Continuing Medical Education Questions: March 2017

Comparison of left versus right lateral starting position on colonoscopy: a systematic review and meta-analysis of randomized controlled trials

Background

Modifying patient position during colonoscopy has been proposed as a simple and inexpensive technique to increase luminal distention and improve navigation through the large bowel. The left lateral (LL) decubitus starting position is commonly used during colonoscopy. However, reports indicate that other starting positions may offer additional benefit. We aimed to determine if the right lateral (RL) starting position compared to the standard LL starting position could improve outcomes in colonoscopy.

Methods

We searched PubMed, Medline, and EMBASE through June 2020 to identify studies comparing RL and LL starting positions during colonoscopy. The primary outcomes included mean cecal insertion time and cecal intubation rate, and adverse events were assessed by pooling data using a random-effects model expressed in terms of odds ratio (OR), mean difference, and 95% confidence interval (CI).

Results

We identified 5 randomized controlled trials, including 809 participants, that compared LL vs. RL colonoscopy. The pooled OR for cecal intubation rate was 1.3 (95%CI 0.8-2.3; P=0.3). The mean difference in mean cecal insertion time was 0.08 (95%CI -0.09 to 0.26; P=0.4). Heterogeneity between studies was low (I ²=0%). No complications were reported in either arm of the study. Pain scores assessed using a visual analog scale were comparable among both arms of the study.

Conclusion

The RL starting position for colonoscopy was comparable to the LL and offered no additional benefit in terms of cecal intubation time, intubation rate, or patient discomfort.

Effect of left lateral tilt-down position on cecal intubation time: a 2-center, pragmatic, randomized controlled trial

BACKGROUND AND AIMS

Colonoscopy insertion is technically challenging, time-consuming, and painful, especially for the sigmoid. Several pilot studies indicated that the (left) tilt-down position could facilitate the insertion procedure, but no formal trials have been published to demonstrate its efficacy. We performed this study to verify the benefits of the left lateral tilt-down position (LTDP) on the insertion process.

METHODS

This 2-center prospective trial randomized unsedated patients to the LTDP or left lateral horizontal position (LHP) to aid insertion. The primary outcome measure was cecal intubation time (CIT). Secondary outcome measures included decending colon intubation time (DIT), pain score of insertion, acceptance of unsedated colonoscopy for future examinations, difficulty score for insertion, and the adverse event rate of colonoscopy.

RESULTS

Two hundred fifty-eight patients were randomized to the LTDP (128) or LHP (130) in 2 centers. The median CIT and DIT were shorter with patients positioned in LTDP than in LHP (CIT, 280.0 vs 339.5 s, P < .001; DIT, 53.0 vs 69.0 s, P < .001, respectively) and patients with high and low body mass index (BMI) benefited more from LTDP than from LHP, as opposed to patients with normal BMI. In addition, colonoscopy insertion in LTDP was less painful (3.4 ± 1.6 vs 4.0 ± 1.7, P = .02) and less difficult (3.1 ± 1.9 vs 3.7 ± 1.4, P < .001), showing a higher tendency to acceptance of unsedated colonoscopy (82.9% vs 73.8%, P = .08). The rates of adverse events were extremely low and did not differ significantly in the 2 groups.

CONCLUSIONS

LTDP for colonoscopy insertion can reduce insertion time and pain, and potentially improves patients' acceptance of unsedated colonoscopy. (Clinical trial registration number: NCT02842489.).