硝普钠控制性降压对呼气末动脉二氧化碳分压差生理无效腔影响  

The Effects of Sodium Nitroprusside-Controlled Hypotension on the Arterial-to-end-tidal Carbon Dioxide Gradient and Physiological Dead Space/tidal Volume Ratio

作　　者：张强[1] 彭丽萍[1] 李朝阳[1] 叶庆明[1] 吴冬[1] 熬杰 

机构地区：[1]深圳市南山区人民医院麻醉科,518052

出　　处：《医药导报》2004年第1期32-34,共3页Herald of Medicine

摘　　要：目的 :观察硝普钠 (SNP)控制性降压对呼气末与动脉二氧化碳分压差 [P(a ET)CO2 ]及生理无效腔(Vdphys Vt)的影响。方法 :鼻窦手术患者 2 0例 ,入室后快速诱导气管内麻醉 ,静吸复合维持麻醉。手术开始后静脉滴注硝普钠快速降压到平均动脉压 (MAP)基础水平的 5 0 %～ 60 %。分别于手术开始后 10min(降压即刻T0 ) ,降压开始后 2 0min(T1 ) ,40min(T2 )和停止降压后 2 0min(T3) ,四个时相分别记录MAP、心率 (HR)、Vt、PETCO2 ,并同步采集桡动脉血行血气分析。计算每时相的P(a ET)CO2 以及Vdphys Vt。结果 :PETCO2 T1 、T2 时点明显低于T0 时点 (P <0 .0 1)。血压恢复后的T3时点与T0 时点无差异 (P >0 .0 5 )。PaCO2 下降约 7% ,但各时点比较差异无显著性 (P >0 .0 5 )。P(a ET)CO2 T1 、T2时点明显高于T0 时点 (P <0 .0 1)。血压恢复后的T3时点与T0 时点无差异 (P >0 .0 5 )。Vdphys VT1 、T2 时点明显高T0 时点 (P <0 .0 1)。血压恢复后的T3时点与T0 时点无差异 (P >0 .0 5 )。结论 :SNP控制降压到MAP为基础值 5 0 %～ 60 %时 ,Vdphys Vt增加 ,P(a ET)CO2 增加。PETCO2 不能反映PaCO2 水平。但PaCO2 下降不明显 ,因此呼吸参数不需要改变。Objective:To prospectively assess the magnitude of changes in the arterial-to-end tidal carbon dioxide gradient [P(a-ET)CO 2] as well as in the ratio of physiological dead space to tidal volume (Vdphys/Vt) during controlled sodium nitroprusside-induced hypotensive anaesthesia, and to evaluate whether or not ventilatory requirements remain unaltered during this procedure. Method:Twenty adult patients with American Society of Anesthesiologists' physical status I and II undergoing nasal sinus surgery were selected. A standard anaesthetic procedure was followed for all cases, using propofol, succinylcholine, fentanyl, and isoflurane. Mean arterial blood pressure (MAP) was reduced to 50%-60% of baseline in all patients using a sodium nitroprusside infusion. The end-tidal carbon dioxide tension(P ETCO 2), the arterial carbon dioxide tension(PaCO 2), MAP, heart rate(HR), and expiratory minute volume were recorded during a period of normal arterial blood pressure(T 0), during hypotension (T 1, T 2)and during a period of normal arterial blood pressure after hypotension(T 3). Results:A significant decrease in PaCO 2 and P ETCO 2 from T 0 to T 1 and T 2 (P<0.01) was noted, as was a significant increase in P(a-ET)CO 2 and in the Vdphys/Vt ratio (P<0.01) during the same period. Conclusion:The decrease in P ETCO 2 does not reflect the changes in PaCO 2. The larger increase in P(a-ET)CO 2 is mainly due to the increase in the Vdphys/Vt ratio. During anaesthesia, once normocapnia is achieved with normal arterial blood pressure, there is hardly any need to change the ventilation during the period of controlled hypotension.

关 键 词：硝普钠 降压 控制性 呼气末与动脉二氧化碳分压差 生理无效腔 

分 类 号：R972.4[医药卫生—药品]