Inhalational Anesthetic Agents

Sevoflurane, (CF3)2-CH-O-CFH2

sevoflurane
Relatively low solubility and nonpungency make it an excellent choice for inhalational induction.

Physical Properties

  • vapor pressure = 160 mmHg at 20 deg C
  • low solubility (lambdablood:gas = 0.65)
  • moderate vapor pressure (160 mmHg at 20 degrees C)

Organ System Effects

Cardiovascular
  • mild negative inotrope
  • little or no tachycardia
  • so cardiac output not as well maintained as with isoflurane or desflurane
  • may prolong the QT interval
Respiratory
  • depresses respiration
  • bronchodilator
CNS
  • general anesthesia, MAC = 2.0
  • slightly increases CBF and ICP
  • decreases CMRO2

Biotransformation and Toxicity

  • rate of metabolism = 5% (ten times that of isoflurane)
  • inorganic fluoride is a metabolic product soda lime (NOT calcium hydroxide) degrades sevoflurane to compound A
    • nephrotoxic in rats
    • accumulation of compound A increases with
      • increased respiratory gas temperature
      • low-flow anesthesia
      • dry barium hydroxide absorbent
      • high sevoflurane concentrations
      • time
  • some recommend minimum total fresh gas flows of 2 L/min and
  • avoid if preexisting renal dysfunction
  • metal and environmental impurities can degrade sevoflurane to hydrogen fluoride
    • can produce acid burn of respiratory mucosa
    • degradation minimized by adding water during manufacture and packaging in special plastic containers

Contraindications





Send Comments to Greg Gordon MD, gjg@po.cwru.edu
Department of Anesthesiology
The MetroHealth System
2500 MetroHealth Drive
Cleveland, Ohio 44109-1998
Phone: (216) 778-4801
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