Propofol versus midazolam for premedication: a placebo‑controlled, randomized double‑blinded study

It has been previously reported that subhypnotic doses of propofol could offer an advantage over midazolam for premedication. This study was designed to test the hypothesis that a 20 mg IV dose of propofol would be more effective than a standard 2 mg IV dose of midazolam for reducing acute anxiety prior to induction of anesthesia.

One hundred twenty outpatients scheduled to undergo orthopedic surgery were randomly assigned to one of three study groups: control (saline); propofol (20 mg); or midazolam (2 mg). Immediately before administering the study medication, each patient evaluated their level of acute anxiety and sedation on 11‑point verbal rating scales (VRSs) 0=none- 10=highest, and they were also shown a picture. Upon arrival in the OR ~5 min after administering the study medication, anxiety and sedation levels were reassessed and a second picture was shown. At discharge from the recovery area, anxiety and sedation levels and their ability to recall the two pictures were reassessed.

Compared to the saline group, both propofol and midazolam produced significant increases in the patient's level of sedation upon entering the OR (+2.5±2.4 vs. +4.6±2.5 and +5.2±2.3, respectively [p<0.001]). Propofol was effective as midazolam compared to saline in reducing the patient's level of preinduction anxiety (from 3.2±2.2 to1.8±1.8 vs. 3.1±2.2 to 2.3±2.1 and 2.7±1.8 to 2.8±2.1, respectively). Propofol produced more pain on injection and midazolam significantly reduced recall of the second picture.

When administered ~5 min prior to entering the OR, propofol, 20mg IV, was as effective as midazolam 2mg IV in reducing anxiety.