Analysis of Infusion Patterns of Propofol and Remifentanil During Rigid Bronchoscopy Under Total Intravenous Anesthesia

OBJECTIVES: We analyzed the dosage pattern of anesthetic drugs administered to maintain anesthesia during rigid bronchoscopy. METHODS: We enrolled a total of 81 patients who underwent rigid bronchoscopy under total intravenous anesthesia between April 2015 and March 2019. Anesthesia was maintained using propofol (target brain concentration 2.0 - 6.0 µg/mL) and remifentanil (target brain concentration 2.0 - 6.0 ng/mL). We analyzed the dosage patterns of the anesthetic agents during the procedure, as well as the changes in the dose of the anesthetic agents and the number of procedures repeated in the same patient. RESULTS: The dose of propofol administered per minute to maintain anesthesia was inversely correlated with the total operation time (r(2) = 0.355, β = -0.067, P < 0.000) but was not significantly correlated with the number of times the procedure was repeated. The dose of remifentanil did not significantly differ during repeated procedures in the same patient. CONCLUSIONS: The dose of propofol infusion tended to decrease over time during the rigid bronchoscopy procedure. This pattern was specific to propofol but not to remifentanil using TIVA. Understanding the pharmacokinetic properties of anesthetic drugs will help in their appropriate administration.