Résumé
Objective To investigate the effects of dexmedetomidine on the end-tidal concentration of sevoflurane during recovery from breast cancer surgery under general anaesthesia. Methods A total of 120 patients undergoing unilateral breast cancer radical operation were randomly divided into four groups:group C (infusion of saline, n=30), group D0.5 [infusion of dexmedetomidine 0.5μg/(kg·h) during operation, n=30], group D0.6 [dexmedetomidine 0.6μg/(kg·h), n=30] and group D0.7 [dexmedetomidine 0.7 μg/(kg · h), n=30]. The end-tidal concentrations of sevoflurane during surgery and postoperation were observed. The end-tidal concentration of sevoflurane on palinesthesia was recorded. The time from stopping administration of anesthetic drug to palinesthesia and the operation time were recorded. The palinesthesia of patients from general anaesthesia and the degree of emergence agitation of the patient were measured using Riker ’s sedation-agitation scale. The operation time, anesthesia time, intraoperative remifentanil dosage, intraoperative auditory evoked potential index (AAI), sevoflurane inhalation concentration and the corresponding time were recorded. Results There were no significant differences in clinical data, remifentanil dosage, operation time and AAI between four groups. The anesthesia time was longer in group D0.7 than that in the other three groups (P7 was lower in groups D0.5, D0.6 and D0.7 (P4 was significantly higher in group D0.6 and group D0.7 than that in group C and group D0.5, but the ratio of score>6 was lower (P3 was higher in group D0.7 than that of other three groups (P<0.05). Intraoperative cardiac tachycardia was found in group D0.6 and group D0.7 (4 cases, 13%and 8cases, 7%). Conclusion Sevoflurane inhalation anesthesia and intravenous infusion of dexmedetomidine 0.6μg/(kg·h) can effectively reduce intraoperative sevoflurane dosage, the end-tidal concentration of sevoflurane during recovery, and the occurrence of agitation in patients undergoing general anesthesia.
Résumé
Objective To observe the minimum effective local anesthetic dose of intra-articular ropivacaine with dexmedetomidine for analgesia after knee arthroscopy in patients.Methods Seventy-two patients (35 males,37 females,aged 60-75 years,ASA grade Ⅰ or Ⅱ)undergoing knee arthro-scopy under total intravenous anesthesia were randomly divided into two groups (n =36 each):ropiv-acaine group (group R)and ropivacaine with dexmedetomidine group (group DR);Ropivacaine was injected intra-articularly in group C,and dexmedetomidine 1 μg/kg with ropivacaine was injected intra-articularly in group DR.ED50 of ropivacaine was determined by the sequence method.VAS score3 two hours after operation was rated as effective.The initial dose was 3 mg and according to the effective or ineffective results in previous patient,a dose of ropivacaine was decreased or increased 1.1 times to the previous patient.BP,HR,VAS Score,and OAA/S score were recorded five minutes preoperatively(T0 ),1 h (T1 ),2 h (T2 ),3 h (T3 ),6 h (T4 ),12 h (T5 ),24 h (T6 ),and 48 h (T7 ) after operation in two groups.Results There was no significant difference between the two groups with regard to the BP,HR,VAS Score,and OAA/S score.ED50 of ropivacaine for analgesia after knee arthroscopy was 0.31% (95%CI 0.30%-0.32%),and ED50 of ropivacaine with dexmedetomi-dine for analgesia after knee arthroscopy was 0.14% (95% CI 0.14%-0.1 5%). Conclusion Intra-articular administration of ropivacaine with dexmedetomidine could provide superior postoperative analgesia.The dose of ropivacaine for analgesia after knee arthroscopy should be reduced when combined with dexmedetomidine in patients.