title: The effective time and concentration of nitrous oxide to reduce venipuncture pain in children.
abstract: OBJECTIVE
  To investigate the time of administration and concentration of inhaled nitrous oxide (N(2)O) needed to reduce the pain associated with intravenous (i.v.) cannulation in children.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Operating room of a children's hospital.
  
  
  METHODS
  73 ASA physical status I and II children, aged 6-15 years, scheduled for elective day or non-day surgery.
  
  
  METHODS
  Children were randomly allocated to one of 4 groups prior to i.v. insertion of a 24-gauge catheter in the dorsum of the hand: Group 1 (n = 18): 50% N(2)O in O(2) for three minutes; Group 2 (n = 18): 50% N(2)O in O(2) for 5 minutes; Group 3 (n = 18): 70% N(2)O in O(2) for three minutes; or Group 4 (n = 19): 70% N(2)O in O(2) for 5 minutes.
  
  
  METHODS
  Just after the venous cannulation, degree of pain was assessed by examining the faces of the patient by the parent and an operating room nurse.
  
  
  RESULTS
  Pain scores obtained from parents of children in Groups 3 and 4 were significantly lower than from those in Groups 1 and 2. Pain scores from the nurse in Group 3 was significantly lower than those in Group 1. However, there was no significant difference in pain score between Group 3 and Group 4. Frequency of side effects was similar among the 4 groups.
  
  
  CONCLUSIONS
  Seventy percent N(2)O in O(2) given for three minutes was effective for reducing venipuncture pain in children.
authors.affiliation: Department of Anesthesiology, Yamanashi Prefectural Central Hospital, Yamanashi 400-8506, Japan. vzz06573@nifty.com
authors.forename: Atsushi
authors.initials: A
authors.lastname: Furuya
authors.forename: Masaki
authors.initials: M
authors.lastname: Ito
authors.forename: Tasuku
authors.initials: T
authors.lastname: Fukao
authors.forename: Mayumi
authors.initials: M
authors.lastname: Suwa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nishi
authors.forename: Yoh
authors.initials: Y
authors.lastname: Horimoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sato
authors.forename: Katsumi
authors.initials: K
authors.lastname: Okuyama
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Ishiyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsukawa
mesh_terms: D000293:Adolescent; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D004305:Dose-Response Relationship, Drug; D005149:Facial Expression; D005260:Female; D006225:Hand; D006776:Hospitals, Pediatric; D006801:Humans; D008297:Male; D009609:Nitrous Oxide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement / Q000379:methods; D018962:Phlebotomy / Q000009:adverse effects*; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide