下胸段硬膜外阻滞在单肺通气期间对肺内分流的影响

THE EFFECT OF LOWER THORACIC EPIDURAL BLOCK ON INTRAPULMONARY SHUNT(QS/QT) DURING ONE-LUNG VENTILATION

目的探讨全麻下下胸段硬膜外阻滞对单肺通气期间肺内分流(Qs/Qt)的影响。方法术中需行单肺通气的30例择期开胸手术患者,ASAⅡ～Ⅲ,随机分为全麻组(GA组,n=15),全麻复合下胸段硬膜外组(GE组,n=15)。两组病人分别于麻醉前、双肺通气30min、单肺通气5、15、30min时采动脉血及混合静脉血,行血气分析,并计算出Qs/Qt等。结果两组患者在单肺通气后5、15、30min,Qs/Qt均增加(P<0.01),动脉氧分压(PaO2)较双肺通气时下降(P<0.01)。但在各时间点两组Qs/Qt以及PaO2无显著性差异。结论下胸段硬膜外阻滞对单肺通气期间肺内分流和动脉氧合无明显影响,可安全用于开胸单肺通气患者的麻醉。

OBJECTIVE: TO STUDY THE EFFECT OF LOWER THORACIC EPIDURAL BLOCK ON INTRAPULMONARY SHUNT(QS/QT) DURING ONE-LUNG VENTILATION. METHODS: 30 PATIENTS,ASA GRADE Ⅱ-Ⅲ,UNDERGOING ELECTIVE THORACOTOMY WERE RANDOMLY ASSIGNED TO TOW GROUPS: GENERAL ANESTHESIA GROUP (GA,N=15) AND GENERAL ANESTHESIA COMBINED WITH LOWER THORACIC BLOCK GROUP(GE,N=15). ARTERIAL BLOOD AND MIXED VENOUS BLOOD SAMPLES 3ML WERE OBTAINED AT THE TIME BEFORE ANESTHESIA,30MIN AFTER TOTAL LUNG VENTILATION, AND AT 5, 15, 30 MIN AFTER ONE-LUNG VENTILATION RESPECTIVELY. PAO2/FIO2 WERE RECORDED, QS/QT WAS CALCULATED FORM FORMULA. RESULTS: AT THE OBSERVATION POINTS (5, 15 AND 30 MIN AFTER ONE-LUNG VENTILATION), QS/QT INCREASED AND PAO2 DECREASED SIGNIFICANTLY (P < 0.01) COMPARED WITH THAT DURING TOTAL LUNG VENTILATION. BETWEEN GROUP GA AND GROUP GE, THERE WAS NO SIGNIFICANT DIFFERENCE IN QS/QT AND PAO2 AT EACH INTERVAL. CONCLUSIONS: LOWER THORACIC EPIDURAL BLOCK DOES NOT AFFECT INTRAPULMONARY SHUNT AND ARTERIAL OXYGENATION DURING ONE-LUNG VENTILATION,IT COULD BE A SAFE TECHNIQUE OF ANESTHESIA FOR GENERAL THORACIC SURGERY.