Retrograde amnesia produced with the use of propofol for sedation in Caesarean section.

T.Masuda A.Akatsuka S.Kato A.Yoshino* S.Nagashima* S.Ogawa*

Department of Anaesthesia,Yokohama Central Hospital,Yokohama,Japan

Department of Anaesthesiology, Nihon Univ. School of Medicine,Tokyo,Japan*

Background:

Propofol induced prograde amnesia have been reported previously. Propofol induced retrograde amnesia, however, have not yet been reported and it is still controversial.We, therefore, evaluated the effects of propofol on the retrograde amnesia with the patient who underwent Caesarean section comparing with the midazolam.

Patients and methods:

Fifty-five ASA 1-2 patients scheduled to undergo Caesarean section under combined spinal and epidural anaesthesia participated. Patients who underwent threatened premature labor caused by early amniorrhexis etc. and twin pregnancy were excluded. They were premedicated with atropine and were randomly divided into two groups depending upon the sedatives used for sedation after delivery; group P (n=30) received propofol and group M (n=25) received midazolam. In group P, sedation was produced with an initial bolus infusion of 2mg/kg propofol over 1 minute followed by continuous infusion maintaining the sedation level with Ramsay's score of 5-6. In group M, sedation was produced with a single bolus 3mg midazolam and additional same dose was administered as required. Each study drugs were given 30 seconds after confirmating that the patients meet their babies. Each patient was also told that the baby was boy or girl. After the operation was finished, all the patients were interviewed whether or not they remember meeting their babies and the sex of the babies.In M group,subjects received Flumazenil for awakening. In case the patients recall neither meeting the babies nor the sex, it was defined as 'retrograde amnesia'.

Results:

There were no significant differences with respect to age, weight, height, duration of sedation or duration of operation between the P and M groups.

Five of thirty patients in P-group remember neither they meet with their babies nor the sex, and so was 0 of twenty-five in M-group.

Discussion:

In our study, the rate of the patients who did not recall the memory which patients recognized before the propofol was given was significantly higher in P group (17%) than in M group (0%). This means that the propofol is possible to produce retrograde amnesia whereas the midazolam is not. (Fisher's exact P-value=0.041)Since many patients undergoing Caesarean section prefer to be sedated after delivery, we have to consider what sedatives should be used for sedation. It is necessary to take possible advantage and disadvantage due to the use of propofol into consideration during Caesarean section.

Conclusion:

Propofol is possible to cause retrograde amnesia.