Effects Of Sedative Agents Under Spinal Anesthesia On Post-Operative Cognitive Dysfunction Of The Elderly – A Comparison Between Propofol And Midazolam

Kazumi Kakutani¹, Teruko Tajima¹, Nobuyo Kuriyama¹, Osamu Ueno¹, and Yoshio Hatano²
Department of Anesthesia, Wakayama Rosai Hospital1
Department of Anesthesiology, Wakayama Medical University²

Background:

Propofol and midazolam have been frequently used as adequate sedatives during regional anesthesia because of their rapid onset and short duration;  however, the use of these drugs requires more careful attention for the elderly because of the relative longer duration. Moreover, they might cause post-operative cognitive dysfunction ( POCD ). The purpose of this study is to compare the effects of sedative agents under spinal anesthesia on POCD of the elderly.

Methods:

Thirtyfive patients over 70 years undergoing elective surgical repair of femoral neck fractures were retrospectively enrolled in this study. Premedication consisted of 0 ~ 20 mg famotidine and 0 ~ 0.125 mg triazolam. After establishment of spinal anesthesia with 0.5% isobaric bupivacaine, patients received randomly the continuous propofol infusion  ( group P ), intermittent midazolam administration ( group M ), and no treatment  ( group O ). The doses of sedatives were adjusted to maintain the sedation which seemed to be sleeping and difficult to arouse. The mental impairment especially as for delirium during postoperative 7 days was observed and analyzed.

Results:

Demographic data, age and duration of anesthesia were comparable in three groups. Fifteen patients of all developed POCD. The incidence of POCD were 18%, 44% and 75% in group P, M and O, respectively. There was a significant difference between group P and group O. Although 78% of patients over 90 years developed POCD, they could discharge.

Conclusion:

The incidence of POCD of the elderly was significantly less in group P than in group O. There was no significant difference between group P and group M.