Low- Versus High-Dose Combination of Midazolam-Ketamine for Oral Premedication in Children for Ophthalmologic Surgeries

Singapore Med J. 2011 Jul;52(7):512-6.


Introduction: Midazolam and ketamine are useful for oral premedication in children to allay anxiety. We compared the effects of midazolam with a combination of high- and low-dose ketaminemidazolam as an oral premedication.

Methods: This is a randomised, controlled prospective study conducted in 87 children who were scheduled for ophthalmologic surgeries. Group M received oral midazolam 0.5 mg/kg, Group MKL received oral midazolam 0.25 mg/kg and ketamine 3 mg/kg, and Group MKH received midazolam 0.5 mg/kg and ketamine 6 mg/kg. Standard general anaesthesia technique was used. Sedation levels and ease of parental separation were noted.

Results: A linear increasing trend in sedation was seen in the preoperative sedation scores of all the three groups. At 30 minutes, 23 children in Group MKH had good sedation scores as opposed to 20 in Group MKL and 12 in Group M. The best parental separation time was much shorter in the combination groups. There were no statistically significant differences in the parental separation scores, mean response to induction and mask acceptance. The time to reach Aldrete score of 10 was shorter in Group MKL (22 +/- 5 min) and Group M (36 +/- 1 min) compared to Group MKH (52 +/- 2 min). Group MKH had a higher incidence of excessive salivation compared to the other groups.

Conclusion: A combination of low-dose midazolam and ketamine is as effective as high-dose midazolam and ketamine for achieving optimum anxiolysis and a faster recovery, with a lower incidence of excessive salivation in children undergoing ophthalmic surgery.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Anti-Anxiety Agents / administration & dosage*
  • Anti-Anxiety Agents / adverse effects
  • Anxiety / prevention & control*
  • Child
  • Child, Preschool
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Combinations
  • Female
  • Humans
  • Infant
  • Ketamine / administration & dosage*
  • Ketamine / adverse effects
  • Linear Models
  • Male
  • Midazolam / administration & dosage*
  • Midazolam / adverse effects
  • Ophthalmologic Surgical Procedures*
  • Preanesthetic Medication*
  • Prospective Studies


  • Anti-Anxiety Agents
  • Drug Combinations
  • Ketamine
  • Midazolam