title: Sub-Tenon's anesthesia in vitreoretinal surgery: a needleless technique.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of "needleless" regional anesthesia via the sub-Tenon's route without adjunct facial nerve or subconjunctival block for vitreoretinal surgery.
  
  
  METHODS
  Forty-eight consecutive patients were included and studied prospectively. The number, time, and volume of anesthetic solutions given were recorded. Any complications such as severe intraocular pressure rise or orbital hemorrhage were noted. Within 24 hours after surgery, the patients were asked to grade their level of pain during the procedure using a standard 10-point visual analog scale. The use of postoperative analgesic agents was recorded from the nurses' notes. Patient demography, number of previous vitreoretinal operations, preoperative diagnosis, and operative procedures performed were recorded.
  
  
  RESULTS
  Thirty-seven (77%) patients needed only one or two infiltrations of anesthetic solution (range 1-5, mean 2.1). Ninety-two percent of patients reported a pain score of 0-2 on the visual analog scale (range 0-5, mean 1.17). Ninety percent of patients required no analgesic or just acetaminophen for the control of postoperative pain. The other patients received a single dose or multiple doses of codeine. All patients had adequate akinesia and anesthesia. No complications were encountered.
  
  
  CONCLUSIONS
  Needleless regional anesthesia appears to be safe and effective and can thus be considered as an alternative method of anesthesia in suitable vitreoretinal cases.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT.
authors.forename: A K
authors.initials: AK
authors.lastname: Kwok
authors.forename: M R
authors.initials: MR
authors.lastname: Van Newkirk
authors.forename: D S
authors.initials: DS
authors.lastname: Lam
authors.forename: D S
authors.initials: DS
authors.lastname: Fan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage; D003238:Connective Tissue / Q000187:drug effects*; D005123:Eye / Q000187:drug effects*; D005260:Female; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000008:administration & dosage; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D012164:Retinal Diseases / Q000601:surgery*; D012449:Safety; D014821:Vitrectomy / Q000379:methods
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D006821:Hyaluronoglucosaminidase; D002045:Bupivacaine