Opioid Effects on Cognitive Function Following Colonoscopy

In this study we aimed to compare the effects of sedation provided by propofol with the addition of the short-acting opioid alfentanil and long-acting opioid fentanyl on cognitive functions, pain, side effects during the procedure and the endoscopist and patient satisfaction.

Following the approval of Kırıkkale University ethics committee, 150 patients ages between 18 and 65 ASA I-III scheduled for elective endoscopy and colonoscopy will be enrolled in the study.

After obtaining written informed consent, APAIS (The Amsterdam Preoperative Anxiety and Information Scale) and MMTS (Mini Mental Test Scoring) tests will given to patients. Following TDT (Trieger Dot Test) and DSST (Digit Symbol Substitution Test), the patients will be randomly allocated to either Propofol-Alfentanil (Group A), Propofol-Fentanyl (Group F) or Propofol-Control (Group P) which consists of 50 patients each.

The patients in Group A will be given 100 mcg/kg/min propofol infusion and 10 mcg/kg loading dose of alfentanil and 5 mcg/kg additional bolus of alfentanil whenever FPS (Faces Pain Scale) is greater than 3 or the patients can not tolerate the procedure.

The patients in Group F will be given 100 mcg/kg/min propofol infusion and 1 mcg/kg loading dose of fentanyl and 5 mcg/kg additional bolus of fentanyl whenever FPS (Faces Pain Scale) is greater than 3 or the patients could not tolerate the procedure.

Group P is designated as the control group and the patients will be given 100mcg/kg/min infusion and sedation will be achieved via 1 mg/kg propofol loading dose and 0.5 mg/kg propofol additional bolus will be given whenever the patients can not tolerate the procedure or FPS is greater than 3.

BIS values, mean arterial pressures, heart rates, peripheral oxygen saturations will be recorded in all three groups. FPS and VAS (Visual Analogue Scale) values will be evaluated.

Patients with intraprocedural desaturation, hypo- or hypertension, brady- or tachycardia, nausea, vomiting and apnea will be recorded. Total amounts of drugs administered will be recorded.

Infusions will be ceased at the end of the procedure and the time for OAAS/S to exceed 3 will be recorded and TDT and DSST will be repeated at 5, 15 and 30th minutes. Patient and endoscopist satisfaction will be evaluated in all cases.

Inclusion criteria

• Ages between 18-65
• American Society of Anesthesiologists classification I-III
• Patients scheduled to undergo elective colonoscopy or endoscopy and colonoscopy

Exclusion criteria

• Patients younger than 18 or older than 65
• Mini mental test score < 26
• APAIS (The Amsterdam Preoperative Anxiety and Information Scale) >10
• Serious systemic disease
• Neuropsychiatric disorder
• Chronic alcohol abuse
• Morbid obesity
• History of anesthesia in the last 7 days
• Known allergy to study drugs