Non-invasive carbon dioxide monitoring during moderate sedation at different oxygen flow rates in patients undergoing endoscopic retrograde cholangio-pancreatography

Mostafa, Mohamed F.; Mamdouh Osman, Ayman; Reda Mohamed Abdallah, Ahmed; Mostafa Thabet, Ahmed; Abbas Hassan, Shimaa

doi:TEJA-2022-0231

Non-invasive carbon dioxide monitoring during moderate sedation at different oxygen flow rates in patients undergoing endoscopic retrograde cholangio-pancreatography

Authors

TEJA-2022-0231

Abstract

Background
All patients receiving sedation to facilitate endoscopic procedures should have monitoring of cardiorespiratory parameters before, during, and after administration of sedation/analgesia. We evaluated the effects of different O flow rates on the non-invasive CO monitoring (EtCO) in adult patients that were breathing spontaneously under moderate sedation during ERCP.
Methods
This prospective randomized double-blind study was conducted on 120 patients assigned randomly to one of the three equal groups (n = 40) (Group I; 2 L/min oxygen flow rate, Group II; 4 L/min oxygen flow rate, and Group III; 6 L/min oxygen flow rate). Primary outcome was EtCO at the end of procedure. Secondary outcomes included peripheral O saturation, hemodynamics, time to recovery, total propofol dose, patients’ satisfaction, sedation score, and complications.
Results
EtCO increased significantly between the studied groups at pre-intervention, induction, 5, 10, 20, and 30 min but without any clinical significance (p-value ˂ 0.05). The HR changes were statistically significant at 10 and 20 min after induction of anesthesia. While SpO, MBP, and RR differences were statistically not significant between groups throughout the whole study periods (p-value >0.05). Arterial blood gas analysis showed PCO was significantly different between the study groups but still within the normal range of readings, while pH and HCO showed statistically insignificant differences between the three groups.
Conclusion
The study demonstrated that different O flow rates did not affect the non-invasive EtCO measurements by the Dual-Guard device during moderate sedation in patients undergoing ERCP. Non-invasive EtCO monitoring can provide an early warning sign of hypoventilation during moderate sedation.

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