title: Intracranial pressure and cardiopulmonary variables during isoflurane or sevoflurane anesthesia at various minimum alveolar concentration multiples in normocapnic dogs.
abstract: OBJECTIVE
  To compare effects of isoflurane and sevoflurane on intracranial pressure and cardiovascular variables at 1.0, 1.5, and 2.0 times the minimum alveolar concentration (MAC) in mechanically ventilated normocapnic dogs.
  
  
  METHODS
  6 healthy male Beagles.
  
  
  METHODS
  The individual MAC was determined for each agent with an electrical stimulus. After a minimum of 1 week, anesthetic induction by use of a mask with one of the inhalation anesthetics selected randomly was followed by mechanical ventilation and instrumentation for measurement of intracranial pressure and cardiovascular variables. Heart rate; systolic, mean, and diastolic arterial blood pressures; central venous pressure; mean pulmonary arterial pressure; pulmonary artery occlusion pressure; cardiac output; intracranial pressure (ICP); core body temperature; end-tidal inhalation anesthetic and carbon dioxide concentration; and arterial blood gas values were measured after attaining equilibrium at 1.0, 1.5, and 2.0 MAC of each inhalation anesthetic. Cardiac index, systemic vascular resistance, pulmonary vascular resistance, and cerebral perfusion pressure (CPP) were calculated.
  
  
  RESULTS
  Mean ICP did not differ within and between anesthetics at any MAC. Compared with equipotent concentrations of isoflurane, the CPP and mean values for systolic, mean, and diastolic arterial blood pressures were increased at 2.0 MAC for sevoflurane, whereas mean values for mean and diastolic arterial blood pressures and systemic vascular resistance were increased at 1.5 MAC for sevoflurane.
  
  
  CONCLUSIONS
  Although ICP was similar in healthy normocapnic dogs, CPP was better maintained during 2.0 MAC for sevoflurane, compared with isoflurane.
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA. chohan@vetmed.wsu.edu
authors: Amandeep S
authors: AS
authors: Chohan
authors: Stephen A
authors: SA
authors: Greene
authors: Robert D
authors: RD
authors: Keegan
authors: Tamara L
authors: TL
authors: Grubb
authors: Annie V
authors: AV
authors: Chen
mesh_terms: D000280:Administration, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007427:Intracranial Pressure / Q000187:drug effects*; D007530:Isoflurane / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage* / Q000493:pharmacokinetics; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000378:metabolism*; D011897:Random Allocation; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D007530:Isoflurane