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Objective To evaluate the reliability of autologous blood withdrawal during cesarean section. Methods Fifteen patients preoperatively diagnosed with pernicious placenta previa and∕or accrete by using ultrasound and magnetic resonance imaging, aged 20-35 yr, weighing 55-75 kg, at≥36 weeks of gestation, were enrolled in the study. Blood containing amniotic fluid from the surgical field was collected, and the washed blood was processed using cell?salvage machine and then filtered using a leukocyte depletion filter during cesarean section. The 20 ml blood samples collected included maternal central venous blood after delivery of fetus, unwashed blood, washed blood and filtered blood. The fetal squamous cells were counted using papanicolaou staining. The concentrations of a?fetoprotein, tissue factor, endothelin?1 and histamine were measured by enzyme linked immunosorbent assay. The fetal red blood cells were counted using the acid elution method and HE staining. Results Compared with unwashed samples, the tissue factor concentrations were significantly increased, and the fetal squamous cell count, concentrations of a?fetoprotein and endothelial?1, and fetal red blood cells were decreased in the washed samples. Compared with washed samples, the fetal squamous cell count, concentrations of a?fetoprotein and fetal red blood cells were significantly decreased in filtered samples. Compared with maternal venous blood samples, the tissue factor concentrations were significantly increased, and the fetal squamous cell count and concentrations of a?fetoprotein and endothelial?1 were decreased in filtered samples. Conclusion Autologous blood withdrawn during cesarean section can be used for reinfusion in cesarean section.
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Objective To investigate the effect of PXR* 1B polymorphism on postoperative analgesia with fentanyl in the patients undergoing gynecological operation.Methods A total of 102 female patients from Henan province, of Han nationality, aged 20-50 yr, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ , with body mass index of 14.8-30.0 kg/m2, scheduled for elective abdominal total hysterectomy or myomectomy under general anesthesia, were enrolled in this study.PXR genetic polymorphic sites were analyzed by polymerase chain reaction (PCR)-direct DNA sequencing.PXR* 1B haplotype was analyzed by the PHASE V.2.1 software.The patients were assigned into 3 groups according to their genotypes: PXR* 1B haplotype group (group PXR* 1B), non-PXR* 1B haplotype group (group n-PXR* 1B) and PXR* 1B/PXR * 1B group (group PXR* 1B/PXR* 1B).Postoperative pain was assessed with visual analogue scale (VAS) score.When VAS ＞ 3, fentanyl 20 μg was injected intermittently until VAS ≤ 3, and then a pump was connected to perform patient-controlled intravenous analgesia (PCIA) with fentanyl.PCIA solution contained fentanyl 1.0 mg and droperidol 5 mg in 100 ml of normal saline.The PCA pump was set up with a 2 ml bolus dose, a 5 min lockout interval and background infusion at a rate of 0.5 ml/h.The number of successfully delivered doses was set at 7 times, and the maximal amount of fentanyl was 145 μg.If exceeding the maximal dose, the VAS score was still more than 3, nonsteroidal anti-inflammatory drugs were given as rescue medication.VAS score immediately after the end of operation, and the consumption of fentanyl within 24 h after operation were recorded.Midazolam 0.1 mg/kg was injected intravenously during induction of general anesthesia, and 1 h later venous blood samples were collected for determination of plasma 1'-hydroxymidazolam and midazolam concentrations.The ratio of 1'-hydroxymidazolam concentration to midazolam concentration was calculated to reflect the activity of CYP3A4.Results No patients required rescue anesthetics in the three groups.There were 27 cases in group PXR * 1B, 53 cases in group n-PXR* 1B, and 22 cases in group PXR* 1B/PXR* 1B.PXR* 1B allele frequency was 37.2％.There was no significant difference in VAS score immediately after the end of operation, consumption of fentanyl within 24 h after operation, and activity of CYP3A4 between the three groups (P＞0.05).Conclusion PXR* 1B polymorphism has no effect on postoperative analgesia with fentanyl in the patients undergoing gynecological operation, and is not one of the genetic factors producing individual variation in postoperative analgesia.
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Objective To establish in vitro metabolism of fentanyl by human liver microsomes in Chinese population.Methods Thirty patients undergoing elective operation on liver were enrolled in the study.Normal liver specimens were obtained during removal of liver and gall for preparation of liver microsomes (by calcium precipitation) which were used for establishment of the liver microsomal incubation system for fentanyl.Fentanyl served as the metabolic substrate in the incubation reaction.The concentration of fentanyl in the incubation medium was detected at 0,5,10,15,20 and 30 min of incubation using HPLC-UV.Sufentanil served as the interior label element.The n-hexane-ethanol absolute was used to extract the sample.The chromatographic column used in this method was Grace C18 (4.6 mm × 250.0 mm,5 μm).The mobile phase was methyl cyanide-KH2PO4 buffer solution with the flow rate of 1.0 ml/min,detection wavelength of 205 nm and sample size of 20 μl.Linear regression analysis was performed by using the least-squares method.The specimens of the blank incubation system with the final concentration of fentanyl 0.6,2.4 and 10.0 μg/ml were obtained to determine the recovery,precision and stability.The metabolic rate of fentanyl in human hepatic microsomes was calculated.Results Fentanyl and the interior label element sufentanil were separated completely,and the retention time were 5.730 and 9.336 min,respectively.Endogenous matrix of microsomes did not interfere with the analysis.Regression equation was C =0.945 8A-0.140 4,R2 =0.999 2.C was the concentration of fentanyl,and A was the peak area ratio of fentanyl versus sufentanil.The recovery of incubation system with low,medium and high concentrations of fentanyl was 85％-115％,and relative standard deviation (RSD) was less than 10％.The RSD of intra-and inter-day precision and stability was less than 10％.The method was proved to meet the requirements of biological sample analysis.The metabolic rate of fentanyl was (1.6 + 0.8) nmol/min per milligram protein in human hepatic microsomes of 30 cases.Conclusion The in vitro metabolism of fentanyl by human liver microsomes is convenient,and the detectability is high,so it can be used for the research on the in vitro metabolism of fentanyl in Chinese population.