Relationship between genetic variation in the α-adrenergic receptor and the cardiovascular effects of dexmedetomidine in the Chinese Han population / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

There are differences in individual cardiovascular responses to the administration of dexmedetomidine, a highly selective α-adrenergic receptor (ADRA2A) agonist. The aim of this study was to investigate ADRA2A gene polymorphisms in the Chinese Han population and their association with the cardiovascular response to intravenous dexmedetomidine infusion. Sixty elective surgery patients of Chinese Han nationality were administered 1 µg/kg dexmedetomidine intravenously over 10 min as a premedication. ADRA2A C-1291G and A1780G polymorphism status was determined in these patients, and their relationships to changes in blood pressure and heart rate after dexmedetomidine administration were analyzed. There were neither significant differences in systolic or diastolic blood pressure changes in individuals with different A1780G and C-1291G genotypes after dexmedetomidine administration, nor in heart rates among the different A1780G genotypes. However, there were significant differences in changes in heart rates in patients with different C-1291G genotypes. There were no significant differences in the sedative effects of dexmedetomidine among different A1780G and C-1291G genotypes. Logistic regression revealed that the C-1291G polymorphism was associated with differential decreases in heart rate after intravenous infusion of dexmedetomidine. These findings indicate that the ADRA2A C-1291G polymorphism can affect heart rate changes in patients after intravenous infusion of dexmedetomidine.

Gender Affects the Median Effective Dose and 95% Effective Dose of Oxycodone for Blunting the Hemodynamic Response to Tracheal Intubation in Narcotic-Naïve Adult Patients / 中华医学杂志(英文版)

Background@#Intravenous (IV) oxycodone has been used at induction to prevent an intubation reaction. The aims of the current study were to calculate the median effective dose (ED) and the 95% effective dose (ED) of an IV bolus of oxycodone that blunts the hemodynamic response to tracheal intubation with propofol according to gender and to observe the adverse events of induction-dose oxycodone.@*Methods@#Adult patients who required general anesthesia and tracheal intubation were enrolled. Tracheal intubation was performed using unified TD-C-IV video laryngoscopy and an ordinary common endotracheal tube. Dixon's up-and-down method was used to obtain EDdata for women and men separately. The initial dose of oxycodone was 0.2 mg/kg for women and 0.3 mg/kg for men (step size was 0.01 mg/kg). Next, a dose-response curve from the probit analysis was generated to determine the EDand EDto blunt the intubation reaction in female and male patients. Adverse events following oxycodone injection were observed for 5 min before propofol injection.@*Results@#Sixty-three patients were analyzed, including 29 females and 34 males. According to the probit analysis, the ED and EDof oxycodone required to blunt the intubation reaction in women were 0.254 mg/kg (95% confidence interval [CI], 0.220-0.328 mg/kg) and 0.357 mg/kg (95% CI, 0.297-2.563 mg/kg), respectively. In men, the ED and EDwere 0.324 mg/kg (95% CI, 0.274-0.381 mg/kg) and 0.454 mg/kg (95% CI, 0.384-2.862 mg/kg), respectively. Men required 28% more oxycodone than women for induction (P < 0.01). The most common adverse events were dizziness (87.3%), vertigo (66.7%), sedation (74.6%), and respiratory depression (66.7%).@*Conclusions@#Oxycodone can be used for induction to prevent intubation reactions. Gender affected the EDand EDof oxycodone for blunting the tracheal intubation reaction.

Dexmedetomidine Attenuates Neuropathic Pain by Inhibiting P2X7R Expression and ERK Phosphorylation in Rats

α2-Adrenoceptor agonists attenuate hypersensitivity under neuropathic conditions. However, the mechanisms underlying this attenuation remain largely unknown. In the present study, we explored the potential roles of purinergic receptor 7 (P2X7R)/extracellular signal-regulated kinase (ERK) signaling in the anti-nociceptive effect of dexmedetomidine in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. An animal model of CCI was adopted to mimic the clinical neuropathic pain state. Behavioral hypersensitivity to mechanical and thermal stimuli was determined by von Frey filament and Hargreaves' tests, and the spinal P2X7R expression level and ERK phosphorylation were analyzed using western blot analysis and immunohistochemistry. In parallel with the development of mechanical and thermal hyperalgesia, a significant increase in P2X7R expression was noted in the ipsilateral spinal cord on day 7 after CCI. Intrathecal administration of dexmedetomidine (2.5 µg) for 3 days not only attenuated neuropathic pain but also inhibited the CCI-induced P2X7R upregulation and ERK phosphorylation. Intrathecal dexmedetomidine administration did not produce obvious effects on locomotor function. The present study demonstrated that dexmedetomidine attenuates the neuropathic pain induced by CCI of the sciatic nerve in rats by inhibiting spinal P2X7R expression and ERK phosphorylation, indicating the potential therapeutic implications of dexmedetomidine administration for the treatment of neuropathic pain.

Perioperative Single-Donor Platelet Apheresis and Red Blood Cell Transfusion Impact on 90-Day and Overall Survival in Living Donor Liver Transplantation / 中华医学杂志(英文版)

<p><b>Background:</b>Although many previous studies have confirmed that perioperative blood transfusion is associated with poor outcomes after liver transplantation (LT), few studies described the influence of single-donor platelet apheresis transfusion in living donor LT (LDLT). This study aimed to assess the effect of blood products on outcomes for LDLT recipients, focusing on apheresis platelets.</p><p><b>Methods:</b>This retrospective study included 126 recipients who underwent their first adult-to-adult LDLT. Twenty-four variables including consumption of blood products of 126 LDLT recipients were assessed for their link to short-term outcomes and overall survival. Kaplan-Meier survival curve and the log-rank test were used for recipient survival analysis. A multivariate Cox proportional-hazard model and a propensity score analysis were applied to adjust confounders after potential risk factors were identified by a univariate Cox analysis.</p><p><b>Results</b>Patients who received apheresis platelet transfusion had a lower 90-day cumulative survival (78.9% vs. 94.2%, P = 0.009), but had no significant difference in overall survival in the Cox model, compared with those without apheresis platelet transfusion. Units of apheresis platelet transfusion (hazard ratio [HR] = 3.103, 95% confidence interval [CI]: 1.720-5.600, P < 0.001) and preoperative platelet count (HR = 0.170, 95% CI: 0.040-0.730, P = 0.017) impacted 90-day survival independently. Multivariate Cox regression analysis also found that units of red blood cell (RBC) transfusion (HR = 1.036, 95% CI: 1.006-1.067, P = 0.018), recipient's age (HR = 1.045, 95% CI: 1.005-1.086, P = 0.025), and ABO blood group comparison (HR = 2.990, 95% CI: 1.341-6.669, P = 0.007) were independent risk factors for overall survival after LDLT.</p><p><b>Conclusions:</b>This study suggested that apheresis platelets were only associated with early mortality but had no impact on overall survival in LDLT. Units of RBC, recipient's age, and ABO group comparison were independent predictors of long-term outcomes.</p>

Can Dexmedetomidine Improve Arterial Oxygenation and Intrapulmonary Shunt during One-lung Ventilation in Adults Undergoing Thoracic Surgery? A Meta-analysis of Randomized, Placebo-controlled Trials / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>One-lung ventilation (OLV) is a common ventilation technology during thoracic surgery that can cause serious clinical problems. We aimed to conduct a meta-analysis to compare oxygenation and intrapulmonary shunt during OLV in adults undergoing thoracic surgery with dexmedetomidine (Dex) versus placebo to assess the influence and safety of using Dex.</p><p><b>METHODS</b>Randomized controlled trials comparing lung protection in patients who underwent thoracic surgery with Dex or a placebo were retrieved from PubMed, EMBASE, MEDLINE, Cochrane Library, and China CNKI database. The following information was extracted from the paper: arterial oxygen partial pressure (PaO2), PaO2/inspired oxygen concentration (PaO2/FiO2, oxygenation index [OI]), intrapulmonary shunt (calculated as Qs/Qt), mean arterial pressure (MAP), heart rate (HR), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, superoxide dismutase (SOD), and malondialdehyde (MDA).</p><p><b>RESULTS</b>Fourteen randomized controlled trials were included containing a total of 625 patients. Compared with placebo group, Dex significantly increased PaO2/FiO2(standard mean difference [SMD] = 0.98, 95% confidence interval [CI] [0.72, 1.23], P < 0.00001). Besides, Qs/Qt (SMD= -1.22, 95% CI [-2.20, -0.23], P = 0.020), HR (SMD= -0.69, 95% CI [-1.20, 0.17], P = 0.009), MAP (SMD= -0.44, 95% CI [-0.84, 0.04], P = 0.030), the concentrations of TNF-α (SMD = -1.55, 95% CI [-2.16, -0.95], P <0.001), and IL-6 (SMD = -1.53, 95% CI [-2.37, -0.70], P = 0.0003) were decreased in the treated group, when compared to placebo group. No significant difference was found in MDA (SMD = -1.14, 95% CI [-3.48, 1.20], P = 0.340) and SOD (SMD = 0.41, 95% CI [-0.29, 1.10], P = 0.250) between the Dex group and the placebo group. Funnel plots did not detect any significant publication bias.</p><p><b>CONCLUSIONS</b>Dex may improve OI and reduce intrapulmonary shunt during OLV in adults undergoing thoracic surgery. However, this conclusion might be weakened by the limited number of pooled studies and patients.</p>

Progress on perioperative monitoring of cerebral blood flow autoregulation / 浙江大学学报·医学版

Cerebral blood flow autoregulation is physiologically protective mechanism to maintain the stability of cerebral blood flow. Once autoregulation is impaired, the cerebral blood flow fluctuates with blood pressure, leading to the risk of brain ischemia or cerebral hyperemia. Multiple research results indicate that cerebral blood flow can be monitored indirectly and continuously with transcranial Doppler, near infrared spectroscopy or ICP. The correlation coefficient calculated by the surrogate for cerebral blood flow and blood pressure is used to judge cerebral blood flow autoregulation. When the correlation coefficient is close to 1, cerebral blood flow will be passively fluctuated by blood pressure, indicating autoregulation is impaired. When the coefficient is less than 0, cerebral blood flow will not be changed with blood pressure, indicating autoregulaiton is intact. The status of autoregualtion is closely associated with mortality or poor neurological outcomes in patients with cardiac surgery underwent cardiopulmonary bypass, liver transplantation patients or patients with deep trendelenburg position for long time or beach chair position. Continuous monitoring of cerebral blood flow autoregulation can identify the lower or the upper limit of autoregulation, and provide information to individualize the perioperative management of blood pressure.

Epidural fentanyl decreases the minimum local analgesic concentration of epidural lidocaine / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Epidural lidocaine can be used when regional anesthesia needs to be established quickly, but the effect of co-administering epidural fentanyl on the minimum local analgesic concentration (MLAC) of lidocaine is not known. We compared the MLAC of epidural lidocaine in combination with different doses of fentanyl for epidural anesthesia in adults.</p><p><b>METHODS</b>One hundred and twenty patients requiring epidural analgesia were randomly allocated to receive 20 ml of one of four solutions: lidocaine, or lidocaine plus fentanyl 1 µg/ml, 2 µg/ml, or 3 µg/ml. The first patient in each group was administered 1% lidocaine weight by volume; subsequent patients received a concentration determined by the response of the previous patient to a higher or lower concentration according to up and down sequential allocation in 0.1% increments. Efficacy was assessed using a visual analog pain scale, and accepted if this was = 10 mm on a 100 mm scale within 30 minutes. The extent of motor block and of nausea and vomiting were recorded at 30 minutes after administration of the epidural solution and two hours after surgery, respectively.</p><p><b>RESULTS</b>The MLAC of lidocaine in those receiving lidocaine alone was 0.785% (95%CI 0.738 - 0.864). A significant dose-dependent reduction was observed with the addition of fentanyl: the MLAC of lidocaine with fentanyl at 2 µg/ml was 0.596% (95%CI 0.537 - 0.660) and 0.387% with fentanyl at 3 µg/ml (95%CI 0.329 - 0.446, P < 0.001).</p><p><b>CONCLUSION</b>Epidural fentanyl significantly reduces the dose of lidocaine required for effective epidural analgesia in adults without causing adverse side effects.</p>

Downregulation of endothelin-1 by somatostatin improves liver function of recipients undergoing adult-to-adult living donor liver transplantation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The aim of this study was to investigate the possible effect of somatostatin on the liver function of recipients undergoing living donor liver transplantation.</p><p><b>METHODS</b>Forty recipients were randomized into group A (n = 20) and group B (n = 20). Recipients in group A received no somatostatin whereas somatostatin was administrated for recipients in group B perioperatively. Liver function, the plasma concentration of endothelin-1 and nitric oxide, the intragraft expressions of endothelin-1 and inducible nitric oxide syntheses at 2 hours after declamping of the portal vein were compared between the two groups.</p><p><b>RESULTS</b>Compared to group A, alanine transaminase values in group B were significantly reduced at 2 hours after portal vein declamping, at the end of the operation and postoperation day 1 (P < 0.05), whereas aspartate aminotransferase values in group B decreased at 30 minutes after portal vein clamping, at 2 hours after portal vein declamping and at the end of the operation (P < 0.05). Total bilirubin values in group B were reduced significantly at 2 hours after portal vein declamping and at the end of the operation when compared to group A (P < 0.05). Intragraft expression of endothelin-1 was significantly downregulated at 2 hours after declamping of the portal vein accompanied with a reduction of plasma concentration of endothelin-1 in the peripheral blood (P < 0.05).</p><p><b>CONCLUSIONS</b>Somatostatin had a protective effect on liver function during the early phase after declamping of portal vein for recipients undergoing living donor liver transplantation, and the possible mechanism might be partially attributed to the downregulation of endothelin-1.</p>

Effect of dexmedetomidine on bispectral index and auditory evoked potential index during anesthesia with target controlled infusion of propofol and remifentanyl / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the effect of dexmedetomidine (Dex) on bispectral index (BIS) and auditory evoked potential index (AAI) during anesthesia with target controlled infusion (TCI) of propofol and remifentanyl.</p><p><b>METHODS</b>Thirty adult patients (ASA I approximate, equalsII) who were scheduled for elective thyroidectomy were monitored with BIS, AAI, ECG, blood pressure, end-tidal CO(2), and pulse oximeter before and during anesthesia. Anesthesia was induced by TCI with propofol 4 mg/L and remifentanyl 1 mu g/kg. After loss of consciousness the patients were intubated after rocuronium 0.6 mg/kg intravenous injection, remifentanyl was then infused at 0.2 microg/(kg x min)(-1) and propofol infusion (Ct) was titrated to maintain a BIS value at 50 +/- 3. At 10 min after stabilization of anesthesia the patients were randomly and double-blindly divided into 2 groups: Group D (n=15) received Dex 0.4 mu g/kg iv administered over 5 min and Group C (n=15) received equal volume of normal saline. Values of BIS, AAI, MAP, HR were recorded every 2 min within 20 min after the administration of the drugs.</p><p><b>RESULTS</b>Before anesthesia the BIS index was 90 +/- 2 in Group D and 92 +/- 2 in Group C, AAI was 81 +/- 1 in Group D and 78 +/- 1 in Group C. In anesthesia with target controlled infusion of propofol, BIS index showed a significant decrease with the i.v. administration of Dex 0.4 microg/kg, while AAI remained unchanged. In Group C, both of BIS and AAI remained unchanged after saline injection.</p><p><b>CONCLUSION</b>During propofol and remifentanyl anesthesia, after the administration of Dex, BIS value demonstrates a predominant decrease, whereas AAI shows no changes.</p>

Ammonia induces upregulation of aquaporin-4 in neocortical astrocytes of rats through the p38 mitogen-activated protein kinase pathway / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Astrocyte swelling is an important consequence of hepatic encephalopathy, and aquaporin-4 has been reported to play a vital role in this swelling. Ammonia causes astrocyte swelling and is also known to modulate aquaporin-4 expression in the astrocyte foot processes. The purpose of this study was to explore the mechanism of ammonia-induced aquaporin-4 expression, which has been suggested to involve the p38 mitogen-activated protein kinase pathway.</p><p><b>METHODS</b>We exposed cultured astrocytes to ammonium chloride, an in vitro model of hepatic encephalopathy. The purity of cultured astrocytes was evaluated by fluorescent glial fibrillary acidic protein labeling; cell morphology was assessed by light microscopy; the expression of aquaporin-4, phospho-p38, and p38 were detected by Western blotting analysis. Statistical analysis was performed by one-way factorial analysis of variance, and the relationship between variables was calculated by linear regression using SPSS version 13.0 program for Windows (SPSS, Chicago, IL, USA).</p><p><b>RESULTS</b>The purity of cultured astrocytes was (96.6 +/- 1.4)%. Astrocytes swelled significantly when exposed to 5 mmol/L ammonium chloride for 24 hours as compared to non-exposed astrocytes. Co-treatment with 10 micromol/L SB203580 (an inhibitor of p38) attenuated the degree of ammonium chloride induced astrocyte swelling. Western blotting analysis revealed that the expression levels of phospho-p38 and aquaporin-4 in ammonium chloride treated cells were significantly increased relative to the control group (P < 0.001); SB203580 co-treatment inhibited the increased expression of phospho-p38 and aquaporin-4 relative to the ammonium chloride treated group (P = 0.002 and P = 0.015 respectively). The phosphorylation of p38 and upregulation of aquaporin-4 were highly correlated (r = 0.909). There were no significant differences in total p38 expression among the groups (P = 0.341).</p><p><b>CONCLUSIONS</b>Ammonium chloride induced upregulation of aquaporin-4 in astrocytes is regulated by the p38 mitogen-activated protein kinase pathway. Inhibiting p38 activation prevented ammonium chloride induced aquaporin-4 protein upregulation.</p>

Tramadol inhibits c-fos expression in spinal cord dorsal horn and serum IL-6 levels induced by plantar incision in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate effect of tramadol on c-fos expression in spinal cord dorsal horn and serum IL-6 levels induced by plantar incision in rats.</p><p><b>METHODS</b>The Brennan pain model was induced by incision on the planter surface of left hind paw in rats. Forty-eight rats were randomly divided into six groups: Sham group (Group C), control group (Group I,pretreatment with saline 5 ml), three tramadol pretreatment groups (Group T1, T10 and T20,pretreated with 1 mg/kg, 10 mg/kg and 20 mg/kg tramadol, respectively) and one tramadol treatment group (Group PT10, treated with tramadol 10 mg/kg immediately after operation). Pain behavior was assessed by withdrawal threshold to von Frey filament stimulation intensity, response latency of the hind paw to radiant thermal and a cumulative pain score 2 h after incision. Fos-positive neurons in spinal cord were identified by the immunohistochemical technique. Serum IL-6 levels were measured by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>WithdrawIal threshold to von Frey filament stimulation intensity and response latency of the hind paw to radiant thermal in Group I were significantly lower than those in Group C (P<0.01). Cumulative pain score in Group I was significantly higher than that in Group C (P<0.01). In Groups of T10 and T20, withdrawal threshold to von Frey filament stimulation intensity and response latency of the hind paw to radiant thermal were significantly higher than those in Group I (P<0.01), cumulative pain score was significantly lower than that in Group I in a dose-dependent manner (P<0.01), and were also those in Group PT10. The greatest density of Fos-positive neurons was located in lamine I-II in Group I. Serum IL-6 levels were significantly elevated in Group I. Pretreatment with tramadol showed a dose-depended inhibitory effect on c-fos expression and serum IL-6 production,but not in Group T1. Administration of tramadol postoperatively also suppressed the c-fos expression and serum IL-6 production as showed in PT10 but were weaker than those in Group T10.</p><p><b>CONCLUSION</b>Pretreatment with tramadol can produce dose-dependent inhibitory effect on c-fos expression in spinal cord dorsal horn and then suppress the inflammatory response to the trauma.</p>

Effect of tramadol on immune responses and nociceptive thresholds in a rat model of incisional pain / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To evaluate the effects of tramadol on the proinflammatory responses in a rat model of incisional pain by investigating its effects on nociceptive thresholds and serum interleukin-6 (IL-6) and IL-2 levels.</p><p><b>METHODS</b>Forty-two male Sprague-Dawley (SD) rats scheduled for plantar incision were randomly divided into 7 groups (n=6 in each group). Rats in Group 1 receiving general anesthesia with no incision were served as control; At 30 min before skin incision, Groups 2 to approximately 5 were given 5 ml normal saline or 1, 10, and 20 mg/kg tramadol, respectively, intraperitoneally (i.p.); Group 6 received 10 mg/kg tramadol after operation; Group 7 received 10 mg/kg tramadol before incision, followed by 200 microg/kg naloxone after operation. Mechanical allodynia was measured by electronic von Frey filament to evaluate the nociceptive thresholds 1 h before incision, and 1 h and 2 h after operation. Serum IL-6 and IL-2 levels were measured by enzyme-linked immunosorbent assay (ELISA) 2 h after operation.</p><p><b>RESULTS</b>Mechanical thresholds decreased significantly and serum IL-6 level increased significantly after operation in Group 2 compared with control (P<0.01), and these changes were reversed respectively by tramadol in a dose-dependent manner (P<0.05 and P<0.01, respectively). IL-2 level remained unchanged after operation in Group 2, but decreased in Group 3 (P<0.05), then gradually returned to the normal level in Groups 4 and 5. The intraperitoneally injected tramadol (10 and 20 mg/kg) produced a potent and dose-dependent antinocicptive effect on the lesioned paw. The antinocicptive effects of tramadol were partially antagonized by naloxone (200 microg/kg), suggesting an additional non-opioid mechanism.</p><p><b>CONCLUSION</b>The results suggest that tramadol could be a good choice for the treatment of pain under the conditions that immunosuppression may be particularly contraindicated.</p>

Anesthetic management of emergent critical tracheal stenosis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Two case reports of emergent anesthesia of critical tracheal stenosis are presented. The use of extracorporeal circulation may be a lifesaving method for these patients. Two patients both with severe lower tracheal stenosis were admitted with severe inspiratory dyspnea. The first patient had a tracheal tube inserted above the stenosis in the operating room, but ventilation was unsatisfactory, high airway pressure and severe hypercarbia developed, therefore extracorporeal circulation was immediately initiated. For the second patient, we established femoral-femoral cardiopulmonary bypass prior to induction of anaesthesia, and intubated above the tracheal tumor orally under general anesthesia, then adjusted the endotracheal tube to appropriate depth after the tumor had been resected. The patient was gradually weaned from cardiopulmonary bypass. The two patients all recovered very well after surgery. Surgery is lifesaving for patients with critical tracheal stenosis, but how to ensure effective gas exchange is crucial to the anesthetic management. Extracorporeal circulation by the femoral artery and femoral vein cannulation can gain good gas exchange even if the trachea is totally obstructed. Therefore, before the induction of anesthesia, we should assess the site and degree of obstruction carefully and set up cardiopulmonary bypass to avoid exposing the patient to unexpected risks and the anesthesiologist to unexpected challenges.

Determination of propofol in cerebral spinal fluid by HPLC with fluorescence detection / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish a method for determining propofol in human cerebrospinal fluid (CSF).</p><p><b>METHODS</b>Reverse phase high-performance liquid chromatography (HPLC) with fluorescence detection was applied to quantitative analysis. CSF samples were centrifuged (12,500 r/min for 3 min) and filtered (the diameter of the filter is 0.45 microm). Twenty mul of supernatant was directly injected and separated by Supelco Discovery C(18)column. The mobile phase was composed of methanol-water (80:20); the flow rate was 1 ml/min, and the column temperature was 30 degree. The fluorescence detective waves were: lambda ex=276 nm and lambda em=310 nm.</p><p><b>RESULTS</b>The linear range of propofol in CSF was 5-200 ng/ml (r=0.9994). The recovery rates for high, intermediate and low concentrations were 101.2%, 99.8%, 98.8%, respectively. The RSD of inter-day assay was 1.55%, 1.73%, 6.01% and it of intra-day assay was 1.69%, 2.37%, 8.60%. The limit of detection proved to be 2 ng/ml.</p><p><b>CONCLUSION</b>The method is rapid, simple, accurate and sensitive for measurement of propofol concentration in CSF.</p>

Dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation in humans / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To compare the dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation (OLT) in humans.</p><p><b>METHODS</b>Twenty male patients undergoing liver transplantation were randomly assigned to two comparable groups of 10 patients each to receive a continuous infusion of rocuronium or atracurium under intravenous balanced anesthesia. The response of adductor pollicis to train-of-four (TOF) stimulation of unlar nerve was monitored. The infusion rates of rocuronium and atracurium were adjusted to maintain T1/Tc ratio of 2%~10%. The total dose of each drug given during each of the three phases of OLT was recorded.</p><p><b>RESULTS</b>Rocuronium requirement, which were (0.468+/-0.167) mg/(kg.h) during the paleohepatic phase, decreased significantly during the anhepatic phase to (0.303+/-0.134) mg/(kg.h) and returned to the initial values at the neohepatic period ((0.429+/-0.130) mg/(kg.h)); whereas atracuruim requirements remained unchanged during orthotopic liver transplantation.</p><p><b>CONCLUSIONS</b>This study showed that the exclusion of the liver from the circulation results in the significantly reduced requirement of rocuronium while the requirement of atracurium was not changed, which suggests that the liver is of major importance in the clearance of rocuronium. A continuous infusion of atracurium with constant rate can provide stable neuromuscular blockade during the three stages of OLT.</p>