title: Thromboelastographic study of the effect of manipulation of central veins on coagulability of venous blood.
abstract: OBJECTIVE
  To measure whole blood coagulability in vitro using thromboelastography before and after direct and indirect manipulation of the internal jugular and subclavian veins.
  
  
  METHODS
  We studied 10 patients (American Society of Anaesthesiologists (ASA) grades I or II) with malignant disease of the head and neck who were having selective neck dissections. We excluded patients with diabetes, those who were being given any anticoagulant, those who were actively infected, and those with known coagulopathy. We took 3 ml samples of venous blood during insertion of a peripheral cannula, after insertion of a central venous cannula, and after dissection of the internal jugular vein. Thromboelastography was done on recalcified citrated samples within 1h of sampling. The variables r, k, alpha angle, and maximum amplitude were recorded at each point and the values before and after manipulation were compared using t-tests.
  
  
  RESULTS
  The only change was seen in the variable r, which showed an insignificant increase in coagulability.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Oral and Facial Specialities Department, Mid Yorkshire Hospitals NHS Trust, Aberford Road, West Yorks WF1 4DG, UK. david.mitchell@panp-tr.northy.nhs.uk
authors.forename: David A
authors.initials: DA
authors.lastname: Mitchell
authors.forename: Heather
authors.initials: H
authors.lastname: Gorton
mesh_terms: D001777:Blood Coagulation / Q000502:physiology*; D001809:Blood Viscosity / Q000502:physiology; D002405:Catheterization, Central Venous; D002406:Catheterization, Peripheral; D004210:Dissection; D006258:Head and Neck Neoplasms / Q000097:blood / Q000601:surgery; D006801:Humans; D007601:Jugular Veins / Q000503:physiopathology* / Q000601:surgery; D037981:Neck Dissection; D010865:Pilot Projects; D013350:Subclavian Vein / Q000503:physiopathology*; D013916:Thrombelastography; D013997:Time Factors