Effect of Parecoxib as an Adjunct to Patient-Controlled Epidural Analgesia after Abdominal Hysterectomy: A Multicenter, Randomized, Placebo-Controlled Trial.

OBJECTIVE: This multicenter, randomized, placebo-controlled study evaluated the efficacy and side effects of parecoxib during patient-controlled epidural analgesia (PCEA) after abdominal hysterectomy. METHODS: A total of 240 patients who were scheduled for elective abdominal hysterectomy under combined spinal-epidural anesthesia received PCEA plus postoperative intravenous parecoxib 40 mg or saline every 12 h for 48 h after an initial preoperative dose of parecoxib 40 mg or saline. An epidural loading dose of a mixture of 6 mL of 0.25% ropivacaine and 2 mg morphine was administered 30 min before the end of surgery, and PCEA was initiated using 1.25 mg/mL ropivacaine and 0.05 mg/mL morphine with a 2-mL/h background infusion and 2-mL bolus with a 15-min lockout. The primary end point of this study was the quantification of the PCEA-sparing effect of parecoxib. RESULTS: Demographic data were similar between the two groups. Patients in the parecoxib group received significantly fewer self-administrated boluses (0 (0, 3) vs. 7 (2, 15), P < 0.001) and less epidural morphine (5.01 ± 0.44 vs. 5.95 ± 1.29 mg, P < 0.001) but experienced greater pain relief compared with the control group (P < 0.001). Patient global satisfaction was higher in the parecoxib group than the control group (P < 0.001). Length of hospitalization (9.50 ± 2.1, 95% CI 9.12~9.88 vs. 10.41 ± 2.6, 95% CI 9.95~10.87, P = 0.003) and postoperative vomiting (17% vs. 29%, P < 0.05) were also reduced in the parecoxib group. There were no serious adverse effects in either group. CONCLUSION: Our data suggest that adjunctive parecoxib during PCEA following abdominal hysterectomy is safe and efficacious in reducing pain, requirements of epidural analgesics, and side effects. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01566669).

[Protective Effect of Ulinastatin against Activation of Tourniquet-Induced Platelet Mitochondria Apoptotic Signaling].

OBJECTIVE: To investigate the protective effect of ulinastatin against the activation of tourniquet-induced platelet mitochondria apoptotic signaling. METHOD: 44 patients with unilateral lower limb operation and tourniquet application were randomly divided into normal saline group and ulinastatin group, and were treated with normal saline and ulinastatin respectively. 12 patents with unilateral lower limb operation but without tourniquet application were enrolled in control group. Lipid hydroperoxide (LPO) in serum was detected by LPO assay kit, the content of ATP was examined by fluorescein-luciferase assay kit; the change of mitochondrial membrane potential (Δ ψm) was detected by JC-1 mitochondrial membrane potential kit; the content of cytoplasmic cytochrome C was examined by Cytochrome C ELISA kit; Caspase-3 activity was detected by Caspase-3 fluorometric assay kit. RESULTS: As compared with control group, the patients in normal saline group exhibited significant platelet mitochondrial dysfunction which characterized by low ATP level and low mitochondrial membrane potential (Δ ψm) (P < 0.05). Tourniquet application resulted in the activation of the mitochondria apoptotic signaling in platelet, displaying increase in the serum LPO level, release of mitochondrial cytochrome C into the cytoplasm, and activation of caspase-3 (P < 0.05). These alterations above-mentioned were obviously improved by ulinastatin treatment (P < 0.05). CONCLUSION: Tourniquet induces platelet mitochondrial dysfunction and mitochondria-dependent apoptotic signaling activation, which can be improved by ulinastatin treatment.

Propofol inhibits lipopolysaccharide-induced tumor necrosis factor-alpha expression and myocardial depression through decreasing the generation of superoxide anion in cardiomyocytes.

TNF-α has been shown to be a major factor responsible for myocardial depression in sepsis. The aim of this study was to investigate the effect of an anesthetic, propofol, on TNF-α expression in cardiomyocytes treated with LPS both in vivo and in vitro. In cultured cardiomyocytes, compared with control group, propofol significantly reduced protein expression of gp91phox and phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2) and p38 MAPK, which associates with reduced TNF-α production. In in vivo mice studies, propofol significantly improved myocardial depression and increased survival rate of mice after LPS treatment or during endotoxemia, which associates with reduced myocardial TNF-α production, gp91phox, ERK1/2, and p38 MAPK. It is concluded that propofol abrogates LPS-induced TNF-α production and alleviates cardiac depression through gp91phox/ERK1/2 or p38 MAPK signal pathway. These findings have great clinical importance in the application of propofol for patients enduring sepsis.

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.

[Effect of propofol on proliferation and differentiation of rat embryonic neural stem cells in vitro].

OBJECTIVE: To investigate the effect of propofol on the proliferation and differentiation of rat embryonic neural stem cells in vitro. METHODS: Embryonic neural stem cells of fetal Wistar rats (gestational age of 14-16 days) in primary culture, after identification for nestin expression, were divided into control group, introlipid group, and propofol groups (treated with propofol at the doses of 5, 25, 50, and 100 µmol/L). The changes in the proliferation of the embryonic neural stem cells after the treatments were observed using Brdu incorporation assay. In the course of induced differentiation of the embryonic neural stem cells, 50 µmol/L propofol was added in the cells to assess its impact on the differentiation of the cells by immunohistochemical detection of NeuN and GFAP expressions. RESULTS: More than 95% of the embryonic neural stem cells in primary culture were Nestin-positive. The percentages of Brdu-positive cells showed no significant changes after treatment with different concentrations of propofol, whereas the addition of 50 µmol/L propofol resulted in a significant increase of NeuN-positive cell percentage to (23.1∓0.9)% as compared with that of (13.4∓0.8)% in the control group (P<0.05) without affecting the GFAP-positive cells. CONCLUSION: Clinically relevant doses of propofol have no obvious effect on the proliferation of rat neural stem cells cultured in vitro, but can induce their differentiation into neuron-like cells.

[Effect of propofol at different effect-site concentrations on approximate entropy of transient evoked otoacoustic emission signals in adults].

OBJECTIVE: To study the effect of propofol at different effect-site concentrations on approximate entropy (ApEn) of transient evoked otoacoustic emission (TEOAE) signals in adults and investigate the possibility of using ApEn for monitoring anesthesia depth. METHODS: Fifteen ASA class I or II patients (aged 18-49 years with normal hearing) undergoing elective surgery under general anesthesia were enrolled in this study. Anesthesia was maintained with target-controlled infusion of propofol. With the effect-site concentrations of 1, 2, 3 and 4 microg/ml, TEOAE signals were monitored and recorded before and after anesthesia. ApEn of TEOAE in 4 frequency ranges (0-2, 1-3, 2.5-4.5, and 4-6 kHz) were calculated using MATLAB software. RESULTS: The ApEn of TEOAE in different frequency ranges showed no significant differences at the same effect-site concentration of propofol, or at different effect-site concentrations in the same frequency range (P>0.05). CONCLUSION: Anesthesia with propofol at different effect-site concentrations does not obviously affect ApEn of TEOAE signals in adults, and ApEn can not be used as the indicator for evaluating the depth of anesthesia.

[Effects of hypertonic sodium chloride hydroxyethyl starch 40 injection in treatment of acute intracranial hypertension complicated by hemorrhagic shock in dogs].

OBJECTIVE: To observe the effect of hypertonic sodium chloride hydroxyethyl starch 40 injection (HSH) in treatment of acute intracranial hypertension complicated by hemorrhagic shock in dogs, and explore the mechanism of the effects of HSH. METHODS: Twenty dogs were randomized into 4 equal groups, namely the 7.5% NaCl (HS) group, Ringer-Lactates solution (RL) group, hydroxyethyl strarch (HES) group, and HSH group. Canine models of acute intracranial hypertension complicated by hemorrhagic shock were established by epidural balloon inflation with saline and rapid discharge of the arterial blood. One hour after the induced shock, the dogs were given HS (6 ml/kg), RL of 3-fold volume of blood loss, HES of equivalent volume of blood loss, and HSH 8 ml/kg in the 4 groups, respectively. During the shock and resuscitationperiod, the intracranial pressure (ICP), mean arterial pressure (MAP) and cerebral perfusion pressure (CPP) of the dogs were monitored, and the serum sodium level and plasma osmolality were measured at 30 min, 1 h and 4 h after the resuscitation. RESULTS: All dogs had similar MAP, CPP, and ICP before resuscitation (P>0.05). After resuscitation, the MAP was significantly improved (P<0.01), but the dogs in HSH group exhibited the fastest response; with the exception of the dogs in HS group to have significantly decreased MAP 2 h after resuscitation (P<0.01), all the other dogs maintained the MAP for 4 h. The CPP was also significantly increased after resuscitation (P<0.01), and in HS group, CPP decreased significantly after 2 h (P<0.01), and HSH group maintained the high CPP after 4 h. The ICP was increased significantly in RL and HES groups after resuscitation (P<0.01), reaching the peak level at 1 and 3 h, respectively, but in HS and HSH groups, the ICP decreased significantly to the lowest level at 1 h (P<0.01) which was maintained for 4 h. After resuscitation, the plasma sodium and plasma osmolality were significantly increased in HSH and HS groups. CONCLUSION: In dogs with acute intracranial hypertension and hemorrhagic shock, HSH can effectively resuscitate hemorrhagic shock and decrease ICP, and the effect is longer-lasting than that of HS.

Beta-eudesmol suppresses tumour growth through inhibition of tumour neovascularisation and tumour cell proliferation.

In the present study, we investigated the potential anti-angiogenic mechanism and anti-tumour activity of beta-eudesmol using in vitro and in vivo experimental models. Proliferation of human umbilical vein endothelial cells (HUVEC) stimulated with vascular endothelial growth factor (VEGF, 30 ng/ml) and basic fibroblast growth factor (bFGF, 30 ng/ml) was significantly inhibited by beta-eudesmol (50-100 microM). Beta-eudesmol (100 microM) also blocked the phosphorylation of cAMP response element binding protein (CREB) induced by VEGF (30 ng/ml) in HUVEC. Beta-eudesmol (10-100 microM) inhibited proliferation of HeLa, SGC-7901, and BEL-7402 tumour cells in a time- and dose-dependent manner. Moreover, beta-eudesmol treatment (2.5-5 mg/kg) significantly inhibited growth of H(22) and S(180) mouse tumour in vivo. These results indicated that beta-eudesmol inhibited angiogenesis by suppressing CREB activation in growth factor signalling pathway. This is the first study to demonstrate that beta-eudesmol is an inhibitor of tumour growth.

[Time window for intubation after rocuronium administration during target-controlled infusion of propofol and sulfentanil].

OBJECTIVE: To define the ideal time window for intubation after rocuronium administration during target-controlled infusion (TCI) ofpropofol and sulfentanil. METHODS: One hundred and twenty elective surgical patients (age range 18-55 years) were randomized into 4 groups (n=30) according to the intubation time after administration of the muscle relaxant. Patients with predicted difficult airway were excluded. General anesthesia was induced by TCI of propofol and sulfentanil. A senior anesthesiologist blinded for the randomization performed the intubations at 1, 2, 3, or 4 min after injection of rocuronium, and the vocal card visibility was evaluated upon full exposure of the vocal cord and the intubation conditions assessed according to Cooper's score. RESULTS: The intubation conditions were excellent or good in all patients, but the vocal cord visibility at 2-4 min differed significantly from that at 1 min after rocuronium administration (P<0.01). Suppression of the neuromuscular function 1 min after rocuronium administration differed significantly from that at other time points (P<0.01). CONCLUSION: The condition of vocal cord can be more suitable for intubation at 2-4 min than at 1 min after rocuronium administration as the ideal time window for intubation during TCI of propofol and sulfentanil.

[Effects of hydroxyethyl-starch on hemorheology in patients with chronic liver disease].

OBJECTIVE: To investigate the effects of hemodilution with hydroxyethyl-starch (HES) on hemorheology in patients with chronic liver diseases in vitro. METHODS: Twenty-one healthy volunteers were selected as the control group and 21 patients with chronic liver disease as the study group. Both of the two groups were divided into HSE (n=11) and Ringer's solution (n=10) groups. Venous blood of 12 ml were collected from each subject and aliquoted into 4 samples, one of the 4 samples served as control (sample 1), and the other 3 (samples 2, 3, 4 respectively) were diluted with 6%; HES or Ringer's solution to cause the hematocrit (Hct) decrease to 30%;, 25%; or 20%;. The rheological parameters including Hct, blood viscosity, plasma viscosity, index of red blood cell aggregation (ARBC) and index of red blood cell rigidity (RRBC) were examined. RESULTS: The Hct of the study group was significantly lower than that of the control group (P<0.05), but plasma viscosity and ARBC were significantly higher. After being diluted by HES, the blood viscosity and ARBC decreased significantly in the study group (P<0.05), and were not significantly different from those of the control group (P>0.05) when Hct=25%; and 20%;. The RRBC of the study group was increased, but the increment was significantly higher than that of control group (P>0.05) only when Hct=20%;. CONCLUSION: The ARBC of patients with chronic liver diseases was significantly higher. Hemodilution with 6%; HES could significantly reduce the blood viscosity and ARBC.

[Management of hyperkalemia-induced cardiac arrest in anhepatic stage of orthotopic liver transplantation without venovenous bypass: report of 3 cases].

The causes of high serum potassium-induced cardiac arrest in anhepatic stage of orthotopic liver transplantation were analyzed in 3 cases without venovenous bypass, and the effectiveness of insulin was evaluated in correcting hyperkalemia during the anhepatic stage. To improve the survival rate of patients with such cardiac arrest, early cardiopulmonary resuscitation and timely defibrillation should be performed.

[Respiratory distress syndrome induced by immersion in seawater: a study of canine models].

OBJECTIVE: To study the mechanism of respiratory distress syndrome (RDS) induced by immersion in seawater to provide experimental evidence for its treatment. METHODS: Twelve normal hybrid dogs were randomly assigned into control group (n=4) and SDS model group (n=8). The changes in blood dynamics, blood gas analysis and histological changes in the lung tissues were compared between the 2 groups. The concentration of lactic dehydrogenase (LDH-L) and alkaline phosphatase (ALP) in the bronchoalveolar fluid and blood of the dogs in the model group were tested. RESULTS: The blood dynamics, blood gas analysis and histology of the dogs in the model group were significantly different from those in the control group, and LDH-L and ALP levels increased significantly in the bronchoalveolar fluid of the model group. CONCLUSION: Seawater aspiration into the lungs may lead to RDS, and the canine models used in this study may help explore the mechanism and management of RDS induced by immersion in seawater.

[Treatment of acute lung injury due to sea water aspiration in dogs by early massive bronchoalveolar lavage: an experimental study].

OBJECTIVE: To investigate the therapeutic effects of massive bronchoalveolar lavage at early stage of acute lung injury induced by sea water aspiration. METHODS: Twelve mongrel dogs were subjected to sea water infusion of the entire lungs and were subsequently randomized into 2 groups. The dogs in group A received intravenous saline transfusion 24 h after injury, while those in group B underwent bronchoscopic lavage of injured lungs with 450 ml 0.45% saline 15 min after injury. Unassisted breathing was maintained in both groups, and the gas exchange function of the bilateral lungs and the levels of lactate dehydrogenase, alkaline phosphatase in the bronchoalveolar fluid were observed, with the hemodynamics indices monitored continuously. The lungs of the dogs were finally removed for morphological study under both light and electron microscopes, and the water content and wet- to dry-weight ratio of the lung tissues were determined. RESULTS: A total lavage volume of approximately 30 ml/kg x b.w. was used, and the liquid volume remaining in the lungs after operation ranged from 80 to 120 ml. All the dogs manifested significant declination in pulmonary function after the drowning. PaO2 in group B decreased significantly soon after the lavage but then increased gradually to a higher levels than group A. The dogs in group B had smaller lung water content and lower levels of lactate dehydrogenase and alkaline phosphatase in the bronchoalveolar fluid, showing improved oxygenation in comparison with group A. The inflammatory reaction and edema in lungs were also markedly alleviated in group B. CONCLUSION: Treatment with massive lung lavage in early stage after sea water aspiration can effectively protect the lung tissues from damage and alleviate the inflammatory reaction and pulmonary edema, helping to improve the lung function.

[Changes of oxygen cost of breathing in children and adult during anesthesia and surgery].

OBJECTIVE: To investigate the changes of oxygen cost of breathing (OCB) in children and adult during general anesthesia and surgery. METHODS: This study included 12 elective surgical children and 12 adult patients receiving cerebral surgery. Mechanical ventilation was given during general anesthesia and surgery, and the indices of hemodynamics and respiratory function were measured at 5 min before induction, 1 min before the start of surgery, 30, 60, 120 and 180 min after the start of surgery and at the end of surgery, respectively. RESULTS: Mean arterial pressure (MAP) in the 2 groups did not undergo any conspicuous changes during general anesthesia and surgery (P>0.05), and the heart rate in child group was markedly faster than that in adult group during the whole course (P<0.01). Oxygen consumption (VO2) in 2 groups at 1 min before the start of surgery and 30 min after the start of surgery was significantly higher than that at 5 min before induction (P<0.01), and at these two time points after induction, child group had much higher VO2 (P<0.05) but evidently lower OCB (P<0.01) than in adult group, the latter index remained low till 60 and 120 min after the start of surgery (P<0.05). CONCLUSION: During anesthesia and surgery, VO2 in child group can be much greater than that in Adult group, while OCB markedly lower.

Study of direct lung injury by seawater in canine models.

OBJECTIVE: To study the mechanism of direct lung injury by seawater and explore its possible management. METHODS: To exclude the interference of hypoxia and acidosis during the study of seawater-induced direct lung injury, 18 normal hybrid dogs were randomly assigned into group A (with all lung lobes perfused with seawater), group R (with the right lung lobe perfused with seawater) and group D (with the diaphragmatic lobe of lung perfused with seawater), with 6 dogs in each group. The changes in blood gas dynamics, blood gas acid-base status and electrolytes, along with the histological changes in the lung tissues were comparatively analyzed between the 3 groups. Bronchial microscope was employed to observe the continuous changes in the bronchioles before and after seawater perfusion in group D, and the concentration of the bronchoalveolar fluid and blood LDH-L and ALP levels were tested. RESULTS: The values of PaO(2), PaCO(2), pH, actual bicarbonate (AB), base excess (BE), tidal volume, and respiration rate in groups A and R were significantly different from those in group D (P < 0.01), and in groups A and R, the above measurements at every stage after seawater perfusion were significantly different from those before perfusion (P < 0.01). In group D, however, blood gas dynamics, blood gas acid-base status and electrolytes changed little after seawater perfusion (P > 0.05). In all the groups, obvious lung tissue injuries were observed under optical microscope after seawater perfusion. Observation with electron microscope revealed injuries to type II alveolar epithelial cells, broadened respiratory mucosa, and platelet adherence. Bronchial microscope in group D presented the bronchus filled with bronchoalveolar fluid, and blood LDH-L and ALP levels kept rising significantly (P < 0.01). Within 4 h after seawater perfusion, no pathological changes were seen in the lung tissues without direct contact with seawater. CONCLUSIONS: Seawater inspiration and retention in the lungs may lead to severe direct lung injury, and is the primary factor responsible for acute lung injury after drowning in the sea.

[Ropivacaine or its combination with fentanyl for postoperative patient-controlled epidural analgesia].

OBJECTIVE: To investigate the pain-relieving effects of ropivacaine or its combination with fentanyl in postoperative patient-controlled epidural analgesia. METHODS: Sixty patients (ASA class I to II) scheduled for elective upper abdominal surgery were randomly divided into 4 groups (15 in each group) to receive 2.0 mg/ml ropivacaine (group R), 1.25 mg/ml ropivacaine plus 1.0 microg/ml fentanyl (group RF1), 1.0 mg/ml ropivacaine plus 2.0 microg/ml fentanyl (group RF2), and 1.0 mg/ml ropivacaine plus 4.0 microg/ml fentanyl (group RF4) respectively for patient-controlled analgesia. The bolus injection was set at 3.0 ml, lockout interval at 20 min, and background epidural infusion at 5.0 ml/h. Before and at 0, 6, 12, 24 and 48 h after the surgeries, the data including mean arterial pressure (MAP), heart rate (HR), cumulative consumption volume (CCV) of analgesic solution and visual analog scale (VAS) scores were recorded, observed and the adverse effects such as vomiting, nausea, pruritus, as well as the time of first excretion of intestinal gas. RESULTS: Compared with group R, significantly smaller CCV occurred in groups RF2, RF4 (P<0.01), and RF1 (P<0.05) at each time points postoperatively. No significant differences were noted between the groups in VAS scores. CONCLUSION: The 4 preparations are comparable in terms of analgesic efficacy and adverse effects, but in groups RF2 and RF4, the smaller doses have sufficed the needs.

[Anesthetic management during resection of intratracheal tumor: report of 23 cases].

OBJECTIVE: To summarize our experience in anaesthetic management during the resection of intratracheal tumor. METHODS: A retrospective analysis of the anaesthetic management was conducted in 23 cases of intratracheal tumor resection. The anaesthetic methods were determined according to the location of tumor, the degree of tracheal obstruction and the surgical procedures. RESULTS: No severe complications occurred in relation to the anesthetic procedures. During the operation, the saturation of pulse oxygen (SpO(2)) transiently decreased to below 90 % in 5 cases (21.7 %) but recovered to normal level by aspiration of airway secretions and/or lung inflation. Seventeen patients (73.9 %) were extubated after the operation and returned to the ward safely, while another 6 (26.1 %) were sent to intensive care unit and extubated within 24 h. CONCLUSION: Case-specific anaesthetic plan is necessary before the operation, and it is crucial to maintain good ventilation without interfering with the surgical procedures during the operation.

Effect of patient-controlled epidural analgesia for pain relief after thymectomy in patients with myasthenia gravis.

OBJECTIVE: To evaluate the effect of patient-controlled epidural analgesia (PCEA) with ropivacaine or bupivacaine in relieving pain after thymectomy in patients with myasthenia gravis. METHODS: Twenty adult ASA I-II patients with myasthenia gravis were randomized to receive either 0.125% ropivacaine (Group R, n=10) or 0.125% bupivacaine (Group B, n=10) with a PCEA device after transsternal thymectomy. PCEA (continuous infusion at 1 ml/h, bolus dose of 4 ml and lockout time of 30 min) was implemented via an epidural catheter inserted in the T3-4 intervertebral space. The vital signs and visual analogue scale (VAS), together with cumulative consumption (CC) of ropivacaine or bupivacaine were recorded within 48 h postoperatively. RESULTS: The vital signs, including systolic and diastolic blood pressure, heart rate, SpO2, pH and PaCO2, did not show any significant differences between the 2 groups. The CC of the local anesthetic was significantly higher in group R than that in group B at 24 and 48 h postoperatively, but VAS were not significantly different between the 2 groups which was less than 4 in both groups. CONCLUSIONS: PCEA with low concentration of ropivacaine or bupivacaine may provide effective and safe analgesia after transsternal thymectomy.

[Effects of intraperitoneal CO2 insufflation on hemodynamics and oxygen consumption during intravenous propofol anesthesia combined with epidural block].

OBJECTIVE: To investigate the effects of intraperitoneal CO2 insufflation on the hemodynamics, oxygen consumption (VO2) and carbon dioxide production (VCO2) during intravenous anesthesia with propofol in combination with epidural block. METHODS: Intratracheal intubation was performed after rapid induction of anesthesia and mechanical ventilation was given. Maintenance of anesthesia was achieved using continuous intravenous propofol infusion (2 mg/kg/h) ?N2O inhalation and intermittent epidural administration. Indices of hemodynamics and respiratory function were collected 5 min before induction, 1 min before CO2 insufflation, and 5, 10, 20, 30, 40, 50, 60 min after the start of insufflation and 5 min after the termination of insufflation. RESULTS: The mean arterial pressure (MAP), heart rate (HR), end-tidal PCO2 (P(ET)CO2), VO2 and VCO2 1 min before insufflation were markedly reduced(P<0.01), compared with those recorded before induction. MAP and HR did not undergo any conspicuous changes during CO2 insufflation and 5 min after insufflation termination. Compared with that 1 min before insufflation, PETCO2 was significantly increased 20 min after the start of insufflation (P<0.01), and subsequently carried on the increase though of a lesser scale. VO2 and VCO2 gradually rose after the start of insufflation, and VO2 presented a significantly elevation (P<0.01) 10 min after the insufflation while VCO2 did not show this marked increase(P<0.05) till 20 min after the insufflation in comparison with the levels before insufflation. Subsequently, VO2 continued to rise and VCO2 also retained the increase but of smaller magnitude. CONCLUSION: Intravenous propofol anesthesia combined with epidural block assisted by well-managed excessive ventilation before insufflation can alleviate the adverse effects of CO2 insufflation on respiratory and circulatory systems.