经皮穴位电刺激复合药物全麻行控制性降压对丘脑局部血流的影响

目的观察经皮穴位电刺激(TEAS)复合药物全麻行控制性降压对丘脑血流的影响。方法成年健康雄性比格犬随机均分为单纯药物全麻行控制性降压组(对照组)和TEAS复合药物全麻行控制性降压组(观察组)。对照组采用常规异氟醚吸入全麻联合硝普钠静脉泵注行控制性降压,观察组在常规全麻行控制性降压时复合TEAS,电刺激强度8～10mA,频率2/100Hz,取双侧"曲池"、"合谷"、"足三里"、"三阴交"穴位。两组比格犬均将MAP下降至麻醉前的40%水平,并在40%～45%MAP水平维持60min。在控制性降压开始前(T0)至基础值的70%(T1)、60%(T2)、50%(T3)、40%(T4)及在40%～45%MAP水平维持10min(T5)、20min(T6)、30min(T7)、40min(T8)、50min(T9)、60min(T10)时,观察丘脑局部脑血流(rCBF)的变化。结果在控制性降压开始时,观察组的rCBF(161.80±73.65)PU,明显高于对照组的(84.33±50.65)PU(P<0.05)。与T0时比较,T5～T10时观察组rCBF均明显增高(P<0.05)、T1～T10时观察组rCBF均明显高于对照组(P<0.05)。结论血压降至40%MAP水平维持60min时,TEAS复合药物全麻行控制性降压能明显增加丘脑血流,改善血氧供应,可能有利于脑保护。

Effect of deliberated hypotension on thalamus regional blood flow during general anesthesia combined with transcutaneous electrical acupoint stimulation

Objective To investigate the effect of deliberated hypotension on thalamus regional blood flow during general anesthesia combined with transcutaneous electrical acupoint stimulation(TEAS). Methods Fourteen beagle dogs were randomly divided into treatment group (general anesthesia, n=7) and control group (combined TEAS and general anesthesia, n=7). TEAS(2/100Hz, 8-10 mA) was applied to Quchi (LI 11), Zusanli (ST 36), Hegu (LI 4), Sanyinjiao (SP 6) following isoflurane anesthesia (1vol%). Every dog received nitroprusside-induced hypotension and regional cerebral blood flow of thalamus was detected by laser Doppler at baseline(T0), the time when MAP decreased to 70%(T1),60%(T2),50%(T3), 40%(T4),and 40%-45% maintaining for 10 min(T5), 20 min(T6), 30min(T7), 40 min(T8), 50 min(T9), 60 min(T10). Results The regional cerebral blood flow (rCBF) of treatment group (161.80±73.65) was higher significantly than that of control group(84.33±50.65) during the beginning of hypotension(P<0.05). The rCBF of treatment group was also higher at T5-T10 compared with T0(P<0.05). The rCBF of treatment group at T1-T10 was higher than that of control group(P<0.05).Conclusion TEAS combined with general anesthesia can benefit the brain by increasing thalamus blood flow and improving oxygen delivery during deliberated hypotension when MAP decreased to 40% of baseline for 1 hour.