The Influence of the Severity of Chronic Virus-Related Liver Disease on Propofol Requirements during Propofol-Remifentanil Anesthesia

PURPOSE: The purpose of this study was to investigate the influence of chronic virus-related liver disease severity on propofol requirements. MATERIALS AND METHODS: In this study, 48 male patients with chronic hepatitis B infection were divided into three groups according to Child-Turcotte-Pugh classification of liver function (groups A, B, and C with mild, moderate and severe liver disease, respectively). After intubation, propofol concentration was adjusted by +/-0.3 microg/mL increments to maintain bispectral index in the range of 40-60. Target propofol concentrations at anesthesia initiation, pre-intubation and pre-incision were recorded. RESULTS: The initial concentration used in group C was significantly lower than that used in group A or B (p<0.05), whereas no difference was observed between groups A and B. At pre-intubation, the actual required concentration of propofol increased significantly (3.2 microg/mL) in group A (p<0.05), which lead to significant differences between the groups (p<0.05). At pre-incision, the requirements for propofol decreased significantly in both groups A and B (3.0 microg/mL and 2.7 microg/mL, respectively) compared with those at pre-intubation (p<0.05), and were significantly different for all three groups (p<0.05), with group C demonstrating the lowest requirement (2.2 microg/mL). The required concentrations of propofol at pre-incision were similar to those at induction. CONCLUSION: In this study, propofol requirements administered by target-controlled infusion to maintain similar depths of hypnosis were shown to depend on the severity of chronic virus-related liver dysfunction. In other words, patients with the most severe liver dysfunction required the least amount of propofol.

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>