title: Randomized controlled trial to determine the effectiveness of the Nivatvongs technique versus conventional local anaesthetic infiltration for outpatient haemorrhoidectomy.
abstract: BACKGROUND
  Conventional local anaesthesia in outpatient haemorrhoidectomy, using a diamond-shaped perianal block, is reliable, safe and inexpensive. It allows for early ambulation and short hospital stay. However, without sedation, local infiltration is perceived to be both uncomfortable and painful. Nivatvongs described a technique in which the anaesthetic is injected intra-anally into the insensitive area above the dentate line, allegedly causing less pain.
  
  
  METHODS
  This randomized, controlled, parallel-group, single-blind clinical trial compared the effectiveness of the conventional and Nivatvongs techniques in reducing the pain of anaesthetic infiltration in adult patients undergoing outpatient haemorrhoidectomy. A total of 112 patients were randomized into either treatment (n=57) or control groups (n=55). Assigned surgeon-anaesthetists performed the local anaesthetic infiltration. The Milligan-Morgan technique was used for haemorrhoidectomy. Pain was assessed using a standardized visual analogue scale. Patient and surgeon satisfaction were measured with a pre-validated questionnaire.
  
  
  RESULTS
  Median scores for pain assessment during local anaesthetic infiltration were 2 and 3 in the control and treatment groups, respectively. Patient satisfaction with the method of anaesthetic infiltration and the procedure itself were 3 and 2, respectively, for both groups. The surgeon's overall satisfaction with the technique of anaesthetic infiltration was similar in the two groups. There was no significant difference in any of the outcomes measured.
  
  
  CONCLUSIONS
  Both local anaesthetic techniques for outpatient haemorrhoidectomy were generally effective and well tolerated. The Nivatvongs technique did not confer any significant additional benefit.
authors.affiliation: Division of Colon and Rectal Surgery, Philippine General Hospital, Manila, The Philippines. ramroxas_md@yahoo.com
authors.forename: Manuel Francisco T
authors.initials: MF
authors.lastname: Roxas
authors.forename: Mariam Grace A
authors.initials: MG
authors.lastname: Delima
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000379:methods*; D000772:Anesthesia, Local; D000779:Anesthetics, Local / Q000008:administration & dosage*; D006484:Hemorrhoids / Q000601:surgery*; D006801:Humans; D010147:Pain Measurement
chemical_list: D000779:Anesthetics, Local