Superiority of split dose midazolam as conscious sedation for outpatient colonoscopy

To elucidate the efficacy and safety of a split dose of midazolam in combination with meperidine for colonoscopy.

Eighty subjects undergoing outpatient colonoscopy were randomly assigned to group A or B. Group A (n = 40) received a split dose of midazolam in combination with meperidine. Group B (n = 40) received a single dose of midazolam in combination with meperidine. Outcome measurements were level of sedation, duration of sedation and recovery, degree of pain and satisfaction, procedure-related memory, controllability, and adverse events.

Group A had a lower frequency of significant hypoxemia (P = 0.043) and a higher sedation score on withdrawal of the endoscope from the descending colon than group B (P = 0.043). Group B recovered from sedation slightly sooner than group A (P < 0.002). Scores for pain and memory, except insertion-related memory, were lower in group A one week after colonoscopic examination (P = 0.018 and P < 0.030, respectively). Poor patient controllability was noted by the endoscopist and nurse in group B (P = 0.038 and P = 0.032, respectively).

Split dose midazolam in combination with meperidine resulted in a safer, more equable sedation status during colonoscopic examination and a reduction in procedure-related pain and memory, but resulted in longer recovery time.