title: Hyperoxic ventilation improves survival in pigs during endotoxaemia at the critical hemoglobin concentration.
abstract: OBJECTIVE
  Recently it has been demonstrated that short term hyperoxic ventilation (HV) can improve glucose metabolism, reduce pulmonary and hepatic apoptosis, and improve gastrointestinal perfusion during acute sepsis. However, it is unknown whether additional O(2) improves survival. Therefore we investigated the effects of increased plasma O(2) on survival during extreme anaemia and concomitant endotoxaemia in order to quantify the efficacy of HV.
  
  
  METHODS
  Endotoxaemia (Salmonella abortus equi-LPS) was induced in 14 anesthetized pigs ventilated with room air (FiO(2)=0.21). Simultaneously, animals were haemodiluted by exchange of whole blood for 6% hydroxyethyl starch (200,000:0.5) until the individual critical hemoglobin concentration (Hb(crit)) was achieved (outermost limit of tissue oxygenation). Subsequently, animals were either ventilated with an FiO(2) of 0.21 (NOX, n=7) or an FiO(2) of 1.0 (HOX, n=7), and observed thereafter for 6 h without further intervention.
  
  
  RESULTS
  HV significantly prolonged survival time at Hb(crit) (NOX, 30 [27/35] min; HOX, 172 [111/235] min, p<0.05). In contrast to the NOX group, HV maintained MAP, and improved DO(2) and tissue oxygenation in the HOX group.
  
  
  CONCLUSIONS
  The improvement of survival, oxygen transport and tissue oxygenation seems to underline the efficacy of HV during endotoxaemia and concomitant acute anaemia. Further studies are needed to transfer these results into daily clinical practice.
authors.affiliation: Clinic of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital, Frankfurt am Main, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lauscher
authors.forename: Harry
authors.initials: H
authors.lastname: Kertscho
authors.forename: Anne
authors.initials: A
authors.lastname: Meissner
authors.forename: Kai
authors.initials: K
authors.lastname: Zacharowski
authors.forename: Oliver
authors.initials: O
authors.lastname: Habler
authors.forename: Jens
authors.initials: J
authors.lastname: Meier
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000097:blood / Q000401:mortality / Q000628:therapy*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D018496:Hyperoxia / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D012121:Respiration, Artificial / Q000379:methods*; D015996:Survival Rate
chemical_list: D006454:Hemoglobins