| Part oneObjective:This study was done to evaluate the effects of a single IV bolus dose of lidocaine on the MAC &MAC_BAR of sevoflurane in adults.Methods:180 ASA I or II patients, aged 25~65 yr, undergoing elective surgery on trunk under general anesthesia were equally and randomly divided into 2 groups:MAC group and MAC_BAR group. MAC group was equally and randomly divided into 3 subgroups, lidocaine higher dose group(group HMAC), lower dose group(group LMAC) and control group(group CMAC); MAC_BAR group was equally and randomly divided into 3 subgroups, lidocaine higher dose group(group HMAC_BAR), lower dose group(group LMAC_BAR) and control group(group CMAC_BAR). Every patient in MAC group was induced by sevoflurane inhalation, ventilated by LMA airway. The study medication(2% lidocaine 1.5 mg/kg for group HMAC, 2% lidocaine 0.75 mg/kg for group LMAC, 0.9% saline 5m L for group CMAC) was administered 3 minutes before the skin incision after a 15 minutes equilibration period with preset sevoflurane concentration. The response to skin incision(movement versus no movement) was recorded in the first minute after skin incision. The MAC for sevoflurane was determined using the Dixon ’s up and down method. Values of mean arterial pressure(MAP), heart rate(HR), and BIS were recorded 1minute and 5 minutes after monitored(average as T0), immediately before the administration of the study medication(T1), immediately before the skin incision(T2), and 1minute after the skin incision(T3). Every patient in MAC_BAR group was induced by sevoflurane inhalation, ventilated by LMA airway. The study medication(2% lidocaine 1.5 mg/kg for group HMAC_BAR, 2% lidocaine 0.75 mg/kg for group LMAC_BAR, 0.9% saline 5m L for group CMAC_BAR) was administered 3 minutes before the skin incision after a 15 minutes equilibration period with preset sevoflurane concentration. The response to skin incision(If the HR or MAP value higher than or equal to 115% basal value, incease the preset concentration of sevoflurne;if not, decease the preset concentration of sevoflurne) was recorded in the first minute after skin incision. The MAC-BAR of sevoflurane was determined using the Dixon ’s up and down method. Values of mean arterial pressure(MAP), heart rate(HR), and BIS were recorded 1minute and 5 minutes after monitored(average as T0), immediately before the administration of the study medication(T1), immediately before the skin incision(T2), and 1minute after the skin incision(T3).Results:In MAC group, MAC in group HMAC [2.00%(95%CI 1.80%~2.20%)] was lower than group CMAC [2.20%(95%CI 2.00%~2.40%)] by approximately 9%, was lower than group LMAC [2.18%(95%CI 1.98%~2.38%)] by approximately 10%(P<0.05); No significant difference in the MAC of sevoflurane was noted between group LMAC and group CMAC. In MAC_BAR group, MAC-BAR in group HMAC_BAR [2.59%(95%CI 2.39%~2.77%)]was lower than group CMAC_BAR [3.03%(95%CI 2.85%~3.20%)]by approximately 14.6 %, was lower than group LMAC_BAR [2.99%(95%CI 2.81% ~ 3.16%)]by approximately 13.3%( P<0.05); No significant difference in the MAC-BAR of sevoflurane was noted between group LMAC_BAR and group CMAC_BAR. The values of HR, MAP and BIS all decreased at T2 and increased at T3 in 3 groups(all P<0.05); No significant difference in the HR, MAP or BIS in 3 groups was observed between T0 and T1. The values of HR and BIS in group HMAC_BAR were lower than group CMAC_BAR and L at T2 and T3; The values of MAP in group LMAC_BAR and HMAC_BAR were lower than group CMAC_BAR at T2 and T3; The values of MAP in group HMAC_BAR were lower than group LMAC_BAR at T2(all P<0.05).Conclusion:A single IV 1.5 mg/kg lidocaine decreases the MAC and MAC_BAR of sevoflurane in adults.Part twoObjective:This study was done to evaluate the effects of a single IV bolus dose of lidocaine on the Cp50 and Cp50_BAR of propofol in adults.Methods:120 ASA I or II patients, aged 25~65 yr, undergoing elective surgery on trunk under general anesthesia were equally and randomly divided into 2 groups:Cp50 group and Cp50_BAR group. Cp50 group were equally and randomly divided into 3 subgroups : lidocaine higher dose group(group HCp50), lower dose group(group L Cp50) and control group(group C Cp50); Cp50_BAR group were equally and randomly divided into 3 subgroups : lidocaine higher dose group(group HCp50_BAR), lower dose group(group LCp50_BAR) and control group(group CCp50_BAR). Every patient in Cp50 group was induced by intravenous propofol and remifentanyl, ventilated by LMA airway. The study medication(2% lidocaine 1.5 mg/kg for group HCp50, 2% lidocaine 0.75 mg/kg for group L Cp50, 0.9% saline 5m L for group C Cp50) was administered 3 minutes before the skin incision after a 15 minutes equilibration period with preset propofol concentration. The response to skin incision(movement versus no movement) was recorded in the first minute after skin incision. The value of Cp50 for propofol was determined using the Dixon ’s up and down method. Values of mean arterial pressure(MAP), heart rate(HR), and BIS were recorded 1minute and 5 minutes after monitored(average as T0), immediately before the administration of the study medication(T1), immediately before the skin incision(T2), and 1minute after the skin incision(T3). Every patient in Cp50_BAR group was induced by intravenous propofol and remifentanyl, ventilated by LMA airway. The study medication(2% lidocaine 1.5 mg/kg for group HCp50_BAR, 2% lidocaine 0.75 mg/kg for group LCp50_BAR, 0.9% saline 5m L for group CCp50_BAR) was administered 3 minutes before the skin incision after a 15 minutes equilibration period with preset propofol concentration. The response to skin incision(If the HR or MAP value higher than or equal to 115% basal value, incease the preset concentration of propofol;if not, decease the preset concentration of propofol) was recorded in the first minute after skin incision. The Cp50-BAR for propofol was determined using the Dixon ’s up and down method. Values of mean arterial pressure(MAP), heart rate(HR), and BIS were recorded 1minute and 5 minutes after monitored(average as T0), immediately before the administration of the study medication(T1), immediately before the skin incision(T2), and 1minute after the skin incision(T3).Results:In the Cp50 group, Cp50 in group HCp50 [4.85μg/ml(95%CI 3.62~5.95)] was lower than group CCp50 [8.53μg/ml(95%CI 7.38~9.57)] by approximately 0.43%, was lower than group LCp50 [7.840μg/ml(95%CI 6.728~8.911)] by approximately 38%(P<0.05); No significant difference in the Cp50 of propofol was noted between group LCp50 and group CCp50. The values of HR, MAP and BIS all decreased at T2 and increased at T3 in 3 subgroups(all P<0.05); No significant difference in the HR, MAP or BIS in 3 subgroups was observed between T0 and T1. The values of HR and BIS in group HCp50 were lower than group CCp50 and LCp50 at T2 and T3; The values of MAP in group LCp50 and H were lower than group CCp50 at T2 and T3; The values of MAP in group HCp50 were lower than group LCp50 at T2(all P<0.05). In the Cp50_BAR group. The Cp50-BAR of propofol in group H [7.713μg/ml(95%CI 6.214~9.119)] was lower than group CCp50-BAR [9.782μg/ml(95%CI 8.293~11.219)] by approximately 21%, was lower than group LCp50-BAR [9.544μg/ml(8.113~10.925)] by approximately 19%(P<0.05); No significant difference in the Cp50-BAR of propofol was noted between group LCp50-BAR and group CCp50-BAR. The values of HR, MAP and BIS all decreased at T2 and increased at T3 in 3 subgroups(all P<0.05); No significant difference in the HR, MAP or BIS in 3 subgroups was observed between T0 and T1. The values of HR and BIS in group HCp50-BAR were lower than group CCp50-BAR and LCp50-BAR at T2 and T3; The values of MAP in group LCp50-BAR and HCp50-BAR were lower than group CCp50-BAR at T2 and T3; The values of MAP in group HCp50-BAR were lower than group LCp50-BAR at T2(all P<0.05).Conclusion:A single IV 1.5 mg/kg lidocaine decreases the Cp50 and Cp50 BAR of propofol. |
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