Objective To evaluate the blood-saving effect of different doses of tranexamic acid in patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB).Methods Ninety ASA physical status l-Ⅲ patients,aged 18-60 yr,with body mass index of 16-25 kg/m2,scheduled for elective cardiac valve replacement with CPB,were equally and randomly divided into 3 groups using a random number table:control group (group C),large-dose tranexamic acid group (group TL) and small-dose tranexamic acid group (group TS).Anesthesia was induced with iv injection of midazolam,sufentanil and pipecuronium.The patients were endotracheally intubated and mechanically ventilated.Anesthesia was maintained with inhalation of isoflurane and iv injection of midazolam,sufentanil and pipecuronium.After induction of anesthesia,tranexamlc acid 20 mg/kg was intravenously infused over 30 min,followed by continuous infusion at 20 mg· kg-1 · h-1 until the end of operation in group TL,tranexamlc acid 10 mg/kg was intravenously infused over 30 min,followed by continuous infusion at 10 mg· kg-1 · h-1 until the end of operation in group TS,while the equal volume of normal saline was given instead in group C.Venous blood samples were taken before induction,at the end of operation and at 24 h after operation for determination of hemoglobin (Hb),hematocrit (Hct),and platelct count (Plt).The volume of chest tube drainage was collected and recorded at 6 and 24 h after operation.The requirement for transfusion of allogeneic red blood cells was also recorded.The development of death and complications during days of hospitalization was recorded.Results Compared with group C,the volume of chest tube drainage was significantly decreased,the requirement for transfusion of allogeneic red blood cells was reduced (P ＜ 0.05),while no significant changes were found in Hb,Hct and Plt at each time point in TL and TS groups (P ＞ 0.05).There was no significant difference in the parameters mentioned above between group TL and group TS (P ＞ 0.05).The development of death and complications during days of hospitalization was not observed in the three groups.Conclusion Small-dose tranexamlc acid is suitable for blood-saving effect in patients undergoing cardiac valve replacement with CPB,that is loading dose of 10 mg/kg and maintenance dose of 10 mg· kg-1· h-1.

ObjectiveTo compare the changes in renal blood flow in elderly and adult patients during laparoscopic cholecystectomy.MethodsSixty ASA Ⅰ or Ⅱ patients of both sexes,aged 18-75 yr,weighing 48-78 kg,undergoing elective laparoscopic cholecystectomy were enrolled in this study.The patients were divided into 2 groups according to the age ( n =30): group Ⅰ young and middle-age (18-60 yr) and group Ⅱ elderly (61-75 yr).Anesthesia was induced with midazolam,fentanyl,propofol and vecuromium and maintained with infusion of propofol and remifentanil,isoflurane inhalation and intermittent iv boluses of vecuromium.The patients were intubated and mechanically ventilated.PETCO2 was maintained at 30-40 mm Hg.The probe of transesophageal echocardiography (TEE) was inserted into esophagus after tracheal intubation.The internal diameter and time integral of left renal artery were measured by TEE before pneumoperitoneum (baseline) and at 1,5,10,15,20 and 30 min of pneumoperitoneum and 1,5 min after deflation.The blood flow of left renal artery (LRAF) was calculated.The maximal derease in LRAF during pneumoperitoneum was analyzed.ResultsThe internal diameter and time integral of left renal artery and LRAF were significantly decreased during peumoperitoneum and at 1 min after deflation in both groups ( P ＜ 0.05).LRAF before peumoperitoneum was significantly lower,and the time point of LRAF maximum decrease during pneumoperitoneum was later in group Ⅱ than in group Ⅰ ( P ＜ 0.05).ConclusionThe renal blood flow is temporary decreased during laparoscopic cholecystectomy both in young and middle age and elderly patients.The time point of LRAF maximum decrease in elderly patients is later than that in adult patients.

Objective To observe the outcomes of satellite ganglion block(SGB)via posterior edge of stcmoclcidomastoid approach.Methods SGB was performed in 2 400 patients,who wererandomly divided into two groups with l 200 cases each.The puncture of SGB in group SPA was via posterior edge of sternocleidomastoid approach and that in group TPA via traditional paratracheal approac}L The same local anesthetics was used in two groups.The success rate(Horner'S syndrome appearance)and complications were compared.Results The success rate was higher in group SPA than that in group TPA(97% VS.92%)(P<0.05).Repeated puncture was needed in 16 cases ingroup SPA,which were less than 98 cases in group TPA(P<0.05).Laryngeal nerve block wasoccurred in 24 cases in group SPA.which were less than 37 cases in group TPA(P<0.05).Conclusion Compared to the traditional paratracheal approach,SGB via posterior edge ofsternocleidomastoid approach has the advantages of clear positioning,easy puncture,higher success rate and less complications.

Objective To determine the accuracy of renal blood flow assessment by transesophageal echocardiography (TEE) during carbon dioxide (CO2) pneumoperitoneum.Methods The left renal arterial diameter (RAD) and the Doppler velocity time integral (VTI) were measured by TEE before peumoperitoneum (T0, baseline), at 1, 5, 10, 15, 20 and 30 min of pneumoperitoneum and 1 and 5 min after deflation in 35 patients undergoing elective laparoscopic cholecystectomy. The left renal blood flow (LRBF) and the left renal blood perfusion resistance (LRPR) were calculated according to the following formulae: LRBF = 1/4π x RAD2 x VTI x HR, LRPR = MAP/LRBF.Three months later, the TEE images of 10 cases were randomly selected and reviewed by the same and another research team member to check the repeatability and consistency of the LRBF determination during operation, respectively. The quality of the TEE images was evaluated by another specialist.Results Before pneumoperitoneum, 94% of the TEE images were rated as satisfactory. There was no significant difference between the qualities of the TEE images obtained before and during pneumoperitoneum. The variabilities between the RADs measured by TEE during and 3 months after operation were 9.28% by the same team member and 8.71% by another team member. The variabilities between the VTIs measured by TEE during and 3 months after operation were 5.61% by the same team member and 6.25% by another team member. The linear regression analysis of the LRBF showed that the slope and the intercept were 1.05 and 31.4 ml/min respectively by the same member and 0.92 and 47.3 ml/min respectively by another member. The LRBF was decreased during pneumoperitoneum and the LRPR was increased.Conclusion TEE can be used to accurately monitor the changes in renal blood flow during CO2 pneumoperitoneum.

Objective To evaluate the effects of pulmonary static inflation with different pressures on postoperative lung function in patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB).Methods Sixty ASA Ⅱ or Ⅲ patients,aged 26-70 yr,weighing 47-78 kg,undergoing elective cardiac valve replacement with CPB,were randomly divided into 2 groups (n =30 each):pulmonary static inflation with 5 cm H2O group (group L) and with 10 cm H2O group (group H).In L and H groups,pulmonary static inflation was performed with the pressure maintained at 5 and 10 cm H2O,respectively,after stopping mechanical ventilation during CPB.Arterial blood samples were taken before skin incision and at 1,3 and 6 h after termination of CPB for blood gas analysis.The alveolar-arterial oxygen pressure difference (D(A-a)O2),respiratory index (RI) and oxy.genation index (OI) were calculated.The indwelling time of endotracheal tube after operation and duration of ICU stay were recorded.Results Compared with group L,D(A-a)O2 and RI were significantly decreased and OI was increased at 1,3 and 6 h after termination of CPB,the incidence of OI less than 300 mm Hg was decreased (P ＜ 0.05),and no significant change was found in the indwelling time of endotracheal tube after operation and duration of ICU stay in H group (P ＞ 0.05).Collusion Pulmonary static inflation with 10 cm H2O can better improve postoperative pulmonary diffusion function than with 5 cm H2O in patients undergoing cardiac valve replacement with CPB.

Objective To evaluate the effects of small dose of dopamine on the renal blood flow in the elderly patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Sixty elderly patients,of ASA physical status Ⅱ or Ⅲ,aged 65-74 yr,weighing 52-77 kg,scheduled for elective cardiac valve replacement under CPB,were randomized to receive either normal saline (group C,n =30) or dopamine (group D,n =30).After beginning of surgery,CPB was established routinely.In group D,dopamine was continuously infused for 20 min at a rate of 2 μg· kg-1 · min-1 starting from 10 min after the hearts were perfused with cardioplegic solution for the first time,while the equal volume of normal saline was given in group C.The left renal blood flow velocity was measured by transesophageal echocardiography and mean arterial pressure was recorded before and after dopamine infusion.Blood samples were obtained before surgery and at 24 h after surgery for determination of blood urea nitrogen concentrations.Results Blood urea nitrogen concentrations were significantly increased at 24 h after surgery than that before surgery in the two groups.There was no significant difference in mean arterial pressure and the left renal blood flow velocity before and after dopamine infusion between the two groups.Conclusion Small dose of dopamine (2 μg· kg-1· min-1) dose not increase the renal blood flow or improve the postoperative renal function in the elderly patients undergoing cardiac valve replacement under CPB.

Objective To investigate the changes in renal blood flow during laparoscopic cholecystectomy.Methods Thirty-two ASA Ⅰ patients (10 male, 22 female) aged 18-64 yr, weighing 45-81 kg undergoing laparoscopic cholecystectomy were included in this study. Anesthesia was induced with midazolam, fentanyl,propofol and vecuronium and maintained with isoflurane inhalation, continuous infusion of propofol and remifentanil and intermittent iv boluses of vecuronium. The patients were intubated and mechanically ventilated. PET CO2 was maintained at 30-40 mm Hg. The probe of transesophageal echocardiography (TEE) was inserted into esophagus after tracheal intubation. The internal diameter and blood flow velocity and time integral of left renal artery and descending aorta were measured by TEE before (baseline) and at 1, 5, 10, 15, 20 and 30 min of pneumoperitoneum and 1 and 5 min after deflation. The blood flow of left renal artery (LRAF) and decending aorta (DAF) were calculated. The maximal decrease in LRAF and DAF and LRAF/DAF were analyzed. Results LRAF and DAF decreased significantly during pneumoperitoneum compared to the baseline and recovered after deflation. LRAF and DAF decreased maximally by 40% (95% confidence interval (95% CI) 31%-49% ) and 38% (95% CI 31%-44% ) at 8.9 min (95% CI 5.5-12.4 min) and 6.7 min (95% CI 4.0-9.5 min) of pneumoperitoneum respectively. There was no significant change in LRAF/DAF ratio during pneumoperitoneum. Conclusion The renal blood flow decreases at 1-30 min of pneumoperitoneum with the maximum degree of decrease about 40% at about 9 min of pneumoperitoneum and the reason is related to the decrease in the cardiac output.

Objective To compare the onset time, duration and adverse effects of stellate ganglion block (SGB) with different concentrations of lidocaine. Methods Two hundred and forty ASA Ⅰ or Ⅱ patients (97 male, 143 female) aged 37-76 yr weighing 48-79 kg were randomly divided into 3 groups ( n = 80 each): group A, B and C received unilateral SGB with 8 ml of 0.6%, 0.8% and 1.0% lidocaine respectively. Unilateral SGB was performed by the same anesthesiologist in all patients. Successful SGB was verified by Homer's syndrome. The onset time, duration and adverse effects were recorded. Results Homer's syndrome was observed in all patients. There was no significant difference in onset time among the 3 groups. The duration of action was significantly longer in group B and C than in group A and in group C than in group B. There was no significant difference in the adverse effects including recurrent laryngeal nerve block, brachial plexus block, local anesthetic intoxication and transient loss of consciousness among the 3 groups. Conclusion SGB can be induced with either 0.6%, 0.8% or 1.0% lidocaine with comparable effectiveness. We suggest using lower concentration of lidocaine.

Objective To investigate the effect of preconditioning with different concentrations of sevoflurane on hypoxia-reoxygenation(H/R)-induced apoptosis in rat hippocampal neurons and the role of mitochondrial KATP(mito-KATP)channels.Methods Primary cultured hippocampal neurons isolated from newborn SD rats(＜24h)of both sexes,weighing 5-6 g,were randomly divided into 7 groups with 48 wells and 12 dishes in each one:control group(C group),H/R group,preconditioning with 6%,4%and 2% sevoflurane groups(S1-3 groups),5-hydroxydecanoate(5-HD,mito-KATP channel blocker)100 μmol/L preconditioning group(5-HD group)and preconditioning with 5-HD 100 μmol/L+6% sevoflurane group(5-HD+S group).The neurons were exposed to 4 h hypoxia followed by 24 h reoxygenation. In S1-3 groups, preconditioning was performed with 6% , 4% and 2% sevoflurane respectively before H/R. In 5-HD group, preconditioning was performed with 5-HD (final concentration 100 μmol/L) before H/R. In 5-HD + S group, preconditioning was performed with 5-HD 100 μmol/L and 6% sevoflurane before H/R. The neuronal viability, apoptosis rate and expression of Bcl-2 and Bax were determined after 24 h reoxygenation.Results The neuronal viability was significantly lower,while the apoptosis rate and expression of Bcl-2 and Bax were significantly higher in the other 6 groups than in group C(P＜0.01).The neuronal viability and expression of Bcl-2 were significantly higher,while the apoptosis rate and Bax expression were lower in S1-3 groups than in group H/R. There was no significant difference in the parameters mentioned above between 5-HD and 5-HD + S groups(P＞0.05).The neuronal viability and expression of Bcl-2 were significantly lower, while the apoptosis rate and Bax expression were higher in S2, S3 and 5-HD + S groups than in group S1, and in group S3 than in group S2(P＜0.0l) .Conclusion Sevoflurane preconditioning can inhibit H/R-induced apoptosis in rat hippocampal neurons and reduce the injury to neurons in a concentration-dependent manner, and the underlying mechanism may be related to activation of mito-KATP channels, up-regulation of Bcl-2 expression and down-regulation of Bax expression.