title: Perioperative opioid requirements are decreased in hypoxic children living at altitude.
abstract: OBJECTIVE
  To investigate the effect of altitude on perioperative opioid requirements in otherwise healthy children.
  
  
  OBJECTIVE
  To investigate whether children living and having surgery at high altitude received different doses of fentanyl than those living and having surgery at sea level.
  
  
  BACKGROUND
  Recent studies in animals (Anesthesiology, 105, 2006 and 715) and children with obstructive sleep apnea (Anesthesiology, 105, 2006 and 665; Anesthesiology 100, 2004 and 806) suggest that analgesic effects of exogenous opioids are enhanced by hypoxia. However, the effects of hypoxia on perioperative narcotic requirements in otherwise healthy children have not been previously reported.
  
  
  METHODS
  We reviewed retrospectively the opioid requirements of pediatric patients who underwent cleft lip or palate surgery during Smile Network International mission trips to Cusco and Lima, Peru between 2007 and 2009. Patients who had surgery at high altitude were compared to those who had surgery at sea level. All patients received a standardized anesthetic with intravenous fentanyl as the only perioperative opioid.
  
  
  RESULTS
  Hundred and two patients had surgery at 3399 m above sea level (masl) (Cusco) and 169 patients had surgery at 150 masl (Lima). Patients at high altitude had significantly lower baseline oxygen saturations (92 ± 4% vs 98 ± 3%; P < 0.001) and received 40% less opioid (1.2 ± 0.8 vs 2.0 ± 1.4 μg·kg(-1) per h; P < 0.001) compared to patients at sea level.
  
  
  CONCLUSIONS
  Opioid administration was reduced in otherwise healthy children with altitude-induced chronic hypoxia when compared to non-hypoxic children undergoing similar operations under similar anesthetic regimens. Whether this difference is due to altitude or altitude-induced hypoxia, requires further study.
authors.affiliation: Department of Anesthesiology, Mayo Foundation for Education and Research, Rochester, MN 55905, USA. rabbitts.jennifer@mayo.edu
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Rabbitts
authors.forename: Cornelius B
authors.initials: CB
authors.lastname: Groenewald
authors.forename: Niki M
authors.initials: NM
authors.lastname: Dietz
authors.forename: Carmen
authors.initials: C
authors.lastname: Morales
authors.forename: Jukka
authors.initials: J
authors.lastname: Räsänen
mesh_terms: D000531:Altitude; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D002675:Child, Preschool; D002971:Cleft Lip / Q000601:surgery; D002972:Cleft Palate / Q000601:surgery; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D000860:Hypoxia; D009056:Mouth Abnormalities / Q000601:surgery*; D019990:Perioperative Care / Q000379:methods*; D010568:Peru; D012189:Retrospective Studies
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl