Prospective randomised comparison of IV midazolam / meperidine versus IV ketamine in pediatric endoscopy

Sedation for pediatric endoscopy is unsatisfactory in that it is time consuming, and the post-procedure recovery process is slow. Aim: To perform a randomised study comparing a typical high-dose midazolam / meperidine regimen with a low-dose ketamine regimen. Methods: 30 children (median age 3.5 yr, range 0.2-16.4 yr) were randomised to receive midazolam / meperidine (n=15) or ketamine (n=15). Sedation was administered in repeated IV boluses according to a pre-determined protocol. Patients were closely monitored with continuous pulse oximetry until recovery. Oxygen was administered if the saturation fell below 94%. Results: In the midazolam / meperidine group the doses given were: midazolam - median 0.4mg/kg(range 0.12-1mg/kg); meperidine- median 2mg/kg (range 0.8-2mg/kg). Those in the ketamine group each received a small dose of IV midazolam (<1 yr - 0.5mg; 1-5 yr - 1mg; >5 yr - 2 mg) in order to prevent hallucinations. An anticholinergic agent (glycopyrrolate 2μg/kg) was given to reduce respiratory secretions. The median dose of ketamine given was 1.5mg/kg (range 1-3mg/kg). In all cases the endoscopic procedure was sucessfully completed. Agitation necessitating restraint occurred in 4 of 15 in the midazolam / meperidine group, compared with 1 of 15 in the ketamine group. Half of the patients in each group received face mask O₂ according to protocol. No serious adverse events occurred during or after the procedures. Transient post-procedure vomiting occurred in one patient given midazolam / meperidine. In both groups patients old enough for interview had total amnesia for the procedure. The sedation process was faster with ketamine (median 5 min, range 2-15 min) than with midazolam / meperidine (median 12 min, range 3-37 min) (p < 0.01). The interval from completion of the procedure to discharge from the recovery ward was much shorter with ketamine (median 7 min, range 3-27 min) than midazolam / meperidine (45 min, range 2 min-4hr) (p < 0.005). Conclusion: Low-dose IV ketamine offered distinct advantages in terms of rapid sedation and a shorter recovery time. This can contribute both to efficiency and patient safety.