Intraoperative multiple intercostal nerve blocks exert anesthetic-sparing effect: A retrospective study on the effect-site concentration of propofol infusion in nonintubated thoracoscopic surgery

Less general anesthetic is required in patients with regional blocks than in those without, as assessed through commonly used anesthesia monitoring parameters such as blood pressure, heart rate, and bispectral index (BIS). Although intraoperative regional anesthesia has become more widely adopted, few studies have confirmed or monitored its anesthetic-sparing effects. Using recent reports of nonintubated video-assisted thoracoscopic surgery (VATS) by BIS-targeted propofol infusion and intraoperative multilevel thoracoscopic intercostal nerve blocks (TINBs), this retrospective study investigated whether the anesthetic-sparing effect can be realized by reducing the effect-site concentration (Ce) to the targeted BIS level or by reducing the blood pressure at the onset of regional blocks.