Comparison of Upper Airway Ultrasonography With End-Tidal Capnography for the Confirmation of Endotracheal Tube Placement in Patients Requiring General Anesthesia

Abstract

Introduction End-tidal capnography (EtCO₂) has been the gold standard method for confirmation of endotracheal intubation. Upper airway ultrasonography (USG) is a new promising method for confirming endotracheal tube (ETT) placement and has the potential to become the first-line non-invasive airway assessment tool in the future thanks to widespread POCUS knowledge, greater technology improvements, portability, and availability of ultrasound in the majority of essential areas. Hence our study aimed to compare upper airway USG and EtCO₂ for the confirmation of ETT placement in patients undergoing general anesthesia. Aim To compare the upper airway USG with EtCO₂ for confirmation of ETT placement in patients requiring general anesthesia for elective surgical procedures. The objectives of the study were to compare the time taken for confirmation, and the number of correct identification of tracheal and esophageal intubation by both upper airway USG and EtCO₂. Materials and methods After obtaining institutional ethical committee (IEC) approval, a prospective randomized comparative study involving 150 patients under American Society of Anesthesiologists (ASA) grade I and II requiring endotracheal intubation for elective surgeries under general anesthesia was randomized into two groups, Group U-upper airway USG and Group E-EtCO₂ with 75 patients in each group. ETT placement confirmation was done by upper airway USG in Group U and by EtCO₂ in Group E and the time taken for confirmation of ETT placement and correct identification of esophageal and tracheal intubation by USG and EtCO₂ was noted. Results The demographic details among both groups were statistically insignificant. Upper airway USG had a faster average confirmation time of 16.41 seconds when compared to EtCO₂ which took an average confirmation time of 23.56 seconds. In our study, upper airway USG was able to identify esophageal intubation with 100% specificity. Conclusion Upper airway USG can be a reliable method and can be employed as a standard method for confirmation of ETT location in patients undergoing elective surgeries under general anesthesia when compared to EtCO₂.

Keywords: capnography; endotracheal tube; general anesthesia; intubation; upper airway ultrasonography.