右美托咪啶对单肺通气时肺内分流及氧合的影响

Effect of dexmedetomidine combined with sevoflurane on intrapulmonary shunt and oxygenation during one-lung ventilation

目的探讨右美托咪啶对单肺通气时肺内分流及氧合的影响。方法将40例择期行单肺通气肺叶切除术的肺癌患者按随机数字表法分为0.9%氯化钠溶液组(C组)和右美托咪啶组(D组),各20例,D组静脉泵注右美托咪啶,负荷剂量0.5μg/kg(4μg/ml),10min内泵完,并按0.3μg/(kg·h)持续泵注至术毕前半小时,C组予等量0.9%氯化钠溶液。记录患者一般临床资料,并分别于双肺通气后10min(T_1)、单肺通气后10min(T_2)、单肺通气后60 min(T_3)、恢复双肺通气后10 min(T_4),行血气分析计算肺内分流率(Qs/Qt)及氧合指数(PaO_2/FiO_2),并记录各时间点的呼末七氟醚浓度(ETsev)。结果两组患者手术时间、单肺通气时间及各时间点pH值比较差异均无统计学意义(均P>0.05);在T_1时,两组患者Qs/Qt和PaO_2/FiO_2无统计学差异(P>0.05);与T_1时相比,两组患者在T_2、T_3时Qs/Qt均明显增加,而PaO_2/FiO_2均明显降低,差异均有统计学意义(均P<0.05);与C组相比,D组在T_2、T_3时Qs/Qt明显降低,而PaO_2/FiO_2明显增加,差异均有统计学意义(均P<0.05);D组各时间点ETsev较C组均明显减少,差异有统计学意义(均P<0.05)。结论右美托咪啶可以缓解单肺通气时肺内分流、提高氧合,在一定程度上预防单肺通气时低氧血症的发生。

Objective To investigate the effect of dexmedetomidine combined with sevoflurane on intrapulmonary shunt and oxygenation during one- lung ventilation （OLV）. Methods Forty patients undergoing OLV during elective thoracic surgery were randomly al ocated to two groups：group C（saline, n=20） and group D（dexmedetomidine, n =20）. Arterial blood and central venous blood samples were taken for gas analysis as fol ows：10 min after two- lung ventilation （T1）, 10 min （T2） and 60 min （T3） after one- lung ventilation and 10 min after restoration two- lung ventilation （T4）, intrapulmonary shunt （Qs/Qt）, oxy-genation index （PaO2/FiO2） and end- tidal sevoflurane concentration （ETsev） were calculated. Results There was no significant difference in operative time, OLV time and PH values at different time points （P〈0.05） between groups C and D. Qs/Qt and PaO2/FiO2 at T1 showed no significant difference between two groups. Compared to T1, in both groups Qs/Qt at T2 , T3 increased significantly, while PaO2/FiO2 decreased. Compared with group C, Qs/Qt in group D at T2, T3 was significantly decreased, while PaO2/FiO2 increased （P〈0.05）. ETsev at T1~T4 in group D was lower than that in group C（P〈0.05）. Conclusion Dexmedetomi-dine infusion decreases intrapulmonary shunt and improve oxygenation, and it may prevent the hyoxemia during OLV in thoracic surgery.