar dislocations by sex.There were also similar median and peak years in females and males. Overall while patellardislocations are uncommon they are even less likely to occur at the extremes of age. Furtherunderstanding of the epidemiology may lead to improved injury prevention.

269 Emergency Department Observation UnitAdmission as an Alternative to Inpatient Admissionfor Trauma Activation Patients

Bledsoe J, Bossart P, Bernhisel K, Sugerman PA-C S, Madsen T/University ofUtah, Salt Lake City, UT

Study Objective: Many emergency department observation units do not haveprotocols in place for observation of patients who present as trauma activations. Atour 35,000 visits/year ED in a level one trauma center, we implemented a traumaprotocol for the emergency department observation unit. We then collected data onall trauma observation unit admissions to evaluate for safety, efficiency and admissionrates, and compared this to data from the same period for a more traditional,accepted observation unit protocol: the chest pain protocol.

Methods: We performed a retrospective chart review of all observation unitpatients admitted under the trauma protocol from April 1, 2006 to May 31, 2007.Exclusion criteria for observation unit admissions included: abnormal vital signs,positive FAST exam, abnormal EKG, abnormal chest radiograph, abnormal head CT,GCS �14, or multi-system trauma. We evaluated these patients for safety, length ofstay and admission rates.

Results: Over the 14-month study period, 346 were patients admitted to the

observation unit under the trauma protocol. Of the observation unit admissions,

S124 Annals of Emergency Medicine

84.6% were trauma II activations, and 3.8% were trauma I activations. There wereno deaths, intubations, loss of vital signs or other adverse events. When compared tothe 531 chest pain protocol patients admitted during this same period, the traumaprotocol average length of stay was 766 minutes (12 hours 46 mintes), and 872minutes (14 hours 32 minutes) for chest pain protocol admits (p�0.001). Theadmission rate for trauma protocol patients to inpatient status was 11.5%, comparedto chest pain admission rate from the observation unit of 12.2% (p�0.695).

Conclusion: The observation unit is a safe and efficient alternative to inpatientadmission for the evaluation and observation of the minimally injured traumaactivation patient. Rates of admission from the observation unit and length of staywere comparable to a more traditional observation unit protocol.

270 C-reactive Protein as a Serum Biomarker in theEvaluation of Patients With Minor Head Injury andNormal Mental Status in the EmergencyDepartment

Phillips S, Glickman SW, Stanley LJ, Preston RJ, Grant GA, Laskowitz DT,Cairns CB/Duke University Medical Center, Durham, NC; University of NorthCarolina Medical Center, Chapel Hill, NC

Background: While clinical decision rules have been developed to help cliniciansdecide whether to obtain neuro-imaging in patients with minor head injury, computedtomography (CT) scans are not readily available in settings such as rural locations andmilitary arenas. A blood-based point of care test to rule out intracranial pathology wouldbe valuable in the acute evaluation of patients in these settings and could further guideimaging decisions in the hospital.

Study Objective: The objective of this study was to assess the potential of a fiveserum biomarkers of neuronal injury in the emergency department (ED) to predictintracranial pathology on non-contrast CT in patients with minor head injury.

Methods: In this prospective study, patients presenting to at an academic medicalcenter ED with minor traumatic head injury and Glasgow Coma Score (GCS) of 15 werescreened by trained study personnel for study eligibility. Patients were evaluated by thetreating physician and only those requiring a non-contrast CT brain study were enrolled.Serum samples were drawn in the ED, and plasma levels of biomarkers related to braininjury, including D-dimer, C-reactive protein (CRP), matrix metalloproteinase-9 (MMP-9), S-100�, BNP, and caspase-c, were measured by immunoassay. The primary outcomewas defined as the presence of acute intracranial pathology on the initial CT scan.Additional outcomes included in-hospital death and hospital length of stay (LOS).Logistic regression analysis was performed for each bio-marker.

Results: Twenty-one patients (mean age 49.2, age range 19-86) were enrolled. Amongthese patients, 7 (33%) had a positive finding of pathology on CT, including 4 withsubarachnoid hemorrhage, 2 with subdural hematoma, and 1 with cerebral contusion. Allpatients survived to hospital discharge. Patients with positive CT findings had a mean LOS of6 days (SD 2.4) versus 1.2 days (SD 0.1) with a normal CT (p0.05 for all markers). In contrast,C-reactive protein had a strong association with intracranial pathology (ROC 0.88, likelihoodtest p�0.01). Mean serum CRP levels were 26.0 ug/ml (SD 8.3) among patients with anegative head CT and 85.0 (SD 15.0) with a positive head CT. When the threshold for thelogistic model for CRP was set at the first quartile, this resulted in a sensitivity of 93%(specificity 71%) for detecting intracranial pathology.

Conclusions: These results suggest that CRP may add valuable diagnosticinformation in the early evaluation of patients with minor head injury and normalmental status (GCS 15). Given the possibility of a point of care platform, a biomarkerstrategy may prove valuable to triage patients in both the ED and out-of-hospitalsettings following mild blunt traumatic brain injury.

271 Hypothermia in Burn Victims

Singer AJ, Taira BR, Thode Jr HC, McCormack JE, Shapiro MJ/Stony BrookUniversity, Stony Brook, NY

Study Objectives: Hypothermia is associated with increased morbidity andmortality in burn victims. Concerns that cooling of large burns may result inhypothermia have limited cooling to small burns. We determined the incidence ofhypothermia in burn victims and its association with burn size, depth, and mortality.

Methods: Study Design-Secondary analysis of county trauma registry (TR).Setting-Suburban/rural county with a population of 1.5 million with 1 burn center.Subjects-Burn patients between 1994 and 2007 who met trauma registry criteria.Measures-Information was obtained from the TR, which collects standardized

demographic and clinical data from all hospitals in the county including burn size,

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