The association of regional block with intraoperative opioid consumption in patients undergoing video-assisted thoracoscopic surgery: a single-center, retrospective study.

BACKGROUND: Regional block, such as thoracic epidural analgesia (TEA), thoracic paravertebral block (TPVB), or serratus anterior plane block (SAPB) has been recommended to reduce postoperative opioid use in recent guidelines, but the optimal options for intraoperative opioid minimization remain unclear. The aim of this study was to evaluate the intraoperative opioids-sparing effects of three regional blocks (TEA, TPVB, and SAPB) in patients undergoing video-assisted thoracoscopic surgery (VATs). METHODS: This was a retrospective study of the adults undergoing VATs at a tertiary medical center between January 2020 and February 2022. According to the type of regional block used, patients were classified into 4 groups: GA group (general anesthesia without any regional block), TEA group (general anesthesia combined with TEA), TPVB group (general anesthesia combined with TPVB), and SAPB group (general anesthesia combined with SAPB). Cases were matched with a 1:1:1:1 ratio for analysis by age, sex, ASA physical status, and operation duration. The primary outcome was the total intraoperative opioid consumption standardized to Oral Morphine Equivalents (OME). Multivariable linear regression was used to estimate the association of the three regional blocks with the OME. RESULTS: A total of 2159 cases met the eligibility criteria. After matching, 168 cases (42 in each group) were included in analysis. Compared with GA without any reginal block, the use of TEA, TPVB, and SAPB reduced the median of intraoperative OME by 78.45 mg (95% confidence interval [CI], -141.34 to -15.56; P = 0.014), 94.92 mg (95% CI, -154.48 to -35.36; P = 0.020), and 11.47 mg (95% CI, -72.07 to 49.14; P = 0.711), respectively. CONCLUSIONS: The use of TEA or TPVB was associated with an intraoperative opioid-sparing effect in adults undergoing VATs, whereas the intraoperative opioid-sparing effect of SAPB was not yet clear.

An improved surgical instrument without coupled motions that can be used in robotic-assisted minimally invasive surgery.

In order to enhance the dexterity of surgical instruments in robotic-assisted minimally invasive surgery, the robot is generally configured so as to have a wrist. However, this configuration has a problem in that there is a coupling of the motions of the wrist and the end-effector. In this paper an improved surgical instrument is proposed that eliminates the coupled motion using a compensation mechanism. The design concept behind the compensation mechanism can be applied to other types of surgical instruments. The performance of the proposed surgical instrument is validated by mechanical performance testing and animal experiments, which indicate that the problem of the coupled motion is successfully solved and the instrument is able to perform surgical tasks.