Conclusion: Despite department guidelines, errors in initiating PEP after sexual

assault were common. Because effective PEP involves a strict adherence to a regimen

and close follow-up, we are now studying the effectiveness of a real-time

computerized prompt referring the physician to the PEP recommendations.

isolates of H influenzae. The reasons for these trends were not determined but may be

a result of a change in clinician prescribing practices away from b-lactam drugs.

38 Shock Index Combined With Focused Abdominal Sonography forTrauma Examination as a Predictor for Therapeutic Laparotomy inBlunt Trauma

Nielson JA, Allen TL, Gilmore KM, Chan KJ, Snow GL, Stevens MH/LDS Hospital, Salt

Lake City, UT

Study objectives: The focused abdominal sonography for trauma (FAST)

examination was developed to help rapidly identify those blunt trauma patients who

require emergency laparotomy. Since then, the clinical use of the FAST examination

has expanded. When applied to hemodynamically stable blunt trauma patients, the

FAST examination is less sensitive for any injury and particularly the need for

laparotomy. Combining FAST results with a measure of hemodynamic stability

might better predict the need for emergency laparotomy as a therapeutic

intervention and thus give a more meaningful predictive value to the positive test.

We therefore sought to determine whether a first measured shock index of 1 or

greater, when combined with a positive FAST examination, better predicts the need

for therapeutic laparotomy in blunt trauma patients than FAST alone.

Methods: This is a retrospective, case-control study using the institutional trauma

database at an American College of Surgeons–verified Level I trauma center during

2003. Patients were included in the study if injured by blunt mechanism and if they

required the highest level of trauma team activation by standardized institutional

criteria. Patients were excluded if they had previous peritoneal lavage or transfusion

or were younger than 14 years. The sensitivity, specificity, positive predictive value

(PPV), and negative predictive value (NPV) of the test (positive FAST plus shock

index $1) for therapeutic laparotomy were calculated, along with 95% confidence

intervals (CIs). The first emergency department recorded values for heart rate and

systolic blood pressure were used to calculate the shock index.

Results: Four hundred ninety-one patients were included in the study, 27 of

whom underwent emergency laparotomy (rate 5.50%). Two of these laparotomies

were classified as nontherapeutic. Of the 464 patients without laparotomy, 303

(65.3%) were men, with a mean age of 37.2 years. Of the patients with laparotomy,

17 (63.0%) were men, with a mean age of 38.4 years. Motor vehicle collisions were

the mechanism of injury in 50.4% and 66.7% of those without and with laparotomy,

respectively. The mean presenting Glasgow Coma Scale score was 12 versus 8 for

R E S E A R C H F O R U M A B S T R A C T S

36 Pharyngitis Treatment by Emergency Physicians From 1995 to 2001:Do Our Antibiotic Choices Conform to National Guidelines?

Salen PN, Reed J, Schultz J/St. Luke’s Hospital, Bethlehem, PA

Study objectives: Group A b-hemolytic streptococci (GABHS) is the only common

cause of pharyngitis warranting antibiotics. Penicillin and erythromycin are

recommended for GABHS in adults ($12 years) by the Infectious Diseases Society of

America (IDSA); aminopenicillins are recommended for children (\12 years)

because of their palatability. We assessed trends in emergency department (ED)

antibiotic therapy for pharyngitis patients.

Methods: This retrospective, observational study used the National Hospital

Ambulatory Medical Care Survey ED data, which annually conducts population-

weighted, randomized sampling of EDs nationwide, from 1995 to 2001. Outcome

measures were treatment with antibiotics according to IDSA guidelines.

Comparisons were made with Pearson x2 and analysis of variance; a was set at 0.01.

Results: Fifty-one percent of the pharyngitis cohort received antibiotics. During

the 7-year study period, antibiotic use decreased for children from 62% to 47%

(P\.009) and for adults from 56% to 49% (P\.001). Recommended antibiotic use

decreased from 49% to 30% for children (P\.001) and decreased from 21% to 9%

for adults (P\.001). Penicillin and aminopenicillin therapy for children decreased

from 45% to 27% (P\.006), with a subsequent increase in extended macrolides (eg,

azithromycin, clarithromycin) from 0% to 9% (P\.001). For adults, penicillin and

erythromycin use decreased from 9% to 6% (P\.003) and 12% to 3% (P\.001),

respectively. Concurrently, extended macrolide and fluoroquinolone (eg,

levofloxacin, gatifloxacin) use increased from 3% to 13% (P\.001) and 0.8% to 2.5%

(P\.002), respectively. Emergency physicians prescribed antibiotics for 54% of

pharyngitis cases compared with 43% for residents and 61% for physician extenders

(P\.008). Emergency physicians prescribed recommended antibiotics to 20%

compared with 18% for residents and 23% for physician extenders (P\.22).

Conclusion: From 1995 to 2001, there was a trend toward less antibiotic usage for

ED pharyngitis patients, with a concurrent increase in use of expensive, broad-

spectrum antibiotics.

37 Antimicrobial Resistance Among Clinical Isolates of Haemophilusinfluenzae in the United States

Heilmann KP, Beekman SE, Dickson EW, Doern GV/University of Iowa, Iowa City, IA

Study objectives: Increasing rates of b-lactamase production and antimicrobial

resistance by respiratory tract pathogens continue to be a concern in the treatment of

a variety of infections commonly cared for in the emergency department setting. We

determine the current antimicrobial susceptibility patterns and b-lactamase

production rates of Haemophilus influenzae and compare them with our results from

the previous 6 years.

Methods: A total of 5,445 isolates were collected from patients with H influenzae

respiratory tract infections between 1994 and 2002. The most recent study was

completed using specimens collected during the winter of 2001 to 2002 and

included 1,025 strains. b-Lactamase production was assessed with the nitrocefin disc

assay; broth microdilution antimicrobial susceptibility testing with 16 antimicrobial

agents was performed according to National Committee for Clinical Laboratory

Standards guidelines.

Results: The rate of b-lactamase production was 36.4% in 1994 and decreased in

each of the subsequent study periods (1997, 31%; 1999, 30.8%; and 28.9% in 2001 to

2002). Susceptibility rates of greater than 96% were found with amoxicillin/clavularic

acid, cefuroxime, cefpodoxime, cefixime, ciprofloxacin, azithromycin,

chloramphenicol, tetracycline, and telithromycin. Susceptibility rates to ampicillin

(67.5%), cefprozil (88.1%), and cefaclor (87.3%) were unchanged during the study

period. Only trimethoprim/sulfamethoxazole (74.5% versus 100% in 1994) and

clarithromycin (60.5% versus 71.2 in 1994) revealed a decreasing rate of susceptibility

between 1994 and 2002.

Conclusion: Since 1994 to 1995, b-lactamase production has decreased and

trimethoprim/sulfamethoxazole and clarithromycin resistance has increased in clinical

those without and with laparotomy, and the mean Injury Severity Score was 16.9

versus 33.7 for those without and with laparotomy. Three hundred forty-four

patients had FAST results recorded for analysis. The sensitivity of a positive FAST

examination plus shock index of 1 or greater for therapeutic laparotomy was 44.0%

(95% CI 26.3 to 62.8%), specificity 99.4% (95% CI 98.0 to 99.9%), and PPV 84.6%

(95% CI 60.5 to 97.1), whereas the NPV was 95.7% (95% CI 93.2 to 97.6).

Conclusion: Although the sensitivity for a positive FAST examination and a shock

index of 1 or greater to predict therapeutic laparotomy is low, the PPV of the test is

quite high. The combination of FAST results plus first measured vital signs (even if

they later respond to intravenous fluid or transfusion) indicates a high likelihood of

the need for therapeutic laparotomy.

39 The Effect of Ethanol Intoxication on the Response to UncontrolledHemorrhage in a Rodent Model

Sinert R, Tillotson R, Adar E, Peng J/SUNY-Downstate Medical Center, Kings County

Hospital, Brooklyn, NY

Study objectives: Ethanol intoxication has been shown to have significant

hemodynamic and metabolic effects after hemorrhage, according to studies using

fixed-volume controlled blood loss models. We present an acute ethanol-intoxicated

uncontrolled hemorrhage model in which we tested the null hypothesis that there

would be no difference in the hemorrhage volumes and hemodynamic responses

between ethanol intoxicated (EtOH1) rats and nonintoxicated (EtOH–) rats.

Methods: Forty Sprague-Dawley rats were anesthetized with Althesin by the

intraperitoneal route (IP). Twenty (EtOH1) rats received a 3 g/kg dose of 20%

ethanol (IP) 60 minutes before uncontrolled hemorrhage. The ETOH– rats received

an equivalent volume of normal saline solution IP. The femoral artery was cannulated

by cutdown to monitor the mean arterial blood pressure (MAP) and to obtain blood

samples for lactate. Twenty (10 EtOH1, 10 EtOH–) rats underwent uncontrolled

hemorrhage by 75% tail amputation. Twenty (10 EtOH1, 10 EtOH–) rats served as

O C T O B E R 2 0 0 4 4 4 : 4 A N N A L S O F E M E R G E N C Y M E D I C I N E S 1 3