Abstracts in this issue were prepared by residents in the Denver General/St Anthony's/St Joseph Hospitals Emergency Medicine Residency Program.

ABSTRACTS Harvey W Meisiin, MD, FACEP Co-Editor Chief, Section of Emergency Medic ine University of Ar izona Col lege of Medic ine

Vincent J Markovchick, MD, FACEP Co-Editor Emergency Medical Services Denver General Hospital

HEPARIN; STREPTOKINASE; VENOUS THROMBOSIS

Pooled analyses of randomized trials of s t reptokinase and heparin in phlebographical ly documented acute deep venous thrombosis Goldhaber SZ, Buring JE, Lipnick R J, et al Am J Med 76:393-397 Mar 1984

Results were pooled from six randomized studies compar- ing intravenous streptokinase with heparin anticoagulation for treating acute proximal deep venous thrombosis (DVT), in which phlebography was used to confirm the diagnosis and to assess therapy. In the analysis, each separate trial was treated as one stratum, and information from each stratum was then combined to provide an estimate of the mean overall effect, thereby avoiding comparisons of patients in one trial directly with those in another. Thrombolysis was achieved 3.7 times more often among patients treated with streptokinase than among patient s treated with heparin. In the studies that allowed comparison of these drugs for ma- jor bleeding complications, however, there were 2.9 times more complications with streptokinase than with heparin (95% confidence limits 1.1, 8.1; P = .04). The authors sug~ gest future trials of sufficient sample size to evaluate fur- ther the efficacy and safety of fibrinolytic agents to deter- mine optimal therapy for acute proximal DVT.

Elizabeth Black, MD

NECK INJURY; NECK TRAUMA

Select ive management of penetrat ing neck injuries: A prospect ive study Narrod JA, Moore EE Arch Surg 119:574-578 May 1984

This prospective study was undertaken to assess the fea- sibility of a selective approach to operative exploration of penetrating neck wounds. During a four-year period 77 pa- tients with anterior penetrating neck wounds (those violat- ing the platysma muscle) were evaluated at the Denver General Hospital. Patients with bleeding, hematomas, cre- pitations, dysphagia, dysphonia, or an impaired mental sta- tus (rendering their conditions nonevaluative) had prompt explorations. Preoperative angiography was performed in pa- tients for the following: 1) level I injuries (below the top of the sternal notch), 2) multiple level II wounds (between the

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angle of the mandible and the sternal notch), and 3) sus- pected level III carotid injuries (cephalad to the angle of the mandible). Esophageal studies were obtained in patients with level I injuries and in those patients who underwent formal neck exploration. Forty-eight patients (62%) had prompt neck explorations based on the preceding criteria and 85% were found to have major injuries. Of the 29 pa- tients observed, none required subsequent exploration. An- cillary diagnostic procedures in the observed patients con- sisted of arteriography in four, esophageal contrast studies in five, esophagoscopy in two, and laryngoscopy in one~ The average hospita] stay for observation was 1.8 days, compared to 10.4 days for the explored group. Average hospitalization following negative neck exploration was 2.8 days. The au- thors conclude that their experience confirms the safety and cost effectiveness of selective exploration for penetrating neck injuries.

William H Campbell, MD

HYOID; TRACHEA

Hyoid bone elevation: A sign of t racheal t ransect ion Poiansky A, Resnick D, Sofferman RA, et al Radiology 150:117-120 Jan 1984

Radiographic analysis of the position of the hyoid bone was done in both normal patients and those with severe neck trauma. It was found that elevation of the hyoid bone was a valuable and reliable indicator that transection of the trachea had occurred. The hyoid bone is U-shaped and is made up of the body and two greater and lesser comua. The normal position of the body is when it lies entirely below a line that is parallel to the top of C-3. The normal distance between the greater cornua and the ipsilateral angle of the mandible should be greater than 2 cm. Flexion and exten- sion of the neck did not significantly alter these rela- tionships. Four cases of tracheal transection were presented, all of which had positive findings on the lateral cervical spine x-ray film. The elevated hyoid bone is due to the trau- ma-induced rupture of the infrahyoid musculature, which allows the suprahyoid musculature to be unopposed and thus pull the hyoid bone cephalad. [Editor's note: Transec- tion of the trachea presents one of the most challenging and difficult problems in emergency medicine. ED cri- cothyroidotomy is usually contraindicated, and all efforts should be directed toward mobilizing a surgical team for definitive management in the operating room.]

Eva M Carey, MD

Annals of Emergency Medicine 743/151