右美托咪啶对单肺通气时肺内分流及氧合的影响

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（T1）、单肺通气后10min（T2）、单肺通气后60 min（T3）、恢复双肺通气后10 min（T4），行血气分析计算肺内分流率（Qs/Qt）及氧合指数（PaO2/FiO2），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T1时，两组患者Qs/Qt和PaO2/FiO2无统计学差异（P＞0.05）；与T1时相比，两组患者在T2、T3时Qs/Qt均明显增加，而PaO2/FiO2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T2、T3时Qs/Qt明显降低，而PaO2/FiO2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。

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

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.