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Background: We previously developed an automated total intravenous anesthesia control system that uses new closed-loop system algorithms to administer propofol, remifentanil, and rocuronium based on the bispectral index and train-of-four data. We recently improved this automated control system by adding a safety mechanism and using a modified monitoring device. Methods: Patients scheduled for elective surgery were randomly assigned to closed-loop feedback control (automatic group) or the manual administration of propofol, remifentanil, and rocuronium (manual group). The proportion of time during which the proper management of three-agent anesthesia was maintained during surgery was determined as the primary endpoint. Results: The proportion of time during which the three components of sedation, analgesia, and muscle relaxation were adequately controlled was 87.21 ± 12.79% in the automatic group, which was non-inferior to the proportion of 65.19 ± 20.16% in the manual group (p < 0.001). Adverse events during the operative or postoperative observation periods were significantly less frequent in the automatic group (54 patients, 90.0%) than in the manual group (60 patients, 100.0%; p = 0.027). Conclusion: Our three-agent automated control system, which features an improved muscle relaxation monitor and safety mechanism added to the basic control algorithms, maintained sedation, analgesia, and muscle relaxation appropriately in a manner non-inferior to anesthesiologists without compromising safety. [ABSTRACT FROM AUTHOR]

Purpose: The true incidence of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) events, and the predictive risk factors are not well-defined in patients who undergo major lower extremity arthroplasty such as total hip arthroplasty (THA) or total or partial knee arthroplasty (TPKA). Using multidetector computed tomography (MDCT), pulmonary angiography (CTA), and MDCT venography (CTV), we investigated the prevalence of VTE and its predictive risk factors in patients for whom the guideline recommends prophylaxis. Methods: The electronic records of patients who underwent elective THA or TPKA at our institution from April 2010 through July 2013 were surveyed. We examined a total of 1,163 patient records for 986 patients who had undergone MDCT seven days after THA or TPKA. Results: No PE-related deaths occurred in this study, though arterial embolization was needed for major bleeding in two cases. CTA-CTV revealed VTE in 51 (4.4 %) patients, PE in 20 (1.7 %), and DVT in 43 (3.3 %). Five of 51 patients had symptoms suggestive of DVT. In the logistic regression model, the type of surgery (TPKA > THA), patient age, and body mass index (BMI) were identified as predictive risk factors for VTE. Conclusions: This observational study showed that the overall incidence of VTE after THA and TPKA is 4.4 % in patients receiving recommended antithrombotic prophylaxis. TPKA is associated with a higher incidence of VTE than of THA, and greater BMI and older patient age are also independent risk factors. [ABSTRACT FROM AUTHOR]