title: General anesthesia with sevoflurane decreases myocardial blood volume and hyperemic blood flow in healthy humans.
abstract: BACKGROUND
  Preservation of myocardial perfusion during general anesthesia is likely important in patients at risk for perioperative cardiac complications. Data related to the influence of general anesthesia on the normal myocardial circulation are limited. In this study, we investigated myocardial microcirculatory responses to pharmacological vasodilation and sympathetic stimulation during general anesthesia with sevoflurane in healthy humans immediately before surgical stimulation.
  
  
  METHODS
  Six female and 7 male subjects (mean age 43 years, range 28-61) were studied at baseline while awake and during the administration of 1 minimum alveolar concentration sevoflurane. Using myocardial contrast echocardiography, myocardial blood flow (MBF) and microcirculatory variables were assessed at rest, during adenosine-induced hyperemia, and after cold pressor test-induced sympathetic stimulation. MBF was calculated from the relative myocardial blood volume multiplied by its exchange frequency (β) divided by myocardial tissue density (ρT), which was set at 1.05 g·mL(-1).
  
  
  RESULTS
  During sevoflurane anesthesia, MBF at rest was similar to baseline values (1.05 ± 0.28 vs 1.05 ± 0.32 mL·min(-1)·g(-1); P = 0.98; 95% confidence interval [CI], -0.18 to 0.18). Myocardial blood volume decreased (P = 0.0044; 95% CI, 0.01-0.04) while its exchange frequency (β) increased under sevoflurane anesthesia when compared with baseline. In contrast, hyperemic MBF was reduced during anesthesia compared with baseline (2.25 ± 0.5 vs 3.53 ± 0.7 mL·min(-1)·g(-1); P = 0.0003; 95% CI, 0.72-1.84). Sympathetic stimulation during sevoflurane anesthesia resulted in a similar MBF compared to baseline (1.53 ± 0.53 and 1.55 ± 0.49 mL·min(-1)·g(-1); P = 0.74; 95% CI, -0.47 to 0.35).
  
  
  CONCLUSIONS
  In otherwise healthy subjects who are not subjected to surgical stimulation, MBF at rest and after sympathetic stimulation is preserved during sevoflurane anesthesia despite a decrease in myocardial blood volume. However, sevoflurane anesthesia reduces hyperemic MBF, and thus MBF reserve, in these subjects.
authors: Department of Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, Postbus 7057, 1007 The Netherlands. c.bulte@vumc.n
authors: Carolien S E
authors: CS
authors: Bulte
authors: Jeroen
authors: J
authors: Slikkerveer
authors: Otto
authors: O
authors: Kamp
authors: Martijn W
authors: MW
authors: Heymans
authors: Stephan A
authors: SA
authors: Loer
authors: Stefano F
authors: SF
authors: de Marchi
authors: Rolf
authors: R
authors: Vogel
authors: Christa
authors: C
authors: Boer
authors: R Arthur
authors: RA
authors: Bouwman
mesh_terms: D000328:Adult; D000465:Algorithms; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D001810:Blood Volume / Q000187:drug effects*; D002395:Catecholamines / Q000097:blood; D003080:Cold Temperature; D003326:Coronary Circulation / Q000187:drug effects*; D003627:Data Interpretation, Statistical; D004452:Echocardiography / Q000379:methods; D005260:Female; D006321:Heart / Q000187:drug effects*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D008297:Male; D008738:Methyl Ethers; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011312:Pressure; D000077149:Sevoflurane; D014664:Vasodilation / Q000187:drug effects
chemical_list: D018685:Anesthetics, Inhalation; D002395:Catecholamines; D008738:Methyl Ethers; D000077149:Sevoflurane