Recovery of cardiac electrophysiological alterations by heart rate complexity based on multiscale entropy following liver transplantation.

Autonomic nervous dysfunction is a known cardiac sequalae in patients with end-stage liver disease and is associated with a poor prognosis. Heart rate analysis using nonlinear models such as multiscale entropy (MSE) or complexity may identify marked changes in these patients where conventional heart rate variability (HRV) measurements do not. To investigate the application of heart rate complexity (HRC) based on MSE in liver transplantation settings. Thirty adult recipients of elective living donor liver transplantation were enrolled. HRV parameters using conventional HRV analysis and HRC analysis were obtained at the following time points: (1) 1 day before surgery, (2) postoperative day (POD) 7, (3) POD 14, (4) POD 90, and (5) POD 180. Preoperatively, patients with MELD score ≥ 25 had significantly lower HRC compared to patients with lower MELD scores. This difference in HRC disappeared by POD 7 following liver transplantation and subsequent analyses at POD 90 and 180 continued to show no significant difference. Our results indicated a significant negative correlation between HRC based on MSE analysis and liver disease severity preoperatively, which may be more sensitive than conventional linear HRV analysis. HRC in patients with MELD score ≧ 25 improved over time and became comparable to those with MELD < 25 as early as in 7 days.

Immunocyte profiling changes in patients received epidural versus intravenous analgesia after pancreatectomy: A randomized controlled trial.

BACKGROUND: Perioperative immunosuppressants, such as surgical stress and opioid use may downregulate anti-cancer immunocytes for patients undergoing pancreatectomy. Thoracic epidural analgesia (TEA) may attenuate these negative effects and provide better anti-cancer immunocyte profile change than intravenous analgesia using opioid. METHODS: We randomly assigned 108 adult patients undergoing pancreatectomy to receive one of two 72-h postoperative analgesia protocols: one was TEA, and the other was intravenous patient-controlled analgesia (IV-PCA). The perioperative proportional changes of immunocytes relevant to anticancer immunity-namely natural killer (NK) cells, cytotoxic T cells, helper T cells, mature dendritic cells, and regulatory T (Treg) cells were determined at 1 day before surgery, at the end of surgery and on postoperative day 1,4 and 7 using flow cytometry. In addition, the progression-free survival and overall survival between the two groups were compared. RESULTS: After surgery, the proportions of NK cells and cytotoxic T cells were significantly decreased; the proportion of B cells and mature dendritic cells and Treg cells were significantly increased. However, the proportions of helper T cells exhibited no significant change. These results were comparable between the two groups. Furthermore, there were no significant differences in progression-free survival (52.75 [39.96] and 57.48 [43.66] months for patients in the TEA and IV-PCA groups, respectively; p = 0.5600) and overall survival (62.71 [35.48] and 75.11 [33.10] months for patients in the TEA and IV-PCA groups, respectively; p = 0.0644). CONCLUSIONS: TEA was neither associated with favorable anticancer immunity nor favorable oncological outcomes for patients undergoing pancreatectomy.

Comparisons in analgesic effects between ultrasound-guided erector spinae plane block and surgical intercostal nerve block after video-assisted thoracoscopic surgery: A randomized controlled trial.

STUDY OBJECTIVE: This study aimed to compare the analgesic effects of anesthesiologist-administrated erector spinae plane block (ESPB) and surgeon-administrated intercostal nerve block (ICNB) following video-assisted thoracoscopic surgery (VATS). DESIGN: Randomized, controlled, double-blinded study. SETTING: Operating room, postoperative recovery room and ward in two centers. PATIENTS: One hundred patients, ASA I-III and scheduled for elective VATS. INTERVENTIONS: The anesthesiologist-administrated ESPB under ultrasound guidance or surgeon-administrated ICNB under video-assisted thoracoscopy was randomly provided during VATS. Regular oral non-opioid analgesic combined with intravenous rescue morphine were prescribed for multimodal analgesia after surgery. MEASUREMENTS: The primary outcomes were the pain score and morphine consumption during 48 h after surgery. Postoperative pain intensity were assessed using the 10-cm visual analogue scale at 1 h, 24 h, and 48 h after surgery. Morphine consumption at these time points was compared between the two study groups. Furthermore, oral weak opioid rescue analgesic was also provided at 24 h after surgery. Postoperative quality of recovery at 24 h was also assessed using the QoR-15 questionnaire, along with duration of chest tube drainage and hospital stay were compared as secondary outcomes. MAIN RESULTS: Patients in the two study groups had comparable baseline characteristics, and surgical types were also similar. Postoperative VAS changes at 1 h, 24 h, and 48 h after surgery were also comparable between the two study groups. Both groups had low median scores (<4.0) at all time points (all p > 0.05). Patients in the ESPB group required statistically non-significant higher 48-h morphine consumption [3 (0-6) vs. 0 (0-6) mg in the ESPB group and ICNB group respectively; p = 0.135] and lower numbers of oral rescue analgesic (0.4 ± 1.2 vs. 1.0 ± 1.8 in the ESPB group and ICNB group respectively; p = 0.059). Additionally, patients in the two study groups had similar QoR15 scores and lengths of hospital stay. CONCLUSIONS: Both anesthesiologist-administered ultrasound-guided ESPB and surgeon-administered VATS ICNB were effective analgesic techniques for patients undergoing VATS for tumor resection.

Early prediction of mortality at sepsis diagnosis time in critically ill patients by using interpretable machine learning.

This study applied machine learning for the early prediction of 30-day mortality at sepsis diagnosis time in critically ill patients. Retrospective study using data collected from the Medical Information Mart for Intensive Care IV database. The data of the patient cohort was divided on the basis of the year of hospitalization, into training (2008-2013), validation (2014-2016), and testing (2017-2019) datasets. 24,377 patients with the sepsis diagnosis time < 24 h after intensive care unit (ICU) admission were included. A gradient boosting tree-based algorithm (XGBoost) was used for training the machine learning model to predict 30-day mortality at sepsis diagnosis time in critically ill patients. Model performance was measured in both discrimination and calibration aspects. The model was interpreted using the SHapley Additive exPlanations (SHAP) module. The 30-day mortality rate of the testing dataset was 17.9%, and 39 features were selected for the machine learning model. Model performance on the testing dataset achieved an area under the receiver operating characteristic curve (AUROC) of 0.853 (95% CI 0.837-0.868) and an area under the precision-recall curves of 0.581 (95% CI 0.541-0.619). The calibration plot for the model revealed a slope of 1.03 (95% CI 0.94-1.12) and intercept of 0.14 (95% CI 0.04-0.25). The SHAP revealed the top three most significant features, namely age, increased red blood cell distribution width, and respiratory rate. Our study demonstrated the feasibility of using the interpretable machine learning model to predict mortality at sepsis diagnosis time.

Efficacy of intraoperative thoracoscopic intercostal nerve blocks in nonintubated and intubated video-assisted thoracic surgery: A randomized study.

BACKGROUND: The efficacy of thoracoscopic intercostal nerve blocks (TINBs) for noxious stimulation from video-assisted thoracic surgery (VATS) remains unclear. The efficacy of TINBs may also be different between nonintubated VATS (NIVATS) and intubated VATS (IVATS). We aim to compare the efficacy of TINBs on analgesia and sedation for NIVATS and IVATs intraoperatively. METHODS: Sixty patients randomized to the NIVATS or IVATS group (30 each) received target-controlled propofol and remifentanil infusions, with bispectral index (BIS) maintained at 40-60, and multilevel (T3-T8) TINBs before surgical manipulations. Intraoperative monitoring data, including pulse oximetry, mean arterial pressure (MAP), heart rate, BIS, density spectral arrays (DSAs), and propofol and remifentanil effect-site concentration (Ce) at different time points. A two way ANOVA with post hoc analysis was applied to analyze the differences and interactions of groups and time points. RESULTS: In both groups, DSA monitoring revealed burst suppression and α dropout immediately after the TINBs. The Ce of the propofol infusion had to be reduced within 5 min post-TINBs in both NIVATS (p < 0.001) and IVATS (p = 0.252) groups. The Ce of remifentanil infusion was significantly reduced after TINBs in both groups (p < 0.001), and was significantly lower in NIVATS (p < 0.001) without group interactions. CONCLUSION: The surgeon-performed intraoperative multilevel TINBs allow reduced anesthetic and analgesic requirement for VATS. With lower requirement of remifentanil infusion, NIVATS presents a significantly higher risk of hypotension after TINBs. DSA is beneficial for providing real-time data that facilitate the preemptive management, especially for NIVATS.

Validation of Chinese version of a global anesthetic recovery questionnaire: A multicenter observational trial on ObsQoR-11.

BACKGROUND: The obstetric quality of recovery (ObsQoR-11) is considered one of the best patient-reported outcome measures of post-cesarean recovery. However, it has been neither validated in Chinese nor evaluated at >24 h after delivery. METHODS: Parturients from three hospitals (n = 279) completed the Chinese ObsQoR-11 at 24 h (T1) and 96 h (T2) after elective cesarean delivery. Convergent validity was assessed by correlation of Chinese ObsQoR-11 with a 100-mm numerical rating scale (NRS) of general health status; discriminant validity of good recovery (NRS ≥ 70-mm); and construct validity by correlation with influential factors to post-cesarean recovery. The reliability and responsiveness were also assessed. RESULTS: The Chinese ObsQoR-11 correlated moderately with the NRS [T1: r = 0.38 (95% confidence interval: 0.28-0.48), p < 0.0001; T2: r = 0.43 (95% confidence interval: 0.32-0.52), p < 0.0001] and discriminated between good and poor recovery [T1: mean (SD) score: 64 (20) vs 49 (17), p < 0.0001; T2: median (IQR) score: 81 (66-94) vs. 61 (53-72); p = 0.0002]; weakly correlated with gestational age, successful breastfeeding, and operation time. It was reliable (internal consistency: 0.75 (T1) and 0.82 (T2); split-half: 0.77 (T1) and 0.85 (T2); test-retest intraclass correlation coefficient r > 0.6 for each item) and responsive (Cohen effect size: 0.88; standardized response mean: 0.81). CONCLUSION: The Chinese ObsQoR-11may be used for assessing recovery at 24 h and 96 h after cesarean delivery. However, its' cutoff value for good recovery may be lower than that of other versions.

Effects of Goal-Directed Hemodynamic Therapy Using a Noninvasive Finger-Cuff Monitoring Device on Intraoperative Cerebral Oxygenation and Early Delayed Neurocognitive Recovery in Patients Undergoing Beach Chair Position Shoulder Surgery: A Randomized Controlled Trial.

BACKGROUND: Perioperative cerebral desaturation events (CDEs) and delayed neurocognitive recovery are common among patients undergoing beach chair position (BCP) shoulder surgery and may be caused by cerebral hypoperfusion. This study tested the hypothesis that the application of goal-directed hemodynamic therapy (GDHT) would attenuate these conditions. METHODS: We randomly assigned 70 adult patients undergoing BCP shoulder surgery to GDHT group or control at a 1:1 ratio. Cerebral oxygenation was monitored using near-infrared spectroscopy, and GDHT was administered using the ClearSight pulse wave analysis system. The primary outcome was CDE duration, whereas the secondary outcomes were CDE occurrence, delayed neurocognitive recovery occurrence, and Taiwanese version of the Quick Mild Cognitive Impairment (Qmci-TW) test score on the first postoperative day (T 2 ) adjusted for the baseline score (on the day before surgery; T 1 ). RESULTS: CDE duration was significantly shorter in the GDHT group (0 [0-0] vs 15 [0-75] min; median difference [95% confidence interval], -8 [-15 to 0] min; P = .007). Compared with the control group, fewer patients in the GDHT group experienced CDEs (23% vs 51%; relative risk [95% confidence interval], 0.44 [0.22-0.89]; P = .025) and mild delayed neurocognitive recovery (17% vs 40%; relative risk [95% confidence interval], 0.60 [0.39-0.93]; P = .034). The Qmci-TW scores at T 2 adjusted for the baseline scores at T 1 were significantly higher in the GDHT group (difference in means: 4 [0-8]; P = .033). CONCLUSIONS: Implementing GDHT using a noninvasive finger-cuff monitoring device stabilizes intraoperative cerebral oxygenation and is associated with improved early postoperative cognitive scores in patients undergoing BCP shoulder surgery.

Changes in the quick mild cognitive impairment test over time: A normative study in an adult sample in Taiwan.

BACKGROUND: The Quick Mild Cognitive Impairment (Qmci) test has been suggested to be an easy-to-use and precise screening tool for detecting postoperative cognitive dysfunction (POCD). To provide essential information for future POCD studies in Taiwan, the present study provided data regarding the Taiwan version of the Qmci (Qmci-TW) test conducted in the normative Taiwanese population and changes in them over time. METHODS: The present study recruited adult native Taiwanese volunteers without known neurologic or psychiatric diseases. All enrolled participants received protocolized serial Qmci-TW test at baseline, 2-day follow-up, and 6-month follow-up. RESULTS: In total, 30 participants, 15 men and 15 women, were enrolled in this study. The baseline Qmci-TW score ranged from 55 to 80, with a mean of 68.9 and a standard deviation (SD) of 7. At 2-day follow-up, the mean Qmci-TW test score was significantly higher (by 5.3; SD = 7.3) than that at baseline (P = 0.001). At 6-month follow-up, the mean Qmci-TW score was 71.3 (SD = 6.1), with no significant difference compared with that at baseline. The decline in Qmci-TW scores by > 9 points on postoperative day 1 and by > 11 points at 6-month follow-up was the criterion for POCD. CONCLUSION: The present study provided data regarding the Qmci-TW test conducted in the normative Taiwanese population and its time trajectory during the 6-month follow-up.

Influence of scalp block on oncological outcomes of high-grade glioma in adult patients with and without isocitrate dehydrogenase-1 mutation.

High-grade gliomas are notorious for a high recurrence rate even after curative resection surgery. Studies regarding the influence of scalp block on high-grade gliomas have been inconclusive, possibly because the condition's most important genetic mutation profile, namely the isocitrate dehydrogenase 1 (IDH1) mutation, had not been analyzed. Therefore, we conducted a single-center study including patients with high-grade glioma who underwent tumor resection between January 2014 and December 2019. Kaplan-Meier survival analysis revealed that scalp block was associated with longer progression-free survival (PFS; 15.17 vs. 10.77 months, p = 0.0018), as was the IDH1 mutation (37.37 vs. 10.90 months, p = 0.0149). Multivariate Cox regression analysis revealed that scalp block (hazard ratio: 0.436, 95% confidence interval: 0.236-0.807, p = 0.0082), gross total resection (hazard ratio: 0.405, 95% confidence interval: 0.227-0.721, p = 0.0021), and IDH1 mutation (hazard ratio: 0.304, 95% confidence interval: 0.118-0.784, p = 0.0138) were associated with better PFS. Our results demonstrate that application of scalp block, regardless of IDH1 profile, is an independent factor associated with longer PFS for patients with high-grade glioma.

Accuracy of dynamic preload variables for predicting fluid responsiveness in patients with pediatric liver cirrhosis: A prospective study.

BACKGROUND: We have previously reported that dynamic preload variables predicted fluid responsiveness in adult patients with liver cirrhosis. However, pediatric patients with cirrhosis may present with unique hemodynamic characteristics, and therefore, the predictive accuracy of these variables in such patients must be clarified. AIMS: To investigate the accuracy of dynamic preload variables for predicting fluid responsiveness in pediatric patients with cirrhosis. METHODS: A total of 27 pediatric patients with cirrhosis undergoing orthotopic liver transplantation were enrolled in this study. Patients' pulse pressure variation, stroke volume variation, stroke volume index, and central venous pressure were measured using the calibrated pulse contour cardiac output system. The plethysmographic variability index was measured using a Masimo Radical 7 co-oximeter. During the hepatic dissection phase of the surgery, repeated intraoperative fluid challenges with 10 mL kg-1 of crystalloid within 15 minutes were administered. Fluid responsiveness was defined as an increase in stroke volume index of ≥15% after fluid challenge. RESULTS: A total of 61 fluid challenges were administered resulting in 15 fluid responders and 46 fluid nonresponders. Fluid challenge induced significant decreases in all three dynamic preload variables but not in the fluid nonresponders. However, the area under the receiver operating characteristic curves for pulse pressure variation, stroke volume variation, plethysmographic variability index, and central venous pressure for predicting fluid responsiveness were 0.67 (95% confidence interval: 0.52-0.82; P = .0255), 0.68 (95% confidence interval: 0.54-0.83; P = .0140), 0.56 (95% confidence interval: 0.40-0.71; P = .4724), and 0.57 (95% confidence interval: 0.40-0.74; P = .4192), respectively. CONCLUSIONS: Dynamic preload variables do not predict fluid responsiveness in pediatric patients with liver cirrhosis.

Association between Early Acute Respiratory Distress Syndrome after Living-Donor Liver Transplantation and Perioperative Serum Biomarkers: The Role of Club Cell Protein 16.

BACKGROUND: Acute respiratory distress syndrome (ARDS) after living-donor liver transplantation (LDLT) is not uncommon, but it lacks the biomarkers for early detection. Club cell protein 16 (CC16), high-motility group box 1 protein (HMGB1), interleukin-1ß (IL-1ß), and IL-10 have been reported as relevant to the development of ARDS. However, they have not been investigated during LDLT. METHODS: Seventy-three consecutive recipients undergoing LDLT were enrolled and received the same perioperative care plan. Perioperative serum CC16, HMGB1, IL-1ß, and IL-10 levels were measured at the pretransplant state, 30 minutes after reperfusion, postoperative day 1 (POD1), and POD3. ARDS was diagnosed according to the 2012 Berlin definition. RESULTS: Of the 73 recipients, 13 developed ARDS with significantly longer durations of mechanical ventilation and intensive care unit stay. Serum CC16 levels on POD1 increased significantly from the pretransplant state in the ARDS group but not in the non-ARDS group. Pretransplant serum CC16 levels were also higher in the ARDS group. The area under the receiver operating characteristic curves for POD1 serum CC16 levels used to discriminate ARDS was 0.803 (95% confidence interval: 0.679 to 0.895; p < 0.001). By comparison, HMGB1, IL-1ß, and IL-10 were not associated with ARDS after LDLT. CONCLUSION: The higher pretransplant serum CC16 level and its increased level on POD1 were associated with the development of early ARDS after LDLT. This trial is registered with NCT01936545, 27 August 2013.

Non-intubated thoracoscopic surgery for lung cancer in patients with impaired pulmonary function.

BACKGROUND: Patients with impaired lung function or chronic obstructive pulmonary disease (COPD) are considered high-risk for intubated general anesthesia, which may preclude them from surgical treatment of their lung cancers. We evaluated the feasibility of non-intubated video-assisted thoracoscopic surgery (VATS) for the surgical management of lung cancer in patients with impaired pulmonary function. METHODS: From August 2009 to June 2015, 28 patients with impaired lung function (preoperative forced expiratory volume in 1 second <70% of the predicted value) underwent non-intubated VATS using a combination of thoracic epidural anesthesia or intercostal nerve block, and intra-thoracic vagal block with target-controlled sedation. RESULTS: Eighteen patients had primary lung cancers, 4 had metastatic lung cancers, and 6 had non-malignant lung tumors. In the patients with primary lung cancer, lobectomy was performed in 4, segmentectomy in 3 and wedge resection in 11, with lymph node sampling adequate for staging. One patient required conversion to intubated one-lung ventilation because of persistent wheezing and labored breathing. Five patients developed air leaks more than 5 days postoperatively while subcutaneous emphysema occurred in 6 patients. Two patients developed acute exacerbations of pre-existing COPD, and new-onset atrial fibrillation after surgery occurred in 1 patient. The median duration of postoperative chest tube drainage was 3 days while the median hospital stay was 6 days. CONCLUSIONS: Non-intubated VATS resection for pulmonary tumors is technically feasible. It may be applied as an alternative to intubated general anesthesia in managing lung cancer in selected patients with impaired pulmonary function.

Nonintubated laryngomicrosurgery with Transnasal Humidified Rapid-Insufflation Ventilatory Exchange: A case series.

BACKGROUND: Nonintubation anaesthesia for laryngomicrosurgery (LMS) provides both excellent visualization of the surgical field and complete examination on vocal cord. However, adequate oxygenation remains challenging during nonintubated LMS. Recently, transnasal humidified rapid-insufflation ventilator exchange (THRIVE) has been reported effectively maintaining apneic oxygenation in patient with difficult airways. The feasibility and safety of nonintubated LMS with THRIVE was evaluated in this case series. METHODS: From September 2016 to February 2017, a total of 23 patients receiving nonintubated LMS were included. Anaesthesia was induced and maintained through target-controlled propofol infusion and muscle relaxation with THRIVE oxygen support. Perioperative data were collected from medical records and analysed. RESULTS: The mean (±SD) duration of the operation was 12.4 (±4.4) min. The mean (±SD) total anaesthesia time (from induction to emergence) was 24.1 (±6.4) min. 22 patients received nonintubated LMS with surgical satisfaction without intraoperative desaturation. One patient who underwent laryngeal tumour biopsy experienced a single episode of desaturation. A 5.5-mm tracheal tube was needed for short-term mechanical ventilation to regain SpO2 to 100%. No significant complication was noted in all patients. All patients discharged as per schedule on the next day after surgery as intubated LMS patients in our hospital. CONCLUSION: Nonintubated LMS with THRIVE is a feasible and safe alternative to intubated LMS with a small size tracheal tube to provide a better surgical field. However, for patients with easy-bleeding tumor, intubated LMS remains suggestive for better airway protection.

The role of autonomic dysfunction in predicting 1-year mortality after liver transplantation.

BACKGROUND & AIMS: Model for end-stage liver disease (MELD) score has been extensively used to prioritize patients for liver transplantation and determine their prognosis, but with limited predictive value. Autonomic dysfunction may correlate with increased mortality after liver transplant. In this study, two autonomic biomarkers, complexity and deceleration capacity, were added to the predicting model for 1-year mortality after liver transplantation. METHODS: In all, 30 patients with end-stage liver diseases awaiting liver transplantation were included. Complexity and deceleration capacity were calculated by multi-scale entropy and phase-rectified signal averaging, respectively. Different combinations of autonomic factors and MELD score were used to predict mortality rate of liver transplant after 1-year follow-up. Receiver-operating characteristics curve analysis was performed to determine clinical predictability. Area under the receiver-operating characteristics curve represents the overall accuracy. RESULTS: The 1-year mortality rate was 16.7% (5/30). The overall accuracy of MELD score used for predicting mortality after liver transplantation was 0.752. By adding complexity and deceleration capacity into the predicting model, the accuracy increased to 0.912. Notably, the accuracy of the prediction using complexity and deceleration capacity alone was 0.912. CONCLUSION: Complexity and deceleration capacity, which represent different dynamical properties of a human autonomic system, are critical factors for predicting mortality rate of liver transplantation. We recommend that these pre-operative autonomic factors may be helpful as critical adjuncts to predicting model of mortality rate in prioritizing organ allocation.

Patterns of perioperative thoracic fluid indices changes in liver transplantation with or without postoperative acute lung injury.

BACKGROUND/PURPOSE: Postoperative acute lung injury (ALI) after liver transplantation is clinically relevant and common. The perioperative thoracic fluid indices changes as well as the association with ALI in liver transplantation have not been thoroughly investigated. METHODS: A total of 52 consecutive adult recipients for elective living donor liver transplantation were enrolled. Each recipient received the same perioperative care plan. Thoracic fluid indices, including the cardiac index, intrathoracic blood volume index (ITBVI), extravascular lung water index (EVLWI), and pulmonary vascular permeability index (PVPI), were obtained at seven time points (pretransplantation, anhepatic phase, 30 minutes after reperfusion, 2 hours after reperfusion, and postoperative days 1-3) using the pulse contour cardiac output system. The indices of those who developed ALI (PaO2/FiO2 < 300 mmHg with lung infiltrates on chest X-ray) were compared with the indices of those who did not. RESULTS: Recipients who developed postoperative ALI had longer mechanical ventilation duration and had a higher model for end-stage liver disease score, required more platelet transfusion, and were higher in pretransplant EVLWI and PVPI level. During the anhepatic phase, ITBVI, central venous pressure, cardiac index, and EVLWI decreased and PVPI increased. After transplantation, ITBVI increased above pretransplant status, while EVLWI and PVPI were comparable in both groups. CONCLUSION: Recipients who did or did not develop ALI after liver transplantation had a longer mechanical ventilation duration and showed different patterns of perioperative thoracic fluid indices, especially in the pretransplant status of PVPI level. Knowledge of these perioperative changes may provide clinicians with helpful information to make postoperative care choices.

Intraoperative multiple intercostal nerve blocks exert anesthetic-sparing effect: A retrospective study on the effect-site concentration of propofol infusion in nonintubated thoracoscopic surgery.

OBJECTIVE(S): Less general anesthetic is required in patients with regional blocks than in those without, as assessed through commonly used anesthesia monitoring parameters such as blood pressure, heart rate, and bispectral index (BIS). Although intraoperative regional anesthesia has become more widely adopted, few studies have confirmed or monitored its anesthetic-sparing effects. Using recent reports of nonintubated video-assisted thoracoscopic surgery (VATS) by BIS-targeted propofol infusion and intraoperative multilevel thoracoscopic intercostal nerve blocks (TINBs), this retrospective study investigated whether the anesthetic-sparing effect can be realized by reducing the effect-site concentration (Ce) to the targeted BIS level or by reducing the blood pressure at the onset of regional blocks. METHODS: A retrospective study of a prospectively collected case series of non-intubated VATS. RESULTS: Data on 56 adult patients who underwent nonintubated VATS were collected and analyzed. The mean operative time was 121 ± 32 minutes. BIS levels before and after one-lung ventilation/TINBs and surgery were 48% ± 11% and 47% ± 12%, respectively. The Ce of propofol infusion decreased significantly from 3.4 ± 0.8 µg/mL to 3.0 ± 0.7 µg/mL (p < 0.01) after surgery with TINBs. Blood pressure did not change significantly, whereas the heart rate increased moderately but significantly (77 ± 14 beats/minute to 82 ± 15 beats/minute, p < 0.01). CONCLUSION: With comparable BIS and blood pressure in the subsequent surgical procedure, the adequacy of anesthesia and the anesthetic component provided by intraoperative TINBs and vagal nerve could be monitored adequately. The anesthetic-sparing effect of intraoperative nerve blocks can be realized when the Ce of propofol infusion was reduced to the target BIS level.