Central Line Study

Inclusion Criteria: Adult patients in the emergency department who require ultrasound guided central line placement are eligible for participation and will be referred for participation in the study by the clinical team. Exclusion Criteria: * Inherited, acquired, or medication related coagulopathy or thrombocytopenia (platelets \< 100,000). Patients will not be excluded for use of aspirin or other anti-platelet medication. * Previous central venous access at the same anatomical site. * Any indwelling catheter or wire that could potentially interfere with central line placement * Anterior border of the target vein deeper than 3.5cm Or for any clinical feature that would interfere with obtaining informed consent including dementia, delirium, or encephalopathy, as determined by the clinical attending physician.