title: Entonox as an analgesic agent during panretinal photocoagulation.
abstract: OBJECTIVE
  Panretinal photocoagulation (PRP) reduces the risk of visual loss in proliferative diabetic retinopathy but some patients cannot tolerate PRP because of pain. Inhaled Entonox was evaluated as an analgesic during PRP.
  
  
  METHODS
  A randomised, crossover, double masked pilot study was performed. Patients inhaled either air or Entonox and half the PRP was applied. The treatment was completed with the alternate inhaled gas. Patients graded pain experienced during both stages of the treatment using a visual analogue scale. Pain scores were compared using a paired t test.
  
  
  RESULTS
  20 patients participated. Mean pain scores from the Entonox and air treatments were 2.94 (SD 2.73) versus 3.73 (SD 3.20) respectively (p<0.03).
  
  
  CONCLUSIONS
  Entonox can be used as a safe and effective analgesic agent during PRP treatment.
authors.affiliation: Department of Ophthalmology, St Thomas's Hospital, London, UK. HelenLCook@aol.com
authors.forename: H L
authors.initials: HL
authors.lastname: Cook
authors.forename: R S B
authors.initials: RS
authors.lastname: Newsom
authors.forename: E
authors.initials: E
authors.lastname: Mensah
authors.forename: M
authors.initials: M
authors.lastname: Saeed
authors.forename: D
authors.initials: D
authors.lastname: James
authors.forename: T J
authors.initials: TJ
authors.lastname: Ffytche
mesh_terms: D000280:Administration, Inhalation; D000700:Analgesics / Q000008:administration & dosage*; D019162:Anesthetics, Combined / Q000008:administration & dosage*; D018592:Cross-Over Studies; D003930:Diabetic Retinopathy / Q000601:surgery*; D004311:Double-Blind Method; D006801:Humans; D008028:Light Coagulation / Q000379:methods*; D009609:Nitrous Oxide / Q000008:administration & dosage*; D010100:Oxygen / Q000008:administration & dosage*; D010147:Pain Measurement / Q000379:methods; D010865:Pilot Projects
chemical_list: D000700:Analgesics; D019162:Anesthetics, Combined; C001147:Entonox; D009609:Nitrous Oxide; D010100:Oxygen