title: Sub-Tenon's anesthesia with aspirin, warfarin, and clopidogrel.
abstract: OBJECTIVE
  To review the frequency of hemorrhagic complications with sub-Tenon's anesthesia in patients on aspirin, warfarin or clopidogrel.
  
  
  METHODS
  St. James's University Hospital, Leeds, United Kingdom.
  
  
  METHODS
  Data were collected prospectively for patients having elective phacoemulsification under sub-Tenon's anesthesia. Seventy-five patients were on aspirin, 65 were on warfarin, and 40 were on clopidogrel. Seventy-five patients on no anticoagulants were used as the control group. No changes in the anticoagulant regimen were made prior to surgery.
  
  
  RESULTS
  No sight-threatening hemorrhagic complications were noted, and no surgery was postponed or cancelled due to an anesthesic complication. Subconjunctival hemorrhage occurred in 19% in the control group, 40% in the clopidogrel group, 35% in the warfarin group, and 21% in the aspirin group. The warfarin and clopidogrel groups had the highest incidence of subconjunctival hemorrhage (P<.05). The incidence of hemorrhages involving more than 1 quadrant was highest in these 3 groups; however, this did not achieve statistical significance (P = .37, Fisher exact test).
  
  
  CONCLUSIONS
  Data from this study support the continued use of anticoagulant agents among routine users during cataract surgery using a sub-Tenon's block.
authors.affiliation: Mersey Deanery, Liverpool, United Kingdom. nishant6377@aol.com
authors.forename: Nishant
authors.initials: N
authors.lastname: Kumar
authors.forename: Sharmila
authors.initials: S
authors.lastname: Jivan
authors.forename: Peter
authors.initials: P
authors.lastname: Thomas
authors.forename: Hamish
authors.initials: H
authors.lastname: McLure
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000188:drug therapy; D002561:Cerebrovascular Disorders / Q000188:drug therapy; D000077144:Clopidogrel; D003229:Conjunctival Diseases / Q000209:etiology; D003238:Connective Tissue; D005130:Eye Hemorrhage / Q000209:etiology; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D018918:Phacoemulsification; D011446:Prospective Studies; D012307:Risk Factors; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin