Purpose
Optimal level of sedation and respiratory pattern both play important roles in non-intubated thoracoscopic surgery. Common intravenous anesthetics, fentanyl and propofol, cause respiratory depression. Dexmedetomidine, as a highly selective alpha2 adrenergic agonist, exhibits anxiolytic, sedative, and analgesic properties. It is devoid of respiratory depression, and had been approved for non-intubated procedural sedation. However, little is known about its feasibility and safety in non-intubated thoracoscopic surgery.
Patients and Methods
We evaluated 33 patients with lung tumors who underwent non-intubated thoracoscopic surgery using a combination of dexmedetomidine and propofol between February 2016 and September 2017. During anesthetic induction, dexmedetomidine infusion was provided at a constant rate of 0.5 μg/kg/hr through the whole procedure. Target-controlled infusion with propofol was administered to achieve a bispectral index value between 40 and 60.
Results
There was no conversion to tracheal intubation. Intraoperative consumption of fentanyl was 69.7 ± 33.5 mcg, and 14 patients (42%) did not require an incremental dose. Eighteen patients (55%) experienced bradycardia during the procedure and required inotropic agents. There were 4 patients (22%) experienced lower oxygen saturation (SpO2 < 90%) and did not sustain for more than 5 min. During surgery, the mean PaCO2 was 43.1 ± 7.4 mmHg, which was generally lower that patients who were maintained without dexmedetomidine. After surgery, dizziness developed in 5 patients, urinary retention in 1, nausea in 7, and 2 patients experienced vomiting requiring medication. During the perioperative period, 15 patients (45%) did not require morphine, including 4 patients underwent lobectomy and 2 segmentectomy.
Conclusion
Our study demonstrated that nonintubated thoracoscopic using a combination of dexmedetomidine and propofol is feasible. Its analgesic property may extend into the postoperative period with morphine-sparing effect. It may be provided as an intraoperative adjuvant to reduce opioid related adverse effects and improve postoperative outcomes in nonintubated thoracic surgery.

05 / Use of Dexmedetomidine in Non-intubated Thoracoscopic Surgery