Objective To determine the incidence of pre- and postoperative myocardial ischemia (MI) in patients undergoing noncardiac surgery and to identify the predictors of perioperative MI. Methods One hundred and fifty patients (99 male, 51 female) aged 42-89 yr, weighing 35-87 kg undergoing elective noncardiac surgery were enrolled in this study. Patients with left or right bundle branch block, left ventricular hypertrophy, low voltage on ECG using limb leads, being treated with digoxin or on artificial pacemaker were excluded from the study. The patients were premedicated with intramuscular atropine 0.5 mg and phenobarbital sodium 0.1 g, and were monitored continuously with dynamic ECG (DMS Holler 5.0 USA) for at least 12 h before surgery and 48 h after surgery. The incidence of MI, the number of ischemic episodes, the duration of MI and the area under the ST curve per hour were computed pre- and postoperatively. Factors that could affect MI including age, sex, weight, ASA class, history of cardiac disease, cardiac risk factors, cardiac medication, anesthesia, surgery, laboratory and other physiological data were also recorded. The potential predictors of perioperative MI were identified by univariate model and were then entered into multivariate logistic models. Results The incidence of preoperative MI was 4.7% and postoperative MI was 22.7 % . The incidence of MI and number of ischemia episodes achieved peak levels at 12-24 h after operation, while the duration of MI and the area under the ST curve peaked at 0-12 h after operation. Predictors of postoperative MI were : preoperative MI identified by ECG, age ≥ 65 yr, ASA class ≥ Ⅲ , history of angina, or hypertension or diabetes and high VAS score. Conclusion Postoperative MI usually develops on the first day after surgery. The patients at high risk for developing postoperative MI can be identified by predictors.

Objective To investigate the effect of 50Hz magnetic field on the monoamine neurotransmitters contents in the hippocampus of rats. Methods 32 male SD rats were divided into 4 groups, exposed to 50 Hz magnetic field at the density of 0, 0.1, 1.2, and 1.6 mT, 2 h a day for a certain time. The contents of NE, E, DA and 5-HT were measured by HPLC. Results The contents of NE, DA and 5-HT in hippocampus were increased when the young rats were exposed to 1.2 and 1.6 mT for 10 days, the changes of monoamine neurotransmitters in 0.1 mT exposed group was not significant. The increase in monoamine neurotransmitters was disappeared when the 1.6 mT exposed group stop being exposed to the magnetic field for 30 days, while the monoamine neurotransmitters contents were decreased when the young rats were continuously exposed to 1.2 mT for 90 days. The contents of NE, DA and 5-HT, except E, in the old rats were decreased significantly when exposed to 0.1 mT intensity for 8 months. Conclusion Magnetic field exposure may affect the monoamine neurotransmitters content in the hippocampus, which may be responsible for the changes of learning and memory of rats induced by 50 Hz magnetic field exposure.

Objective:Through the discussion on the purchasing mode of hospital equipment in China, fully understand the advantages and disadvantages of various procurement ways, choose reasonable acquisition method, optimize acquisition method, standardize the procurement management objective.Methods: By using the method of analogy, comparison of the four main acquisition methods. By the comparative analysis, the scope of each purchase way was confirmed. Results: Public bidding was better for more than 500000 yuan or the treasury payment items, competitive negotiation approach applies to 50000 yuan-500000 yuan purchase project. Consultation approach can be applied to 50000 yuan purchase project. Information project procurement preferred to methods of government procurement.Conclusion: Reasonable choices of purchasing and proper optimization has significant meaning for equipment purchasing and management in hospital.

Objective To investigate the activity of autonomic nervous system (ANS) in elderly patients with diabetes mellitus ( DM) after non-cardiac surgery. Mehtods Thirty ASA Ⅰ-Ⅲ patients aged ≥ 60 yrs undergoing elective abdominal surgery or operation on the lower limbs were assigned to one of 2 groups ( n =15 each) : DM group and non-DM group. The patients were monitored with Holter (DMS Co, U.S. A) the day before and on the 1st and 2nd day after operation. Heart-rate variability (HRV) including total power (TP), high frequency (HF), low frequency (LF), very low frequency (VLF) and LF/HF ratio were recorded. Results TP and HF were significantly lower in DM group than in non-DM group before operation ( P

Objective To explore the most effective formula to predict the catheterization length of the right internal jugular vein by an-terior approach. Methods Sixty-seven cases performed with right internal jugular vein catheterization from January 2013 to June 2013 were enrolled in this study and 4 formulas were selected to predict the catheterization lengths. Comparing their predicted lengths with the actual lengths defined as the lengths of the internal catheters which terminals were inserted to a accurate position,and analyse their predictive validi-ty. Results The predictive error percentages of the 4 formulas were all less than 15%. Comparing the predicted lengths and the actual lengths, there was no difference between the predicted length of the 1st formula and the actual one(P>0. 05),and the predicted lengths of the other three formulas were significantly less than the actual ones(P<0. 05). Comparing the mean absolute predictive errors of the 4 formu-las in the 3 height groups of 150~159 cm,160~169 cm and 170~179 cm,respectively,those of the 4th formula were all significantly higher than those of the 1st formula in all the 3 groups(P<0. 05);and no differences between those of the 2nd or the 3rd formula and those of the 1st formula were observed(P>0. 05). Conclusion The predictive error of all the 4 formulas is less than 15%, and the 1st formula is simple,practical and associated with a much smaller error,more suitable to estimate the length of the right internal jugular vein catheterization by anterior approach.

Objective To investigate the effects of dexmedetomidine on oxidative stress response after operation in patients with acute craniocerebral trauma. Methods Sixty patients who underwent intracranial hematoma and decompressive craniectomy within 24 h after acute craniocerebral trauma,were randomly divided into midazolam group and dexmedetomidine group(n=30). All patients were maintained seda-tion for 12 h after operation. Mean arterial blood pressure (MAP),heart rate (HR),blood glucose,S-100B protein (S-100B),malond-ia1ehyde(MDA) and superoxide dismutase (SOD) were recorded at the end of operation(T0),3 h(T1),6 h(T2),12 h(T3) after opera-tion. Results Postoperative MAP, HR and blood glucose were stability in two groups. MAP, HR and blood glucose of dexmedetomidine group were lower than those of midazolam group(P<0. 05). The serum concentrations of S-100B and MDA gradually reduced,and the serum levels of SOD gradually increased at T1 ~T3 in two groups. Compared with midazolam group, these changes were significantly higher in dexmedetomidine group(P<0. 05). Conclusion Dexmedetomidine can protect the brain by maintaining haemodynamic stability and attenu-ating oxidative stress response after operation in patients with acute craniocerebral trauma.

Objective To explore the effect of comorbidities on the surgical outcomes of elderly patients with hip fracture. Methods The Age,gender,weight,type of fracture,preoperative comorbidities and surgical outcomes of 117 patients aged 80 yr or over who undergoing hip fracture surgery in our hospital were recorded. Patients were divided into rehabilitation group and postoperative in-hospital death group ac-cording to surgical outcomes. The potential predictors of postoperative in-hospital death were identified by univariate model and were then entered into multiple Logistic regression analysis. Results Twenty three patients(19. 7%)had no comorbidity,94 patients(80. 3%)had one or more comorbidities. Ten patients(8. 5%)died in hospital after the operation. Predictors of postoperative in-hospital death were preoperative respiratory diseases and three or more comorbidities. Conclusion Surgical outcomes of elderly patients with hip fracture may be predicted by analysing preoperative comorbidities. Preoperative preparations must be sufficient in order to ensure successful operation.

BACKGROUND:As a leading technique in the treatment of primary stenosis by posterior spinal endoscopy through unilateral approach and bilateral decompression using single channel endoscopy,the long-term efficacy needs to be further observed.There are few reports on the scope of intraoperative resection and few relevant studies on biomechanics and finite element analysis. OBJECTIVE:A three-dimensional finite element model was established to evaluate the effects of bilateral lumbar canal decompression under a one-hole split endoscope on lumbar range of motion and intradiscal pressure,to provide suggestions for clinical operation and theoretical basis for further clinical research. METHODS:A complete L3-L5 vertebral body model was reconstructed by CT images of nine healthy volunteers,which was used as the preoperative model M1.The simulated surgical resection range of L4-L5 was performed,and 1/4,1/3 and 1/2 of bilateral facet joints were removed respectively to obtain models M2,M3 and M4.The range of motion and the maximum Von Mises stress of the four models were compared in the six directions of forward bending,backward extension,left and right bending,and left and right rotation. RESULTS AND CONCLUSION:(1)The L3-L5 finite element model established in this study was effective,and the range of motion was within the range of previous solid studies under six motion states.(2)Compared with the M1 model,the L4-L5 lumbar spine range of motion increased with the increase of resection range in M2 with M3 and M4 models under forward bending,left and right bending and left and right rotation loading,and the difference was significant(P＜0.05).Under posterior extension loading,there was no significant difference in lumbar range of motion between M1 and M2(P＞0.05),but there was a significant difference of M1,M3 and M4(P＜0.05).(3)The range of motion of the L3-L4 lumbar spine had no significant change with the increase of bilateral facet arthrotomy(P＞0.05).(4)There was a significant difference in the maximum value of L4-L5 Von Mises between M1 and M2(P＜0.05),and there was a significant difference in the maximum value of L4-L5 Von Mises between M1 and M3,M4(P＜0.01),and the maximum value of L4-L5 lumbar von Mises increased with the increasing range of bilateral facet joint resection.Resection of more than 1/3 was particularly obvious.(5)The maximum value of Von Mises in the L3-L4 lumbar spine was increased with the increase of the resection range under forward bending,left and right bending and left and right rotation loading and the difference was significant(P＜0.05).(6)The results exhibited that the L4-L5 lumbar motion and intervertebral disc pressure increased with the increase of the excision range.Intervertebral disc pressure at L3-L4 increased with the increased extent of excision,but the lumbar range of motion was not significantly affected.In conclusion,the stability of the operative segment may be affected by the increase in the scope of facet joint resection.Although the immediate stability of adjacent segments is not affected,it may accelerate disc degeneration.

Objective:To investigate the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with maintenance hemodialysis (MHD) in Jiangsu province during SARS-CoV-2 pandemic in China from December 7, 2022 to January 27, 2023, and to analyze the influencing factors of all-cause death.Methods:It was a multi-center cross-sectional investigation. Structured questionnaire was used to collect patient information by medical staff of each hemodialysis center (room) as investigators. Part of the demography data and laboratory examination data came from the Jiangsu Province Hemodialysis Data Information System. MHD patients from hemodialysis centers (rooms) at all levels of medical institutions and independent hemodialysis institutions in Jiangsu province during the outbreak of SARS-CoV-2 infection were included, and the clinical characteristics and all-cause mortality of confirmed and suspected cases of SARS-CoV-2 infection were analyzed.Results:Questionnaire surveys and data analysis on 57 278 patients in 407 hemodialysis centers (rooms) were completed, accounting for 90.41% of the total number of MHD patients (63 357 cases) in Jiangsu province during the same period. There were 24 038 cases (41.97%) of SARS-CoV-2 infection and 14 805 cases (25.85%) of suspected infection, which were widely distributed in all dialysis centers in Jiangsu province. After clinical classification of 38 843 confirmed and suspected SARS-CoV-2 infection cases, 3 662 cases were severe and critical cases, accounting for 9.43% of the infected and suspected cases. Among the patients who had completed the questionnaires, there were 1 812 all-cause deaths, with an all-cause mortality rate of 3.16%. Multivariate logistic regression analysis showed that elderly (taking ≤50 years as a reference, 51-59 years: OR=1.583, 95% CI 1.279-1.933, P=0.001; 60-69 years: OR=3.972, 95% CI 3.271-4.858, P<0.001; 70-79 years: OR=7.236, 95% CI 5.917-8.698, P<0.001; ≥80 years: OR=11.738, 95% CI 9.459-14.663, P<0.001), male ( OR=1.371, 95% CI 1.229-1.529, P<0.001), and co-infection with hepatitis B virus (HBV) (positive serum HBV surface antigen, OR=0.629, 95% CI 0.484-0.817, P<0.001) were independent influencing factors for all cause mortality. Receiver-operating characteristic curve analysis showed that the area under the curve for male, age and current HBV infection prediction of all-cause death was 0.529 ( P<0.001), 0.724 ( P<0.001) and 0.514 ( P=0.042), respectively, and the cut-off value for age prediction of all-cause death was 65.5 years old. Compared with patients without HBV infection, MHD patients with HBV infection significantly reduced the proportion of severe and critically ill patients, all-cause hospitalizations and all cause deaths when infected with SARS-CoV-2 (4.99% vs. 6.41%, χ2=6.136, P=0.013; 8.90% vs. 11.44%, χ2=11.662, P<0.001; 2.01% vs. 3.37%, χ2=10.713, P=0.001, respectively). Conclusion:The MHD patients in Jiangsu province are susceptible to SARS-CoV-2. Elderly age and male gender are independent risk factors for death in MHD patients during the epidemic, while the HBV infection may be a protective factor for death of MHD patients infected with SARS-CoV-2.