title: Could anti-inflammatory actions of catecholamines explain the possible beneficial effects of supranormal oxygen delivery in critically ill surgical patients?
abstract: OBJECTIVE
  To evaluate the literature regarding antiinflammatory actions of cytokines, evaluate randomized controlled trials (RCTs) of supranormal oxygen delivery, and suggest alternative mechanism(s) for possible beneficial effects of supranormal oxygen delivery in critically ill surgical patients.
  
  
  METHODS
  Literature review using Medline and review of selected illustrative studies.
  
  
  RESULTS
  Catecholamines (epinephrine, norepinephrine, isoproterenol, and dopamine) in general inhibit tumor necrosis factor-alpha (TNF) production and may enhance interleukin-6 (IL-6) and IL-10 production. Phosphodiesterase inhibitors also inhibit TNF and may enhance IL-10. All studies used models (cell, animal, or humans infused with endotoxin) of sepsis. RCTs of supranormal oxygen delivery show decreased mortality in high-risk surgical patients; however, prevention or reversal of tissue hypoxia may not be the mechanism of benefit. Antiinflammatory effects of catecholamines are a potential and, to date, unexplored mechanism of the benefit of supranormal oxygen delivery in critically ill surgical patients.
  
  
  CONCLUSIONS
  Catecholamines may modulate cytokine response beneficially and could be a mechanism of decreased morbidity and mortality of supranormal oxygen delivery in high-risk surgical patients.
authors.affiliation: Critical Care Medicine, St. Paul's Hospital and University of British Columbia, Vancouver, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Uusaro
authors.forename: J A
authors.initials: JA
authors.lastname: Russell
mesh_terms: D000893:Anti-Inflammatory Agents / Q000378:metabolism / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism / Q000494:pharmacology*; D003422:Critical Care; D016207:Cytokines / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D010100:Oxygen / Q000008:administration & dosage*; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy; D011182:Postoperative Care; D016032:Randomized Controlled Trials as Topic; D018805:Sepsis / Q000628:therapy*
chemical_list: D000893:Anti-Inflammatory Agents; D002395:Catecholamines; D016207:Cytokines; D010100:Oxygen