The effect of midazolam-thiopental coinduction on recovery in minor surgery

PURPOSE

The effects of midazolam-thiopental coinduction on recovery were investigated and compared with thiopental induction.

METHODS

Fifty patients, ASA 1 or 2, undergoing minor orthopedic surgery, were randomly divided into coinduction and thiopental groups. During preoxygenation, the patients received midazolam 0.1 mg.kg(-1) (coinduction group) or saline (thiopental group) 1 min before induction of anesthesia with thiopental. Isoflurane and nitrous oxide were used to maintain anesthesia. Isoflurane concentration was adjusted to keep blood pressure within +/-20% of the preoperative value. The time to awaken (open eyes, give name and birth-date) and the time to discharge readiness were recorded. Psychomotor tests, including simple light reaction time (SLRT), sedation analogue scale (SAS), and digit span test, were performed pre- and postoperatively.

RESULTS

The induction dose of thiopental was significantly lower in the coinduction group. End-tidal isoflurane concentration during surgery was also lower in the coinduction group. There were no significant differences in awakening times and discharge readiness between the two groups. Although SAS values were lower in the coinduction group than in the thiopental group 8 and 24 h after anesthesia, other test results were similar in both groups. The frequency of nausea and vomiting in the recovery period was lower in the coinduction group.

CONCLUSION

We conclude that midazolam-thiopental coinduction is a suitable technique when used in conjunction with isoflurane in day-case surgery.

The effect on intraocular pressure of endotracheal intubation or laryngeal mask use during TIVA without the use of muscle relaxants

BACKGROUND

Depolarizing and non-depolarizing muscle relaxants possess many untoward side effects. In most patients endotracheal intubation may be performed with a propofol and alfentanil combination. The purpose of this study was to compare the effect on intraocular pressure (IOP) and haemodynamics of endotracheal (ET) intubation or laryngeal mask (LMA) insertion during total intravenous anaesthesia (TIVA) without the use of muscle relaxants.

METHODS

In a randomised study, 20 patients scheduled for elective orthopaedic surgery were assigned to two groups of 10 patients. Anaesthesia was induced with i.v. alfentanil 40 micrograms/kg and propofol 2.5 mg/kg. LMA insertion or ET intubation was achieved by the same anaesthesiologist. Airway score, insertion score, patient response and haemodynamics were recorded. IOP measurements were recorded before and after induction, 1 and 2 min after ET intubation or LMA insertion, and 1 and 2 min after extubation.

RESULTS

Mean arterial pressure and heart rate after insertion of the airway management devices was significantly higher than induction values in the ET group (P < 0.05), while during 2-3 min no significant changes were observed in LMA group. In all patients following propofol and alfentanil induction, IOP was significantly lower than preinduction values (P < 0.001). IOP following extubation was significantly higher than preinduction values in the ET group, but not in the LMA group (P < 0.001).

CONCLUSION

During TIVA without the use of muscle relaxants neither LMA insertion nor ET intubation increased the IOP, but ET extubation did.