Objective To compare dexmedetomidine versus midazolam sedation for myocardial protection in the patients undergoing percutaneous coronary intervention (PCI).Methods Sixty patients with acute myocardial infarction who required for emergency PCI,were selected and randomly divided into 2 groups (n =30 each) using a random number table:dexmedetomidine group (group D) and midazolam group (group M).In group D,a loading dose of dexmedetomidine 1 μg/kg was infused intravenously for 10 min before surgery.In group M,midazolam 0.05 mg/kg was injected intravenously before surgery.Dexmedetomidine 0.2-1.4 μg· kg-1 · h-1 and midazolam 0.02-0.10 mg·kg-1 ·h-1 were given via a pump during surgery until the end of surgery in the two groups.The RASS score was maintained at-2-2 in two groups.Before administration and on 3rd day after surgery,cardiovascular color doppler ultrasound was performed to record left ventricular ejection fraction (LVEF),venous blood samples were collected for determination of the levels of serum myocardial enzyme and cardiac troponin I (cTnI),and the development of surgical complications,duration of ICU stay and length of hospital stay were recorded.Results Compared with group M,the activities of serum creatine kinase,creatine kinase isoenzyme-MB,aspartate amino transferase and lactic dehydrogenase and cTnI concentrations were significantly decreased,LVEF was increased,and duration of ICU stay and length of hospital stay were shortened in group D.There was no significant difference in the development of postoperative complications between the two groups.Conclusion Dexmedetomidine sedation provides better efficacy for myocardial protection and prognosis and is more suitable for sedation than midazolam in the patients undergoing PCI.

Objective To compare the time course of distribution and elimination of gelatin and lactated Ringer's solution (LR) by volume kinetics and mass balance analysis during hemorrhagic shock in dogs, and try to design and optimize fluid therapy in a more scientific manner. Methods Twenty dogs were randomly divided into 4 groups: CL group, CG group, BL group, and BG group. Each animal was subjected to two randomly ordered experiments that separated for at least 1 week. In the first phase, plasma volume expansion was studied in the state of anesthesia, animals received 30 mL/kg of LR (CL group) or 10 mL/kg of gelatin (CG group) over 30 min. In the second phase, plasma volume expansion was studied in the state of hemorrhagic shock, animals received 30 mL/kg of LR (BL group) or 10 mL/kg of gelatin (BG group) over 30 min. Hb concentration and Hct were measured every 5 min during and after infusion for 90 min. Hemodynamic parameters were recorded at the same time. The distribution and elimination of infused fluid were studied by volume kinetics, based on serial analysis of hemoglobin dilution in arterial blood, and by mass balance that incorporated volume calculations derived from volume kinetic analysis and measurements of urinary volumes. Results When a one-volume kinetic model was fitted to the data, the value of V and Kr in CG, BL, and BG group were significantly smaller than those in CL group (P<0.05), which could be found from the computer-generated curves.When a two-volume kinetic model was fitted to the data, the value of V1, Kr, Kt in BL group were significantly smaller than those in CL group (P<0.05). The calculations based on mass balance corresponded to the predicted based on volume kinetics. The change of central volume (CCV) in BL, BG, and CG group was significantly greater than those in CL group (P<0.05). The VEE in BG and CG group was significantly higher than that in BL and CL group. The value of VEE in BL group was significantly higher than that in CL group (P<0.05). Conclusions Both of the efficacy of lactated Ringer's solution and gelatin increased significantly in the state of hemorrhagic shock, and the former increased more.

Objective To evaluate the effect of dexmedetomidine on the inflammatory responses in brain tissues in septic rats.Methods Seventy-two male Sprague-Dawley rats,aged 10 weeks,weighing 250-280 g,were randomly divided into 4 groups (n =18 each):control group (group C); sepsis group (group lipopolysaccharide (LPS)) ; distilled water group (group DW) and dexmedetomidine group (group D).Sepsis was induced by intraperitoneal injection of LPS 5 mg/kg (dissolved in normal saline 1 ml) in groups LPS,DW and DEX,while normal saline 1 ml was injected intraperitoneally in group C.Distilled water 20 μl was injected into the lateral cerebral ventricle in group DW,while dexmedetomidine 3 μg/kg (dissolved in distilled water 20μl) was injected into the lateral cerebral ventricle in group DEX.Six animals were sacrificed at 1,2 and 6 h after administration and hippocampi were removed for determination of TNF-α and IL-6 contents (by ELISA) and TLR4 mRNA expression in hippocampal tissues (by RT-PCR).Results Compared with group C,TNF-α and IL-6 contents in hippocampus tissues were significantly increased at each time point after administration in group LPS (P ＜ 0.05).Compared with group LPS,no significant change was found in TNF-α and IL-6 contents in hippocampal tissues (P ＞ 0.05),and TLR4 mRNA expression was significantly up-regulated at each time point after administration in group DW (P ＜ 0.05).Compared with group DW,TNF-α and IL-6 contents in hippocampal tissues were significantly decreased at each time point after administration,and TLR4 mRNA expression was significantly up-regulated at 2 and 6 h after administration in group DEX (P ＜ 0.05).Conclusion Dexmedetomidine can reduce inflammatory responses in brain tissues in septic rats via down-regulating TLR-4 mRNA expression.

Objective:To investigate the effect of oxycodone hydrochloride on patients with analgesic effect and immune function of intestinal tumor after operation.Methods:50 patients with intestinal tumor from June 2014 to December 2016 who were treated in our hospital were selected randomly to divide into oxycodone group and fentanyl group with 25 cases in each group.Patients in oxycodone group were given oxycodone hydrochloride intravenous injection of 5mg 15 minutes before the end of surgery;and patients in fentany group were given fentany intravenous injection of 50ug 15 minutes before the end of surgery.Visual analogue scale (VAS),ramsey sedation score were observed at 3 h (T0),6 h (T1),12 h (T2),24 h (T3) 48 h (T4) after operation,Levels of serum tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6) and IL-10 CD4+,CD8+,CD4+/CD8+ and NK cells measured before anesthesia,and at T2,T3,T4 respectively.Results:At time point of T1,T2,Ramsey scores of oxycodone group were significantly lower than that of fentany group (P＜0.05),At time point ofT0,T3,T4,Ramsey scores of the two groups showed no significant difference (P＞0.05).At time point of T2,T3,T4,levels of serum TNF-α,IL-6 and IL-10 of two groups of patients were significantly higher than those of anesthesia before (P＜0.05),TNF-α,IL-6 and IL-10 ofoxycodone group was significantly lower than those of fentany group (P＜0.05).At time point ofT2,T3,T4,CD4+/at CD4+ of the two groups were significantly decreased,and CD8+ was significantly increased(P＜0.05).Levels of CD4+,CD4+/CD8+ of oxycodone group was significantly higher than that of fentany group (P＜0.05),and level ofCD8+ was significantly higher than that of fentany group.At time point of T2,T3,NK cells of two groups were significantly decreased,NK cells of oxycodone group were significantly higher than that of oxycodone group (P＜0.05).Differences among postoperative nausea,vomiting,respiratory depression,dizziness,skin itching incidence of two groups of patients were not statistically significant (P＞0.05).Conclusion:Oxycodone hydrochloride has little effect on the immune function of patients with intestinal tumor,and it is suitable for Postoperative analgesia of patients with intestinal tumor.

Objective To investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.Methods Twenty ASA Ⅰ or Ⅱ patients,aged 20-64 years,with body mass index (BMI) of 20-30 kg/m2,scheduled for elective orthopedic operation were enrolled in this study.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium,and maintained with sevoflurane,fentanyl and cisatracurium.Then the patients received endotracheal intubation and mechanical ventilation.Heart rate (HR),mean arterial blood pressure (MAP),central venous pressure (CVP),arterial pressure-based cardiac output (APCO),SW,systemic vascular resistance (SVR) and cardiac index (Cl) were recorded 5 minutes after endotracheal intubation.Blood was taken from the central vein at a rate of 30-50 ml/min and the volume was 5％ of the whole blood volume,and then haemodynamic parameters mentioned above were recorded after the haemodynamics were kept stable for 5 minutes.Blood was taken again with the method mentioned above and the haemodynamic parameters were recorded.Then 6％ hydroxyethyl starch (HES) 130/0.4 was infused at 50-70 ml/min via the right internal jugular vein,and the volume was equal to 5％ of the whole blood volume,and then haemodynamic parameters were recorded after the haemodynamics was kept stable for 5 minutes.Fluid replacement was performed again using the method mentioned above and the haemodynamic parameters were recorded.Linear correlation of the changes in blood volume (difference between the blood volume at each time point and the baseline value) with dSVV (difference between the value monitored at each time point and the baseline value) was analyzed.Results Significant changes were found in SW,APCO and Cl after each change in blood volume (P ＜ 0.05 or 0.01),while no significant changes were found in HR,MAP,CVP and SVR after each change in blood volume.The change in blood volume was negatively correlated with dSVV (r =-0.875,P ＜ 0.01).Conclusion There is high correlation between SVV and blood volume during hypovolemia.And SVV can reflect the changes in blood volume accurately and can be used for volume therapy during hypovolemia.

ObjectiveTo investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.MethodsTwenty ASA Ⅰ or Ⅱ patients,aged 20-64 yr,with body mass index 20-30 kg/m2,scheduled for elective orthopedic operation,were studied.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium and maintained with sevoflurane,fentanyl and cisatracurium.The patients were tracheal intubated and mechanically ventilated.HR,MAP,CVP,arterial pressure-based cardiac output (APCO),SVV,systemic vascular resistance (SVR) and cardiac index (CI) were recorded 5 min after tracheal intubation.Blood was taken from central vein at a rate of 30-50 ml/min,the volume was 5％ of the whole blood volume and the haemodynamic parameters mentioned above were recorded after the haemodynamics was kept stable for 5 min.Blood was taken again as the method mentioned above and the haemodynamic parameters were recorded.6％ HES 130/0.4 was then infused at 50-70 ml/min via right internal jugular vein,the volume was equal to 5 ％ of the whole blood volume and the haemodynamic parameters were recorded after the haemodynamics was kept stable for 5 min.Fluid replacement was performed again using the method mentioned above and the haemodynamic parameters were recorded.Linear correlation of the change in blood volume (difference between the blood volume at each time point and the baseline value) with dSVV (difference between the value monitored at each time point and the baseline value) was analyzed.ResultsThere was significant change in SVV,APCO and CI after each change in blood volume ( P ＜ 0.05 or 0.01),while there was not always significant change in HR,MAP,CVP and SVR after each change in blood volume.The change in blood volume was negatively correlated with dSVV ( r =- 0.875,P ＜ 0.01 ).ConclusionThere is high correlation between SVV and blood volume during hypovolemia and SVV can reflect the change in blood volume accurately and be used for volume therapy during hypovolemia.

Objective:To evaluate the sedative effect of remimazolam for induction of general anesthesia in elderly patients.Methods:One hundred patients of both sexes, aged 65-75 yr, with American Society of Anesthesiologists physical status Ⅱ or Ⅲ, undergoing elective general anesthesia requiring tracheal intubation, were divided into 4 groups ( n=25 each) using a random number table method: propofol group (group P) and three different doses of remimazolam groups (group R1, group R2 and group R3). In group P, general anesthesia was induced with propofol 1.5 mg/kg intravenously injected over 30 s, cisatracurium 0.2 mg/kg and fentanyl 4 μg/kg were intravenously injected when bispectral index (BIS) value ≤ 60, and endotracheal intubation was performed.In R1, R2 and R3 groups, general anesthesia was induced with 0.2, 0.3 and 0.4 mg/kg of remimazolam intravenously injected over 30 s, respectively, cisatracurium 0.2 mg/kg and fentanyl 4 μg/kg were intravenously injected when BIS value ≤ 60, and endotracheal intubation was performed.When the BIS value was > 60 during the induction of anesthesia, propofol 0.5 mg/kg was intravenously injected per time for rescue sedation in group P, and remimazolam 0.05 mg/kg was intravenously injected per time for rescue sedation until the BIS value ≤ 60, with the interval between the two injections > 1 min in R1, R2, and R3 groups.The onset time of propofol or remazolam was recorded.The occurrence of hypertension, hypotension, bradycardia, hypoxemia, injection pain and rescue sedation during the induction of anesthesia was recorded.The occurrence of intraoperative awareness was recorded during follow-up at 1 day after surgery. Results:Compared with group P, the rate of rescue sedation was significantly increased in group R1, the incidence of hypoxemia was significantly reduced in R1 and R2 groups, the onset time was significantly prolonged, and the incidence of hypotension, bradycardia and injection pain was decreased in R1, R2 and R3 groups ( P<0.05). Compared with group R1, the rate of rescue sedation was significantly decreased in R2 and R3 groups ( P<0.05). Compared with R1 and R2 groups, the incidence of hypoxemia was significantly increased in group R3 ( P<0.05). There was no significant difference in the incidence of hypotension, hypoxemia and injection pain among R1 group, R2 group and R3 group ( P>0.05). No hypertension and intraoperative awareness was found in the four groups. Conclusion:Remimazolam can be safely and effectively used for sedation during induction of general anesthesia in elderly patients, and the optimal dose is 0.3 mg/kg.

Objective To investigate the clinical effects of Dexmedetomidine on analgesia and postoperative cognitive function in elderly patients with lumbar spine surgery.Methods The patients were randomly divided into the control group (n=88) and the study group (n=100).The patients in the study group were treated with Dexmedetomidine at a loading dose of 1.0 μg/kg for 15 min,and 0.3 μg · kg-1 · h 1 was continuously pumped.The anesthetic mode and drugs in the control group were similar to those in study group,except that Dexmedetomidine in the study group was replaced with physiological saline in the control group.Intraoperatively used dose of analgesic drugs,and pain and cognitive function changes were compared between the two groups.Results The intraoperatively used doses of Remifentanil,Fentanyl and propofol were significantly lower in the study group than in the control group (P＜0.05).The VAS scores were markedly lower in the study group than in the control group (2.6±0.5 vs.4.5± 1.2,t=4.9398,P=0.0000).The MMSE scores were higher in the study group than in the control group (28.0 ± 1.3 vs.26.0 ± 2.5,t =-6.6484,P=0.0000).Conclusions Intraoperative use of Dexmedetomidine for treatment of the elderly patients with lumbar surgery will not only reduce the perioperatively used dose of analgesic and sedative drug,but also reduce postoperative pain and improve postoperative cognitive function.

Objective:To explore the postoperative analgesic effect of Dexmedetomidine on elderly patients with colorectal cancer under the guidance of the concept of rapid recovery after surgery.Methods:A total of 230 elderly patients with colorectal cancer who underwent laparoscopic surgery in our hospital from March 2018 to September 2020 were randomly divided into an observation group(receiving Dexmedetomidine auxiliary general anesthesia, n=115)with aged(66.6±4.6)years, male 59, and control group(receiving normal saline auxiliary general anesthesia, n=115), with aged(67.0±4.6)years, male 61.The analgesic effect, hemodyna mic index, postoperativeout of bed activity time, gastrointestinal fuction recovery time postoperative hospital stay and adverse reactions were observed.Results:The pain scores at 4, 8, 12, 24 and 48 h after operation were lower in the observation group than in control group(all P<0.05). The recovery rate of postoperative analgesic drugs was 13.9% in the observation group and 24.3% in the control group( χ2=4.047, P<0.05). Ramesay scores were higher in the observation group than in the control group( P<0.05). Fluctuations of postoperative heart rate and blood pressure were lower in the observation group than in the control group( P<0.05). The total incidence of adverse reactions was lower in the observation group(11.3%)than in the control group(24.3%)( χ2=6.678, P<0.05). Conclusions:Under the guidance of the concept of rapid recovery after surgery, Dexmedetomidine can improve the postoperative analgesic effect in elderly patients with colorectal cancer, reduce the incidence of adverse reactions, and have stable hemodynamics.

Objective:To investigate the effects of Dexmedetomidine on postoperative pain and stress response in elderly patients undergoing laparoscopic colorectal cancer surgery.Methods:A total of 150 elderly patients who had undergone laparoscopic radical resection of colorectal cancer in our hospital from June 2019 to December 2020 were divided into two groups using the random number table method, the control group(n=75)and the study group(n=75). In the study group, Dexmedetomidine 0.5 μg/kg was injected intravenously over 10 min before induction of anesthesia and maintained at 0.5 μg/kg/h until 30 min before the end of surgery.Changes in heart rate, mean arterial pressure, postoperative pain and stress response index scores were compared between the two groups.Results:The MAP and HR in the study group at T1(10 min after administration), T2(immediately after endotracheal intubation), T3(30 min after pneumoperitoneum)and T4(leaving the operating room)were significantly lower than in the control group( P<0.05); The concentrations of norepinephrine and epinephrine in the study group were lower than those in the control group at T2, T3 and T4(all P<0.05); Pain scores of patients in the study group were lower than those in the control group at T4 and T5( P<0.05); Compared with the control group, the study group used less intraoperative Sufentanil[(65.5±7.0)μg vs.(76.2±7.6)μg, t=8.968, P=0.000], needed a lower number of PCIA compressions 24 h after surgery[(6.3±2.3) vs.(9.5±3.0), t=7.331, P=0.000]and had a shorter length of PACU stay[(23.4±4.0)min vs.(30.2±5.7)min, t=8.457, P=0.000]. Conclusions:Dexmedetomidine used in laparoscopic colorectal cancer surgery in elderly patients can reduce the use of sufentanil and the length of PACU stay time, improve postoperative pain scores and reduce stress response, and therefore should be recommended.