Objective:To evaluate the modified efficacy of thoracic paravertebral block (TPVB) combined with general anesthesia in the patients undergoing laparoscopic radical nephrectomy.Methods:Eighty patients, aged 38-64 yr, with body mass index of 18-24 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective laparoscopic radical nephrectomy, were selected and randomly divided into 2 groups ( n=40 each) using a random number table method: general anesthesia group (group GA) and TPVB combined with general anesthesia group (group TPVB+ GA). A paravertebral catheter was placed at T 8 and T 10 under ultrasound guidance before induction of anesthesia, and 0.5% ropivacaine 10 ml was administered via the catheter in group TPVB+ GA.Anesthesia was induced with propofol, sufentanil, etomidate and rocuronium and maintained by intravenous infusion of propofol and remifentanil.Patient-controlled intravenous analgesia was performed with sufentanil, ketorolac tromethamine and tropisetron at the end of surgery.When postoperative visual analog scale score≥4, tramadol 50 mg was intravenously injected as rescue analgesic.Immediately before anesthesia induction (T 0), at 5 min after establishing pneumoperitoneum (T 1), at 2 h of pneumoperitoneum (T 2), and immediately after the end of pneumoperitoneum (T 3), and at 24 h after operation (T 4), venous blood samples were collected for determination of plasma norepinephrine concentrations (by enzyme-linked immunosorbent assay), plasma cortisol level (using radioimmunoassay), and blood glucose concentrations were measured.The intraoperative consumption of sufentanil and remifentanil was recorded.The intraoperative hypertension, hypotension, and bradycardia were recorded, and the nausea and vomiting, pruritus, and requirement for rescue analgesia occurred within 24 h after surgery were recorded. Results:Compared with group GA, the plasma concentrations of norepinephrine, cortisol and blood glucose were significantly decreased at T 1-4, the intraoperative consumption of sufentanil and remifentanil was reduced, and the postoperative requirement for rescue analgesia was decreased in group TPVB+ GA ( P<0.05). There was no significant difference in the incidence of intraoperative and postoperative adverse reactions between the two groups ( P>0.05). Conclusion:TPVB combined with general anesthesia is helpful in carrying out the anesthetic model of low-consumption opioids and is more helpful in inhibiting intraoperative and postoperative stress responses and postoperative pain responses than general anesthesia alone when used for laparoscopic radical nephrectomy.

OBJECTIVE To establish a method for simultaneous determination of 7 anti-tumor drugs （irinotecan， capecitabine， paclitaxel， docetaxel， tamoxifen， letrozole and methotrexate） in human plasma and apply it to the clinic. METHODS After precipitating with a methanol-acetonitrile mixture （1∶ 1， V/V） containing 0.1% formic acid， liquid chromatography-tandem mass spectrometry （LC-MS/MS） was used to determine the plasma concentration， using deuterium isotopes of each analyte as internal standards. The chromatography was performed on the Agilent Eclipse Plus C18 column with a gradient elution of water （containing 0.1% formic acid+0.04% 5 mmol/L ammonium formate） as mobile phase A and acetonitrile （containing 0.1% formic acid） as mobile phase B. The flow rate was 0.6 mL/min， and the column temperature was set at 40 ℃ . The sample size was 10 μL， and the analysis lasted for 5.5 min. Electrospray ionization was used in positive and negative ion mode， and multiple reaction monitoring mode was used. The ion pairs used for quantitative analysis were m/z 587.1→167.1 （irinotecan）， m/z 360.1→244.1 （capecitabine）， m/z 876.4→308.0 （paclitaxel）， m/z 830.3→304.2 （docetaxel）， m/z 372.1→129.1 （tamoxifen）， m/z 284.1→242.1 （letrozole）， and m/z 455.0→ 308.0 （methotrexate）. A total of 97 patients with malignant tumors in our hospital were selected to measure the plasma concentrations of 7 anti-tumor drugs using the above method. RESULTS The linear ranges of irinotecan， capecitabine， paclitaxel， docetaxel， tamoxifen， letrozole and methotrexate were 2-1 000 ng/mL （r＝0.994 3）， 20-10 000 ng/mL （r＝0.997 5）， 2-1 000 ng/mL （r＝0.997 9）， 1-500 ng/mL （r＝0.995 8）， 1-500 ng/mL （r＝0.995 2）， 1-500 ng/mL （r＝0.996 4）， 10-5 000 （r＝0.997 7）， respectively. The quantitative lower limits were 2， 20， 2， 1， 1， 1 and 10 ng/mL； RSDs of intra-assay precision were 0.08%-14.86% （n＝6）. RSDs of inter-batch precision were 1.51%-11.55% （n＝3）， and the accuracies were 89.17%-114.93% （n＝6）. The matrix effects ranged from 89.89%-119.74% （n＝6）. RSDs of the stability tests were 1.98%-14.88% （n＝6）. The results of E-mail：hangpengzhou@163.com clinical application showed， the average plasma concentrations of irinotecan， capecitabine， paclitaxel and docetaxel were 704.09， 909.40， 36.45， 150.43 ng/mL， respectively. The values of the coefficient of variation were 25.24%， 62.65%， 122.69%， and 92.27%. CONCLUSIONS The established LC-MS/MS method is simple and rapid， and can be used for the simultaneous determination of 7 commonly used anti-tumor drugs in the plasma of patients with malignancy.