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

Abstract

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