ABSTRACT
Objective To investigate effects of different concentrations of dexmedetomidine on onset time and clinical time-effect of rocuronium in the processes of the total intravenous anesthesia.Methods Sixty patients with elective anesthesia breast modified radical mastectomy,aged 26 to 55 years,were randomly divided into four groups of 15 patients.Group A (control group):uniform within 10 min before induction of anesthesia saline infusion (NS ; 0.25 ml/kg) ; group B:dexmedetomidine given initial dose 0.3 μg/kg uniform within 10 min before induction of anesthesia infusion finished,anesthesia period 0.3 μg/(g · h) continuous infusion until the end of surgery; group C:dexmedetomidine given initial dose 0.6 μg/kg uniform within 10 min before anesthesia infusion finished,during anesthesia with continuous infusion 0.6 μg/'(kg · h) until the end of surgery ; and group D:dexmedetomidine given initial dose 1 μg/kg uniform within 10 min before anesthesia infusion finished,during anesthesia to 1 μg/(kg · h) continuous infusion to the end of surgery.Patients after the burglary were under multi-monitor vital signs monitoring blood pressure (BP),heart rate (HR),oxygen saturation (SPO2),electrocardiogram (ECG),and after intubation monitoring end-tidal carbon dioxide (EtCO2),recording time T0 and T25.Results No significant difference was found at the T0 time in each group.However,the T25 time (48 ± 6) min in group C and (51 ±6) min in group D was significant longer than that (40 ±6)min in group A (P ＜0.05).The mean artery pressure(MAP) of group C and D [(88.76 ± 7.06)mmHg,(87.89 ± 6.95)mmHg] were significantly lower than group A after dexmedetomidine infusion 5 min later(P ＜ 0.05); The HR of groups B and C [(60.80 ± 7.11)bpm,(63.31 ± 5.78)bpm] were significantly lower than group A before induction (P ＜ 0.05).The HR of group D was significantly lower than group A before induction and after infusion 5 and 30 min later[(66.40 ± 9.49) bpm,(60.52 ± 7.45) bpm,(61.32 ± 7.11) bpm,P ＜ 0.05].Conclusions Under the status of total intravenous anesthesia,different concentrations of dexmedetomidine did not affect the onset time of rocuronium,but dexmedetomidine given up to a certain concentration could enhance the clinical time-effect of rocuronium.
ABSTRACT
Objective To explore the effect of dexmedetomidine on hemodynamics in hypertensive patients undergoing thyroid surgery with local anesthesia.Methods Sixty patients with preoperatively diagnosed class Ⅰ to Ⅱ hypertension undergoing selective thyroidectomy were randomly divided into D (dexmedetomidine) and M (midazolam) groups (30 patients in each group).Doses of dexmedetomidine 0.5 μg/kg were finished in 20 minutes injection in patients of D group before the start of the surgery,then sequentially maintained at the rate of 0.1 ～ 0.5 μg/ (kg · h) with decreasing speed of 0.1 μg/(kg · h) when systolic pressure kept down to 110 mmHg or heart rare down to 60 bpm or Ramsay score of 3 points.The patients in M group were injected with midazolam 0.04 mg/kg 20 minutes before the start of surgery,then maintained at the rate of 0.02 ～ 0.05 mg/(kg · h),decreasing speed of 0.1 mg/(kg · h) to keep Ramsay score of 3 points if necessary.Two groups of patients with Ramsay score of 3 points but a high blood pressure (higher than 30％ of basic level) or heart rate (more than 100 bpm) were treated with drugs during operation.Record the systolic pressure,diastolic pressure,heart rate and Ramsay score at the time of before medication (T0),the injection of local anesthetics (T1),the start of surgery (T2),pain compliments required additional local anesthetics (T3),dealing with gland (T4) and the end of surgery,VAS in 8 h after operation and adverse reaction were recorded.Results In D group,the dosages of urapidil and esmolol [(10 ±5)mg and (0 ±0)mg] were significantly less than those in patients of M group [(60 ± 10) mg and (80 ±5) mg,t =14.82,t =19.78,P ＜ 0.05].Blood pressure and heart rate were all significantly decreased at the time of T1,T2 and T5 when comparing with T0(P ＜0.05 orP ＜0.01),and only heart rate was significantly decreased at the time of T3 and T4 (P ＜ 0.05).While in M group,blood pressure and heart rate were higher than basic levels at the time of T3 and T4 (P ＜ 0.05).Besides,lower blood pressure and heart rate were less than those in M group at all observed time expect T0 (P ＜ 0.05).Conclusions Good sedation effects can be produced by both dexmedetomidine and midazolam in hypertensive patients undergoing thyroid surgery with local anesthesia,but dexmedetomidine was determined more suitable in sedation and anti-hypertension in patients with light to moderate hypertension for better hemodynamic stability effect with local anesthesia.
ABSTRACT
Objective To investigate the effect of intrathecal injection (IT) of dexmedetomidine targeting Toll-like receptor 3 (TLR3) on neuropathic pain and spinal cord levels of TLR3 mRNA,interleukin-1β(IL-1β),tumor necrosis factor-alpha (TNF-α) proteins in rat model of chronic constriction injury (CCI).Methods Male Sprague-Dawley rats were randomly divided into five groups(n =10):the sham group(intrathecal normal saline,IT NS),CCI group (CCI + IT NS),DEX-pre group (CCI + IT DEX pre 2ds),DEX-post group (CCl + IT DEX post 7ds) and DEX + ATIP group (CCI + IT DEX + ATIP).The lumbar intrathecal catheters were implanted in L5_6 of rats and CCI models were established as previously described.The thermal and mechanical nociceptive thresholds were assessed by paw withdrawal latency(PWL) to radiant heat and yon Frey filaments.The DEX was administered intrathecally for 7 days starting from 2 day before surgery or 7day after surgery.The spinal cord expression of TLR3 mRNA was assessed by real-time polymerase chain reaction (PCR).Levels of IL-1β,TNF-α in spinal cord were detected by enzyme-linked immunosorbent assay (ELISA).Results Compared with the sham group,animals in CCI group had significandy lower mechanical (F =12.73,P ＜ 0.05) and thermal pain thresholds (F =14.65,P ＜ 0.05),higher expression of TLR3 mRNA (F =11.03,P ＜ 0.05) and levels of IL-1 β (F =9.67,P ＜ 0.05),TNF-α(F =8.78,P ＜ 0.05) in the spinal cord (P ＜ 0.05).Rats in DEX-pre group had significantly higher mechanical (F =11.03,P ＜ 0.05) and thermal pain thresholds (F =15.03,P ＜ 0.05) and significantly lower expression of TLR3 mRNA (F =14.65,P ＜0.05) and levels of IL-1β (F =12.51,P＜0.05,TNF-α (F =9.01,P ＜0.05) in the spinal cord compared with those in the CCI group (at any observed time points after ligation,but most significantly at 7 d).And the effects of DEX-pre group were abated by IT ATIP at the same time or 7days after surgery alone (P ＜ 0.05).Conclusions Intrathecal injection of DEX can decrease the levels of inflammatory factors by decreasing the TLR3 mRNA in the spinal cord of rats and prophylactic relieve the neuropathic pain induced by CCI.