A prospective randomized control study comparing classic laryngeal mask airway with Guedel's airway for tracheal tube exchange and smooth extubation

INTRODUCTION: Extubation in deep plane of anesthesia followed by Guedel's oropharyngeal airway (OPA™) insertion is a routine method to avoid hemodynamic changes associated with tracheal extubation. Exchange of endotracheal tube (ETT) with Classic laryngeal mask airway (LMA™) prior to emergence from anesthesia also serves similar purpose. We had compared the hemodynamic changes involved during this ETT/LMA™ and ETT/OPA™ exchange technique. MATERIAL AND METHODS: This was a randomized prospective study on ASA I and 2 patients undergoing elective surgery under general anesthesia. These patients were randomly divided into two groups i.e. OPA group and LMA group of 50 patients each. Hemodynamic parameters i.e. systolic blood pressure (SBP) and heart rate (HR) were recorded during exchange of ETT with OPA™ or LMA™. Coughing / bucking during removal of OPA™ and LMA™, and presence of post operative sore throat for both the groups were also graded and recorded. Data within the groups have been analyzed using paired “t” test while those between the groups were analyzed using unpaired “t” test. Chi square test was used to analyze grades of coughing and post operative sore throat. RESULTS: In both groups, hemodynamic parameters rose significantly as OPA™/LMA™ was placed (P < 0.05) and then started declining. Hemodynamic parameters continued to fall in LMA group after extubation. However in OPA group, hemodynamic parameters continued to rise even after extubation and declined only when OPA™ was removed. There was no statistical significant difference between the LMA and OPA group in respect to coughing and post operative sore throat. CONCLUSION: LMA™ is superior to OPA™ for exchange of ETT as it provides greater hemodynamic stability.