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Objective:To investigate the effects of dexmedetomidine on perioperative cardiac adverse events in elderly patients with coronary heart disease.Methods:Sixty elderly patients,who were diagnosed as coronary heart disease and underwent gastric cancer operation,were randomly divided into 2 groups (n=30):the dexmedetomidine group (Dex group) and the control group.In the Dex group,dexmedetomidine was administered intravenously at 0.5 μtg/(kg.h) after a bolus infusion at 0.5 μg/kg for 10 min before anesthesia induction.In the control group,equal volume of normal saline was infused instead of dexmedetomidine.The 2 groups received the same anesthesia treatment.The venous bloods were collected at the preoperative 0 h and postoperative 24 h.The concentrations of cardiac troponin (cTnⅠ),N-terminal pro-brain natriuretic peptide (NT-proBNP) and hypersensitive C-reactive protein (hs-CRP) were determined.The ECG was monitored at the above time and the postoperative incidence of cardiac adverse events was recorded.Results:The levels of cTnⅠ,NT-proBNP and hs-CRP in serum were elevated in the 2 groups after the operation.Compared with the control group,the levels of cTnⅠ,NT-proBNP and hs-CRP were significantly decreased in the Dex group (P＜0.05).Compared with the control group,the incidence ofbradycardia were significantly increased,while the myocardial ischemia and tachycardia were significantly decreased in the Dex group during the operation (P＜0.05);the incidence of silent myocardial ischemia and arrhythmia was significantly reduced at 3 days after operation in the Dex group (P＜0.05).Conclusion:Dexmedetomidine could decrease the incidence of cardiac adverse events in elderly patients with coronary heart disease.
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Objective To compare the cost-effectiveness of closed-loop versus open-loop infusion of propofol guided by bispectral index (BIS) in elderly patients undergoing abdominal surgery.Methods Sixty American Society of Anesthesiologists physical status Ⅱ patients of either sex,aged 65-75 yr,with body mass index of 18 25 kg/m2,undergoing elective open gastrointestinal tumor resection with general anesthesia,were allocated into closed-loop target-controlled infusion (TCI) group (group C) and open-loop TCI group (group O) using a random number table.Propofol was given using closed-loop TCI,and the target BIS value was set at 45-55 in group C.In group O,the target plasma concentration (2.0-3.5 μg/ml)of propofol was adjusted to maintain the BIS value at 45-55.Remifentanil was given by TCI with the target plasma concentration of 2-8 ng/ml in both groups.The total consumption of propofol and remifentanil,time rate of maintaining BIS value within the target range,development of intraoperative hypertension and hypotension,emergence time,tracheal extubation time,time for recovery of orientation,first ambulation time,time to first flatus and length of postoperative hospital stay were recorded.The development of nausea and vomiting and delirium within 3 days after operation and intraoperative awareness was recorded.The cost of anesthetics and total cost of anesthesia were calculated.Results Compared with group O,the total consumption of propofol was significantly decreased,the total consumption of remifentanil was increased,the time rate of maintaining BIS value within the target range was increased,the emergence time,tracheal extubation time and time for recovery of orientation were shortened,the cost of propofol and total cost of anesthesia were decreased (P＜0.05),and no significant change was found in the cost of remifentanil,incidence of postoperative delirium and nausea and vomiting,first ambulation time,time to first flatus or length of postoperative hospital stay in group C (P＞0.05).Intraoperative awareness was not found in two groups.Conclusion Compared with open-loop infusion of propofol guided by BIS,closed-loop infusion of propofol guided by BIS is a cost-effective method of anesthesia in elderly patients undergoing abdominal surgery.
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Objective To evaluate the role of mitochondrial ATP-sensitive potassium(mito-KATP) channels in dexmedetomidine-induced attenuation of myocardial ischemia-reperfusion(I∕R)injury in rats. Methods Forty pathogen-free healthy male Sprague-Dawley rats, aged 8-12 weeks, weighing 200-350 g, were divided into 5 groups(n=8 each)using a random number table: sham operation group(group S), I∕R group, dexmedetomidine group(group DEX), a specific mito-KATPchannel blocker 5-hydroxyde-canoate(5-HD)group(group 5-HD)and dexmedetomidine plus 5-HD group(group DEX+5-HD). Myo-cardial I∕R was produced by occlusion of the anterior descending branch of the left coronary artery for 30 min followed by 120 min reperfusion in pentobarbital sodium-anesthetized rats. Dexmedetomidine 5 μg∕kg was intraperitoneally injected at 15 min prior to reperfusion in group DEX.5-HD 40 mg∕kg was intraperitoneally injected at 30 min prior to reperfusion in group 5-HD. In group DEX+5-HD, 5-HD 40 mg∕kg and dexme-detomidine 5 μg∕kg were intraperitoneally injected at 30 and 15 min prior to reperfusion, respectively. The parameters of cardiac function such as left ventricular systolic pressure(LVSP), left ventricular end-dias-tolic pressure(LVEDP)and the maximum rate of increase or decrease in left ventricular pressure(±dp∕dtmax)were recorded before ischemia(T0)and at 60 and 120 min of reperfusion(T1,2). Blood samples were collected from the carotid artery at the end of reperfusion for determination of the concentrations of cre-atine kinase-MB(CK-MB)and cardiac troponin I(cTnI)in serum. The animals were then sacrificed, and hearts were removed for determination of the myocardial infarct size in the left ventricular myocardial tissues. Results Compared with group S, the LVSP and ±dp∕dtmaxwere significantly decreased, and the LVEDP was increased at T1-2, and the concentrations of CK-MB and cTnI in serum and myocardial infarct size were increased in the other groups(P<0.05). Compared with group I∕R, the LVSP and ±dp∕dtmaxwere signifi-cantly increased, and the LVEDP was decreased at T1-2, and the concentrations of CK-MB and cTnI in ser-um and myocardial infarct size were decreased in group DEX, and the LVSP and ±dp∕dtmaxwere significant-ly increased at T1-2, the concentrations of CK-MB and cTnI in serum and myocardial infarct size were de-creased(P<0.05), and no significant change was found in LVEDP in group DEX+5-HD, and no signifi-cont change was found in the parameters mentioned above in group 5-HD(P>0.05). Compared with group DEX, the LVSP and ±dp∕dtmaxwere significantly decreased, and the LVEDP was increased at T1-2, and the concentrations of CK-MB and cTnI in serum and myocardial infarct size were increased in DEX+5-HD group(P<0.05). Conclusion The mechanism by which dexmedetomidine attenuates myocardial I∕R inju-ry is partially related to promotion of mito-KATPchannel opening in rats.
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Objective To compare the postoperative analgesic effect of the single dose of oxycodone and dezocine in patients who underwent gynecological laparoscopic operation. Methods Sixty patients who underwent elective gynecological laparoscopic operation were randomly divided into two groups (n=30): oxycodone group (group O) and dezocine group (group D). Fifteen minutes before the end of surgery, oxycodone 0.1 mg/kg was given in O group, and dezocine 5 mg was given to D group. Twenty minutes before the end of surgery, tropisetron 5 mg was given to both groups. Analgesia was maintained by propofol-remifentanil with TCI. The mean arterial pressure (MAP) and heart rate (HR) of T1, T2, T3 and T4 were recorded respectively in both two groups. After the operation, pain of visual analogue scale (VAS) was assessed in 2 h ,4 h , 6 h and 24 h, respectively. Results There were no significant differences in MAP and HR between two groups at T1, T2, T3 and T4 (P＞0.05). The VAS score was significantly lower in group O than that of group D (P＜0.05). There was significant difference in the incidence of nausea between the two groups (P＜0.05). Conclusion Single dose of oxycodone 0.1 mg/kg can be used for postoperative analgesia after gynecological laparoscopic operation, and which has better analgesia than that of dezocine, except for the adverse reaction of nausea.
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Objective To investigate the optimum ratio of medicine dosage for dexmedetomidine mixed with oxycodone used for patient-controlled intravenous analgesia (PCIA) after gastrointestinal surgery.Methods Eighty patients of both sexes, aged 35-64 yr, weighing 55-75 kg, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ , undergoing elective gastrointestinal surgery, were randomly divided into 4 groups (n=20 each) using a random number table: oxycodone group (group O), and different ratios of medicine dosage when dexmedetomidine was added to sufentanil groups (OD1-3 groups).At 15 min before the end of surgery, oxycodone 0.1 mg/kg was injected intravenously, and PCIA pump was connected simultaneously.In group O, the PCIA solution contained oxycodone 1.00 mg/kg in 100 ml of normal saline.In group OD1, the PCIA solution contained oxycodone 1.00 mg/kg and dexmedetomidine 2.5 μg/kg in 100 ml of normal saline.In group OD2 , the PCIA solution contained oxycodone 0.75 mg/kg and dexmedetomidine 2.5 μg/kg in 100 ml of normal saline.In group OD3, the PCIA solution contained oxycodone 0.50 mg/kg and dexmedetomidine 2.5 μg/kg in 100 ml of normal saline.The PCIA pump was set up to deliver a 0.5 ml bolus dose with a 15-min lockout interval and background infusion at 2 ml/h.Oxycodone 0.05 mg/kg was injected intravenously as a rescue analgesic, and visual analogue scale score was maintained ≤ 4.The requirement for rescue analgesics was recorded.The requirement for the rescue analgesic was recorded within 48 h after surgery.The number of successfully delivered doses, and occurrence of adverse reactions such as bradyeardia, hypotension, nausea, vomiting, over-sedation, somnolence, pruritus, and respiratory depression were recorded.Patient's satisfaction with analgesia was recorded at 72 h after surgery.Results No patients required the rescue analgesic or developed over-sedation, vomiting, respiratory depression and hypotension in the four groups.Compared with group O, the incidence of somnolence was significantly increased in group OD1, the incidence of nausea, somnolence, bradycardia and pruritus was decreased in OD2 and OD3 groups, and the degree of patient's satisfaction with analgesia was increased in OD1-3 groups (P＜0.05).Compared with group OD1, the incidence of nausea, somnolence, bradycardia and pruritus was significantly decreased in OD2 and OD3 groups, the degree of patient's satisfaction with analgesia was increased in group OD3 (P＜0.05) , and no significant was found in the degree of patient's satisfaction with analgesia in group OD2 (P＞0.05).Compared with group OD2, no significant was found in the incidence of adverse reactions (P＞0.05) , and the degree of patient's satisfaction with analgesia was significantly decreased in group OD3 (P＜0.05).The number of successfully delivered doses was significantly larger in group OD3 than in O, OD1 and OD2 groups (P＜0.05).Conclusion Dexmedetomidine 2.5 μg/kg added to oxycodone 0.75 mg/kg is the optimum ratio of medicine dosage when used for PCIA after gastrointestinal surgery.