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Objective To observe the effectiveness of dexmedetomidine on postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic cholecystectomy.Methods Seventy patients (17 males,53 females,aged 20-65 years,ASA grade Ⅰ or Ⅱ) undergoing laparoscopic cholecystectomy were randomized to receive either dexmedetomidine (group R,n=35) or dexamethasone (group D,n=35).The patients in the group R received 0.5 μg/kg bolus dose and maintenance dose at the rate of 0.5 μg·kg-1·h-1 of dexmedetomidine before intubation.The patients in the group D received 8 mg dexamethasone before intubation.The BP and HR were recorded at the following points: on arrival in the operating room (T1),before intubation (T2),5 minutes after intubation (T3),5 minutes after the beginning of the operation (T4),30 minutes after the beginning of the operation (T5),at the end of operation (T6) and 5 minutes after extubation (T7).The inhaling concentration of sevoflurane,extubation time,operation time and anesthesia time were recorded.The incidence of nausea and vomiting were recorded at 8,24,48 hours after operation.Results The incidence of nausea and vomiting at each point were similar between two groups.The HR at T2-T7 in group D was significantly lower.But MAP was similar between two groups.Conclusion 0.5 μg/kg bolus dose and maintenance dose at the rate of 0.5 μg·kg-1·h-1 of dexmedetomidine reduced the incidence of PONV in patients undergoing laparoscopic cholecystectomy,similar to dexamethasone.
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Objective To investigate the effect of gabapentin on the activation of glial cells in the spinal cord after chronic constrictive injury (CCI) to sciatic nerve in rats.Methods Twenty-four male SD rats weighing 180-220 g were randomly divided into 3 groups (n = 8 each): group Ⅰ sham operation (group S), group Ⅱ CCI and group Ⅲ gabapentin + CCI. Right sciatic nerve was exposed and 4 loose ligatures were placed with 6-0chromic catgut. Seven days after operation gabapentin 50 mg/kg in 5 ml was given by intragastric gavage twice a day for 5 days in group Ⅲ. Paw withdrawal threshold to mechanical stimulation with von Frey filaments was measured one day before (baseline) and at 7, 15 d after operation. The animals were killed at 15 d after operation. The lumbar segment L4-5 of the spinal cord was removed. Immunohistochemical double mark technique was used to detect the activation of astrocytes and microglias in the spinal cord. Results Paw withdrawal threshold to mechanical stimulation was significantly decreased on the 7th and 15th day after CCI operation in group CCI as compared with group S. After 5 day treatment with gabapentin, the withdrawal threshold to von Frey hair stimulation was significantly higher in group Ⅲ than in group Ⅱ . The activation of astrocytes and microglias in the spinal cord was significantly enhanced in group CCI as compared with group S. Treatment with gabapentin significantly inhibited CCI-induced activation of astrocytes and microglias in the spinal cord. ConclusionGabapentin reduces neuropathic pain by inhibiting activation of glial cells in the spinal cord.