Association between perioperative statin use and postoperative pain after total knee arthroplasty.

BACKGROUND AND OBJECTIVES: Data is insufficient to determine whether perioperative statin use increases or decreases postoperative pain. This study aimed to investigate the association between perioperative statin use and pain outcomes after total knee arthroplasty performed under spinal anesthesia. METHODS: This is a retrospective, observational study based on medical records from a tertiary hospital between January 2005 and October 2017. Medical records of patients who underwent elective total knee arthroplasty under spinal anesthesia as inpatients were analyzed. Pain outcomes were compared through postoperative day (POD) 3 in patients who were taking statins perioperatively versus patients who were not taking statins. RESULTS: A total of 1088 propensity-matched participants were included in the final analysis (544 patients in the statin group and 544 patients in the non-statin group). The total morphine equivalent consumption through POD 3 was higher in the statin group than in the non-statin group (mean (SD), statin group: 525.4 (119.7) vs non-statin group: 495.3 (115.3), 95% CI of the difference: 15.9 to 44.4, p<0.001). In the linear regression analysis, the total morphine equivalent consumption through POD 3 was 30.14 mg higher in the statin group compared with the non-statin group (95% CI 15.93 to 44.35; p<0.001). CONCLUSIONS: Perioperative statin use is associated with a significant increase in postoperative opioid consumption after total knee arthroplasty performed under spinal anesthesia; however, this increase was so marginal that its clinical importance remains controversial.

Association between perioperative cholesterol level and analgesia after video-assisted thoracoscopic surgery.

BACKGROUND: Cholesterol plays an important role in the action of opioid analgesics, but its association with postoperative pain has not been clarified. Our study examined the association of pre- and postoperative total serum cholesterol (TSC), and change between the pre- and postoperative TSC levels with postoperative pain outcomes in patients with non-small cell lung cancer (NSCLC) who underwent video-assisted thoracoscopic surgery (VATS) lobectomy. METHODS: We retrospectively reviewed medical records of patients with NSCLC who underwent VATS lobectomy at the Seoul National University Bundang Hospital in South Korea. We sought to determine the association between preoperative TSC, TSC on postoperative day (POD) 0-1, and pre- and postoperative changes in TSC by comparing numeric rating scale (NRS) scores on POD 0, 1, and 2 and total morphine equivalent consumption on POD 0-2. Multivariate linear regression analyses were used, and P < 0.05 was considered statistically significant. RESULTS: A total of 1,720 patients with NSCLC who underwent VATS lobectomy were included in the analysis. The change in TSC, preoperative TSC, and postoperative TSC showed no associations with morphine equivalent consumption on POD 0-2 (P > 0.05). In addition, the changes in TSC, preoperative TSC, and postoperative TSC were not associated with postoperative NRS pain score on POD 0, 1, and 2 (P > 0.05). CONCLUSIONS: Our results indicated that no significant association was observed between pre- and postoperative TSC level and postoperative pain outcome after VATS lobectomy of the lung.

The effect of a mixture of 2.7% sorbitol-0.54% mannitol solution on blood coagulation: an invitro, observational healthyvolunteer study using rotational thromboelastometry (ROTEM).

BACKGROUND: We investigated the effect of irrigation fluid on coagulation according to the hemodilution level using rotational thromboelastometry (ROTEM). METHODS: Venous blood was taken from 12 healthy volunteers and divided into four specimen tubes that were diluted to various levels (0%, 10%, 20%, and 40%) using an irrigation fluid composed of 2.7% sorbitol and 0.54% mannitol. RESULTS: Significant prolongation of clotting time was observed in the 40% diluted sample using both INTEM (P = 0.009) and EXTEM (P = 0.001) assays. However, the clot formation time was prolonged significantly in the 10%, 20%, and 40% diluted samples using both INTEM (P < 0.001) and EXTEM (P = 0.002, P < 0.001, and P < 0.001, respectively) assays. A significant decrease of α-angle of INTEM and EXTEM were observed in the 10% (P < 0.001), 20% (P < 0.001 and P = 0.001, respectively), and 40% (P < 0.001) groups compared with the 0% dilution group. The maximum clot firmness (MCF) of INTEM decreased significantly in the 20% (P < 0.001) and 40% (P < 0.001) diluted samples. In the MCF of EXTEM and FIBTEM assays, 10% (P = 0.009 and P = 0.015, respectively), 20% (P = 0.001), and 40% (P < 0.001) samples showed a significant decrease compared with the 0% sample. Nevertheless, most of the ROTEM values were within the reference range, except the 40% sample. CONCLUSIONS: Blood became hypocoagulable when it was diluted in vitro with a fluid composed of 2.7% sorbitol and 0.54% mannitol.