Apoptosis, Proliferation, and Autophagy Are Involved in Local Anesthetic-Induced Cytotoxicity of Human Breast Cancer Cells.

Breast cancer accounts for almost one quarter of all female cancers worldwide, and more than 90% of those who are diagnosed with breast cancer undergo mastectomy or breast conservation surgery. Local anesthetics effectively inhibit the invasion of cancer cells at concentrations that are used in surgical procedures. The limited treatment options for triple-negative breast cancer (TNBC) demonstrate unmet clinical needs. In this study, four local anesthetics, lidocaine, levobupivacaine, bupivacaine, and ropivacaine, were applied to two breast tumor cell types, TNBC MDA-MB-231 cells and triple-positive breast cancer BT-474 cells. In addition to the induction of apoptosis and the suppression of the cellular proliferation rate, the four local anesthetics decreased the levels of reactive oxygen species and increased the autophagy elongation indicator in both cell types. Our combination index analysis with doxorubicin showed that ropivacaine had a synergistic effect on the two cell types, and lidocaine had a synergistic effect only in MDA-MB-231 cells; the others had no synergistic effects on doxorubicin. Lidocaine contributed significantly to the formation of autophagolysosomes in a dose-dependent manner in MDA-MB-231 cells but not in BT-474 cells. Our study demonstrated that the four local anesthetics can reduce tumor growth and proliferation and promote apoptosis and autophagy.

Mitochondrial Dysfunction Involved in the Cytotoxicity of Tramadol in Human Endometrial Carcinoma Cells.

Tramadol is a common anesthetic used to treat cancer pain, including endometrial cancer, but its function in endometrial cancer remains unclear. The purpose of this study was to elucidate the antitumor effects of tramadol on human endometrial cancer cells. Colony formation, BrdU, cell cycle profiles, apoptosis, ROS, and Western blot analyses were used to study the response of endometrial cancer cells to tramadol. JC-1 and seahorse metabolic flux assays were used to detect the effect of tramadol on mitochondria in endometrial cancer cells. Combination index was used to detect the interaction of tramadol with chemotherapy drugs in endometrial cancer cells. In this study, we found that tramadol was able to inhibit proliferation and induce cell cycle arrest, ROS generation, and apoptosis in two types of endometrial cancer cells. In addition, tramadol treatment also induced mitochondrial dysfunction in endometrial cancer cells by causing a loss of mitochondrial membrane potential and a decreased oxygen consumption rate. More importantly, the synergetic effect of tramadol with doxorubicin or cisplatin was further confirmed in endometrial cancer cells by the results of the combination index and apoptosis assay. In summary, our findings indicate that tramadol has an antitumor effect on endometrial cancer cells, which might serve as a potential adjuvant therapy strategy for endometrial cancer.

Adjunctive dexmedetomidine infusion in open living donor hepatectomy: A way to enhance postoperative analgesia and recovery.

BACKGROUND: Open living donor hepatectomy (OLDH) is a highly painful procedure. Advanced strategies for enhancing perioperative analgesia and accelerating recovery are needed for patients undergoing OLDH. This study evaluated the effects of intravenous infusion of dexmedetomidine (DEX) during OLDH on postoperative analgesia and recovery. METHODS: This prospective, randomised, double-blinded, and placebo-controlled study included 34 patients randomised to a control group (group C) and a DEX group (group D). Utilisation of intravenous patient-controlled analgesia (IV-PCA) pump, pain intensity, and postoperative recovery variables were recorded. Moreover, intraoperative anaesthetic consumption, hemodynamic parameters, and fluid status were also recorded. RESULTS: During the first 24 hours after surgery, patients in group D had a lower pain intensity. The cumulative numbers of IV-PCA pump presses and fentanyl consumption within 24 and 48 hours postoperatively in group C were significantly higher than in group D. The time to first IV-PCA attempt was prolonged in group D. In addition, faster flatus passage was observed in group D. Intraoperatively, fewer anaesthetic agents were required in group D. Less fluctuation in hemodynamics and reduced bleeding were also found in group D. CONCLUSIONS: The present study revealed that the addition of intravenous infusion of DEX during OLDH provided several benefits in relieving postoperative pain and promoting recovery. Therefore, we concluded that intraoperative DEX infusion may play an important role in enhancing the recovery of patients undergoing OLDH.

Efficacy and airway complications of Parker Flex-Tip tubes and standard endotracheal tubes during airway manipulation: A meta-analysis and trial sequential analysis.

BACKGROUND: Despite reported superior intubation outcomes associated with Parker Flex-Tip (PFT) tubes compared with those associated with standard polyvinylchloride tubes, the efficacy and safety of PFT tubes remain uncertain. OBJECTIVES: To compare the intubation outcomes between PFT and conventional standard polyvinylchloride tubes. DESIGN: Meta-analysis of randomised controlled trials. DATA SOURCES: Embase, Medline, Google Scholar, PubMed and the Cochrane controlled trials register from inception until 3 January 2021. ELIGIBILITY CRITERIA: All randomised trials comparing intubation outcomes between PFT (PFT group) and standard polyvinylchloride (standard polyvinylchloride group) tubes. RESULTS: Analysis of the 13 eligible trials showed no significant difference in successful first-attempt intubation rate [risk ratio (RR) 1.20, 95% confidence interval (CI) 0.99 to 1.44] (6 trials, 568 participants), trauma risk (RR 0.83, 95% CI 0.67 to 1.03) (5 trials, 501 participants) as well as the overall risks of epistaxis (RR 0.58, 95% CI 0.26 to 1.31) (3 trials, 262 participants), sore throat (RR 0.90, 95% CI 0.70 to 1.17) (4 trials, 451 participants) and hoarseness (RR 0.71, 95% CI 0.44 to 1.14) (4 trials, 451 participants) between the two groups. However, the intubation time was slightly shorter (weighted mean difference -4.2 s, 95% CI -7.4 to -1.0 s) (8 trials, 759 participants) and the risks of severe epistaxis (RR 0.15, 95% CI 0.03 to 0.84) (3 trials, 262 participants) and overall difficulty in airway manipulation (RR 0.48, 95% CI 0.29 to 0.80) (8 trials, 647 participants) were lower in the PFT group than those in the standard polyvinylchloride group. Trial sequential analysis conclusively confirmed a shorter intubation time with PFT tubes than with standard polyvinylchloride tubes, whereas other intubation outcomes were inconclusive. CONCLUSION: The use of PFT tubes for airway manipulation was associated with a shorter intubation time compared with the standard polyvinylchloride tubes. The results of trial sequential analysis suggest the need for further trials and meta-analysis to compare other intubation outcomes associated with the two devices. TRIAL REGISTRATION: PROSPERO CRD42020197670.

Propofol-based total intravenous anaesthesia is associated with better survival than desflurane anaesthesia in hepatectomy for hepatocellular carcinoma: a retrospective cohort study.

BACKGROUND: Previous studies have shown that anaesthetic technique can affect outcomes of cancer surgery. We investigated the association between anaesthetic technique and patient outcomes after elective hepatectomy for hepatocellular carcinoma. METHODS: This was a retrospective single-centre cohort study of patients who received elective hepatectomy for hepatocellular carcinoma from January 2005 to December 2014. Patients were grouped according to propofol or desflurane anaesthesia. Kaplan-Meier analysis was performed and survival curves were constructed from the date of surgery to death. After propensity matching, univariable and multivariable Cox regression models were used to compare hazard ratios for death. Subgroup analyses were performed for tumour-node-metastasis staging and distant metastasis and local recurrence. RESULTS: A total of 492 patients (369 deaths, 75.0%) with desflurane anaesthesia and 452 (139 deaths, 30.8%) with propofol anaesthesia were eligible for analysis. After propensity matching, 335 patients remained in each group. In the matched analysis, propofol anaesthesia had a better survival with hazard ratio of 0.47 (95% confidence interval, 0.38-0.59; P<0.001). Subgroup analyses also showed significantly better survival in the absence of distant metastasis (hazard ratio, 0.47; 95% confidence interval, 0.37-0.60; P<0.001) or local recurrence (hazard ratio, 0.22; 95% confidence interval, 0.14-0.34; P<0.001) in the matched groups. CONCLUSIONS: Propofol anaesthesia was associated with better survival in hepatocellular carcinoma patients who underwent hepatectomy. Prospective studies are warranted to evaluate the effects of propofol anaesthesia on surgical outcomes in hepatocellular carcinoma patients.

Propofol-based Total Intravenous Anesthesia Is Associated with Better Survival Than Desflurane Anesthesia in Colon Cancer Surgery.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Previous research has shown different effects of anesthetics on cancer cell growth. Here, the authors investigated the association between type of anesthetic and patient survival after elective colon cancer surgery. METHODS: A retrospective cohort study included patients who received elective colon cancer surgery between January 2005 and December 2014. Patients were grouped according to anesthesia received: propofol or desflurane. After exclusion of those who received combined propofol anesthesia with inhalation anesthesia or epidural anesthesia, survival curves were constructed from the date of surgery to death. After propensity matching, univariable and multivariable Cox regression models were used to compare hazard ratios for death. Subgroup analyses were performed for tumor-node-metastasis staging and postoperative metastasis. RESULTS: A total of 706 patients (307 deaths, 43.5%) with desflurane anesthesia and 657 (88 deaths, 13.4%) with propofol anesthesia were eligible for analysis. After propensity matching, 579 patients remained in each group (189 deaths, 32.6%, in the desflurane group vs. 87, 15.0%, in the propofol group). In the matched analyses, the propofol-treated group had a better survival, irrespective of lower tumor-node-metastasis stage (hazard ratio, 0.22; 95% CI, 0.11 to 0.42; P < 0.001) or higher tumor-node-metastasis stage (hazard ratio, 0.42; 95% CI, 0.32 to 0.55; P < 0.001) and presence of metastases (hazard ratio, 0.67; 95% CI, 0.51 to 0.86; P = 0.002) or absence of metastases (hazard ratio, 0.08; 95% CI, 0.01 to 0.62; P = 0.016). Simple propensity score adjustment produced similar findings. CONCLUSIONS: Propofol anesthesia for colon cancer surgery is associated with better survival irrespective of tumor-node-metastasis stage.

Association between extracellular signal-regulated kinase expression and the anti-allodynic effect in rats with spared nerve injury by applying immediate pulsed radiofrequency.

BACKGROUND: The application of pulsed radiofrequency (PRF) close to the dorsal root ganglia, or peripheral nerves, has been demonstrated to be effective for the treatment of chronic neuropathic pain conditions. The goal of this study was to investigate the analgesic effect of immediate PRF treatment after nerve injury and its possible cellular alterations in the dorsal horn of the spinal cord in rats with spared nerve injury (SNI). METHODS: Neuropathic pain was achieved in a SNI neuropathic pain model by ligating and cutting the common peroneal and tibial branches of the left sciatic nerve, leaving the sural nerve intact. Wistar rats were divided into four groups that received different treatments, i.e., SNI and PRF for 6 min at 45 V (SNI + PRF-45 V), at 60 V (SNI + PRF-60 V), SNI alone, and sham groups. After the SNI surgery, each rat was immediately given the PRF treatment (500 kHz, rate of 2 Hz, 20 ms duration, temperature below 42 °C) on the left sciatic nerve 0.3-0.4 cm proximal to the injured site. The behavioral measurements included mechanical allodynia and cold allodynia of the ipsilateral hind paw and were performed during the 28 days that followed the SNI surgery and PRF treatment. Total extracellular signal-regulated kinase 1 and 2 (ERK1/2) and phospho-ERK1/2 were measured using Western blot in the ipsilateral spinal cord from animals in the different groups. RESULTS: The three groups of rats with nerve injuries manifested a lower paw withdrawal threshold (PWT) in the behavioral measurement of mechanical allodynia and a shorter painful-behavior duration in the cold allodynia test over 28 days. Mechanical allodynia measurement showed that both the PRF-45 V and PRF-60 V treatment groups exhibited a more prominent antiallodynic effect than did the SNI group from days 1 to 28 after surgery. Similarly, in comparison with the SNI group, both the SNI + PRF-45 V and SNI + PRF-60 V groups had significant inhibition on the cold allodynia measurement from days 1 to 28 after surgery. Furthermore, the activation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) in the ipsilateral spinal dorsal horn of SNI rats was effectively inhibited in the SNI + PRF-45 V and SNI + PRF-60 V groups for 28 days after surgery. CONCLUSIONS: Immediate PRF application on the proximal nerve injury site provided a significant inhibition of neuropathic pain formation, accompanied by the inhibition of ERK activation.

Matrix Metalloproteinase-9 Production following Cardiopulmonary Bypass Was Not Associated with Pulmonary Dysfunction after Cardiac Surgery.

BACKGROUND: Cardiopulmonary bypass (CPB) causes release of matrix metalloproteinase- (MMP-) 9, contributing to pulmonary infiltration and dysfunction. The aims were to investigate MMP-9 production and associated perioperative variables and oxygenation following CPB. METHODS: Thirty patients undergoing elective cardiac surgery were included. Arterial blood was sampled at 6 sequential points (before anesthesia induction, before CPB and at 2, 4, 6, and 24 h after beginning CPB) for plasma MMP-9 concentrations by ELISA. The perioperative laboratory data and variables, including bypass time, PaO2/FiO2, and extubation time, were also recorded. RESULTS: The plasma MMP-9 concentrations significantly elevated at 2-6 h after beginning CPB (P < 0.001) and returned to the preanesthesia level at 24 h (P = 0.23), with predominant neutrophil counts after surgery (P < 0.001). The plasma MMP-9 levels at 4 and 6 h were not correlated with prolonged CPB time and displayed no association with postoperative PaO2/FiO2, regardless of reduced ratio from preoperative 342.9 ± 81.2 to postoperative 207.3 ± 121.3 mmHg (P < 0.001). CONCLUSION: Elective cardiac surgery with CPB induced short-term elevation of plasma MMP-9 concentrations within 24 hours, however, without significant correlation with CPB time and postoperative pulmonary dysfunction, despite predominantly increased neutrophils and reduced oxygenation.

An analysis of anesthesia-controlled operating room time after propofol-based total intravenous anesthesia compared with desflurane anesthesia in ophthalmic surgery: a retrospective study.

BACKGROUND: Anesthetic techniques can contribute to reduction of anesthesia-controlled time to improve operating room (OR) efficiency. However, little is known about the difference in anesthesia-controlled time between propofol-based total IV anesthesia (TIVA) and desflurane anesthesia (DES) techniques for ophthalmic surgery under general anesthesia. METHODS: We performed a retrospective analysis using hospital databases to compare the anesthesia-controlled times of ophthalmic surgery patients receiving either TIVA via target-controlled infusion with propofol/fentanyl or desflurane/fentanyl-based anesthesia between January 2010 and December 2011. The various time intervals (surgical time, incision to surgical completion and application of dressings; anesthesia time, start of anesthesia to extubation; extubation time, surgery complete and dressings applied to extubation; time in OR, arrival in the OR to departure from the OR; postanesthetic care unit (PACU) stay time, arrival in the PACU to discharge from the PACU to the general ward; and total surgical suite time, arrival in the OR to discharge from the PACU to the general ward) that comprise a patient's hospital stay and the incidence of postoperative nausea and vomiting were compared between the 2 anesthetic techniques. RESULTS: We included data from 1405 patients, with 595 patients receiving TIVA and 810 receiving DES. The extubation time was faster (TIVA-DES = -1.85 minutes, 99.2% confidence interval [CI], -2.47 to -1.23 minutes) and the PACU stay time was shorter (TIVA-DES = -3.62 minutes, 99.2% CI, -6.97 to -0.10 minutes) in the TIVA group than in the DES group. However, there was no significant difference in total surgical suite time between groups (TIVA-DES = -5.03 minutes, 99.2% CI, -11.75 to 1.69 minutes). We performed the random-effects analyses while stratifying for procedure and showed that the extubation time in the TIVA group was faster by 14% (99.2% CI, 9% to 19%, P < 0.0001) relative to the DES group, and the PACU stay time was faster by 5% (99.2% CI, 1% to 10%, P = 0.002). Significantly fewer patients suffered postoperative nausea and vomiting and required rescue therapy in the TIVA group than in the DES group (11.3% vs 32.2%, risk difference 21.0%, 95% CI, 16.9% to 25.1%, P < 0.001 and 23.9% vs 54.0%, risk difference 30.1%, 95% CI, 18.3% to 42.0%, P = 0.002, respectively). CONCLUSIONS: In our hospital, the use of TIVA reduced the mean time to extubation by at least 9% and PACU stay time by more than 1% when compared with the use of DES anesthesia for ophthalmic surgery.

Rosiglitazone attenuates cerebral vasospasm and provides neuroprotection in an experimental rat model of subarachnoid hemorrhage.

BACKGROUND: Glutamate and oxidative stress play important roles after subarachnoid hemorrhage (SAH). The ability to modulate glutamate transporter 1 (GLT-1) and the antioxidative effect of rosiglitazone have been demonstrated. We investigated the neuroprotective effect of rosiglitazone after SAH. METHODS: SAH was induced by double blood injection. The rats were randomly divided into sham, SAH + vehicle, and SAH + rosiglitazone groups and treated with dimethyl sulfoxide, dimethyl sulfoxide, and 6 mg/kg of rosiglitazone, respectively, at 2 and 12 h after SAH induction and then daily for 6 days. Cerebrospinal fluid dialysates were collected 30 min before SAH induction and then daily for 7 days for glutamate measurement. Mortality, body weight, and neurological scores were also measured daily. On day 7 after SAH, the wall thickness and the perimeter of the basilar artery (BA), neuron variability, GLT-1 levels, glial fibrillary acidic protein (GFAP) expression and activity, and malondialdehyde, superoxide dismutase, and catalase activities were also evaluated. RESULTS: Rosiglitazone improved survival (relative risk = 0.325) and neurological functions and reduced neuronal degeneration (5.7 ± 0.8 vs. 10.0 ± 0.9; P < 0.001) compared with the SAH + vehicle group. Rosiglitazone also lowered glutamate levels by 43.5-fold and upregulated GLT-1 expression by 1.5-fold and astrocyte activity by 1.8-fold compared with the SAH + vehicle group. The increase in BA wall thickness was significantly attenuated by rosiglitazone, whereas the perimeter of the BA was increased. In addition, rosiglitazone abated the 1.9-fold increase in malondialdehyde levels and the 1.6-fold increase in catalase activity after SAH. CONCLUSION: Rosiglitazone reduced SAH mortality, neurological deficits, body weight loss, GFAP loss, and cerebral vasospasm by preventing the neurotoxicity induced by glutamate and oxidative stress.

Propofol-based total intravenous anesthesia is associated with less postoperative recurrence than desflurane anesthesia in thyroid cancer surgery.

BACKGROUND: The effects of anesthesia in patients undergoing thyroid cancer surgery are still not known. We investigated the relationship between the type of anesthesia and patient outcomes following elective thyroid cancer surgery. METHODS: This was a retrospective cohort study of patients who underwent elective surgical resection for papillary thyroid carcinoma between January 2009 and December 2019. Patients were grouped according to the type of anesthesia they received, desflurane or propofol. A Kaplan-Meier analysis was conducted, and survival/recurrence curves were presented from the date of surgery to death/recurrence. Univariable and multivariable Cox regression models were used to compare hazard ratios for recurrence after propensity matching. RESULTS: A total of 621 patients (22 deaths, 3.5%) under desflurane anesthesia and 588 patients (32 deaths, 5.4%) under propofol anesthesia were included. Five hundred and eighty-eight patients remained in each group after propensity matching. Propofol anesthesia was not associated with better survival compared to desflurane anesthesia in the matched analysis (P = 0.086). However, propofol anesthesia was associated with less recurrence (hazard ratio, 0.38; 95% confidence interval, 0.25-0.56; P < 0.001) in the matched analysis. CONCLUSIONS: Propofol anesthesia was associated with less recurrence, but not mortality, following surgery for papillary thyroid carcinoma than desflurane anesthesia. Further prospective investigation is needed to examine the influence of propofol anesthesia on patient outcomes following thyroid cancer surgery.

Predicting the optimal concentration of remifentanil for skull pin fixation with hemodynamic and analgesia nociception index monitoring.

Inadequate antinociception during skull pin fixation may cause hemodynamic instability in intracranial surgery. The optimal concentration of remifentanil to provide adequate antinociception and stable hemodynamics during skull pin fixation under analgesia nociception index monitoring is unknown. This study is to assess the 90% effective concentration of remifentanil for skull pin fixation under hemodynamic and analgesia nociception index monitoring. Twenty-six patients were enrolled for intracranial surgery, anesthesia was induced and maintained under total intravenous anesthesia using target-controlled infusion for remifentanil and propofol under analgesia nociception index and bispectral index monitoring. Skull pin fixation was performed at different effect-site concentrations of remifentanil required for Dixon's up-and-down method with a step size of 0.5 ng/ml under bispectral index 40-60. Inadequate antinociception is defined when either ANI < 30 or > 20% in hemodynamic changes from baseline (e.g. heart rate > 100 beats/min, or blood pressure > 180/100 mmHg) and the effect-site concentration of remifentanil is considered as failure. It is considered success as ANI > 30 and < 20% hemodynamic changes from baseline simultaneously. Seven pairs of failure/success were used for probit analysis. The 90% effective concentration of remifentanil for skull pin fixation with adequate antinociception and hemodynamic stability was 4.7 ng/ml.

Tumor Necrosis Factor Alpha: Implications of Anesthesia on Cancers.

Cancer remains a major public health issue and a leading cause of death worldwide. Despite advancements in chemotherapy, radiation therapy, and immunotherapy, surgery is the mainstay of cancer treatment for solid tumors. However, tumor cells are known to disseminate into the vascular and lymphatic systems during surgical manipulation. Additionally, surgery-induced stress responses can produce an immunosuppressive environment that is favorable for cancer relapse. Up to 90% of cancer-related deaths are the result of metastatic disease after surgical resection. Emerging evidence shows that the interactions between tumor cells and the tumor microenvironment (TME) not only play decisive roles in tumor initiation, progression, and metastasis but also have profound effects on therapeutic efficacy. Tumor necrosis factor alpha (TNF-α), a pleiotropic cytokine contributing to both physiological and pathological processes, is one of the main mediators of inflammation-associated carcinogenesis in the TME. Because TNF-α signaling may modulate the course of cancer, it can be therapeutically targeted to ameliorate clinical outcomes. As the incidence of cancer continues to grow, approximately 80% of cancer patients require anesthesia during cancer care for diagnostic, therapeutic, or palliative procedures, and over 60% of cancer patients receive anesthesia for primary surgical resection. Numerous studies have demonstrated that perioperative management, including surgical manipulation, anesthetics/analgesics, and other supportive care, may alter the TME and cancer progression by affecting inflammatory or immune responses during cancer surgery, but the literature about the impact of anesthesia on the TNF-α production and cancer progression is limited. Therefore, this review summarizes the current knowledge of the implications of anesthesia on cancers from the insights of TNF-α release and provides future anesthetic strategies for improving oncological survival.

Comparison of Single Target-Controlled Infusion Pump-Delivered Mixed Propofol and Remifentanil with Two Target-Controlled Infusion Pumps-Delivered Propofol and Remifentanil in Patients Undergoing Breast Cancer Surgery-A Prospective Study.

Total intravenous anesthesia (TIVA) with remifentanil and propofol (RP) is considered to be an ideal type of general anesthesia (GA) for pediatric and adult patients undergoing medical procedures. However, delivery of an RP mixture by target-controlled infusion (TCI) for GA in surgical procedures has not been described. We investigated the merit of this approach for breast cancer surgery. Eighty-four patients (n = 42 per group) were randomly allocated to propofol and remifentanil either delivered by separate TCI pumps (S group) or in an RP mixture by a single TCI pump (M group). Dosages were adjusted based on the bispectral index (BIS) and the analgesia nociception index (ANI). The primary outcomes were adequate anesthesia (BIS 40-60 and ANI 50-70, respectively), acceptable hemodynamic fluctuations (<30% of baseline) with less frequent TCI pump adjustments, bolus injections of anesthetics, and total consumption of anesthetics during the procedure. The secondary endpoints included time of emergence from anesthesia, patient satisfaction, postoperative pain, rescue with opioids, and adverse events. The characteristics of patients, hemodynamic parameters, BIS and ANI scores, duration of surgery, anesthesia, and emergence were not significantly different between groups. The adjustment frequency of TCI was significantly higher in the S group (3 (range 0-6) vs. 2 (0-6) times; p = 0.005). The total dosage of anesthetics, pain rating, patient satisfaction, need for opioids postoperatively, and incidence of adverse events were not significantly different. We have demonstrated that this RP mixture provided adequate hypnotic and analgesic effects under BIS and ANI monitoring in patients undergoing breast cancer surgery within 1 h.