BIS值监测患儿七氟醚复合氧化亚氮麻醉深度的准确性

Accuracy of BIS value for monitoring depth of sevoflurane-nitrous oxide anesthesia in children

目的 评价BIS值监测患儿七氟醚复合氧化亚氮（N2O）麻醉深度的准确性.方法 择期拟在全麻下行腹部手术患儿72例,年龄1～14岁,ASA分级Ⅰ或Ⅱ级,按年龄分层后随机分为3组（n=24）：七氟醚组（S组）、七氟醚＋30% N2O组（SN1组）和七氟醚＋60% N2O组（SN2组）.静脉注射阿托品、利多卡因、异丙酚、罗库溴铵和瑞芬太尼麻醉诱导,气管插管后行机械通气,维持PET CO2 35～45 mm Hg;吸入2.5%七氟醚维持麻醉,SN1组和SN2组分别复合吸入30%和60%N2O.手术开始时调节七氟醚吸入浓度,使七氟醚呼气末浓度（CETSev）分别达到2.5%、2.0%和1.5%,每个CETSev维持10 min视为稳态;此后调节七氟醚吸入浓度,维持BIS值40～60.于麻醉诱导前和CETSev达稳态时记录BIS值;于BIS值40～60维持20 min时记录CETSev（C50）.结果 与S组比较,SN1组BIS值和C50差异无统计学意义（P＞0.05）;与S组及SN1组比较,SN2组BIS值和C50降低（P＜0.05）;S组、SN1组和SN2组BIS值与CETSev间的相关系数分别为-0.736、-0.817和-0.729（P＜0.01）,三组相关系数比较差异无统计学意义（P＞0.05）.结论 BIS值可准确地监测患儿吸人七氟醚复合N2O时的麻醉深度.

Objective To evaluate the accuracy of BIS value for monitoring the depth of sevoflurane-nitrous oxide in children. Methods Seventy-two ASA Ⅰ or Ⅱ children aged 1-14 yr undergoing abdominal surgery were randomly assigned into 3 groups （ n = 24 each） ：sevoflurane group （group S）, sevoflurane ＋ 30% N2O group （group SN1 ）and sevoflurane ＋ 60% N2O （group SN2 ）. Anesthesia was induced with atropine, lidocaine, propofol, rocuronium and remifentanil. After tracheal intubation, the patients were mechanically ventilated. PETCO2 was maintained at 35-45 mm Hg. Anesthesia was maintained with 2.5% sevoflurane combined with 0, 30% and 60% nitrous oxide in group S, SN1 and SN2 respectively. The end-tidal sevoflurane concentration （CETSev） was maintained at 2.5%, 2.0% and 1.5%. Each CETSev was maintained for at least 10 min after the begining of the surgery. Then the CETSev was modified to maintain BIS value at 40-60. BIS value was recorded before anesthesia induction and each stable CETSev. CETSev was recorded at maintaining BIS value of 40-60 for at least 20 min （ C50 ）.Results BIS value and C50 were significantly lower in group SN2 than in group S and SN1 （ P 〈 0.05）, while no significant difference was found between group S and SN1 （ P 〉 0.05）. BIS value was negatively correlated with CETSev in all 3 groups （r = -0.736, -0.817, -0.729, P 〈 0.01）.There was no significant difference in the correlation coefficients among the 3 groups （ P 〉 0.05 ）. Conclusion BIS value can accurately reflect the depth of sevoflurane-nitrous oxide anesthesia in children.