Many well-controlled clinical studies have shown that BIS-guided anesthesia could prevent intraoperative awareness and improve postoperative morbidity and mortality, by optimizing the amount of volatile anesthetics administered to patients. However, we questioned if the previously reported advantages of BIS-guided anesthesia in controlled studies would still apply in real-world settings. This retrospective study based on real-world settings clarified the role of BIS-guided anesthesia in reducing anesthetic consumption. We obtained anesthesia records from an electronic database of a medical center in southern Taiwan. A total of 6,713 cases were enrolled, where 1,324 cases receiving sevoflurane underwent BIS-guided anesthesia and 378 received desflurane; further, 3,819 receiving sevoflurane underwent standard anesthesia practice and 1,192 cases received desflurane. The median (25–75% interquartile values) of the average hourly consumption of sevoflurane or desflurane decreased significantly under BIS-guided anesthesia [10.5 (8.7–13.0) mL/h and 17.4 (13.7–21.1) mL/h, respectively] compared to that under standard anesthesia practice [11.4 (9.0–14.5) mL/h, and 20.2 (15.8–25.0), mL/h, respectively]. Furthermore, the average hourly consumption of these two volatile anesthetics varied inversely with age and anesthesia time in both groups. A significant reduction was found in the hourly consumption of volatile anesthetics in patients under BIS-guided anesthesia compared to standard anesthesia practice in different age groups or different anesthesia time. We concluded that BIS-guided anesthesia could reduce consumption of volatile anesthetics in real-world settings as well.

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis (OA) of the knee, because it alleviates pain and restores function of the knee. However, TKA-associated hemorrhage and subsequent anemia remain a concern. Most previous studies have defined meaningful postoperative bleeding as blood loss > 500 mL or hemoglobin (Hb) drop > 20 g/L. Therefore, we defined significant hemorrhage as a postoperative Hb drop more than 20 g/L in this study, and we investigated possible risk factors related to significant hemorrhage in TKA and whether these risk factors are modifiable. This retrospective study was conducted through a comprehensive review of the perioperative records of patients with OA of the knee who underwent TKA between January 2009 and December 2015 at our hospital. Patients were allocated into two groups: patients in Group A had their Hb drop ≤ 20 g/L; patients in Group B had their Hb drop > 20 g/L. Factors analyzed included sex, age, body mass index (BMI), the American Society of Anesthesiologists (ASA) classification, comorbidities, preoperative platelet count, use of tranexamic acid (TXA), operation time, and type of anesthesia. A total of 3350 patients met the criteria for analysis, with 1782 patients allocated to Group A and 1568 patients to Group B. Five independent risk factors for significant hemorrhage were identified: male sex (odds ratio(OR), 1.29; 95% confidence interval(CI), 1.08–1.53; p = 0.005), age (OR, 1.02; 95% CI, 1.01–1.03; p = 0.001), use of TXA (OR, 0.39; 95% CI, 0.34–0.45; p < 0.001), spinal anesthesia versus general anesthesia (OR, 0.71; 95% CI, 0.56–0.90; p = 0.004), and preoperative platelet count (OR, 0.96; 95% CI, 0.93–0.98; p = 0.001). Of these identified risk factors, preoperative platelet count, use of TXA, and spinal anesthesia are modifiable. These potentially modifiable risk factors need to be taken into consideration when making both the perioperative care and anesthesia plan by surgeons and anesthesiologists, especially in patients at risk of significant hemorrhage.

Adductor canal block (ACB) has gained popularity for postoperative pain control after total knee arthroplasty (TKA). However, its role in TKA has been questioned recently. Our study aimed to clarify the role of ACB in reducing postoperative pain after TKA and to elucidate an optimal timing to perform ACB for better outcomes. We conducted a comprehensive review of the perioperative records of 652 patients undergoing primary TKA from January 2019 to December 2019. Patients were divided into three groups: Group A received general anesthesia without ACB, Group B received ACB before inducing general anesthesia, and Group C received ACB at the post-anesthesia recovery unit (PACU). Patients in Groups B and C had lower pain visual analogue scale (VAS) scores than patients in Group A at the PACU. Opioid consumption was similar among the three groups; however, a slightly higher dose was required by Group A patients. Higher VAS scores were recorded in the ward in Group A than in Groups B and C with the leg at rest. In addition, higher VAS scores were recorded in Group A than in Groups B and C with the leg in continuous passive motion (CPM) training. More patients in Group A (34.9%) quit their first CPM training after a few cycles than those in Groups B (27.0%) and C (20.1%). Group A patients required a higher per kg dose of opioids in the ward than Groups B and C patients. Additionally, the hourly consumption of sevoflurane was similar among the three groups of patients, while Group A and C patients required a higher hourly per kg dose of intraoperative opioids than Group B patients. More patients in Group A (67.6%) and C (61.7%) developed intraoperative hypertension than patients in Group B (52.7%). There was no significant difference in PON (postoperative nausea), POV (postoperative vomiting), postoperative dizziness, or patient satisfaction among the three groups of patients. Group A patients had a longer length of hospital stay compared to Group B and C patients. In conclusion, preoperative ACB could be a better choice for patients undergoing TKA as it decreases intraoperative opioid consumption and facilitates a stable hemodynamic state during surgery.

We investigated the influence of different neuromuscular blocking agents and reversal agents during anaesthesia on early removal of chest tube drainage after video-assisted thoracoscopic surgery (VATS). This retrospective single-centre study included patients who underwent VATS after tracheal intubation under general anaesthesia. Patients received either cisatracurium and neostigmine (n=547) or rocuronium and sugammadex (n=151). Quantitative neuromuscular monitoring was used and one chest tube (size 24 Fr) was inserted. To reduce potential bias, 140 patients from each group were matched by propensity score for sex, age, body mass index and indication for VATS. Primary outcome was duration of chest tube drainage after surgery. Use of rocuronium and sugammadex was associated with a shorter duration of chest tube drainage (2 [1-2] vs 2 [1-3] days; P=0.049) and a 63% reduction in delayed chest tube removal (odds ratio 0.37; 95% confidence interval [CI]: 0.20-0.67; P=0.005). This group also had a lower incidence of postoperative atelectasis (P=0.047) and consolidation (P=0.008). Each 1 h increase in the duration of anaesthesia was associated with a 1.57-fold increase in the delayed removal of the chest tube (95% CI: 1.25-1.96; P=0.005). During general anaesthesia for VATS, compared with cisatracurium and neostigmine, use of rocuronium and sugammadex was associated with a significant decrease in the incidence of postoperative delayed removal of the chest tube, atelectasis, and pulmonary consolidation.

Numerous studies on postoperative nausea and vomiting (PONV) have been carried out since the early days of contemporary surgery. The incidence of PONV has been greatly reduced in recent years and new drugs for PONV keep evolving in the market; however, a substantial number of patients are still under the threat of PONV. Female gender, non-smokers, a history of PONV/motion sickness, and postoperative opioid use are four well-recognized risk factors of PONV. Many potential risk factors reported in previous studies were not consistently presented as predictors for PONV. Two questions then arise; are risk factors clinical setting dependent and are risk factors modifiable? We attempted to answer the questions through a comprehensive review of perioperative records of surgical patients from the Trauma Department of our hospital. As nausea is subjective and no standard is applicable for its measurement, postoperative vomiting (POV) was used as an endpoint in this study. To the best of our knowledge, this is the first study to address the POV issue in surgical trauma patients. A total of 855 patients were enrolled in this study after excluding age below 20 years old, total intravenous anesthesia, desflurane anesthesia, or records with missing data. Our results showed that female gender (OR 4.89) is the strongest predicting factor, followed by a less potent predicting factor—more intraoperative opioid consumption (OR 1.07)—which favor more POV. More intraoperative crystalloid supply (OR 0.71) and a higher body weight (OR 0.9) favor less POV. Other potential risk factors did not reach statistical significance in this study as independent risk factors. Our results also showed that when the intraoperative crystalloid infusion rate is greater than 4 mL/kg/h (OR 0.20), it favors a lower rate of POV; when intraoperative opioid consumption is greater than 12 mg morphine equivalents, MME (OR 1.87), it favors a higher rate of POV. We concluded that dominance of any independent risk factor over other risk factors depends on how individual factors interact with the clinical setting. Some risk factors could be modified, and a cut-off value could be derived to facilitate a better plan for POV prevention.