Comparison of the recovery time of remimazolam besylate and propofol for gastrointestinal endoscopy sedation in elderly patients.

Background: Recovery time is a crucial factor in ensuring the safety and effectiveness of both patients and endoscopy centers. Propofol is often preferred due to its fast onset and minimal side effects. Remimazolam is a new intravenous sedative agent, characterized by its rapid onset of action, quick recovery and organ-independent metabolism. Importantly, its effect can be specifically antagonized by flumazenil. The primary goal of this study is to compare the recovery time of remimazolam besylate and propofol anesthesia during endoscopic procedures in elderly patients. Methods: 60 patients aged 65-95 years who underwent gastrointestinal endoscopy were randomly and equally assigned to two groups: the remimazolam group (Group R) and the propofol group (Group P). The primary measure was the recovery time, defined as the time from discontinuing remimazolam or propofol until reaching an Observer's Assessment of Alertness and Sedation scale (OAA/S) score of 5 (responds readily to name spoken in normal tone). The time required to achieve an OAA/S score of 3 (responds after name spoken loudly or repeatedly along with glazed marked ptosis) was also recorded and compared. Results: The recovery time for Group R (2.6 ± 1.6 min) was significantly shorter than that for Group P (10.8 ± 3.0 min), with a 95% confidence interval (CI): 6.949-9.431 min, p <0.001. Similarly, the time to attain an OAA/S score of 3 was significantly less in Group R (1.6 ± 0.9 min) compared to Group P (9.6 ± 2.6 min), with a 95% CI: 6.930-8.957 min, p <0.001. Conclusion: Our study demonstrated that remimazolam anesthesia combined with flumazenil antagonism causes a shorter recovery time for elderly patients undergoing gastrointestinal endoscopy compared to propofol. Remimazolam followed by flumazenil antagonism provides a promising alternative to propofol for geriatric patients, particularly during gastrointestinal endoscopy.

Relationship between age and remimazolam dose required for inducing loss of consciousness in older surgical patients.

Background: Remimazolam is a new ultra-short-acting benzodiazepine for procedural sedation and general anaesthesia, characterised by rapid onset of action, quick recovery, and organ-independent metabolism. Older patients tend to sustain more treatment-emergent adverse events (TEAEs) and worse perioperative prognoses after receiving remimazolam. However, few studies have investigated the appropriate dose of remimazolam for loss of consciousness (LOC) in geriatric patients. We designed this study to provide evidence for dose references and elucidate the relationship between age and remimazolam requirement for inducing LOC during anaesthesia induction. Methods: Exactly 120 patients scheduled for general surgery under general anaesthesia were included and divided into two groups: Group A (60 patients, 18-64 years) and Group B (60 patients, ≥ 65 years). LOC, defined as a Modified Observer's Assessment of Alertness and Sedation score at 1 had been reached, emerged after all participants received a continuous infusion of remimazolam at a rate of 0.05 mg/kg/min. Results: The remimazolam required for inducing LOC was 0.26 and 0.19 mg/kg in groups A and B, respectively, and the remimazolam dose in group B decreased by 26.9% compared to group A. According to the bivariate linear correlation analysis, remimazolam requirement was negatively correlated with age. Multivariable linear regression models and further adjustments for potential impact factors indicated that age was an independent factor for the remimazolam dose required for LOC. Conclusion: This study demonstrated that age was significantly and independently correlated with the remimazolam requirement for inducing LOC. To obtain haemodynamic stability during the induction of general anaesthesia, appropriately reducing the remimazolam dose is recommended for geriatric patients.

Bilirubin potentiates etomidate-induced sedation by enhancing GABA-induced currents after bile duct ligation.

OBJECTIVES: Our previous clinical trial showed that etomidate requirements to reach an appropriate level of anesthesia in patients with obstructive jaundice were reduced, which means that these patients are more sensitive to etomidate. However, the mechanism is still not completely clear. The present study was aimed to investigate the mechanism by which bilirubin facilitates etomidate induced sedation. METHODS: A bile duct ligation (BDL) rat model was used to simulate obstructive jaundice. Anesthesia sensitivity to etomidate was determined by the time to loss of righting reflex (LORR). Intrathecal injection of bilirubin was used to test the effects of bilirubin on etomidate induced sedation. The modulating effects of bilirubin on GABA responses were studied using the whole-cell patch clamp technique. RESULTS: The time to LORR induced by etomidate was significantly decreased in the BDL groups (p < 0.05), and unconjugated bilirubin in serum and cerebrospinal fluid (CSF) were markedly increased (p < 0.05). The time to LORR induced by etomidate was decreased after intrathecal injection of bilirubin (p < 0.05). A bilirubin concentration of 1.0 µM increased the GABA-induced currents of rat cortical pyramidal neurons (p < 0.05). Furthermore, 1.0 µM bilirubin enhanced GABA-induced currents modulated by etomidate (p < 0.05). CONCLUSIONS: Our results demonstrated that pathologic bilirubin in CSF could enhance etomidate induced sedation. The mechanism may be that bilirubin increase the GABA-induced currents of rat pyramidal neurons.

Downregulation of NUP93 aggravates hypoxia-induced death of cardiomyocytes in vitro through abnormal regulation of gene transcription.

Nuclear pore complex in the nuclear envelope plays an important role in controlling the transportation of RNAs, proteins and other macromolecules between the nucleus and cytoplasm. The relationship between abnormal expression of nucleoporins and cardiovascular diseases is unclear. In this study we investigated how myocardial infarction affected the expression and function of nucleoporins in cardiomyocytes. We separately knocked down 27 nucleoporins in rat primary myocardial cells. Among 27 nucleoporins, knockdown of Nup93, Nup210 and Nup214 markedly increased the expression of ANP and BNP, two molecular markers of cardiomyocyte function. We showed that Nup93 was significantly downregulated in hypoxic cardiomyocytes. Knockdown of Nup93 aggravated hypoxia-induced injury and cell death of cardiomyocytes, whereas overexpression of Nup93 led to the opposite effects. RNA-seq and bioinformatics analysis revealed that knockdown of Nup93 did not affect the overall transportation of mRNAs from the nucleus to the cytoplasm, but regulated the transcription of a large number of mRNAs in cardiomyocytes, which are mainly involved in oxidative phosphorylation and ribosome subunits. Most of the down-regulated genes by Nup93 knockdown overlapped with the genes whose promoters could be directly bound by Nup93. Among these genes, we demonstrated that Nup93 knockdown significantly down-regulated the expression of YAP1. Overexpression of YAP1 partially rescued the function of Nup93 knockdown and attenuated the effects of hypoxia on cell injury and cardiomyocyte death. We conclude that down-regulation of Nup93, at least partially, contributes to hypoxia-induced injury and cardiomyocyte death through abnormal interaction with the genome to dynamically regulate the transcription of YAP1 and other genes. These results reveal a new mechanism of Nup93 and might provide new therapeutic targets for the treatment of ischemia-induced heart failure.

Esketamine-based opioid-free anaesthesia alleviates postoperative nausea and vomiting in patients who underwent laparoscopic surgery: study protocol for a randomized, double-blinded, multicentre trial.

BACKGROUND: Although opioids are commonly prescribed in clinical anaesthesia, the significant side effects attributed to their overuse are raising increasing concerns. One way to reduce perioperative opioid consumption is to apply opioid-reduced anaesthesia (ORA) and even opioid-free anaesthesia (OFA), which involves regional techniques, neuraxial anaesthesia, nonopioid analgesics or combined use. The aim of this study was to investigate whether the application of OFA by using esketamine in intraoperative analgesia could minimize the side effects of postoperative nausea and vomiting (PONV), as well as other short-term side effects related to anaesthesia. METHODS/DESIGN: The study was designed as a prospective, randomized, controlled, multicentre trial. A total of 278 patients were enrolled; participants were nonsmoking female patients aged 18-50 years and scheduled for laparoscopic appendectomy or cholecystectomy, ASA at I-III, with no serious physical or mental diseases. Both groups received usual perioperative care except for the analgesic medication of either esketamine or sufentanil. The primary outcome was the incidence of PONV 3 days after surgery. Secondary outcomes included recovery status, pain, sedation level and overall recovery, delirium and cognition, anxiety and depression and total consumption of analgesic agents. DISCUSSION: This trial may show that the synergy of esketamine and propofol anaesthesia reduces PONV as well as other short-term adverse events, thereby providing a better safety and satisfaction profile of ERAS for laparoscopic appendectomy and cholecystectomy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100047169. Registered on June 9, 2021.

Effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy: a randomized controlled trial.

AIMS: Dexmedetomidine could be an ideal adjuvant to propofol during gastrointestinal endoscopy because it provides both analgesia and sedation without respiratory depression. This study investigates the effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy. METHODS: Ninety adult patients were randomly assigned to Group Control, Group DEX0.5 (0.5 µg/kg dexmedetomidine) or Group DEX1.0 (1.0 µg/kg dexmedetomidine). Anaesthesia during endoscopy was implemented by plasma target-controlled infusion (TCI) of propofol with different doses of dexmedetomidine. TCI concentration of the first patient for each group was 2.5 µg/mL and the consecutive adjacent concentration gradient was 0.5 µg/mL. Median effective concentration (EC50 ) of propofol by TCI for gastrointestinal endoscopy was determined by using the modified Dixon's up-and-down method. Cardiovascular variables were also measured. RESULTS: EC50 of propofol by TCI and 95% confidence interval (CI) for gastrointestinal endoscopy were 3.77 (3.48-4.09), 2.51 (2.27-2.78) and 2.10 (1.90-2.33) µg/mL in Group Control, Group DEX0.5 and Group DEX1.0, respectively. The average percent change from heart rate (HR) baseline was 2.8 (8.9), -7.4 (7.7) and -10.5 (8.8) (P < .001), and the average percent change from mean arterial pressure (MAP) baseline was -10.6 [-24.7; 3.5], -9.5 [-29.2; 11.4] and -4.0 [-27.3; 15.5] (P = .034) in Group Control, Group DEX0.5 and Group DEX1.0, respectively. CONCLUSIONS: Dexmedetomidine reduced the EC50 of propofol by TCI. A 0.5-1 µg/kg dose of dexmedetomidine caused a decrease in HR without bradycardia. The decrease in dosage of propofol with increasing doses of dexmedetomidine caused more stable MAP. Dexmedetomidine is an ideal adjuvant drug to propofol during gastrointestinal endoscopy.

Median Effective Dose of Dexmedetomidine Inducing Bradycardia in Elderly Patients Determined by Up-and-Down Sequential Allocation Method.

Purpose: When dexmedetomidine is used in elderly patients, high incidence of bradycardia is reported. Given age-related physiological changes in this population, it is necessary to know the safety margin between the loading dose of dexmedetomidine and bradycardia. Therefore, we conducted this study to investigate the median effective dose (ED50) of dexmedetomidine causing bradycardia in elderly patients. Methods: Thirty patients with ages over 65 years undergoing elective general surgery were enrolled. The Dixon and Massay sequential method were applied to determine the loading dose of dexmedetomidine, starting from 1.0 µg/kg. The dose for the follow-up subjects increased or decreased according to the geometric sequence with the common ratio 1.2, based on the 'negative' or 'positive' response of the previous subject. Positive mean that the subject developed bradycardia during the test. Hemodynamic data including heart rate and systolic blood pressure were recorded. The level of sedation was assessed with the Observer Assessment of Alertness and Sedation Scale (OAA/S). Results: Bradycardia occurred in 13 patients (43.3%). The ED50 of dexmedetomidine causing bradycardia was 1.97 µg/kg (95% CI, 1.53-2.53 µg/kg). OAA/S scores at 10 min after the beginning of the dexmedetomidine infusion and 10 min after the termination of dexmedetomidine administration showed no significant differences between the positive and negative groups (P > 0.05). Conclusion: The ED50 of dexmedetomidine causing bradycardia in our cohort was higher than clinical recommended dose. A higher loading dose appears acceptable for a faster onset of sedation under careful hemodynamic monitoring. Trial registration: ChiCTR 15006368.

The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients.

It is generally accepted that geriatric patients are more sensitive to propofol than adults; thus, a dose-adjusted propofol is recommended for these patients during the induction of anesthesia. However, for patients aged 75 years and over, established guidelines for propofol induction doses do not provide dose references. To this end, we observed 80 surgical patients (female 39, male 41, American Society of Anesthesiologists physical status score I ∼ II) to access the appropriate dose of propofol for inducing loss of consciousness (LOC). Accordingly, patients were subdivided into group A (20 patients, 45-64 years), group B (20 patients, 65-74 years), group C (20 patients, 75-84 years), and group D (20 patients, ≥ 85 years). All patients received propofol (at a rate of 0.3 mg/kg/min) alone for inducing LOC, which was defined by loss of both eyelash reflex and verbal response. Compared with group A, the propofol requirement for LOC in Group B, C and D decreased by 14.8, 25.2 and 38.5%, respectively. Bivariate linear correlation analysis showed that propofol requirement was negatively correlated with age. After adjusting for potential confounders, age was still an independent factor affecting propofol requirement. In conclusion, the propofol requirement for inducing LOC decreased significantly in elderly patients. We demonstrated that age was an independent factor impacting propofol requirement for LOC during the induction of general anesthesia, implying that the propofol dose for anesthesia induction should be further reduced in elderly surgical patients, especially those aged 75 years and over.

The effect of obstructive jaundice on the sensitivity of intravenous anesthetic of remimazolam: study protocol for a controlled multicenter trial.

BACKGROUND: It is well known that obstructive jaundice could affect the pharmacodynamics of some anesthetics, and the sensitivity of some anesthetics would increase among icteric patients. Remimazolam is a new ultra-short-acting intravenous benzodiazepine sedative/anesthetic, which is a high-selective and affinity ligand for the benzodiazepine site on the GABAA receptor. However, no study has reported the pharmacodynamics of remimazolam in patients with obstructive jaundice. We hypothesize that obstructive jaundice affects the pharmacodynamics of remimazolam, and the sensitivity of remimazolam increases among icteric patients. METHODS/DESIGN: The study will be performed as a prospective, controlled, multicenter trial. The study design is a comparison of remimazolam requirements to reach a bispectral index of 50 in patients with obstructive jaundice versus non-jaundiced patients with chronic cholecystitisor intrahepatic bile duct stones. Remimazolam was infused at 6 mg/kg/h until this endpoint was reached. DISCUSSION: Remimazolam could be suitable for anesthesia of patients with obstructive jaundice, because remimazolam is not biotransformed in the liver. Hyperbilirubinemia has been well-described to have toxic effects on the brain, which causes the increasing of sensitivity to some anesthetics, such as desflurane, isoflurane, and etomidate. Furthermore, remimazolam and etomidate have the same mechanism of action when exerting an anesthetic effect. We aim to demonstrate that obstructive jaundice affects the pharmacodynamics of remimazolam, and the dose of remimazolam when administered to patients with obstructive jaundice should be modified. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100043585 . Registered on 23 February 2021.

The median effective concentration of propofol with different doses of esketamine during gastrointestinal endoscopy in elderly patients: A randomized controlled trial.

AIMS: Propofol may result in hypotension, bradycardia and loss of protective reflexes, especially in elderly patients, while esketamine, a N-methyl-D-aspartate receptor antagonist, has analgesic, anaesthetic and sympathomimetic properties and is known to cause less cardiorespiratory depression. We hypothesized that esketamine may reduce the median effective concentration (EC50 ) of propofol and coadministration is less likely to produce hypotension during gastrointestinal endoscopy in elderly patients. METHODS: Ninety elderly patients, aged 65-89 years, undergoing gastrointestinal endoscopy were randomly assigned into 3 groups: SK0 (control) group (0 mg/kg esketamine); SK0.25 group (0.25 mg/kg esketamine); and SK0.5 group (0.5 mg/kg esketamine). Anaesthesia was achieved by plasma target-controlled infusion of propofol with different bolus doses of esketamine. The EC50 of propofol for gastrointestinal endoscopy was determined by using the up-and-down method of Dixon. The initial plasma target concentration is 2.5 µg/mL and the adjacent concentration gradient is 0.5 µg/mL. Cardiovascular variables were also measured. RESULTS: Propofol EC50 s and its 95% confidence interval for gastrointestinal endoscopy in elderly patients were 3.69 (2.59-4.78), 2.45 (1.85-3.05) and 1.71 (1.15-2.27) µg/mL in the SK0, SK0.25 and SK0.5 groups, respectively (P < .05). The average percent change from baseline mean arterial pressure was -19.7 (7.55), -15.2 (7.14) and -10.1 (6.73), in the SK0, SK0.25 and SK0.5 groups, respectively (P < .001). CONCLUSION: Combination medication of propofol with esketamine reduced the propofol EC50 during gastrointestinal endoscopy in elderly patients compared with administration of propofol without esketamine. Increasing doses of SK with propofol are less likely to produce hypotension with shorter recovery time.

Obstructive Jaundice does not Change the Population Pharmacokinetics of Etomidate in Patients who Underwent Bile Duct Surgery.

BACKGROUND: Etomidate is commonly used in the induction of anesthesia. We have previously confirmed that etomidate requirements are significantly reduced in patients with obstructive jaundice and that etomidate anesthesia during Endoscopic Retrograde Cholangiopancreatography (ERCP) results in more stable hemodynamics compared to propofol. The aim of the present study is to investigate whether obstructive jaundice affects the pharmacokinetics of etomidate in patients who underwent bile duct surgery. METHODS: A total of 18 patients with obstructive jaundice and 12 non-jaundiced patients scheduled for bile duct surgery were enrolled in the study. Etomidate 0.333 mg/kg was administered by IV bolus for anesthetic induction. Arterial blood samples were drawn before, during, and up to 300 minutes after the bolus. Plasma etomidate concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A nonlinear mixed-effects population modeling approach was used to characterize etomidate pharmacokinetics. The covariates of age, gender, height, weight, Body Surface area (BSA), Body Mass Index (BMI), Lean Body Mass (LBM), Total Bilirubin (TBL), Alanine Aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), creatinine (CR), and blood urea nitrogen (BUN) were tested for significant effects on parameters using a multiple forward selection approach. Covariate effects were judged based on changes in the Objective Function Value (OFV). RESULTS: A three-compartment disposition model adequately described the pharmacokinetics of etomidate. The model was further improved when height was a covariate of total clearance [Cl1=1.30+0.0232(HT-162), ΔOFV=-7.33; P<0.01)]. The introduction of any other covariates, including bilirubin and total bile acids, did not improve the model significantly (P>0.01). For the height of 162cm, the final pharmacokinetic parameter values were as follows: V1=1.42 (95% CI, 1.01-1.83, L), V2=5.52 (95% CI, 4.07-6.97, L), V3=63.9 (95% CI, 41.95-85.85, L),Cl1= 1.30 (95% CI, 1.19-1.41, L/min), Cl2= 1.21 (95%CI, 0.95-1.47, L/min), and Cl3=0.584 (95%CI, 0.95-1.21, L/min), respectively. CONCLUSION: A 3-compartment open model might best describe the concentration profile of etomidate after bolus infusion for anesthesia induction. The pharmacokinetics of etomidate did not change by the presence of obstructive jaundice.

Impact of Intraoperative Norepinephrine Support on Living Donor Liver Transplantation Outcomes: A Retrospective Cohort Study of 430 Children.

Norepinephrine (NE) is often administered during the perioperative period of liver transplantation to address hemodynamic instability and to improve organ perfusion and oxygen supply. However, its role and safety profile have yet to be evaluated in pediatric living donor liver transplantation (LDLT). We hypothesized that intraoperative NE infusion might affect pediatric LDLT outcomes. A retrospective study of 430 pediatric patients (median [interquartile range] age, 7 [6.10] months; 189 [43.9%] female) receiving LDLT between 2014 and 2016 at Renji Hospital was conducted. We evaluated patient survival among recipients who received intraoperative NE infusion (NE group, 85 recipients) and those that did not (non-NE group, 345 recipients). The number of children aged over 24 months and weighing more than 10 kg in NE group was more than that in non-NE group. And children in NE group had longer operative time, longer anhepatic phase time and more fluid infusion. After multivariate regression analysis and propensity score regression adjusting for confounding factors to determine the influence of intraoperative NE infusion on patient survival, the NE group had a 169% more probability of dying. Although there was no difference in mean arterial pressure changes relative to the baseline between the two groups, we did observe increased heart rates in NE group compared with those of the non-NE group at anhepatic phase (P=0.025), neohepatic phase (P=0.012) and operation end phase (P=0.017) of the operation. In conclusion, intraoperative NE infusion was associated with a poorer prognosis for pediatric LDLT recipients. Therefore, we recommend the application of NE during pediatric LDLT should be carefully re-considered.

Impact of Surveillance in Chronic Hepatitis B Patients on Long-Term Outcomes After Curative Liver Resection for Hepatocellular Carcinoma.

BACKGROUND: Clinical guidelines recommend surveillance in high-risk population to early detect hepatocellular carcinoma (HCC), when curative treatment such as liver resection can be applied. However, it is largely unknown whether surveillance would provide long-term survival benefits to these high-risk patients who have received curative liver resection for HCC. METHODS: A prospectively maintained database on patients with chronic hepatitis B infection who underwent curative liver resection for HCC from 2003 to 2014 was reviewed. Patients' overall survival and recurrence were compared between the groups of patients whose HCCs were diagnosed by surveillance or non-surveillance, as well as between the groups of patients operated in the first (2003-2008) and second (2009-2014) 6-year periods. RESULTS: Of 1075 chronic hepatitis B patients with HCC, 452 (42.0%) patients were diagnosed by preoperative surveillance. Compared with the non-surveillance group, the OS and RFS rates were significantly better in the surveillance group (both P < 0.001). Surveillance was associated with a 55% decrease in the overall survival risk and a 48% decrease in the recurrence risk (HR 0.45, 95% CI 0.38-0.53, and HR 0.52, 95% CI 0.44-0.61). Compared with the first period, a significant reduction of 12% and 19% in the overall death and recurrence risks, respectively, was observed in the second period (HR 0.88, 95% CI 0.78-0.97, and HR 0.81, 95% CI 0.70-0.95). CONCLUSION: Surveillance for HCC was associated with favorable long-term overall and recurrence-free survival rates after curative liver resection of HCC in patients with chronic hepatitis B.

Association between Anaesthetic Technique and Oncological Outcomes after Colorectal Carcinoma Liver Metastasis Resection.

Background: Recently published studies suggest that the anaesthetic technique used during oncologic surgery can improve patient outcomes. Therefore, the authors evaluated the survival of patients with resected colorectal carcinoma liver metastases (CRCLMs) who received either EGA (general anaesthesia [GA] combined with epidural anaesthesia [EA]) or GA alone. Methods: We conducted an ambispective cohort study including 225 post-surgical CRCLM patients between May 2007 and July 2012 and performed a follow-up investigation of survival in July 2017. Results: The basic characteristics in the two groups were largely similar. The median (quartiles) recurrence interval for all patients was 10 (2.5, 23) months, and the median (quartiles) survival for CRCLM patients post-surgically was 37 (30.5, 51.5) months. Perioperative EA was associated with survival (P =0.039, log-rank test), with an estimated hazard ratio of 0.737 (95% CI 0.551-0.985) in the univariate analysis. Kaplan-Meier estimates of survival for GA and EGA suggested that GA might provide better outcomes than EGA [P=0.028, hazard ratio of 0.7328 (95% CI 0.5433-0.9884)]. Significant differences in anaesthesia techniques were found (P=0.048), with an adjusted estimated hazard ratio of 0.741 (95% CI 0.550-0.998) in the multivariate analysis. Subgroup analyses of patients in different age groups (< 40, ≥ 40 but <60, and ≥ 60 years old) suggested that no significant differences existed among all three subgroups. Conclusions: Compared with EGA, GA may provide a better survival outcome for CRCLM patients. The benefits of anaesthetic techniques in oncological surgery are most likely related to certain cancer types.

The pharmacokinetics of dexmedetomidine in patients with obstructive jaundice: A clinical trial.

OBJECTIVES: Dexmedetomidine, a highly selective central α2-agonist, undergoes mainly biotransformation in the liver. The pharmacokinetics of dexmedetomidine were significantly affected by hepatic insufficiency. The clearance of dexmedetomidine in patients with severe hepatic failure decreased by 50% compared with controls. We tested the hypothesis that the pharmacokinetics of dexmedetomidine would be affected by obstructive jaundice. The prospective registration number of clinical trial is ChiCTR-IPR-15007572. METHODS: 18 patients with obstructive jaundice and 12 non-jaundiced patient controls received dexmedetomidine, 1 µg/kg, over 10 min. Arterial blood samples were drawn before, during, and up to 5 h after the infusion. Plasma dexmedetomidine concentrations were determined by 1290 infinity high performance liquid chromatography coupled with 6470 tandem mass spectrometry. The relevant pharmacokinetic parameters were calculated by non-compartmental analysis using Phoenix WinNonlin 7.0. RESULTS: Plasma clearance of dexmedetomidine was decreased by 33.3% in the obstructive jaundice group as compared with the control group (0.0068±0.0017 vs. 0.0102±0.0033 L/kg/min; P = 0.002). Volume of distribution was decreased by 29.2% in the obstructive jaundice group as compared with the control group (1.43±0.58 vs. 2.02±0.84 L/kg; P = 0.041). CONCLUSIONS: This study demonstrates that the clearance and distribution volume of dexmedetomidine were decreased in patients with obstructive jaundice. It may be advisable to adjust the dose of dexmedetomidine in those patients.

Etomidate Anesthesia during ERCP Caused More Stable Haemodynamic Responses Compared with Propofol: A Randomized Clinical Trial.

BACKGROUND: Propofol may result in hypotension and respiratory depression, while etomidate is considered to be a safe induction agent for haemodynamically unstable patients because of its low risk of hypotension. We hypothesized that etomidate anesthesia during ERCP caused more stable haemodynamic responses compared with propofol. The primary endpoint was to compare the haemodynamic effects of etomidate vs. propofol in ERCP cases. The secondary endpoint was overall survival. METHODS: A total of 80 patients undergoing ERCP were randomly assigned to an etomidate or propofol group. Patients in the etomidate group received etomidate induction and maintenance during ERCP, and patients in the propofol group received propofol induction and maintenance. Cardiovascular parameters and procedure-related time were measured and recorded during ERCP. RESULTS: The average percent change to baseline in MBP was -8.4±7.8 and -14.4±9.4 with P = 0.002, and in HR was 1.8±16.6 and 2.4±16.3 with P = 0.874 in the etomidate group and the propofol group, respectively. MBP values in the etomidate group decreased significantly less than those in the propofol group (P<0.05). The ERCP duration and recovery time in both groups was similar. There was no significant difference in the survival rates between groups ( p = 0.942). CONCLUSIONS: Etomidate anesthesia during ERCP caused more stable haemodynamic responses compared with propofol.

Receptor analysis of differential sensitivity change to succinylcholine induced by nerve injury in rat gastrocnemius.

BACKGROUND: Urgent tracheal intubation is common in intensive care units and the emergency room, and succinylcholine is a first-line neuromuscular blocker used in these situations. Paraplegic or critically ill patients may be at a high risk of receiving succinylcholine because the denervation stage changes nicotinic receptors, which affect the efficacy and safety of succinylcholine. The objective of this study was to determine the receptor subtypes associated with changes in the pharmacodynamics of succinylcholine and its time-line trend. METHODS: Denervated gastrocnemius was collected from tibial nerve transected rats. To determine the 50% effective dose of succinylcholine and rocuronium at 0 (control), 1, 3, 7, 14, and 28 d after denervation, action potential amplitude was monitored by an intracellular recording method. Subunits α1, α7, ε, and γ of the acetylcholine receptor (AChR) were quantified by real-time polymerase chain reaction. Receptor amount and pharmacodynamic changes were analyzed by correlation and regression analysis. RESULTS: The pharmacodynamic change in succinylcholine was a dynamic process, and at the same time α7, ε, and γ-nicotinic AChR genes in denervated muscle were significantly changed but only α7 was closely correlated with the action of succinylcholine. Subunit γ and α7 were related to pharmacodynamic change in the nondepolarizing neuromuscular agent, rocuronium. CONCLUSIONS: Nerve injury may alter nicotinic AChR subtypes in skeletal muscle at different stages, which probably affected the pharmacodynamics of neuromuscular blockers in different ways. Denervation time and stage and the type of neuromuscular blocker and dosage should be taken into consideration when using these drugs in patients with nerve injury.

Awakening concentration of desflurane is decreased in patients with obstructive jaundice.

BACKGROUND: Some studies suggest that behavioral complications of cholestasis, such as fatigue and pruritus, may be associated with altered neurotransmission in the brain. Because inhaled anesthetics primarily act on ion channels and receptors on the neuronal cell membrane and alter synaptic transmission in the central nervous system, it is possible that altered sensitivity to inhaled anesthetics may occur in cholestatic patients. Therefore, the authors compared the minimum alveolar concentration (MAC)-awake of desflurane in obstructive jaundiced patients with the MACawake in nonjaundiced patients. METHODS: Patients underwent inhalational induction of anesthesia with desflurane. MACawake was determined in each patient by observing the response to a verbal command (open eyes on request). An end-tidal anesthetic concentration was maintained at an initial target level of 1.4% for 15 min before a command. If a positive response was observed, the concentration of desflurane was increased by 0.1% and again kept constant for 15 min. The verbal command was then continued. This process was repeated until an end-tidal concentration was reached at which the patient did not respond to command. The anesthetic concentration midway between the value permitting the response and that just preventing the response was defined as MACawake for each patient. RESULTS: The MACawake of desflurane for patients with obstructive jaundice (1.78 +/- 0.19%) was significantly less than those observed for the control group (2.17 +/- 0.25%; P < 0.001) and correlated significantly with serum total bilirubin (r = -0.67, P = 0.0004). CONCLUSIONS: The MACawake of desflurane is reduced in obstructive jaundiced patients compared with nonjaundiced controls.