Introduction Insertion in colonoscopy is technically challenging. Conventionally, colonoscopy begins with patients positioned in the left lateral position (LLP). However, few published studies have explored alternatives and there is consequently little evidence to support LLP. We sought to compare right-lateral (RLP) with LLP to determine which starting position ultimately results in quicker procedures and greatest patient comfort.
Method 167 patients undergoing scheduled colonoscopy were recruited from two London endoscopy units. Subjects were first stratified by age, gender, BMI and experience of endoscopist. Next, patients were randomised to begin colonoscopy in either the LLP or the RLP 1:1 using random permuted blocks. Primary outcome measure was insertion time to caecum and secondary outcome measures included patient comfort measured by visual analogue scale (VAS) and volume of intravenous sedation used. Subsequently, multiple linear regression with backward elimination was used to create a model that identified independent factors that determine insertion time to caecum (SPSS v22).
Results The profiles of age, gender, BMI and experience of endoscopist were similar between the two groups (Table 1).
Median time to reach the caecum was markedly reduced by RLP compared to LLP (498 vs 698 s; P < 0.01) (Figure 1). Women and those who had previously undergone abdominal surgery gained the greatest benefit from right-sided positioning (women RLP vs LLP: 485 vs 782; .05 and abdominal surgery RLP vs LLP: 481 vs 797s; 0.01). Moreover, patients found RLP more comfortable than LLP (2 vs 3 VAS; .02).
There were no differences in the volumes of sedation (mean midazolam RLP vs LLP: 1.8 vs 1.7 mg; P= ns) or analgesia (mean fentanyl RLP vs LLP: 24.7 vs 24.0 μg; P= ns) used for either group. No complications were recorded in either group.
Multiple linear regression confirmed starting position in colonoscopy as an independent factor affecting time to reach the caecum (P = 0.007), along with experience of endoscopist (P < 0.001) and gender (.048).
Conclusion Starting colonoscopy with patients lying on the right rather than the left-lateral position reduced the median insertion time to caecum by over 3 min. Moreover, patients found right-sided positioning more comfortable than left-sided positioning. It appears that technically challenging groups, such as women and patients who have previously undergone abdominal surgery, gain the greatest benefit from RLP. Future work should examine the benefits of right-sided positioning at a broader range of endoscopy centres.
Disclosure of interest None Declared.