Monitored Anesthesia Care with Dexmedetomidine Supplemented by Midazolam/Fentanyl versus Midazolam/Fentanyl Alone in Patients Undergoing Pleuroscopy: Effect on Oxygenation and Respiratory Function

Abstract

Although pleuroscopy is considered a safe and well tolerated procedure with a low complication rate, it requires the administration of procedural sedation and analgesia. The purpose of this study was to assess the effects of dexmedetomidine administration on oxygenation and respiratory function in patients undergoing diagnostic or therapeutic pleuroscopy. Through a prospective, single center, cohort study, we studied 55 patients receiving either a dexmedetomidine intravenous infusion supplemented by midazolam/fentanyl (Group DEX + MZ/F) or a conventional sedation protocol with midazolam/fentanyl (Group MZ/F). Our primary outcome was the changes in lung gas exchange (PaO2/FiO2 ratio) obtained at baseline and at predetermined end points, while changes in respiratory mechanics (FEV1, FVC and the ratio FEV1/FVC) and PaCO2 levels, drug consumption, time to recover from sedation and adverse events were our secondary endpoints (NCT03597828). We found a lower postoperative decrease in FEV1 volumes in Group DEX + MZ/F compared to Group MZ/F (p = 0.039), while FVC, FEV1/FVC and gas exchange values did not differ between groups. We also found a significant reduction in midazolam (p < 0.001) and fentanyl consumption (p < 0.001), along with a more rapid recovery of alertness postprocedure in Group DEX + MZ/F compared to Group MZ/F (p = 0.003), while pain scores during the postoperative period, favored the Group DEX + MZ/F (p = 0.020). In conclusion, the use of intravenous dexmedetomidine during pleuroscopy is associated with a smaller decrease in FEV1, reduction of the consumption of supplementary sedatives and analgesics and quicker awakening of patients postoperatively, when compared to midazolam/fentanyl. Therefore, dexmedetomidine administration may provide clinically significant benefits in terms of lung mechanics and faster recovery of patients undergoing pleuroscopy.