Single use of fentanyl in colonoscopy is safe and effective and significantly shortens recovery time

Colonoscopy remains an uncomfortable examination and many patients prefer to be sedated. The aim of this study was to evaluate the efficacy and safety of intravenous administration of fentanyl in titrated doses compared with intravenous administration of the well-known midazolam in titrated doses.

One hundred twenty-six patients scheduled for ambulatory colonoscopy were randomly assigned to receive either 25 mcg fentanyl (Fentanyl group, n = 66, 35 females, mean age = 61.5 years) and titrated up to 50 mcg or 2 mg midazolam (Midazolam group, n = 60, 33 females, mean age = 63.2 years) and titrated up to 5 mg. Patients graded discomfort on a scale from 0 to 4 and pain on a scale from 0 to 10. Success of the procedure, time to cecum, complications, and recovery time for each patient were independently recorded.

Mean discomfort scores were 0.4 in the Fentanyl group and 1.0 in the Midazolam group (p = 0.002). Similarly, mean scores for pain and anus to cecum time were lower in the Fentanyl group than in the Midazolam group [2.59 vs. 4.43 (p = 0.002) and 8.7 vs. 12.9 min (p = 0.012), respectively]. No adverse events were reported in the Fentanyl group, while in the Midazolam group a decrease in oxygen saturation was noted in 23/60 (35%) patients. Mean recovery time was 5.6 min in the Fentanyl group and 16 min in the Midazolam group (p = 0.014). Mean dosage was 36 mcg for fentanyl and 4.6 mg for midazolam.

Administration of fentanyl in low incremental doses is sufficient to achieve a satisfactory level of comfort during colonoscopy.