ABSTRACT
RATIONALE AND OBJECTIVES: The authors assessed the frequency, sequelae, and risk factors of extravasation of intravenously administered iodinated contrast media. MATERIALS AND METHODS: All patients with local reactions after intravenous injection of contrast media between November 1994 and December 1996 were studied. Comparison was made with data obtained from a control group of 100 patients with no local reactions who underwent contrast material-enhanced computed tomography (CT). RESULTS: Local reactions were reported in 56 (0.25%) of 22,254 patients who received intravenous injections of iodinated contrast media. Fifty-one patients experienced extravasation, and five patients experienced local irritation in the absence of clinically detectable extravasation. Extravasation occurred during CT (n = 46), urography (n = 4), and venography (n = 1). Contrast material was nonionic in 37 cases and conventional ionic in 14 cases of extravasation. Extravasated volumes exceeded 30 mL in 22 patients and 100 mL in six patients. Forty-five (80%) of 56 patients with local reactions had complete resolution of symptoms within 24 hours. Only four patients had symptoms for more than 48 hours. No surgery was required. Compared with the control group, patients with extravasation were significantly more likely to have been injected with small-bore catheters (21 or 22 gauge) and to have been injected at low or high rates. CONCLUSION: Symptoms of contrast medium extravasation usually resolve quickly. In patients with extravasation, injections are more likely to have been performed with techniques that vary from normal practice.
Subject(s)
Contrast Media/adverse effects , Extravasation of Diagnostic and Therapeutic Materials/etiology , Iodine/adverse effects , Blister/chemically induced , Catheterization/instrumentation , Diatrizoate/adverse effects , Diatrizoate Meglumine/adverse effects , Equipment Design , Extravasation of Diagnostic and Therapeutic Materials/diagnosis , Extravasation of Diagnostic and Therapeutic Materials/therapy , Follow-Up Studies , Humans , Injections, Intravenous/adverse effects , Injections, Intravenous/instrumentation , Iohexol/adverse effects , Ions , Irritants/adverse effects , Pain/chemically induced , Phlebography , Risk Factors , Tomography, X-Ray Computed , Treatment Outcome , UrographyABSTRACT
Four antiplatelet components were isolated from Arnebia euchroma. They inhibited the aggregation of washed rabbit platelets caused by collagen, arachidonic acid, platelet-activating factor, ADP, or thrombin. The potency of inhibiting collagen-induced platelet aggregation is in the following order: acetylshikonin (IC50 = 2.1 microM), teracrylshikonin (2.8 microM), beta, beta-dimethylacrylshikonin (4.2 microM), and shikonin (10.7 microM). In rat aorta, acetylshikonin and shikonin inhibited high potassium and norepinephrine-induced contractions, while beta, beta-dimethylacrylshikonin and teracrylshikonin potentiated the phasic contraction caused by norepinephrine.
