Propofol and Dexmedetomidine Versus a Propofol Only Regimen for Sedation During Colonoscopy

In this study, investigators plan to prospectively compare in a randomized, controlled, double-blind trial, the sedation technique for colonoscopy between two groups. Group 1: sedation with dexmedetomidine and propopfol versus group 2: sedation with saline placebo and propofol.

The study will have the following outcome measures for each group.

Primary outcome measure:

Readiness-for-discharge (RFD) at 10, 20 and 30 minutes after the colonoscopic procedure. Ready-for-discharge is defined as attainment of MPADSS score of 9-10.

Secondary outcome measures:

• Total propofol consumption in mg/kg/duration of procedure in minutes;
• Side effects:

• lowest intraoperative percent (%) drop in mean arterial pressure (MAP) from baseline,
• incidence of sustained bradycardic episodes (HR<50 for at least 5 minutes) intraoperatively,
• incidence of apneic episodes intraoperatively requiring positive pressure ventilation.

Methods:

One hundred patients will be recruited and randomized into two groups. For sedation, Group 1 will receive intravenous dexmedetomidine 0.3 ug/kg bolused at the onset of the procedure followed by titrated doses of propofol. Group 2 will receive a saline placebo bolus at the onset of the procedure followed by titrated doses of propofol. A hospital research pharmacist, based on a randomization table, will allocate to the anesthesia provider giving the sedation, the bolus syringe labelled dexmedetomidine/or saline study agent. The anesthesia provider, gastroenterologist, nurses as well as the subject will be blinded as to the syringe's actual content. A Bispectral Index (BIS) Monitor will be used during sedation. All subjects will be targeted to maintain a BIS score between 60-70. Outcome measures will be evaluated for statistical significance in a non-inferiority assessment.

Investigators hypothesize that there will be no difference in the time to discharge between the two treatment groups.

Inclusion criteria

• patients scheduled to undergo colonoscopy at SUNY Downstate Medical Center.

Exclusion criteria

• < 18 years old
• > 75 years old
• Cognitively Impaired patients (Cognitively impaired patients are excluded from the study because our primary outcome involves a very strict discharge criteria that requires the patient to respond to and perform tasks on our pre-existing discharge scale checklist. These may be impossible to assess or will be difficult to standardize for patients whom are Cognitively Impaired.)
• Pregnant patients
• Patients who use a wheelchair or ambulates with crutches (Patients using a wheelchair are excluded from the study because our primary outcome involves a very strict discharge criteria that requires the patient to respond to and perform tasks on our pre-existing discharge scale checklist. These may be impossible to assess or will be difficult to standardize for patients whom who use a wheel-chair).
• Limited exercise tolerance (as this could represent active coronary disease)
• Total body weight greater than 105 kg (due to maximal dose of drug available in randomized syringes containing study drug)
• Propofol, soy, glycerol or dexmedetomidine allergy
• Significant renal impairment
• Significant hepatic impairment
• Inability to read or write in English