Moderate level sedation during endoscopy: a prospective study using low-dose propofol, meperidine/fentanyl, and midazolam

Gastrointest Endosc. 2004 Jun;59(7):795-803. doi: 10.1016/s0016-5107(04)00349-9.


Background: Propofol provides several benefits over benzodiazepine and narcotic agents as a sedative medication for endoscopic procedures, including faster recovery and improved patient satisfaction. However, its use generally has been limited to anesthesiologists because of the risks associated with deep sedation.

Methods: One hundred patients undergoing colonoscopy or EGD were sedated with low-dose propofol, midazolam, and fentanyl (or meperidine). Depth of sedation was assessed at 2-minute intervals by an independent observer by using the American Society of Anesthesiologists criteria. Recovery time was determined by using paired neuropsychometric tests. A post-procedure satisfaction survey and 24-hour follow-up questionnaires were administered.

Results: For colonoscopy and EGD, respectively, the mean propofol dose was 98 mg and 79 mg, the mean midazolam dose was 0.9 mg and 0.8 mg, the mean fentanyl dose was 69 mcg and 63 mcg, and the mean meperidine dose was 42 mg (for both procedures). There were 628 assessments of the level of sedation performed during 74 colonoscopies and 101 assessments during 26 EGDs. The level of sedation was minimal in 77%, moderate in 21%, and deep in 2% of assessments. Nine of the 13 episodes of deep sedation were recorded during colonoscopy and 4 during EGD. In no instance was more than a single assessment of deep sedation recorded during one procedure. Ninety-eight percent of patients were satisfied with the sedation, and 71% returned to their usual activities within 2 hours of discharge. There was no serious adverse event.

Conclusions: Endoscopic sedation with low-dose propofol, a narcotic agent, and midazolam produces a moderate level of sedation. The quality of sedation and measures of recovery are comparable with the results reported with standard-dose propofol.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Analgesics, Opioid / administration & dosage*
  • Colonoscopy
  • Conscious Sedation* / adverse effects
  • Endoscopy, Digestive System*
  • Fentanyl / administration & dosage
  • Humans
  • Hypnotics and Sedatives / administration & dosage*
  • Hypnotics and Sedatives / adverse effects
  • Meperidine / administration & dosage
  • Midazolam / administration & dosage
  • Middle Aged
  • Neuropsychological Tests
  • Patient Satisfaction
  • Propofol / administration & dosage
  • Propofol / adverse effects
  • Prospective Studies


  • Analgesics, Opioid
  • Hypnotics and Sedatives
  • Meperidine
  • Midazolam
  • Fentanyl
  • Propofol