This paper reported the characteristics and regular patterns of the changes in computerized quantitative electrocncephalogram(EEGcq) and frontal electromyogram(EMGf) in 331 patients under the effect of various inhaled and intravenous anesthetics, and the changes in the EEGcq and EMGf during cerebral ischemia caused by serious hypotention or arrhythmia, feeble heartbeat, cardiac electromechanical dissociation and hypoperfusion during extracorporeal circulation. It was found that the amplitude of EEGcq decreased with a"suddenly coming and departing appearance"when the anesthesia with isofl-uorane was excessively deepened or the course of becoming light, that the EEGcq amplitude displayed on the screen showed frequent sharp uprisings when the anesthesia with enfluorane was excessively deepened, that the response of EMGf to various hurtful stimuli presented spikes when anesthesia was inadequate, and that the EMGf showed plateau tracings when the anesthesia was very light.

Objective: To evaluate the effects of isoflurane-nitrous oxide on hemodynamics in patients undergoing cardiac valve replacement. Method:Hemodynamics values were measured with Swan-Ganz technique. Thirty-nine patients were divided into two groups according to their cardiac function before surgery. The patients with cardiac function Ⅱ degree were belong to group Ⅰ and those with cardiac function Ⅲ-Ⅳ degree to group Ⅱ. Result:CI,LVWI, RVWI,HR and MAP decreased significantly in both groups after induction of anesthesia without change in SI. During tracheal intubation and sternotomy,CI and LVWI decreased,PTRI and SVRI increased,particularly in group Ⅱ. During aorta and vena cava intubation the changes of hemodynamics were relatively complicated with CI and SI improved in group Ⅱ and further decreased in group Ⅰ. After CPB,MPAP,PAWP,PTRI and SVRI were decreasad in different degree in both groups with significant increased in CI and SI in group Ⅱ. Conclusion:Induction and maintenance anes thesia with 1.0%-1.5% isoflurane and 40%-50% N_2O are suitable in patients with impaired cardiac function.

The hemodynamics of 49 scheduled patients during anesthesia and opration for mitral and aortic valve replacement were studied with the insertion of SwanGanz catheter and by the method of thermodilution technics.Pre-anesthesia CI and LVWI were in the nor mal range with abnormal MPAP, PCWP, PTRI and RVWI.Increase of RAP and decrease in MPA,PCWP, MAP, CI, LVWI and RVWI were observed during induction of anesthesia. The hemodynamic parameters returned to or exceded the pre-anesthesia values after trachcal intubation and sternotomy. The CI, MAP, MPAP, PCWP, LVWI and RVWI decreased signifi- cantly after insertion of aorta and vena cava catheter. The reduction of MPAP, P(IWP,PTRI and RVWI post-cardiopulmonary bypass (CPB) were significant and persistent with no change of PVRI.The lower MAP,SVRI and deterioration of cardiac performance post-CPB indicate that the administeration of positive inotropir agents and restoration of hematocrit are nec essary as early as possible.

The effects of normothermic or hypothermic cardiopulmonary bypass(CPB)on hemodynamics, plasma levels of endothelin(ET)and atrial natriuetic peptide(ANP)were comparatively studied in dogs with Swan-Ganz catheter technique and radioimmunoassay. The results showed the total peripheral resistance(TPR)during hypothermic CPB was significantly higher than that of the normothermic. Plasm ET levels increased significantly during hypothermic CPB but remained stable during normothermic CPB. Plasma ANP levels almost unchanged during either CPB. Plasma ET level was positively correlated to TPR but ANT level was not. The results suggest that the increased ET levels may be one of the causes of higher TPR during hypothermic CPB;the stable ET levels contributes to the maintenance of cardiovascular function during and after normothermic CPB and the ANP amount secreted beyond the heart has little effect on the plasma level and hemodynamics during CPB.

Objective: To determine the action site of propofol and hydroxybutyrate sodium relaxing mandibular muscles. Method: Eighty adult patients,ASA class Ⅰ or Ⅱ, were randomly divided into four groups (n=20),receiving intravenous propofol 1.5,3.0mg/kg or hydroxybutyrate sodium 50,80mg/kg, respectively. Train-of-four (TOF), double-burst stimulation (DBS), tetanic stimulation (TS)were applied to ulnar nerve-adductor pollicis or mandibular nerve masseter. Result: (1) After intravenous propofol and hydroxybutyrate sodium,T1 (first twitch height of TOF)and TOF ratio of addutor pollicis were kept unchanged. (2)After intravenous propofol ,T1 induced by stimulating mandibular nerve-masseter was similar to before administration and TOF,DBS and TS ratios were significantly increased; (3) after intravenous hydroxybutyrate sodium,TOF ratios of mandibular nerve-masseter remained stable, but T1, DBS and TS ratios significantly reduced. Conclusion:Neuromuscular transmission of ulnar nerve-addutor pollicis is not affected by propofol and hydroxybutyrate sodium. The action place of propofol relaxing the mandibular muscles is located in central nerve system. Hydroxybutyrate sodium blocks neuromuscular transmission of mandibular nerve-masseter.

Objective: To observe the changes of the pulmonary ventilatory function during cardiac valve operation under cardiopulmonary bypass(CPB). Method: Thirty-four patients undergoing cardiac valve operation were selected. The pulmonary function was measured with side stream spirometer. Result: P_(peak) and P_(plat) did not have any significant changes within 60 min after CPB, but increased significantly at the end of surgery and after closure of sternum(P

Objective:To observe the hemodynamic effects of sevoflurane or sevoflurane-N_2O inhalation during induction and maintenance of anesthesia in patients undergoing cardiac valve replacement Method:Forty-four patients were randomly divided into two groups. Group I with 1.0 MAC sevoflurane and groupⅡwith 1.2 MAC sevoflurane-N_2O inhalation. Hemodynamic monitoring was performed with Swan-Ganz catheter technique. Result:The incidence of breath holding, coughing and movement could he hardly observed during the induction. There were no significant changes in HR,PTRI,PVRI and SVRI during the induction,but MAP,CI,LVWI,LVSWI,RVWI and RVSWI decreased significantly (P

Objective To measure 5Fu concentration after intraoperative regional arterial perfusion chemotherapy in gastric antrum cancer patients.Method In this study,32 gastric antrum cancer patients intraoperatively received through right gastroepiploic artery intraarterial perfusion of 5-Fu (1000 mg/m2),and drug conentrations were measured in portal venous blood,peripheral venous blood,peritoneal fluid and in removed cancer tissues 2,5,10,20,30,60 minutes after infusion started by high performance liquid chromatography method.Result 5-Fu in portal vein blood and peritoneal fluid reached peak concentration after 2 minutes at (48.8 ±6.8) μg1/ml and (75.3 ±30.7) μg/ml,respectively.The drug concentration in portal venous blood was (19.2 ± 2.0) μg/ml at 30 minutes and that in peritoneal fluid was (17.3 ±7.4) μg/ml at 60 minutes,both were higher than that of the effective experimental tumor suppressing concentration (15 μg/ml).Peripheral venous blood concentration reached peak concentration of (5.4 ± 2.0) μg/ml at 5 minute.The drug concentration in removed cancer tissues was (80.5 ± 20.1) μg,/ml.Conclusions Regional intraarterial perfusion chemotherapeutics in gastric antrum cancer patients during operation immediately makes the concentration of chemotherapy rise in the portal vein blood and peritoneal fluid and in cancer tissues to a much higher level than that in peripheral blood.This helps kill cancer cells that fell out during the surgery.

Objective To verify the daily delivery accuracy of volumetric-modulated arc therapy (VMAT) and achieve the process quality control (PQC) of linac using statistical process control (SPC)technology.Methods The log files of all treatments were taken out from the linac system.An in-house software which created by Matlab 7.14 was used to analyze the daily parameters accuracy and the mechanism and dose delivery accuracy of the linac for each VMAT,and an daily evaluation report was automatically created for the linac.The stability of the linac and the deviation of the delivery accuracy for various cancer sites were also analyzed.To achieve the process quality control of hnac using SPC technology,the control limit of each parameter was calculated by Johnson alternation and the single value control charts were drawn.Results 76 patients mainly with nasopharyngeal carcinoma,cervical carcinoma,rectal cancer and laryngeal cancer,got the treatment daily with VMAT technology,and a total of 2 446 arcs were delivered by the linac in continuous 16 days.The gantry angle error,y and x collimator position error,MLC leaf position error and dose delivery error were 0.49°,0.09 mm,0.38 mm,0.31 mm,0.05 MU,respectively.Compare to the nasopharynx,uteri,rectal and larynx cancer,it can be seen that the variation factors of dose delivery and gantry angle errors for various cancer sites were higher,which was 8.10％ and 4.54％,respectively.Through the process quality control of the linac,it was found that all the parameters were in control.While some abnormal points arose (the error was greater than UCL),and the ratio of the gantry angle which was out of control (0.45％) was the highest in all parameters.Conclusions linac delivery accuracy could be monitored and verified during the whole VMAT treatment for each patient,and the daily running condition of linac could be monitored.Through the introduction of SPC technology and the control charts,the process quality control of linac in VMAT could be achieved.It is a financial and valid method for the daily quality assurance of linac.

Objective To evaluate the characteristics and clinical suitability of the ArcCHECK diode array for volumetric-modulated arc therapy (VMAT) verification.Methods The intrinsic sensitivity,short and long term reproducibility,dose and dose rate dependence,dose per pulsed dependence,field sizes dependence and directional response of the diodes were measured.The results of the diodes were compared with the measurement results of an ionization chamber and calculated results of treatment planning system.Gamma index was used to analyze the dose difference between the calculation and measurement for random selected 211 verified VMAT plans.Results The ArcCHECK performed well for all tests except directional dependence,which varies from a minimum of-3.9％ (seen only when the beam was incident on the diode at 180°) to a maximum of 7.7％ (approximately at 255°).Average gamma analysis passing rates with 3 mm/3％ for 113 nasopharyngeal cancer,48 cervical cancer and 50 rectal cancer patients VMAT plans were 93.5％,95.7％ and 97.5％,respectively,statistical significance has been found between either two of the groups (t=-12.69-4.88,all P＜ 0.01).Conclusions With proposed calibration method,the ArcCHECK diode array is very suitable for VMAT pretreatment verification,the complexity of VMAT plan is the main factor affecting the passing rate.