Inhalational Anesthetic Agent1 Desflurane

1

Inhalational Anesthetic Agents Desflurane, CF3-CFH-O-CF2H

Introduced in 1992. Physical Properties



vapor pressure = 681 mmHg at 20 degrees C so boils at room temperature at high altitudes (eg, Denver, Colorado), and

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requires special vaporizer

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low solubility permits rapid changes in pA and thus pBrain

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pungent and irritating to the airway

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Organ System Effects Cardiovascular  similar to isoflurane (but does NOT increase coronary artery blood flow)  cardiac output no more than slightly depressed at 1-2 MAC 

rapid increases in pa may -> pronounced tachycardia and hypertension

Respiratory  fast, shallow breathing with incresased p aCO2  airway irritation o

salivation

o

breath-holding

o

coughing

2

o

laryngospasm

CNS 

general anesthesia, MAC = 6.0 cerebral vasodilator, increases CBF and ICP

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marked decrease in CMRO2 tends to cause compensatory vasoconstriction

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EEG effects similar to isoflurane

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Biotransformation and Toxicity  

minimal metabolism in vivo degraded (more than other agents) to potentially harmful levels of carbon monoxide by desiccated carbon dioxide absorbent o

especially by barium hydroxide lime, but also by sodium and potassium hydroxide

o

use of calcium hydroxide minimizes this degradation problem

Contraindications

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malignant hyperthermia susceptibility hypovolemia

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intracranial hypertension

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