Test Characteristics of Emergency Physician-Performed Limited Compression Ultrasound for Lower-Extremity Deep Vein Thrombosis.

BACKGROUND: The current literature suggests that emergency physician (EP)-performed limited compression ultrasound (LCUS) is a rapid and accurate test for deep vein thrombosis (DVT). OBJECTIVE: Our primary objective was to determine the sensitivity and specificity of LCUS for the diagnosis of DVT when performed by a large heterogeneous group of EPs. METHODS: This was a prospective diagnostic test assessment of LCUS conducted at two urban academic emergency departments. The scanning protocol involved compression at the common femoral, superficial femoral, and popliteal veins. Patients were eligible if undergoing radiology department ultrasound of the lower extremity with moderate or high pretest probability for DVT, or low pretest probability for DVT with a positive d-dimer. The enrolling EP performed LCUS before radiology department ultrasound of the same lower extremity. Sensitivity, specificity, and associated 95% confidence intervals (CIs) were calculated with the radiologist interpretation of the radiology department ultrasound as the criterion standard. RESULTS: A total of 56 EPs enrolled 296 patients for LCUS, with a median age of 50 years and 50% female. Fifty (17%) DVTs were identified by radiology department ultrasound, and another five (2%) cases were deemed indeterminate. The sensitivity and specificity of EP-performed LCUS was 86% (95% CI 73-94%) and 93% (95% CI 89-96%), respectively. CONCLUSIONS: A large heterogeneous group of EPs with limited training can perform LCUS with intermediate diagnostic accuracy. Unfortunately, LCUS performed by EPs with limited ultrasound training is not sufficiently sensitive or specific to rule out or diagnose DVT as a single testing modality.

The Denver Seizure Score: anion gap metabolic acidosis predicts generalized seizure.

OBJECTIVES: Anion gap (AG) and serum bicarbonate concentration (BICARB) may help confirm a diagnosis of seizure in an unwitnessed collapse; however, little data exist to support this practice. Our objective was to assess the association between AG metabolic acidosis and generalized seizure and to derive a simple score to predict seizure. METHODS: This was a case-control study at an urban teaching hospital. Patients transported to our emergency department with witnessed loss of consciousness and final confirmed diagnoses of generalized seizure (cases) or syncope (controls) were eligible for enrollment. Multivariable logistic regression analysis was used to model associations between AG, BICARB, and seizure. RESULTS: In 49 cases and 40 controls, patients in the seizure group were more likely to have a lower median BICARB (17 [range, 14-34] vs 23 [range, 20-24], P < .0001) and a higher median AG (22 [range, 9-42] vs 13 [range, 7-21], P < .0001). The Denver Seizure Score was defined, using regression coefficient weighting, as the Δ BICARB plus twice the Δ AG [(24 - BICARB) + (2×(AG - 12))]. The score ranged from -16 to +74 and identified patients as low likelihood (score <0), moderate likelihood (score 0-20), or high likelihood (score >20), with 21% (95% confidence interval [CI], 5%-51%), 40% (95% CI, 26%-56%), and 96% (95% CI, 82%-100%) being categorized as seizure, respectively. CONCLUSIONS: Anion gap metabolic acidosis is associated with generalized seizure. A Denver Seizure Score greater than 20 predicts generalized seizure in the emergency department and may be useful for differentiating patients with unwitnessed loss of consciousness.