title: Double-blind, bilateral pain comparison with simultaneous injection of 2% lidocaine versus buffered 2% lidocaine for periocular anesthesia.
abstract: OBJECTIVE
  Determine if raising the pH of 2% lidocaine with epinephrine 1:100 000 to a physiologic level decreases pain perception during periocular, subcutaneous anesthesia.
  
  
  METHODS
  Double-blind, prospective, randomized study. Simultaneous unilateral injections of buffered and unbuffered lidocaine solutions were given before surgery to patients having bilateral, periocular surgery.
  
  
  METHODS
  Fifty-four consecutive patients (27 male and 27 female; mean age, 68 years; standard deviation, 11 years).
  
  
  METHODS
  Patients were given simultaneous injections of buffered and unbuffered 2% lidocaine with epinephrine 1:100 000. The needles were inserted simultaneously and the anesthesia was injected for a 20-second count for a total volume of 1.0 ml per injected side.
  
  
  METHODS
  After the simultaneous injections, the patients were asked to rate the pain on each side on a Likert-type visual analog scale of 0 to 10.
  
  
  RESULTS
  Sixty-five percent of patients preferred the buffered lidocaine with a scaled pain reduction of 0.9 (P = 0.0005). Additionally, for the patients who believed that the buffered solution was less painful, the mean decrease in scaled pain rating was 2, for a 51% reduction in pain level (P = 0.001). No gender differences were noted.
  
  
  CONCLUSIONS
  Buffering 2% lidocaine with epinephrine 1:100 000 with sodium bicarbonate 8.4% offers a clinically and statistically significant reduction in pain experienced by two-thirds of patients receiving periocular subcutaneous anesthesia.
authors: Department of Ophthalmology, Dwight David Eisenhower Army Medical Center, Augusta, Georgia, USA. mark.n.welch@gmail.com
authors: Mark N
authors: MN
authors: Welch
authors: Craig N
authors: CN
authors: Czyz
authors: Kevin
authors: K
authors: Kalwerisky
authors: David E E
authors: DE
authors: Holck
authors: Lisa D
authors: LD
authors: Mihora
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D019882:Blepharoplasty; D002021:Buffers; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage; D058447:Eye Pain / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D056965:Injections, Intraocular; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000187:drug effects; D010147:Pain Measurement; D011446:Prospective Studies; D015361:Rhytidoplasty; D017693:Sodium Bicarbonate
chemical_list: D000779:Anesthetics, Local; D002021:Buffers; D017693:Sodium Bicarbonate; D008012:Lidocaine; D004837:Epinephrine