Introduction Colonoscopy is an essential modality in gastroenterology but can be technically challenging and cause patient discomfort. By convention, the procedure is started with patients in the left lateral position. The recent ROLCOL study has shown that right lateral starting position may be preferable to left lateral starting position. However, a prone starting position for colonoscopy has not been tested with the same rigour. One study found that obese patients undergo quicker procedures when colonoscopy is started with the patient in the prone position. We sought to test the benefits of prone positioning over conventional left lateral positioning in unselected patients.
Methods 181 consecutive patients undergoing scheduled colonoscopy were stratified according to age, gender, BMI and experience of the endoscopist. Patients were then randomised to begin colonoscopy in either the prone (PP) or left lateral (LP) position. The primary outcome measure was time to reach cecum. Secondary outcome measures included: i) time to reach transverse colon; ii) patient comfort and iii) endoscopist’s perception of procedure difficulty, both assessed by visual analogue scale (VAS).
Results Time to reach cecum was longer for patients randomised to start colonoscopy in the PP compared to the LP (700 s vs. 525 s; p < 0.05). This was in line with a longer time to reach the transverse colon in the PP group (329 s vs. 257 seconds; p < 0.05) as well as an increase in the difficulty perceived by the endoscopist for procedures in which the patient was positioned prone (5 vs. 4 VAS; p < 0.01). The doses of intravenous sedation used (midazolam 2 vs 2 mg; p = 0.27 and fentanyl 50 vs 50 mcg; p = 0.68) and patient comfort scores (3.5 vs. 4 VAS, p = 0.43) were similar between the two groups. In subgroup analysis, a statistically significant increase in time to cecum was shown in particular for female patients positioned prone at the start of colonoscopy (771.5 s vs. 522.5 s, p < 0.01).
Conclusion Starting patients in the prone position led to an increased cecal intubation time and was more technically challenging for the endoscopist. Our results do not, therefore, support the prone position as the optimal starting position for colonoscopy in unselected patients. Future research should focus on elucidating the situations in which position change to prone during colonoscopy is helpful.
Disclosure of Interest None Declared