HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Hypercapnic hyperventilation shortens emergence time from isoflurane anesthesia.

AbstractBACKGROUND:
To shorten emergence time after a procedure using volatile anesthesia, 78% of anesthesiologists recently surveyed used hyperventilation to rapidly clear the anesthetic from the lungs. Hyperventilation has not been universally adapted into clinical practice because it also decreases the Paco2, which decreases cerebral bloodflow and depresses respiratory drive. Adding deadspace to the patient's airway may be a simple and safe method of maintaining a normal or slightly increased Paco2 during hyperventilation.
METHODS:
We evaluated the differences in emergence time in 20 surgical patients undergoing 1 MAC of isoflurane under mild hypocapnia (ETco2 approximately 28 mmHg) and mild hypercapnia (ETco2 approximately 55 mmHg). The minute ventilation in half the patients was doubled during emergence, and hypercapnia was maintained by insertion of additional airway deadspace to keep the ETco2 close to 55 mmHg during hyperventilation. A charcoal canister adsorbed the volatile anesthetic from the deadspace. Fresh gas flows were increased to 10 L/min during emergence in all patients.
RESULTS:
The time between turning off the vaporizer and the time when the patients opened their eyes and mouths, the time of tracheal extubation, and the time for normalized bispectral index to increase to 0.95 were faster whenever hypercapnic hyperventilation was maintained using rebreathing and anesthetic adsorption (P < 0.001). The time to tracheal extubation was shortened by an average of 59%.
CONCLUSIONS:
The emergence time after isoflurane anesthesia can be shortened significantly by using hyperventilation to rapidly clear the anesthetic from the lungs and CO2 rebreathing to induce hypercapnia during hyperventilation. The device should be considered when it is important to provide a rapid emergence, especially after surgical procedures where a high concentration of the volatile anesthetic was maintained right up to the end of the procedure, or where surgery ends abruptly and without warning.
AuthorsDerek J Sakata, Nishant A Gopalakrishnan, Joseph A Orr, Julia L White, Dwayne R Westenskow
JournalAnesthesia and analgesia (Anesth Analg) Vol. 104 Issue 3 Pg. 587-91 (Mar 2007) ISSN: 1526-7598 [Electronic] United States
PMID17312214 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
Chemical References
  • Carbon Dioxide
  • Isoflurane
Topics
  • Adult
  • Anesthesia Recovery Period
  • Anesthesia, Inhalation (instrumentation, methods)
  • Anesthesiology (methods)
  • Carbon Dioxide (metabolism)
  • Female
  • Humans
  • Hypercapnia (chemically induced)
  • Hyperventilation (physiopathology)
  • Isoflurane (pharmacology)
  • Lung (drug effects)
  • Male
  • Respiration (drug effects)
  • Time Factors

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: