Emergency Department compression ultrasound to diagnose proximal deep vein thrombosis.

Emergency Department (ED) patients with suspected deep vein thrombosis (DVT) require an objective vascular study such as ultrasound (US) to confirm the diagnosis prior to treatment or disposition. A simple compression US test of the common femoral vein and popliteal vein reliably detects proximal DVT in symptomatic patients. Application of compression US in the ED by Emergency Physicians (EPs) has been tested in a single previous study. We evaluated the ability of ED compression US, performed by EPs, to diagnose proximal DVT as compared to duplex US performed in a vascular laboratory. A prospective, observational study was conducted on a convenience sample of patients presenting to an ED with lower extremity symptoms and signs suggestive of DVT. Patients with a history of DVT in the symptomatic extremity were excluded. Final diagnosis of DVT was made by color-flow duplex US performed in a vascular laboratory. ED compression US was performed by one of six EP sonographers. In compression US, DVT was diagnosed by the inability to compress the common femoral vein or popliteal vein. The examination was considered indeterminate if the veins could not be clearly identified or compressibility was equivocal. For statistical analysis, an indeterminate examination was considered positive. In those cases where ED compression US was discordant with duplex US, and not indeterminate, we retrospectively reviewed the US findings. There were 76 patients who completed the study, and 18 patients (24%) were diagnosed with DVT by duplex US, among whom ED compression US was positive in 14, negative in 2, and indeterminate in 2. Among 58 patients diagnosed without DVT by duplex US, there were 4 false-positive ED compression US examinations and 10 indeterminate examinations. In all, ED compression US was indeterminate in 12 patients (15.8%). Compared to duplex US, ED compression US had a sensitivity of 88.9% (95% C.I. 65.3-98.6%) and specificity of 75.9% (62.8-86.1). Negative predictive value was 95.7% (85.2-99.5). Among ED patients with the clinical diagnosis of possible DVT, negative ED compression US greatly reduces the likelihood of DVT, such that discharge and outpatient follow-up can be considered. Because of limited specificity, positive results require confirmation, but may justify immediate treatment pending follow-up testing. Indeterminate results can be expected in a significant number of patients and mandate further testing prior to disposition.

Ultrasound-guided brachial and basilic vein cannulation in emergency department patients with difficult intravenous access.

STUDY OBJECTIVE: Emergency department patients who require intravenous access but lack peripheral intravenous sites frequently require central line placement. Blind percutaneous brachial vein cannulation has been proposed as an alternative in these patients but is associated with high failure and complication rates. We evaluated an ultrasound-guided approach to percutaneous deep brachial vein or basilic vein cannulation in ED patients with difficult intravenous access. METHODS: We prospectively enrolled ED patients who required intravenous access in whom there had been 2 unsuccessful attempts at establishing a peripheral intravenous line. Using a 7.5-MHz ultrasound probe, the deep brachial vein or basilic vein was identified and then cannulated with a 2-in, 18- to 20-gauge intravenous catheter. Time from probe placement to cannulation, number of attempts, and complications were recorded. RESULTS: One hundred one patients were enrolled, of whom 50 were injection drug users and 21 were obese. Cannulation was successful in 91 patients (91%) and accomplished on the first attempt in 73 (73%). The mean (+/-SD) time required for cannulation was 77 seconds (+/-129, range 4 to 600 seconds). The line infiltrated or fell out within 1 hour of cannulation in 8 (8%) patients. One patient reported severe pain. There were 2 (2%) cases of brachial artery puncture. CONCLUSION: Ultrasound-guided brachial and basilic vein cannulation is safe, rapid, and has a high success rate in ED patients with difficult peripheral intravenous access.

Diagnostic role of ED ultrasound in deep venous thrombosis and pulmonary embolism.

Proximal deep venous thrombosis (DVT), which may lead to pulmonary embolism (PE), is one of the serious and underrecognized causes of lower extremity pain and swelling. The diagnosis of DVT requires a confirmatory objective test because clinical signs and symptoms are unreliable. Assessment of thigh vein compressibility with real-time ultrasound is an accurate test for DVT that may be performed rapidly at the bedside. Although unproven, we propose that wider use of this test in the emergency department by emergency physicians might increase the diagnosis of DVT, prevent PE, and reduce utilization of other more costly and invasive diagnostic tests. Evaluation of DVT by compression ultrasound may also be incorporated in the diagnostic workup of suspected PE. In the case of a nondiagnostic ventilation/perfusion scan, demonstration of proximal DVT by ultrasound represents a likely source of PE and an indication for anticoagulation, eliminating the need for pulmonary angiography. In the critically ill patient whose presentation is consistent with massive PE, one rapid approach to the diagnosis may be to combine transthoracic echocardiography with lower extremity ultrasound.

Septic endarteritis of the femoral artery following angioplasty.

A case of septic endarteritis that occurred in the femoral artery following percutaneous transluminal coronary angioplasty (PTCA) is reported, and nine previously reported cases of this complication are reviewed. In each case Staphylococcus aureus was identified as the pathogen. For all cases in which a complete clinical description was available, endarteritis occurred following repeated PTCA or repuncture PTCA (i.e., a second catheterization at the original site of insertion for diagnostic purposes). The characteristic manifestations of endarteritis in this setting included bacteremia (all 10 cases), the formation of a pseudoaneurysm (six), distal emboli (five), and regional septic arthritis or osteomyelitis (five of six cases that included the information needed to determine the presence of these conditions). In each case, treatment included 4-6 weeks of iv antibiotics and surgery, most frequently resection of the pseudoaneurysm and vascular bypass. We recommend surveillance for the signs of endarteritis, especially after repeated catheterization, and use of the contralateral site when repeated catheterization is indicated. When the ipsilateral site is used, the administration of prophylactic antibiotics should be considered.

Role of phospholipase A inhibition in amiodarone pulmonary toxicity in rats.

Amiodarone is effective in the treatment of ventricular and supraventricular arrhythmias. In man its clinical use is associated with the accumulation of phospholipid-rich multilamellar inclusions in various tissues including lung, liver and others. This report presents evidence showing that amiodarone is a potent inhibitor of lysosomal phospholipase A from rat alveolar macrophages, J-744 macrophages and rat liver. When compared with other cationic amphiphilic agents which are known to produce phospholipidosis, amiodarone is one of the most potent inhibitors yet discovered. The subcellular localization of amiodarone has been determined in lung and its distribution was consistent with a lysosomal localization. It is hypothesized that amiodarone causes cellular phospholipidosis by concentrating in lysosomes and inhibiting phospholipid catabolism.