Objective: Colonoscopy is a common procedure for diagnostic, therapeutic or surveillance purposes. Pre-procedural fasting and bowel preparation to facilitate the procedure may result in dehydration, which could lead to hypotension during colonoscopy under sedation. The goal of this study is to test the hypothesis that pre-procedural intravenous lactated Ringer’s solution (LRS) preloading decreases the incidence of intra-procedural hypotension during sedation for elective colonoscopy.

Material and Method: Sixty ASA 1 to 2 Patients, aged 18 to 60 years presenting for elective colonoscopy were randomized into 2 groups, control (C group) or preloading group (L group). Before procedure, C group received intravenous LRS of 1 hour maintenance while L group received intravenous LRS 200 ml preloading in 15 minutes prior to colonoscopy. Sedation was achieved by intravenous fentanyl 25 mcg and propofol infusion using target-control infusor (TCI) with preset target of propofol blood level 3.5 to 6 mcg/ml. Primary outcome was the incidence of hypotension, defined as ≥25% decrease in systolic blood pressure from baseline during sedation. Secondary outcome were vasopressor use and post-procedural complications (nausea, vomiting and dizziness).

Results: Fifty-three patients, 28 in C group and 25 in L group, completed the study. The incidence of hypotension were 39.3% in C group and 40.0% in L group (p = 0.958). Vasopressor use and post-procedural complications were either not significantly different between groups.

Conclusion: Pre-procedural intravenous LRS 200 ml preloading cannot prevent hypotension during sedation for elective colonoscopy in ASA 1 to 2 patients.

Keywords: Intravenous fluid, Preloading, Hypotension, Colonoscopy, Elective colonoscopy