Background: We evaluated the incidence of postoperative acute kidney injury (AKI) and complications when remimazolam (RMMZ) or sevoflurane (SEVO) were used in elderly patients undergoing total knee arthroplasty. Methods: Seventy-eight participants aged ≥65 were randomly allocated to either the RMMZ or SEVO group. The primary outcome was the incidence of AKI on postoperative day (POD) 2. The secondary outcomes included intraoperative heart rate (HR), blood pressure (BP), total drug administered, emergence time, postoperative complications on POD 2, and hospital length of stay (HLOS). Results: The incidence of AKI was comparable between the RMMZ and SEVO groups. The doses of intraoperative remifentanil, vasodilators, and additional sedatives were significantly higher in the RMMZ group than in the SEVO group. Overall intraoperative HR and BP tended to remain higher in the RMMZ group. The emergence time in the operating room was significantly faster in the RMMZ group; however, the time required for an Aldrete score ≥ 9 was comparable between the RMMZ and SEVO groups. Postoperative complications and HLOS were comparable between the RMMZ and SEVO groups. Conclusion: RMMZ may be recommended for patients who are expected to decrease in intraoperative vital signs. However, stable hemodynamics with RMMZ were not sufficient to influence the prevention of AKI.

Background: Remimazolam besylate, a newly developed drug, is linked to various anaphylaxis cases. We present a case of remimazolam anaphylaxis confirmed using a provocation test. Case: A 51-year-old female patient was scheduled for humeral pinning. General anesthesia was induced using remimazolam, rocuronium, and remifentanil. After tracheal intubation, the patient experienced decreased blood pressure, increased heart rate, and a systemic rash. Epinephrine was administered repeatedly, and the patient’s vital signs stabilized. Acute phase tryptase levels were within normal limits. After four weeks, intradermal test results were negative. When remimazolam was administered intravenously for the provocation test, facial swelling, flushing, and coughing occurred, which improved with epinephrine. The culprit drug was identified as remimazolam using a provocation test. Conclusions: When anaphylaxis occurs during anesthesia induction, remimazolam should not be ruled out as the causative drug. If the skin test result for remimazolam is negative, a provocation test should be considered. The provocation test should be initiated cautiously at a low dose under careful patient monitoring.

Total hip replacement (THR) is often accompanied by severe postoperative pain. We aimed to study whether oxycodone can be an effective alternative for fentanyl in the management of early postoperative pain after total hip replacement. We conducted a randomized controlled trial on 46 patients scheduled to undergo THR. We followed a standard general anesthetic technique, with endotracheal intubation. Twenty minutes before the end of surgery, single bolus injection of fentanyl, 50 μg (fentanyl group [group F], n = 23) or oxycodone, 4 mg (oxycodone group [group O], n = 23) was administered intravenously. Numeric rating scale (NRS) was used to assess pain in the post-anesthesia care unit (PACU). All patients had intravenous patient-controlled analgesia (PCA) with 10 μg/kg of fentanyl for 48 hours. Intravenous boluses of 50 μg were administered for breakthrough pain. The cumulative opioid dose administered at 6, 12, 24, and 48 h after surgery were recorded. A P value of less than .05 was considered statistically significant. The NRS of group O in the PACU was significantly lower (P <.05); fewer patients in group O required additional fentanyl boluses in the PACU (P <.05). The cumulative opioid requirement was significantly less in group O at 6, 12, 24, and 48 hours after surgery. (P <.05) A single bolus injection of oxycodone is more effective than that of fentanyl in the acute phase of postoperative pain after THR. It may be used as an alternative drug for fentanyl in pain control after orthopedic surgery.

Background: We aimed to evaluate whether the administration of remimazolam as a maintenance agent for general anesthesia affects the occurrence of hypotension compared with sevoflurane when switching to the beach chair position (BCP). Methods: We conducted a prospective randomized controlled trial from June 2023 to October 2023 in adult patients undergoing orthopedic surgery under general anesthesia in the BCP. A total of 78 participants were randomly allocated to the remimazolam (R) or sevoflurane (S) groups. The primary outcome was the incidence of hypotension that occurred immediately after switching to a BCP. The secondary outcomes included differences between the study groups in perioperative blood pressure (BP), heart rate (HR), endotracheal tube extubation time, postoperative complications, and hospital length of stay (LOS). Results: The incidence of hypotension immediately after switching to a BCP was significantly higher in the S group. The risk factors associated with hypotension included sevoflurane administration and a high baseline systolic BP. In the receiver operating characteristic curve analysis for the occurrence of hypotension after the transition to a BCP, the cutoff value for systolic BP was 142 mmHg. The perioperative BP and HR were higher in the R group at several timepoints. Postoperative endotracheal tube extubation time was shorter in the R group. There were no significant differences in the postoperative complications or hospital LOS between the two groups. Conclusions: Remimazolam should be considered as an anesthetic agent to prevent hypotension when switching to BCP, and hypotension may occur frequently in patients with high baseline BP.

A change from the supine to prone position causes hemodynamic alterations. We aimed to evaluate the effect of fluid preloading in the supine position, the subsequent hemodynamic changes in the prone position and postoperative outcomes. This prospective, assessor-blind, randomized controlled trial was conducted between March and June 2023. Adults scheduled for elective orthopaedic lumbar surgery under general anaesthesia were enrolled. In total, 80 participants were randomly assigned to fluid maintenance (M) or loading (L) groups. Both groups were administered intravenous fluid at a rate of 2 ml/kg/h until surgical incision; Group L was loaded with an additional 5 ml/kg intravenous fluid for 10 min after anaesthesia induction. The primary outcome was incidence of hypotension before surgical incision. Secondary outcomes included differences in the mean blood pressure (mBP), heart rate, pleth variability index (PVi), stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index and cardiac index before surgical incision between the two groups. Additionally, postoperative complications until postoperative day 2 and postoperative hospital length of stay were investigated. Hypotension was prevalent in Group M before surgical incision and could be predicted by a baseline PVi >16. The mBP was significantly higher in Group L immediately after fluid loading. The PVi, SVV and PPV were lower in Group L after fluid loading, with continued differences at 2-3 time points for SVV and PPV. Other outcomes did not differ between the two groups. Fluid loading after inducing general anaesthesia could reduce the occurrence of hypotension until surgical incision in patients scheduled for surgery in the prone position. Additionally, hypotension could be predicted in patients with a baseline PVi >16. Therefore, intravenous fluid loading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position. KCT0008294 (date of registration: 16 March 2023).