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.

Ascorbic acid insufficiency induces the severe defect on bone formation via the down-regulation of osteocalcin production.

The L-gulono-γ-lactone oxidase gene (Gulo) encodes an essential enzyme in the synthesis of ascorbic acid from glucose. On the basis of previous findings of bone abnormalities in Gulo (-/-) mice under conditions of ascorbic acid insufficiency, we investigated the effect of ascorbic acid insufficiency on factors related to bone metabolism in Gulo (-/-) mice. Four groups of mice were raised for 4 weeks under differing conditions of ascorbic acid insufficiency, namely, wild type; ascorbic acid-sufficient Gulo (-/-) mice, 3-week ascorbic acid-insufficient Gulo (-/-) mice, and 4-week ascorbic acid-insufficient Gulo (-/-) mice. Four weeks of ascorbic acid insufficiency resulted in significant weight loss in Gulo (-/-) mice. Interestingly, average plasma osteocalcin levels were significantly decreased in Gulo (-/-) mice after 3 weeks of ascorbic acid insufficiency. In addition, the tibia weight in ascorbic acid-sufficient Gulo (-/-) mice was significantly higher than that in the other three groups. Moreover, significant decreases in trabecular bone volume near to the growth plate, as well as in trabecular bone attachment to the growth plate, were evident in 3- or 4-week ascorbic acid-insufficient Gulo (-/-). In summary, ascorbic acid insufficiency in Gulo (-/-) mice results in severe defects in normal bone formation, which are closely related to a decrease in plasma osteocalcin levels.