Patient position change in colonoscopy: Dogmatic or pragmatic?

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.

Pulmonary aspiration during procedural sedation for colonoscopy resulting from positional change managed without oral endotracheal intubation

Background

Pulmonary aspiration under anaesthesia is a feared complication. It is likely that the incidence of aspiration occurring during procedural sedation is underreported; although rare, fatalities do occur. The supine position increases the risk of pulmonary aspiration in gastrointestinal endoscopy during procedural sedation. Immediate oral endotracheal intubation has traditionally been the cornerstone of management for aspiration during anaesthesia; however, this may not be always beneficial when aspiration occurs during procedural sedation. To my knowledge, this is the first case report of aspiration pneumonitis resulting from surgical repositioning during colonoscopy under procedural sedation.

Case presentation

A 72-year-old female underwent elective outpatient diagnostic colonoscopy. Intravenous propofol infusion was commenced for the procedural sedation. A large amount of non-particulate vomitus was expelled from the oropharynx as the patient was repositioned from the left lateral to supine position. Oxygen saturation on pulse oximetry immediately dropped to below 90% during the event. The patient was managed successfully without oral endotracheal intubation.

Conclusions

Anaesthesiologists need to be mindful of factors that raise the risk of aspiration during procedural sedation. Gastrointestinal endoscopy poses a higher risk of aspiration than other procedures, and positional change may be a precipitant. Aspiration that occurs during procedural sedation may be more safely managed by avoiding immediate oral endotracheal intubation.