Isoflurane Fahrenheit Mechanism of Action

Pharmacology: Induction and, particularly, recovery are rapid. Although slight pungency may limit the rate of induction, excessive salivation and tracheobronchial secretions do not appear to be stimulated. Pharyngeal and laryngeal reflexes are diminished quickly. Levels of anesthesia may be changed rapidly with isoflurane. Heart rhythm remains stable. Spontaneous respiration becomes depressed as depth of anesthesia increases and should be closely monitored and supported when necessary.
During induction there is a decrease in blood pressure which returns towards normal with surgical stimulation.
Blood pressure tends to fall during maintenance in direct relation to depth of anesthesia, but cardiac rhythm remains stable. With controlled respiration and normal PaCO₂, cardiac output tends to be maintained despite increasing depth of anesthesia primarily through a rise in heart rate which compensates for a reduction in stroke volume. With spontaneous respiration, the resulting hypercapnia may increase rate and cardiac output above awake levels.
Cerebral blood flow remains unchanged during light isoflurane anesthesia but tends to rise at deeper levels. Increases in cerebrospinal fluid pressure may be prevented or reversed by hyperventilating the patient before or during anesthesia.
Electroencephalographic changes and convulsions are extremely rare with isoflurane. In general, isoflurane produces an EEG pattern similar to that seen with other volatile anesthetics.
lsoflurane appears to sensitize the myocardium to adrenaline. Limited data suggest that subcutaneous infiltration of up to 50 mL of 1:200,000 solution adrenaline does not induce ventricular arrhythmias in patients anesthetized with isoflurane.
Muscular relaxation may be adequate for some intra-abdominal operations at normal levels of anesthesia, but should greater relaxation be required small doses of intravenous muscle relaxants may be used.
lsoflurane may be used for the induction and maintenance of general anesthesia. Adequate data are not available to establish its place in pregnancy.
Relatively little metabolism of isoflurane occurs in the human body. In the postoperative period only 0.17% of the isoflurane taken up can be recovered as urinary metabolites. Peak serum inorganic fluoride values usually average less than 5 micromole/litre and occur about four hours after anesthesia, returning to normal levels within 24 hours. No signs of renal injury have been reported after isoflurane administration.
Known metabolites of isoflurane have been found to be either nontoxic or present in too low a concentration to be harmful.