title: Virtually painless local anesthesia: diluted lidocaine proves to be superior to buffered lidocaine for subcutaneous infiltration.
abstract: BACKGROUND
  Many physicians believe that buffering local anesthetics with sodium bicarbonate is the best technique for reducing the pain and discomfort associated with subcutaneous infiltration.
  
  
  OBJECTIVE
  To compare the level of pain and discomfort associated with subcutaneous infiltration of lidocaine diluted with normal saline to that associated with traditionally buffered lidocaine.
  
  
  METHODS
  In a prospective, double-blind trial, 31 patients were asked to use a visual analog scale to rank the level of pain and discomfort caused by two different solutions of lidocaine with epinephrine. Solution A: 3 mL of 1% lidocaine + epinephrine in 30 mL of bacteriostatic 0.9% sodium chloride in a 1:10 ratio, in which each mL contained 9 mg of sodium chloride and 9 mg of benzyl alcohol. Solution B: 5 mL of 8.4% sodium bicarbonate solution and 50 mL of 1% lidocaine + epinephrine in a 1:10 ratio.
  
  
  RESULTS
  Twenty-eight out of 31 patients reported that the solution of lidocaine diluted with normal saline was the least painful upon injection.
  
  
  CONCLUSIONS
  Pain and discomfort during subcutaneous injection of lidocaine can be reduced by diluting the anesthetic with normal saline in a 1:10 ratio.
authors.affiliation: Wellington Regional Medical Center/Lake Erie University, Wellington, FL, USA. DrMartyZ@aol.com
authors.forename: Martin
authors.initials: M
authors.lastname: Zaiac
authors.forename: Shino Bay
authors.initials: SB
authors.lastname: Aguilera
authors.forename: Larissa
authors.initials: L
authors.lastname: Zaulyanov-Scanlan
authors.forename: Caroline
authors.initials: C
authors.lastname: Caperton
authors.forename: Stacy
authors.initials: S
authors.lastname: Chimento
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000009:adverse effects*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002021:Buffers; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000139:chemically induced* / Q000517:prevention & control*; D010147:Pain Measurement; D017693:Sodium Bicarbonate; D012965:Sodium Chloride; D014662:Vasoconstrictor Agents / Q000008:administration & dosage
chemical_list: D000779:Anesthetics, Local; D002021:Buffers; D014662:Vasoconstrictor Agents; D012965:Sodium Chloride; D017693:Sodium Bicarbonate; D008012:Lidocaine; D004837:Epinephrine