Effects of dexmedetomidine on cardiac electrophysiology in patients undergoing general anesthesia during perioperative period: a randomized controlled trial.

BACKGROUND: Dexmedetomidine has controversial influence on cardiac electrophysiology. The aim of this study was to explore the effects of dexmedetomidine on perioperative cardiac electrophysiology in patients undergoing general anesthesia. METHODS: Eighty-one patients were randomly divided into four groups: groups D1, D2, D3 receiving dexmedetomidine 1, 1, 0.5 µg/kg over 10 min and 1, 0.5, 0.5 µg/kg/h continuous infusion respectively, and control group (group C) receiving normal saline. Twelve-lead electrocardiograms were recorded at the time before dexmedetomidine/normal saline infusion (T1), loading dose finish (T2), surgery ending (T6), 1 h (T7) after entering PACU, 24 h (T8), 48 h (T9), 72 h (T10) and 1 month (T11) postoperatively. Cardiac circulation efficiency (CCE) were also recorded. RESULTS: Compared with group C, QTc were significantly increased at T2 in groups D1 and D2 while decreased at T7 and T8 in group D3 (P < 0.05), iCEB were decreased at T8 (P < 0.05). Compared with group D1, QTc at T2, T6, T7, T9 and T10 and iCEB at T8 were decreased, and CCE at T2-T4 were increased in group D3 significantly (P < 0.05). Compared with group D2, QTc at T2 and iCEB at T8 were decreased and CCE at T2 and T3 were increased in group D3 significantly (P < 0.05). CONCLUSIONS: Dexmedetomidine at a loading dose of 0.5 µg/kg and a maintenance dose of 0.5 µg/kg/h can maintain stability of cardiac electrophysiology during perioperative period and has no significant adverse effects on CCE. TRIAL REGISTRATION: ClinicalTrials.gov NCT04577430 (Date of registration: 06/10/2020).

Median Effective Dose of Lidocaine for the Prevention of Pain Caused by the Injection of Propofol Formulated with Medium- and Long-Chain Triglycerides Based on Lean Body Weight.

OBJECTIVE: To determine the median effective dose (ED50) of prophylactic intravenous lidocaine for the prevention of propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) emulsion injection pain. DESIGN: Prospective trial, Dixon up-and-down sequential method. SETTING: Operating room of a single hospital. PATIENTS: Thirty patients aged 18-65 years with American Society of Anesthesiologists (ASA) status I or II who were scheduled for elective surgery under general anesthesia (GA) were included. INTERVENTIONS: The initial dose of prophylactic lidocaine before propofol MCT/LCT emulsion injection was set at 0.5 mg/kg lean body weight (LBW). The lidocaine dose was adjusted according to the degree of patients' injection pain using the Dixon up-and-down sequential method. MEASUREMENTS: The ED50 and 95% confidence intervals (CIs) of lidocaine were calculated using the Dixon-Massey formula. Vital signs and adverse effects were recorded. In the postanesthesia care unit (PACU), patients were asked if they recalled feeling any injection pain with visual analog scale (VAS) evaluation. RESULTS: The ED50 of lidocaine for the prevention of propofol MCT/LCT emulsion injection pain was 0.306 mg/kg LBW (95% CI, 0.262-0.357 mg/kg LBW). No adverse reactions to lidocaine occurred. In the PACU, 90.9% of patients who experienced injection pain recalled this pain (VAS score, 2.8±1.8). CONCLUSIONS: Prophylactic intravenous lidocaine (0.306 mg/kg LBW) effectively prevented propofol MCT/LCT emulsion injection pain in 50% of patients scheduled for elective surgery under GA with no adverse reaction occurring.

Optimal dose of pretreated-dexmedetomidine in fentanyl-induced cough suppression: a prospective randomized controlled trial.

BACKGROUND: To investigate the optimal dose of pretreated-dexmedetomidine in fentanyl-induced cough (FIC) suppression. METHODS: Patients of 180 undergoing elective surgery with general anesthesia, aged 18-65 years, BMI 18.5-30 kg/m2, ASA I or II, were equally randomized into four groups (n = 45) to receive intravenous pretreatment of dexmedetomidine with 0 (group 1), 0.3 (group 2), 0.6 (group 3) and 0.9 (group 4) mcg/kg over 10 mins, respectively. After the pretreatment, all patients were given a 5-s intravenous injection of fentanyl 4 mcg/kg. The symptoms of irritating cough including the severity and onset time were recorded for 1 min after fentanyl injection. General anesthesia induction was completed with midazolam, propofol and cisatracurium, then endotracheal tube or laryngeal mask was inserted and connected to an anesthesia machine. MAP, HR and SpO2 at the beginning of pretreatment (T0), 3 min (T1), 6 min (T2), 9 min (T3) and 12 min (T4) after the beginning of pretreatment were recorded. Side effects of dexmedetomidine, such as bradycardia, hypertension, hypotension, and respiratory depression were also recorded during the course. RESULTS: Totally 168 patients completed the study. The incidences of cough were 52.4, 42.9, 11.9, and 14.3% in groups 1, 2, 3, and 4, respectively, with no significant differences between groups 1 and 2 (P > 0.05) and between groups 3 and 4 (P > 0.05). The incidence and severity of cough in groups 3 and 4 were significantly lower than those in groups 1 and 2 (P < 0.05). Compared to T0, HR at T2 (P < 0.05), T3 (P < 0.01), and T4 (P < 0.01) decreased significantly and MAP at T4 decreased significantly (P < 0.05) in group 4. Bradycardia occurred in 1 case and respiratory depression occurred in 1 case in group 4. Compared to group 1, the onset time of cough in the other 3 groups were delayed significantly (P < 0.05). CONCLUSION: Pretreated dexmedetomidine 0.6 mcg/kg blous intravenous infusion over 10 mins could reduce FIC effectively without side effects. TRIAL REGISTRATION: This study was registered in ClinicalTrials.gov (NCT03126422), April 13, 2017.

Effects of dexmedetomidine on glucose-related hormones and lactate in non-diabetic patients under general anesthesia: a randomized controlled trial.

BACKGROUND: The aim of this study was to explore the effects of dexmedetomidine on glucose-related hormones and lactate levels in non-diabetic patients undergoing malignant gastrointestinal tumor radical resection. METHODS: Groups D1 and D2 received dexmedetomidine loading dose 1 µg/kg and maintenance dose 0.25 and 0.5 µg/kg/h, respectively. Group C received saline solution. Glucose, lactate, insulin, glucagon, cortisol, epinephrine, norepinephrine and dopamine levels were measured before dexmedetomidine infusion (T1), 1 h after surgery beginning (T2), at surgery ending (T3), and 1 h after transfer to the postanesthesia care unit (T4). RESULTS: Compared with group C, glucose levels increased in group D2 at T2 and reduced in groups D1 and D2 at T4. Lactate levels reduced in groups D1 and D2 at T4. A positive correlation between glucose and lactate levels was found in all groups. Compared with group C, insulin level reduced in group D2 at T2; glucagon levels reduced in groups D1 and D2 at T4; cortisol levels reduced in group D1 at T4 and in group D2 at T3 and T4; epinephrine and norepinephrine levels reduced in group D1 at T4 and in group D2 at T2 and T4; and dopamine level reduced in group D2 at T4. CONCLUSIONS: Dexmedetomidine loading dose 1 µg/kg and maintenance dose 0.25 µg/kg/h produces a stable insulin level and significant postoperative decreases in glucagon, cortisol, epinephrine and norepinephrine secretion with stable maintenance of intraoperative and postoperative blood glucose levels and decreased postoperative lactate levels in non-diabetic patients under general anesthesia.

Effects of Peak Inspiratory Pressure-Guided Setting of Intracuff Pressure for Laryngeal Mask Airway Supreme™ Use during Laparoscopic Cholecystectomy: A Randomized Controlled Trial.

PURPOSE: To determine the effects of peak inspiratory pressure (PIP)-guided intracuff pressure (ICP) modulation of laryngeal mask airway (LMA) Supreme™ during laparoscopic cholecystectomy. METHODS: Totally 120 patients were randomly divided using computer-generated numbers into a control group (n = 60; ICP, 60 cmH2O) and a PIP group (n = 60), in which ICP was increased with 5 cmH2O each time from PIP level until no air leaks from the oropharynx. PIP, ICP, cuff volume (CV), oropharyngeal leak pressure (OLP) and leak fraction (LF) were recorded before and after pneumoperitoneum establishment. Postoperative pharyngolaryngeal complications (sore throat, dysphagia, pharyngeal hematoma, and dysphonia) were also recorded. RESULTS: Demographic data were similar in the two groups. The CV and ICP before and after pneumoperitoneum were significantly lower in the PIP group (CV: 15.6 ± 2.3 mL and 21.0 ± 2.6 mL; ICP: 14.3 ± 2.9 cmH2O and 20.5 ± 3.4 cmH2O) than in the control group (CV: 33.0 ± 2.8 mL and 32.8 ± 1.9 mL; ICP: 60.0 ± 0.1 cmH2O and 60.0 ± 0.1 cmH2O) (P < 0.05). Although OLP was lower in the PIP group (P < 0.05), the LF was similar in the two groups (P > 0.05). There were fewer postoperative pharyngolaryngeal complications in the PIP group (P < 0.05). CONCLUSIONS: Compared with a fixed ICP of 60 cmH2O, PIP-guided ICP modulation during LMA Supreme™ use provided effective airway sealing at a lower CV and ICP, and produced fewer postoperative pharyngolaryngeal complications in patients undergoing laparoscopic cholecystectomy.

Optimal Dose of Dexmedetomidine for Perioperative Blood Glucose Regulation in Non-Diabetic Patients Undergoing Gastrointestinal Malignant Tumor Resection: A Randomized Double-Blinded Controlled Trial.

PURPOSE: To evaluate the optimal dose of dexmedetomidine for perioperative blood glucose regulation in non-diabetic patients with gastrointestinal malignant tumor. METHODS: One hundred patients were randomly divided into four groups: control group (group C), dexmedetomidine 1 µg/kg + 0.25 mcg/kg/h (group D1); + 0.5 mcg/kg/h (group D2); and + 1 mcg/kg/h (group D3). Blood glucose concentrations were measured before dexmedetomidine infusion (T1), 1 h after surgery beginning (T2), at the end of surgery (T3), and 1 h in PACU (T4). Duration of surgery, extubation time, anesthetics doses, adverse reactions, postoperative pulmonary infection, total peritoneal drainage 2 days after surgery and hospital stay were recorded. RESULTS: Compared with T1, blood glucose concentrations were higher at T4 in group C and at T2-4 in groups D1, D2, and D3 (p < 0.01). Compared with group C, blood glucose concentrations were higher at T2 and T3 in groups D2 and D3 (p < 0.05), but significantly lower at T4 in groups D1, D2, and D3 (p < 0.01). Propofol and remifentanil consumption in groups D1, D2, and D3 decreased significantly compared with group C (p < 0.01). In group D3, doses of ephedrine (p < 0.05) and atropine (p < 0.01) were higher, and extubation time was prolonged (p < 0.01) compared with the other groups. The incidence of bradycardia was higher in group D3 than that in group C (p < 0.05). CONCLUSIONS: Dexmedetomidine loading dose of 1 mcg/kg followed by maintenance with 0.25 mcg/kg/h can regulate perioperative blood glucose well in non-diabetic patients undergoing gastrointestinal malignant tumor resection and reduce doses of anesthetics without extending extubation time.