title: Comparison of i.v. cannula and Stevens' cannula for sub-Tenon's block.
abstract: BACKGROUND
  Sub-Tenon's local anaesthesia (STLA) is growing in popularity for ophthalmic surgery, and is widely regarded as safer than the alternative sharp needle techniques. Although safe, STLA is not devoid of risk. Therefore, the effectiveness of a plastic i.v. cannula was compared with the traditional metal Stevens' cannula for delivering STLA.
  
  
  METHODS
  In a randomized, controlled trial, the efficacy of STLA administered by either a Stevens' sub-Tenon's metal cannula or a standard 20 G Optiva i.v. plastic cannula was compared; 120 patients, undergoing cataract surgery, were randomly allocated to one of the two groups. After STLA, the primary outcome measure, kinesia of the globe, was recorded at 5 and 10 min.
  
  
  RESULTS
  There was no significant difference in the mean total ocular movement scores after STLA performed by either the 20 G i.v. cannula or standard 19 G sub-Tenon's cannula (P = 0.10). There was also no significant difference in any of the secondary outcome measures.
  
  
  CONCLUSIONS
  A 20 G Optiva i.v. cannula and the Stevens' sub-Tenon's cannula were equally effective at providing STLA.
authors.affiliation: Department of Anaesthesia, Cheltenham General Hospital, Sandford Road, Cheltenham, Gloucester GL53 7AN, UK. chris.mather@glos.nhs.uk
authors.forename: C M
authors.initials: CM
authors.lastname: Mather
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage; D002387:Cataract Extraction; D004867:Equipment Design; D005133:Eye Movements / Q000187:drug effects; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008670:Metals; D009407:Nerve Block / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D010147:Pain Measurement; D010969:Plastics
chemical_list: D000779:Anesthetics, Local; D008670:Metals; D010969:Plastics; D008012:Lidocaine