Preanesthetic medication of children with midazolam using the biojector jet injector

Background: A rapid, dependable, and economical technique to atraumatically sedate children before anesthesia that does not prolong postanesthesia care unit time remains elusive. The Biojector jet injection system uses carbon dioxide rather than a needle to deliver an intramuscular injection. The dose-response relationship when midazolam is administered was studied using this jet injector. Methods: Forty children (2.3 ± 1.3 yr old) undergoing elective myringotomy and tube placement were randomly assigned in receive 0.05, 0.1, 0.15, 0.2, or 0.3 mg · kg^-1 midazolam injected intramuscularly using the Biojector disposable syringe (0.006-inch orifice). Assessment of each child before, during, and 10 rain after injection, on application of the anesthesia face mask, and every 15 min for 1 h after arrival to the postanesthesia care unit was made by an observer blinded to drug dosage. Results: Face mask tolerance using doses ≥ 0.1 mg · kg^-1 midazolam was acceptable and statistically different from 0.05 mg/kg. Crying on injection tended to increase with increasing dose. All children were awake and arousable, meeting discharge criteria, after 30 min from arrival in the postanesthesia care unit. Conclusions: Midazolam (0.1-0.15 mg · kg^-1) administered using jet injection effectively and rapidly produces sedation, in a manner acceptable to parents, without delaying post-anesthesia care unit discharge.