Abstract
The effect of acute hypocarbia on recovery from anesthesia was studied in twenty-nine patients under enflurane (2%)-nitrousoxide (50%) anesthesia. Patients were intubated with thiobarbiturates (4mg/kg), succinylcholine (1mg/kg) and after keeping stable condition of normocapnic or hypocapnic ventilation, blood gas was analysed. EEG monitoring was started from almost ten minutes before end of operation, blood gas (artery, juglar vein) was analysed and recovery time from anesthesia was counted.
Pjv O2 (oxygen pressure of juglar venous blood) decreased during hypocarbia slightly when compared with normocarbia, while no significant difference of O2ER (oxygen extraction rate) was observed between hypocarbia and normocarbia. On recovery phase after anesthesia, EEG showed the rise of a activity during normocapnia, but the decrease of a activity during hypocarbia. Recovery time from anesthesia was slightly shorter in the patients with normocarbia than that with hypocarbia. Which means that hyperventilation during anesthesia depressed the brain metabolism.Our results suggest that hyperventilation during anesthesia can prolong the recoveryfrom central nervous system depression.
