The following is a summary of “Elevations in End-Tidal CO2 With CO2 Use During Pediatric Endoscopy With Airway Protection: Is This Physiologically Significant?,” published in the May 2023 issue of Pediatrics by Dike, et al.
During endoscopy, inflating the gastrointestinal lumen is necessary for proper visualization. Carbon dioxide (CO) is increasingly used instead of air to minimize post-procedural discomfort due to retained gas. However, recent studies have raised safety concerns regarding using CO during pediatric esophagogastroduodenoscopy (EGD) with an unprotected airway, as it has been associated with transient elevations in exhaled CO2 (end-tidal CO2, EtCO). One possible explanation for these events is the eructation of insufflated gas from the stomach. For a study, researchers sought to differentiate between eructated and absorbed CO by sampling EtCO from a protected airway using either a laryngeal mask airway (LMA) or endotracheal tube (ETT) and to observe any changes in minute ventilation (MV) to rule out hypoventilation events.
The double-blinded, randomized clinical trial compared CO insufflation with air insufflation during EGD with airway protection using either an LMA or ETT. Tidal volume, respiratory rate, MV, and EtCO were automatically recorded every minute. The study cohort’s demographic characteristics were described, and variables such as the percentage of children with peak and transient EtCO ≥ 60 mmHg were compared between the groups.
A total of 195 patients underwent 200 procedures. Transient elevations in EtCO2 ≥ 60 mmHg were more common in the CO group compared to the air group (16% vs. 5%, P = 0.02), with most observations occurring with LMA and fewer with ETT. Post-procedure pain did not differ between the groups, but flatulence was reported more frequently with air insufflation (P = 0.004).
Transient elevations in EtCO2 occurred more frequently with CO2 insufflation than air insufflation during pediatric EGD, even when protecting the airway with an LMA or, to a lesser extent, an ETT. These elevations did not result in changes in MV, and no adverse clinical effects from CO absorption were observed. However, the findings suggested caution should be exercised when considering CO2 insufflation, particularly as the observed benefits of using the gas were minimal.