The metabolism of trifluoperazine (TFP) exhibits atypical kinetic behavior in both human liver microsomes (HLMs) and monkey liver microsomes (MyLM).

Glucuronidation reaction of trifluoperazine (TFP) is a typical probe reaction to phenotype the activity of UDP-glucuronosyltransferase 1A4. The present study aims to compare the metabolic behavior of TFP in the liver microsomes from human and cynomolgus monkey, including the kinetic type and parameters. In vitro human liver microsome incubation system was used. The Eadie-Hofstee plot was used to determine the kinetic type. The results showed that the data for human liver microsomes (HLMs) and monkey liver microsomes (MyLMs)-catalyzed glucuronidation were best fit to the substrate inhibition model. For the metabolism of TFP in HLMs, the kinetic parameters were calculated to be 40 ± 5 and 140 ± 20 µM for K m and K si values, respectively. For the MyLM-mediated metabolism of TFP, the K m and K si values were calculated to be 108 ± 10 and 250 ± 30 µM, respectively. The same metabolic kinetic type and different kinetic parameters were demonstrated for the metabolism of TFP between HLMs and MyLMs. All these data were helpful for understanding the metabolism difference of TFP between human and monkey.

[Effects of parecoxib on morphine dosage in postoperative patient-controlled analgesia following thoracoscope-assisted thoracotomy].

OBJECTIVE: To observe the effect of parecoxib on morphine dosage in patient-controlled analgesia (PCA) following thoracoscope-assisted thoracotomy. METHODS: A consecutive series of 100 patients undergoing thoracoscope-assisted thoracotomy were randomized into 5 groups and received PCA with morphine doses at 0, 5, 10, 15, and 20 mg given in 200 ml saline (groups P(1), P(2), P(3), P(4), and P(5), respectively). Parecoxib (40 mg) was given in all the patients immediately before the operation, and the mixture (4-5 ml) of lidocaine and ropivacaine was administered into the 3 intercostal spaces upper and lower to the incision before chest closure. PCA was administered for each patient. The visual analogue scale (VAS) at rest and coughing and the respiratory functional parameters were recorded at 1, 2, 4, 8, 12, 24, 36, and 48 h after the start of PCA, and the actual and effective button-pressing times (D(1)/D(2)) in PCA were also recorded. RESULTS: No patients showed signs of respiratory inhibition within 24 h after the operation, and the resting VAS was comparable between the groups within the initial 6 postoperative hours. At 8 to 24 h postoperatively, the VAS scores at rest and coughing were significantly higher in P(1) group than in the other groups (P<0.05), and no significant differences were found between the groups at 36 to 48 h. D(1)/D(2) in groups P(1) and P(2) were significantly different from those in the other 3 groups at 4-24 h, but no such difference was found between groups P(3), P(4), and P(5). CONCLUSION: The application of parecoxib may reduce the dosage of morphine in PCA following thoracoscope-assisted thoracotomy and results in good analgesic effect without affecting the patients respiratory function and sputum elimination.

[Experimental study of cerebral protection by retrograde vs selective antegrade cerebral perfusion during deep hypothermic circulatory arrest].

OBJECTIVE: To compare the effect of cerebral protection between retrograde cerebral perfusion (RCP) and selective antegrade cerebral perfusion (SACP) during deep hypothermic circulatory arrest (DHCA) in canine models. METHODS: Fifteen healthy adult dogs were randomly divided into 3 groups (n=5), namely the simple DHCA group (group I), DHCA+RCP group (group II) and DHCA+SACP group (group III). Extrocorporeal circulatory was established routinely in the dogs, and DHCA commenced when the nasopharyngeal temperature was reduced to 18 degrees C. During DHCA, RCP and SACP were applied in groups II and III, respectively. All the models were rewarmed after 90 min of DHCA and the cerebral reperfusion continued for 90 min. Cerebral oxygenous metabolic function, cerebral temperature and ultrastructural changes of the neurons were observed in the 3 groups at different time points during the operation. RESULTS: The jugular venous oxygen saturation (SjvO(2)) increased with the temperature reduction, and then decreased after DHCA commencement, showing significant changes at different time points in groups I and II. SjvO(2) in group III were significantly higher than that in the other two groups after 90 min of DHCA (P=0.000). Brain temperature significantly increased in group I during DHCA as compared with that in groups II and III (P=0.000), but showed no significant difference between the latter two groups (P=0.195). The ultrastructure of the neurons underwent obvious changes after reperfusion for 30 min in group I. In group II the neuronal ultrastructure was basically normal at 60 min during DHCA and changed slightly at 90 min, but in group III no obvious changes were seen at 90 min during DHCA and only slight changes occurred at 30 min of reperfusion. CONCLUSIONS: RCP can not supply enough oxygen but can maintain low cerebral temperature, and provide short-term brain protection. DHCA+SACP provides better brain protection than simple DHCA and DHCA+RCP, and has a promising prospect in cardiac surgery.

[Effects of ambulatory labor analgesia on fetal oxygen saturation].

OBJECTIVE: To observe the effect of ambulatory labor analgesia on fetal oxygen saturation during labor. METHODS: Sixty parturients with uncomplicated term pregnancies were equally divided, according to their personal preference, into ambulatory analgesia group receiving combined spinal-epidural labor analgesia and control group without analgesia administration. All the parturients with ambulatory labor analgesia received sufentanil and ropivacaine administration. Fetal oxygen saturation was monitored continuously during the labor by recording the values every 5 minutes and the mean value was calculated. Umbilical blood was analyzed after fetal delivery and the pH, base excess (BE) value were recorded. RESULTS: In the analgesia group and the control group, the mean values of fetal oxygen saturation was (51.92+/-5.90)% and (50.77+/-6.47)%, respectively, during the first labor stage (P=0.48), and was (44.85+/-6.27)% and (43.12+/-7.34)% during the second labor stage (P=0.32), and the lowest values during the labor was (41.63+/-7.51)% and (40.96+/-7.48)%, respectively (P=0.73), showing no significant differences in the three values between the two groups. CONCLUSION: Ambulatory labor analgesia does not significantly affect fetal oxygen saturation during the entire course of labor.

[Effect of etomidate on hemodynamics in elderly and shock patients during general anesthesia induction].

OBJECTIVE: To investigate the effect of etomidate on the hemodynamics in elderly and shock patients during general anesthesia induction. METHODS: Totally 100 elderly patients or patients with hemorrhagic shock (ASA II -III ) undergoing surgery were studied. Anesthesia was induced with 4 microg/kg of fentanyl, 0.1 mg/kg of vecuronium and 0.2-0.3 mg/kg of etomidate, and the mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI), cardiac acceleration index (ACI), left cardiac work (LCW), and left cardiac work index (LCWI) were recorded using thoracic electrical bioimpedance (TEB) hemodynamic monitoring system before induction and at 1, 2 and 3 min after etomidate injection as well as at 3 min after intubation. RESULTS: After etomidate injection, MAP, HR, SV, SI, CO, CI, ACI, LCW and LCWI were decreased significantly as compared with those before induction (P<0.05). MAP, HR, CO, CI and ACI at 3 min after intubation were higher than those before induction (P<0.05), and the other indices resumed the baseline level. The amplitudes of such changes in the recorded indices was below 20% of the baseline level in the course of anesthesia induction. CONCLUSION: Cardiovascular hemodynamics may vary slightly during the course of induction with etomidate, which is an ideal drug for anesthesia induction for elderly or shock patients with unstable hemodynamics.

[Intravenous propofol combined with fentanyl for anesthesia during ultrasound-guided transvaginal oocyte retrieval].

OBJECTIVE: To compare the clinical efficacy and safety of anesthesia with intravenous propofol combined with fentanyl for ultrasound-guided transvaginal oocyte retrieval. METHODS: Totally 100 unpremedicated infertile women (ASA I-II) scheduled for oocyte retrieval with ultrasound guidance were randomly divided into two groups to receive anesthesia with either intravenous propofol (group A, n=50) or the combination of propofol and fentanyl (group B, n=50). The time when consciousness loss and recovery occurred, dosage of propofol for anesthesia maintenance, mean arterial blood pressure (MAP), heart rate (HR) and oxygen saturation (SpO2) were recorded. RESULTS: There was no significant difference in the time of consciousness loss between groups A and B (58.8+/-3.8 s vs 57.7+/-5.2 s, P=0.283), but consciousness recovery occurred earlier in group B (6.0+/-0.6 min vs 5.7+/-0.4 min, P<0.01). The maintenance dosage of propofol in group B (0.20+/-0.03 mg/kg) was significantly lower than that in group A (0.52+/-0.05 mg/kg, P<0.01). At 2 min after anesthesia induction, the MAP decreased from 11.1+/-0.8 kPa to 8.0+/-0.6 kPa in group A (P<0.05), and from (10.9+/-0.9) kPa to (8.3+/-0.7) kPa in group B(P<0.05), and returned to normal within 2-3 min in both groups. The incidence of low SpO2 (<90%) was lower in group A than in group B ((52% vs 88%, P<0.001). CONCLUSION: Anesthesia with propofol combined with fentanyl may reduce the maintenance dosage of propofol, shorten the time of consciousness recovery during oocyte retrieval with ultrasound guidance, and can be helpful for the patients' early recovery and discharge from hospital.

[Early-stage hemodynamic changes in dogs with gunshot wound in seawater].

OBJECTIVE: To investigate the hemodynamic changes in the early stages of gunshot wound of dogs in seawater for exploring early treatment protocol. METHOD: Fourteen conventional Beagles models undergoing gunshot wound in seawater were used along with another 2 dogs receiving the wound on land to serve as control. After the dogs were rescued from the seawater, the respiration (R), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), central venous pressure (CVP), pulmonary arterial wedge pressure (PAWP), and cardiac output (CO) were measured continuously in the early stages of the wound (53.62+/-12.19 min following injury), followed by statistical analysis of the results. RESULTS: Compared with the control group, the hemodynamic disturbance of the dogs receiving the wound in seawater was relatively severe during the first 15 min of the wound. The mortality tended to descend relevant to the position of the wounds, in the order of the head, chest, abdomen and limbs. CONCLUSIONS: Gunshot wound in seawater may cause severe hemodynamic changes, resulting in progressive dysfunction of circulation and high mortality rate. Early treatment should be targeted at hemodynamic stabilization in accordance to the characteristic changes during the early stages of the wound.