Propofol [diprivan] versus midazolam - flumazenil anaesthesia for direct laryngoscopy

The study.was carried out on 40 patients of both sexes aged from 15-55 years old and with body weight between 55-85 kg scheduled for direct laryngoscopic procedures. Patients were divided randomly into 2 groups, 20 patients each.In the first group, propofol 2 mg/kg was used for induction of anaesthesia and maintained by continuous infusion of 200 micro g/kg/min for 10 minutes, followed by 150 micro g/kg/min for the next 10 minutes and 100 micro g /kg/min Thereafter .In the second group, midazolam 0.3 mg /kg was used for induction and maintained by infusion of 1 micro g/kg/min if the procedure lasted more than 20 minutes. At the recovery placebo was used to reverse the effect of propofol and fIumazeniI was used to reverse the effect of midazolam. Perianaesthetic care was the same for both groups. In both groups we evaluated the operative condition [adequate, inadequate and poor] and the quality of recovery [recovery time, degree of sedation, cooperation and orientation to time and space]. We found that both propofol and midazolam offered an adequate operative anaesthetic condition needed for the procedure but the quality of recovery of propofol was better than that of midazolam even after fIumazenil administration reaching to a conclusion to leave the midazolam - fIumazenil technique to be used in the poor cardiovascular risk patients or in a situation where propofol is not available or contraindicated

Effect of propofol on perception of pain in mice: study on the mechanism of action

Propofol is an intravenous anesthetic used clinically. The latencies of pain threshold of different subhypnotic doses [12.5, 25 and 50 mg kg-1] of propofol administrated intraperitoneally [ip] into mice were measured by using hot plate method technique. The possible mechanism of pain control by propofol was also investigated through blocking beta- endorphin receptors and measuring serum level of beta-endorphin. Morphine [1.5 mg kg-1, ip] was used as reference of reduction of pain sensation. The results showed that propofol in doses of 25 and 50 mg kg-1 increased significantly the latency of pain threshold, but the lower dose [12.5 mg kg-1] failed to produce any significant change. This indicated that propofol reduced pain sensation and this effect is dose-dependent. It was also observed that propofol prevents hyperalgesia produced by prostaglandin [PGE2] [0.5 mg kg-1, ip]. For investigating the mechanism of action of propofol, pretreatment with naloxone [1.0 mg kg-1, ip] abolished significantly the antinociceptive action of propofol. Furthermore, serum level of beta- endorphin was increased significantly after propofol injection particularly at the peak time of propofol action. Serum level of corticosterone was also increased significantly at the time of beta- endorphin release