Identification of factors that influence conscious sedation in gastrointestinal endoscopy

J Korean Med Sci. 2004 Aug;19(4):536-40. doi: 10.3346/jkms.2004.19.4.536.


Although several studies examined factors that influence conscious sedation, investigation was limited into the gender and age. The aim of this prospective study is to identify the clinical variables of successful conscious sedation during gastrointestinal endoscopy. A total of 300 subjects who underwent gastrointestinal endoscopy were enrolled in a prospective fashion. They completed a questionnaire to assess height, weight, drinking, smoking, education level, recent medication, past medical history, previous experience of conscious sedation, preprocedural anxiety, and apprehension about the procedure. Efficacy of sedation and amnesia were evaluated by the subject and the endoscopist. Amnesic and sedative effects were proportionally related with age (p<0.0001). Preprocedural anxiety level was higher in women (p=0.0062), younger subjects (p=0.035), slender subjects (p=0.041), and in those without previous experience of conscious sedation (p=0.0034). This anxiety level was also related to increased pain (p=0.0026) and alertness (p=0.0003) during the procedure. Lower dose of midazolam is needed for sedation in older subjects. Subjects with a high level of preprocedural anxiety such as women, younger subjects, slender subjects, and those without previous experience of conscious sedation should be sedated with great caution because generally, they complain of much more severe pain and alertness during the procedure.

MeSH terms

  • Age Factors
  • Anesthetics, Intravenous / therapeutic use
  • Body Weight
  • Conscious Sedation*
  • Endoscopy, Gastrointestinal*
  • Female
  • Humans
  • Male
  • Midazolam / therapeutic use
  • Pain / drug therapy
  • Prospective Studies
  • Surveys and Questionnaires
  • Treatment Outcome


  • Anesthetics, Intravenous
  • Midazolam