The EC50 of propofol with different doses of dexmedetomidine during gastrointestinal endoscopy: A double-blind, placebo-controlled trial.

PURPOSE: The goal of this study was to evaluate the dose-response relationship between dexmedetomidine and propofol in sedating patients and to determine the optimal dosage of dexmedetomidine during gastrointestinal endoscopy. METHODS: One hundred fifty patients were divided into 5 groups, each receiving a loading dose of dexmedetomidine (0.4, 0.6, 0.8, 1.0 µg/kg) or saline, with propofol for sedation. The median effective concentration (EC50) of propofol was calculated using the modified Dixon up-and-down approach. Adverse effects, vital signs, procedure, and recovery times were recorded. RESULTS: The EC50 of propofol in groups NS, D0.4, D0.6, D0.8, and D1.0 were 3.02, 2.44, 1.97, 1.85, and 1.83 µg/mL, respectively. Heart rate in the dexmedetomidine groups decreased more than the NS group (P < .001). The mean arterial pressure (MAP) in the NS group experienced a decline compared to groups D0.8 and D1.0 when the plasma concentration and effect-site concentration reached equilibrium. Additionally, the respiratory rate was found to be lower in groups NS, D0.4, D0.6, and D0.8 (P < .05). Recovery time in groups D0.8 and D1.0 was longer than the NS group (P < .05). Bruggemann comfort scales score was higher in group D1.0 (P < .05). No significant difference was found in the incidences of hypotension and bradycardia, and the dose of ephedrine and atropine. Respiratory depression was significantly reduced in groups D0.8 and D1.0 compared to the NS group. CONCLUSION: A single dose of 0.6 to 0.8 µg/kg of dexmedetomidine should be recommended in combination with propofol for gastrointestinal endoscopy. And the EC50 of propofol is 1.97 to 1.85 µg/mL.

Ultrasound-guided caudal anaesthesia combined with epidural anaesthesia for caesarean section: a randomized controlled clinical trial.

BACKGROUND: Although epidural anaesthesia and spinal anaesthesia are currently the general choices for patients undergoing caesarean section, these two neuraxial anaesthesia methods still have drawbacks. Caudal anaesthesia has been considered to be more appropriate for gynaecological surgery. The purpose of this study was to compare epidural anaesthesia combined with caudal anaesthesia, spinal anaesthesia and single-space epidural anaesthesia for caesarean section with respect to postoperative comfort and intraoperative anaesthesia quality. METHODS: In this clinical trial, 150 patients undergoing elective caesarean section were recruited and randomized into three groups according to a ratio of 1:1:1to receive epidural anaesthesia only, spinal anaesthesia only or epidural anaesthesia combined with caudal anaesthesia. The primary outcome was postoperative comfort in the three groups. Secondary outcomes included intraoperative anaesthesia quality and the incidences of nausea, vomiting, postdural puncture headache, maternal bradycardia, or hypotension. RESULTS: More patients were satisfied with the intraoperative anaesthesia quality in the EAC group than in the EA group (P = 0.001). The obstetrician was more significantly satisfied with the intraoperative anaesthesia quality in the SA and EAC groups than in the EA group (P = 0.004 and 0.020, respectively). The parturients felt more comfortable after surgery in the EA and EAC groups (P = 0.007). The incidence of maternal hypotension during caesarean section was higher in the SA group than in the EA and EAC groups (P = 0.001 and 0.019, respectively). CONCLUSIONS: Epidural anaesthesia combined with caudal anaesthesia may be a better choice for elective caesarean section. Compared with epidural anaesthesia and spinal anaesthesia, it has a higher quality of postoperative comfort and intraoperative anaesthesia.

Effects of dexmedetomidine combined with etomidate on postoperative cognitive function in older patients undergoing total intravenous anaesthesia: a randomized, double-blind, controlled trial.

BACKGROUND: Etomidate has been advocated for anesthesia in older and critically ill patients because of its hemodynamic stability. Clinical studies have shown that dexmedetomidine has neuroprotective and anti-inflammatory properties and improves postoperative cognitive dysfunction in older patients. The present study was to evaluate the effects of the combination of etomidate and dexmedetomidine with different anaesthesia time on postoperative cognitive function in older patients. METHODS: A total of 132 older patients undergoing ureteroscopic holmium laser lithotripsy were randomly divided into EN group and ED group equally. Patients whose surgery time was less than or equal to 1 h in each group were allocated to short-time surgery group (EN1 group and ED1 group), and whose surgery time was more than 1h were allocated to long-term surgery group (EN2 group and ED2 group). The primary outcome was the score of the Mini-Mental State Examination. The secondary outcomes were State-Trait Anxiety Inventory scores, Riker sedation agitation scores, Zung Self-Rating Depression Scale scores, the memory span for Arabic numerals, the plasma concentrations of S-100 calcium-binding protein B and neuron specific enolase, the time to spontaneous respiration, recovery, and extubation. RESULTS: The MMSE scores at t2-3 were higher in ED1 and ED2 groups than in EN1 and EN2 groups (p<0.05). Compared with ED1 and ED2 groups, the ZSDS scores, the S-AI scores and the T-AI scores at t1-2 were higher in EN1 and EN2 groups (p<0.05), respectively. The recalled Arabic numbers at t1-3 were higher in ED2 group than in EN2 group (p<0.05). The plasma concentration of S-100ß at t1-2 in EN1 group and t1-3 in EN2 group were higher than that in ED1 and ED2 groups (p<0.05), respectively. Compared with ED1 and ED2 groups, the plasma concentrations of NSE were higher at t1-3 in EN1 group and t1-4 in EN2 group (p<0.05), respectively. CONCLUSION: The administration of dexmedetomidine could improve postoperative cognitive dysfunction, emergence agitation, depression and anxiety, attenuate the plasma concentrations of S-100ß and NSE in older patients undergoing total intravenous anaesthesia with etomidate. TRIAL REGISTRATION: Registration number: ChiCTR1800015421, Date: 29/03/2018.

Evaluation of standard breast ultrasonography by adding two-dimensional and three-dimensional shear wave elastography: a prospective, multicenter trial.

OBJECTIVE: To reduce the number of biopsies performed on benign breast lesions categorized as BI-RADS 4-5, we investigated the diagnostic performance of combined two-dimensional and three-dimensional shear wave elastography (2D + 3D SWE) with standard breast ultrasonography (US) for the BI-RADS assessment of breast lesions. METHODS: A total of 897 breast lesions, categorized as BI-RADS 3-5, were subjected to standard breast US and supplemented by 2D SWE only and 2D + 3D SWE analysis. Based on the malignancy rate of less than 2% for BI-RADS 3, lesions assessed by standard breast US were reclassified with SWE assessment. RESULTS: After standard breast US evaluation, 268 (46.1%) participants underwent benign biopsies in BI-RADS 4-5 lesions. By using separated cutoffs for upstaging BI-RADS 3 at 120 kPa and downstaging BI-RADS 4a at 90 kPa in 2D + 3D SWE reclassification, 123 (21.2%) participants underwent benign biopsy, resulting in a 54.1% reduction (123 versus 268). CONCLUSION: Combining 2D + 3D SWE with standard breast US for reclassification of BI-RADS lesions may achieve a reduction in benign biopsies in BI-RADS 4-5 lesions without sacrificing sensitivity unacceptably. CLINICAL RELEVANCE STATEMENT: Combining 2D + 3D SWE with US effectively reduces benign biopsies in breast lesions with categories 4-5, potentially improving diagnostic accuracy of BI-RADS assessment for patients with breast lesions. TRIAL REGISTRATION: ChiCTR1900026556 KEY POINTS: • Reduce benign biopsy is necessary in breast lesions with BI-RADS 4-5 category. • A reduction of 54.1% on benign biopsies in BI-RADS 4-5 lesions was achieved using 2D + 3D SWE reclassification. • Adding 2D + 3D SWE to standard breast US improved the diagnostic performance of BI-RADS assessment on breast lesions: specificity increased from 54 to 79%, and PPV increased from 54 to 71%, with slight loss in sensitivity (97.2% versus 98.7%) and NPV (98.1% versus 98.7%).

Effects of spinal anaesthesia and intravenous general anaesthesia on the absorption of normal salinein patients undergoing hysteroscopic endometrial resection: an observational study.

INTRODUCTION: The absorption of uterine distention fluid during hysteroscopic endometrial resection can cause volumeoverload, which can lead to coagulation dysfunction, acute left heart failure and pulmonary oedema in patients. The effects of spinal anaesthesia and intravenous general anaesthesia on the absorption of normal saline as uterine distention fluid during hysteroscopic surgery remain unclear. The aim of this clinical trial was toobserve the effects of spinal anaesthesia and intravenous general anaesthesia on the absorption of normal saline in patients undergoing hysteroscopic endometrial resection. METHODS: A total of 126 patients undergoing elective hysteroscopic endometrial resection were divided into a spinal anaesthesia group (s group) and a propofol-fentanyl intravenous anaesthesia group (PF group), with 63 cases in each group, and both groups were divided into a short-term group (S1 group and PF1 group) and a long-term group (S2 group and PF2 group) according to the operation time. The primary outcome was the absorption of normal saline, and the secondary outcomes included the perioperative SBP, DBP, HR and SpO2 and postoperative haematocrit values, and the incidence of postoperative complications. RESULTS: The volume of saline absorbed was significantly increased in the S2 and PF2 groups compared with the S1 and PF1 groups (P < 0.001). There was a significant positive correlation between the amount of normal saline absorbed and the operation time (r = 0.895, P < 0.001). The postoperative haematocrit value was slightly lower than that before the operation in all four groups (P < 0.05), and there were no differences in the incidences of urinary retention, sinus bradycardia or hypotension between groups (P > 0.05). CONCLUSIONS: There was no difference in the effects of spinal anaesthesia and intravenous general anaesthesia on the absorption of normal saline during hysteroscopic endometrial resection, and the absorption of normal saline increased accordingly with the extension of operation time.

The effects of remifentanil-propofol combined with dexmedetomidine on cognitive dysfunction in elderly patients after ureteroscopic holmium laser lithotripsy: a double-blind randomized controlled trial.

BACKGROUND: A clinical study indicated that infusion of dexmedetomidine without a loading dose administered intraoperatively provided a smooth and hemodynamically stable emergence and improved the quality of recovery with fewer postoperative side effects and reduced analgesic requirements. The objective was to determine whether administering remifentanil-propofol combined with dexmedetomidine during general anesthesia would decrease the incidence and severity of postoperative emergence agitation, anxiety, and depression without affecting cognitive dysfunction in elderly patients. METHODS: A total of 120 elderly patients scheduled for ureteroscopic holmium laser lithotripsy were randomly allocated to the PR group and administered normal saline, and the PRD group was administered dexmedetomidine 0.4 µg kg-1 h-1 intravenously after the induction of anesthesia and stopped 30 min before the end of surgery. The primary outcome was the Mini-Mental State Examination score. The secondary outcomes were the Richmond Agitation Sedation, the State-Trait Anxiety Inventory, and the Zung Self-Rating Depression Scale scores; the memory span for Arabic numerals; the duration of surgery; and the time to spontaneous respiration, recovery, and extubation. RESULTS: The MMSE scores were lower at T1-2 in the two groups (P < 0.001). The dosage of propofol and remifentanil decreased more significantly in the PRD group than in the PR group (P < 0.001). Both the RASS scores and the incidence of emergence agitation (EA) in the PRD group were significantly lower than those in the PR group at t1-3 (P < 0.001). Compared to the PR group, the ZSDS scores and STAI scores at T1-2 were lower in the PRD group (P < 0.005). The number of the Arabic numbers that were accurately recalled from memory was lower at T2 in the PR group than in the PRD group (P < 0.001). CONCLUSION: Dexmedetomidine administration has no influence on postoperative cognitive dysfunction but could reduce both the dosage of remifentanil and propofol needed during ureteroscopic holmium laser lithotripsy and the incidence and severity of postoperative emergence agitation, anxiety, and depression in elderly patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900021254 . Registered on 3 February 2019.

Effects of dexmedetomidine on intraoperative hemodynamics, recovery profile and postoperative pain in patients undergoing laparoscopic cholecystectomy: a randomized controlled trial.

BACKGROUND: To investigate the optimal dose of dexmedetomidine to maintain hemodynamic stability, prevent of cough and minimize postoperative pain for patients undergoing laparoscopic cholecystectomy. METHODS: One hundred twenty patients were randomly divided into D1, D2, D3 and NS groups, and dexmedetomidine 0.4, 0.6, 0.8µg/kg and normal saline were administrated respectively. Patients' heart rate, systolic blood pressure and diastolic blood pressure were measured at T1-T7. The incidence of cough was recorded. Other parameters were noted, the time of spontaneous respiratory recovery and extubation, visual analogue scale scores and dosage of tramadol. RESULTS: The heart rate, systolic blood pressure and diastolic blood pressure of D2 and D3 groups has smaller fluctuations at T2-3 and T7 compared with NS and D1 groups (P < 0.05). The incidence of cough was lower in D2 and D3 groups than NS group (P < 0.05). The visual analogue scale scores and tramadol dosage of D2 and D3 groups were lower than NS group (P < 0.05). The time of spontaneous respiratory recovery and extubation in D3 group was longer than that in D1 and D2 groups (P < 0.05). CONCLUSIONS: Intravenous infusion of 0.6µg/kg dexmedetomidine before induction can maintain hemodynamic stability, decrease cough during emergence, relieve postoperative pain of patients undergoing laparoscopic cholecystectomy. TRIAL REGISTRATION: ChiCTR1900024801 , registered at the Chinese Clinical Trial Registry, principal investigator: Qin Ye, date of registration: July 28, 2019.

Generation of flat wideband chaos based on mutual injection of semiconductor lasers.

In this Letter, we propose and demonstrate a method to improve the bandwidth and flatness of chaotic signals using a mutual injection structure with two distributed feedback lasers. The frequency detuning and coupling strength are investigated to produce wideband flat chaos. The chaotic signal that the spectrum covers is greater than 50 GHz, which is approximately 6.42 times when compared with the one generated by the optical feedback, with a flatness of 5.6 dB achieved when the coupling strength is 1.635 and the frequency detuning is -33.5 GHz.

Methylation of DACT2 contributes to the progression of breast cancer through activating WNT signaling pathway.

The activation of the Wnt/ß-catenin signaling pathway has been demonstrated to play important roles in breast carcinogenesis and to be associated with a poorer prognosis in breast cancer patients. However, genetic mutation is not the major reason for Wnt/ß-catenin activation in breast cancer. Dishevelled-associated antagonist of ß-catenin homolog 2 (DACT2) is a negative regulator of ß-catenin and acts as a tumor suppressor in numerous cancer types; however, the expression change and potential role of DACT2 in breast cancer is unknown. The present study detected the expression and function of DACT2 in breast cancer progression. It was identified that the expression of DACT2 significantly decreased in breast cancer tissues compared with paired adjacent normal breast tissues. Additional investigation demonstrated that the hypermethylation of DACT2 gene promoter contributes to the loss of the gene in breast cancer. It was also demonstrated that DACT2 is a tumor suppressor in breast cancer and inhibits the proliferation and invasion of breast cancer cells by repressing the expression of ß-catenin target genes associated with tumor growth and metastasis. The present study indicates that the loss of DACT2 may contribute to breast cancer progression and provides a promising therapeutic target for the treatment of breast cancer.