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OverviewInhalation Anesthetic
MAC (vol %) Vapor Press. Part.Coeff.
|
>60 yr
|
Adult
|
Child
|
Infant
|
Neonate
|
mmHG
|
Blood:Gas
|
Brain:Blood
|
Desflurane
|
5.20
|
6.0-7.3
|
8.10
|
10.0
|
9.20
|
664
|
0.42
|
1.29
|
Enflurane
|
1.40
|
1.7
|
----
|
----
|
----
|
175
|
1.91
|
1.4
|
Halothane
|
0.60
|
0.77
|
0.95
|
1.20
|
0.87
|
241
|
2.30
|
2.9
|
Isoflurane
|
1.05
|
1.15
|
1.60
|
1.87
|
1.60
|
238
|
1.40
|
2.60
|
Nitrous Ox.
|
|
104
|
|
|
|
39,000
|
0.47
|
1.10
|
Sevoflurane
|
1.40
|
1.7-2.6
|
2.50
|
3.00
|
3.30
|
160
|
0.60
|
1.70
|
DesfluraneStructure similar to Isoflurane, the only difference is the substitution of a fluorine atom for isoflurane's chloride atom. At inhaled concentrations greater than 6%, the pungency of desflurane may cause irritation, with coughing, breath holding, or laryngospasm
The low solubility of desflurane in blood and body tissues causes a very rapid wash-in and wash-out of anesthetic. The rapid wake-up time is attributable to a blood/gas partition coefficient even lower nitrous oxide.
Characteristic features:
-High vapor pressure
-Ultrashort duration
-Moderate potency
Cardiovascular effects:
-Increasing dose = Decreased SVR
-CO relatively unchanged or slightly depressed at 1-2 MAC
-Moderate rise in HR, CVP, and PAP
-Rapid increases in concentrate lead to transient increases in HR, BP, and catechol. levels
-Not associated w/ increase in coronary blood flow
Respiratory effects:
-Causes a decrease in TV and increase in respiratory rate
-Overall decrease in alveolar ventilation, leads to rise in resting PaCO2
-Depresses ventilatory response to increasing PaCO2
Cerebral effects:
-Decreases cerebral vascular resistance, increases cerebral blood flow, and associated w/ increased ICP at normotension and normocapnia (decrease ICP by hyperventilation)
Halothane