Transient End-Tidal Carbon Dioxide Elevation during Pediatric Upper Endoscopy with Carbon Dioxide Insufflation: Is It True Hypercapnia?

Background:Endoscopic insufflation, long performed using air, is being replaced by carbon dioxide (CO₂) at many pediatric centers, despite limited published data on its use in children. We have previously demonstrated that CO₂use during esophagogastroduodenoscopy (EGD) in non-intubated children is associated with transient elevations of end-tidal CO₂(EtCO₂). This observation raised concerns about possible CO₂inhalation and systemic absorption. Here, we investigate this concern by concurrently measuring both EtCO₂and transcutaneous CO₂(tCO₂) during upper endoscopic procedures in children.Aim:To determine if elevations in EtCO₂levels seen in non-intubated children undergoing CO₂insufflation during EGD are associated with elevated systemic CO₂levels.Methods:Double-blinded, prospective, randomized clinical trial. Children were randomized 1:1 to receive either CO₂or air for endoscopic insufflation. EtCO₂was sampled with a CO₂-sampling nasal cannula and tCO₂was monitored using the Radiometer transcutaneous monitoring device.Results:Fifty nine patients were enrolled; 30 patients in the CO₂insufflation group and 29 in the air group. All patients underwent a procedure involving an EGD. Transient elevations in EtCO₂(defined as >60 mmHg) were observed only in the CO₂insufflation group. This contrasted with the similar elevations of tCO₂between the CO₂and air insufflation groups. None of these events were of clinically significant magnitude or duration.Conclusion:This study demonstrates that the observed transient elevations in EtCO₂seen during EGD in non-intubated children receiving CO₂insufflation are most likely measurements of eructated CO₂without evidence of excessive systemic absorption of CO₂