title: A randomized clinical trial of the effects of ultra-low-dose naloxone infusion on postoperative opioid requirements and recovery.
abstract: BACKGROUND
  Tolerance to remifentanil during sevoflurane anesthesia may increase postoperative analgesic requirements. Low-dose naloxone not only has been shown to block the development of acute opioid tolerance but also to ameliorate undesired opioid-induced side effects. We hypothesized that naloxone prevents the acute opioid tolerance produced by a large dose of remifentanil, and reduces the incidence of opioid-induced side effects.
  
  
  METHODS
  Seventy-two patients undergoing open colorectal surgery were randomly assigned to receive intraoperative remifentanil (1) small dose at 0.1 μg/kg/min; (2) large dose at 0.30 μg/kg/min; or (3) large dose at 0.30 μg/kg/min combined with low-dose naloxone at 0.25 μg/kg/h just after the induction. Cumulative morphine consumption, postoperative pain scores, incidence of opioid-related side effects, time to recovery of bowel function, and length of hospital stay were recorded.
  
  
  RESULTS
  Cumulative morphine consumption at 24 h after surgery was higher in the large-dose remifentanil group (28 ± 12 mg) compared with the small-dose remifentanil group (17 ± 12 mg), and large-dose remifentanil-naloxone group (18 ± 9 mg), (P < 0.001). The median time to return of bowel function was shorter in the large-dose remifentanil-naloxone group than the other two groups (P < 0.05). The median length of hospital stay was lower in the large-dose remifentanil-naloxone group (8 [interquartile range: 8-12] days) compared with the small-dose remifentanil group (12 [interquartile range: 9-15] days) and large-dose remifentanil group (12 [interquartile range: 10-13] days), (P < 0.001).
  
  
  CONCLUSIONS
  Naloxone infusion prevented the acute opioid tolerance, provided a quicker recovery of bowel function, and reduced the length of hospital stay after open colorectal surgery.
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Anesthesiology, Cancer Institute and Hospital, National Cancer Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Peking, China.
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: W
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: X
authors.initials: X
authors.lastname: Duan
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: X
authors.initials: X
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D004311:Double-Blind Method; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D010149:Postoperative Pain / Q000188:drug therapy*; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone