2007 Research Banquet Presentations
Department of Emergency Medicine
Wake Forest University
Immediate Cardiovascular Effects of the Taser Conducted Energy Weapon
Daniel G Barnes Jr, MD
James E Winslow III, MD, MPH
Jim Johnson, PA
Roy Alson, PhD, MD
Charles H. Phillips, EMT-P
William P Bozeman, MD
Study Objectives: The Taser conducted energy weapon is carried and utilized by thousands of police departments across the country, yet concerns exist for the possibility of deleterious cardiac effects from its use. The purpose of this study was to evaluate the immediate cardiovascular effects of Taser exposure in human volunteers, including heart rhythm, pulse rate, and blood pressure.
Methods: Police officers participating in Taser training and testing underwent 1, 3, and 5 second exposures to the Taser model X26. Continuous electrocardiogram monitoring was performed before, during, and after each exposure. Investigators analyzed the electrocardiogram to determine heart rate, rhythm, and morphology. Blood pressure was measured at rest before and approximately 1 minute after the initial 5 second exposure. Paired sample t-test analysis was used to evaluate for differences in measured parameters.
Results: 28 subjects (24 male, 4 female) participated, resulting in 84 Taser exposures. Average age was 34 years (range 24 - 46, Standard Deviation 5.6) with weight of 183 lbs. (range 119 - 225, SD 27) and body mass index of 26.3 (range 20.4 - 31.4, SD 2.76). Normal sinus rhythm or sinus tachycardia was recorded before and after each exposure. No cardiac dysrhythmias were seen. Over all exposures (n=84), mean heart rate increased by 10.9 beats per minute (BPM) (95% CI: 8.2-13.7) from 121.7 to 132.6 BPM (p < 0.001). Heart rate tended to increase with longer duration of Taser exposure, by 9.7 BPM (95% CI: 6.7-12.8) for 1 second exposure (n=28), by 11.1 BPM (95% CI: 6.6-15.5) for 3 second exposure (n=28), and by 12.3 BPM (95% CI: 5.7 - 1.8) for 5 second exposure (n=28), but this did not reach statistical significance. Mean blood pressure increased from 138.6 / 82.8 at rest to 145.8 / 85.6 mmHg after the standard 5 second CEW discharge.
Conclusion: Taser shocks produced no detectable dysrhythmias and a statistically significant increase in heart rate. A dose response relationship was not demonstrated. This study more than doubles the previously reported human subject experience of Taser shock during EKG monitoring and includes a significant number of full 5 second exposures. Overall, Taser exposure appears to be safe and in this population well tolerated from a cardiovascular standpoint
Derivation of a Formula to Predict Patient Volume Based on Temperature at College Football Games
Nicholas E. Kman, M.D.
James Winslow, M.D., M.P.H.
William P. Bozeman, M.D.
Gregory B.Russell, M.S.
Kevin Ehrman, B.S., E.M.T-P
Objective: We sought to explore the relationship between temperature and spectator illness at Division I college football games by deriving a formula to predict the number of patrons seeking medical care based on the ambient temperature and attendance of the game.
Methods: A retrospective review was conducted of medical records from 47 Division I College Football Games at 2 outdoor stadiums from 2001 through 2005. Any person presenting for medical care was counted as a patient seen. Weather data was collected from the National Weather Service. A binomial model was fit to the spectator illness records using the patients seen per attendance as the outcome measure, with temperature as the predictor.
Results: Using a binomial model, a formula was derived to estimate the number of patients needing medical attention based on the temperature and the number of spectators in attendance.
Predicted # of Patients = exp (-7.4383 - 0.24439* Temperature C + 0.0156032 * Temperature C2- 0.000229196 * Temperature3) * number of spectators; all factors were highly significant (p<0.0001).
The model suggests that as the temperature rises, the number of patients seeking medical attention will also increase. The formula demonstrates that an increase in temperature from 20 to 21 degrees Celsius will show an increase in patient encounters from 3.64 to 4.05 visits per 10,000 in attendance (an 11% increase).
Conclusion: These results show that temperature is an important variable to consider when determining the medical resources needed in caring for spectators at outdoor football games. Our model may help providers predict the number of spectators presenting for medical care based on the forecasted temperature and predicted attendance.
Two Years of Emergency Department Patient Complaints: A Descriptive Analysis
Sanjay Kripalani MS4
Howard Blumstein, MD
Objectives: To examine complaints related to Emergency Department care and determine factors associated with higher complaint rates. Such data may be useful in designing complaint prevention efforts and improving patient satisfaction.
Methods: Patient complaints filed regarding ED visits during the years of 2004 and 2005 were obtained from the Department of Patient Relations. Data were extracted from the patient’s medical record using a standardized data collection form. Data elements collected included the nature of the complaint, treatment area within the ED, relationship of the complainant to the patient and patient demographic factors. Corresponding data regarding the ED population as a whole was also obtained. Comparative statistics were used to analyze complaint rates.
Results: For the two years studied, there were 127341 separate ED visits with 246 complaints. 128 came from patients themselves, 58 from parents of patients and the remainder from other people associated with the patient. A total of 327 complaints were recorded (some people had multiple complaints for a single visit). The most common complaints regarded behavior/attitude of staff (n=91, 27.8% of total), poor care (81, 24.8%) and missed diagnosis (45, 13.8%). When comparing complaint rates, a disproportionate number of complaints were generated regarding visits by female patients vs. male (Odds Ratio 1.64 95% CI 1.27-2.12), Caucasian patients vs. minorities (OR 5.08, 95% CI 3.63-7.11), insured vs. uninsured patients (OR 3.07 95% CI 2.18-4.33) and fast track patients vs. those seen in other treatment areas (OR 11.19 95% CI 7.86-15.93).
Conclusions: Complaints were more likely to be generated by Caucasian patients, female patients and insured patients as well as those treated in fast track. The most common complaints involved staff behavior and attitude and quality of care. These factors may be useful in designing complaint prevention programs.
Radiation Exposure of Blunt Trauma Patients
Michael Hughes PA-S,
James E Winslow, MD MPH,
Jeff W. Hinshaw MS, PA-C,
William Bozeman MD, FACEP, FAEM
Background: Many emergency departments and trauma centers utilize extensive radiologic studies to diagnose injuries and characterize physical exam findings in the acute evaluation and resuscitation of patients. A point of concern arises in the cumulative effect these doses radiation have on patients.
Objective: To determine the amount of ionizing radiation received by stable adult blunt trauma patients during the initial 24 hours of resuscitation and care at our Level 1 Trauma Center.
Methods: In this retrospective cohort study, we reviewed the first 100 consecutive stable adult trauma patients who presented to NCBH/Wake Forest University Medical Center during 2006. Individual radiation dose reports from each CT scan were reviewed and standardization tables were used to determine radiation dosing for plain film x-rays. The total dose of radiation from CT scans and X-Rays was then calculated for each patient.
Results: 100 eligible patients presented between January 1, 2006 and March 20, 2006. 86 of these patients had complete records available. There were 68 males and 18 females. The mean age was 36.5 years, the mean Injury Severity Score (ISS) was 18.2. The mean number of plain film studies was 14.0 (range 2 to 64), the mean number of CT scans was 3.6 (range 2 to 10). The mean effective total dose of ionized radiation was 88.9 milliSeiverts (mSv) (95% CI 82.7 to 95.1). This is the approximate equivalent of 2223 chest X-rays. Thirty-eight patients (44%) received in excess of 100 mSv, or 2500 CXR equivalents. The observed mean dose of 88.9 mSv results in a lifetime relative risk for developing cancer of 1.05. The calculated number needed to harm (induce iatrogenic cancer) for an adult males is 43 and for an adult females is 53.
Conclusions: Trauma patients are exposed to significant radiation doses from diagnostic radiographic imaging during initial resuscitation and evaluation.
Methicillin-Resistant S. aureus Skin Infections in the Emergency Department of North Carolina Baptist Hospital
Bryan Glover, MD
Bret Nicks, MD
Background: Community acquired Methicillin-resistant Staph. aureus (CAMRSA) has recently emerged as a major cause of skin and soft tissue infections.
Objective: We sought to determine the prevalence of MRSA among adult patients presenting to our emergency department with purulent skin infections.
Methods: 118 patients have been enrolled thus far in this prospective study. Data about demographics, characteristics of abscess, symptoms, risk factors for MRSA infection, and antibiotic use were collected at presentation. Post-enrollment review of medical record was used to determine culture results, antibiotic sensitivities, and outcomes.
Results: 66% of our cultures grew MRSA. 77% of MRSA cultures were sensitive to clindamycin, vancomycin, trimethaprim-sulfamethoxazole (TMP-SMX), and gentamycin. All MRSA cultures were sensitive to TMP-SMX and vancomycin, however 20% of cultures showed resistance to clindamycin.
Conclusions: CAMRSA has been confirmed as the most common cause of purulent skin infections in our emergency department. A Beta-lactam antibiotic alone is insufficient for treatment for this infection, and clindamycin resistance may preclude its use as well. Treatment of purulent skin infections must include adequate drainage, culturing, close follow up, and coverage of MRSA when empiric antibiotics are indicated.