Effect of lobe bronchus blockade on intrapulmonary shunt during radical esophagus cancer resection / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of lobe bronchus blockade with a branchial blocker on intrapulmonary shunt during radical esophagus cancer resection. Methods Twenty four ASA Ⅰ-Ⅲ patients with normal lung function aged 18-69 yrs undergoing elective radical esophagus cancer resection were randomized into 2 groups ( n = 12 each): group A one-lung ventilation (OLV) and group B lobe bronchus blockode. Radial artery and right internal jugular vein were cannulated for BP and CVP monitoring and blood sampling. Anesthesia was induced with midazolam 50 ?g?kg-1, fentanyl 4 ?g?kg-1, propofol 2 mg?kg-1 and vecuronium 0.1 mg?kg-1. In group A double-lumen tube (DLT) was used while in group B a single lumen endotracheal tube was placed first, then a bronchial blocker was inserted fiberoptically into the bronchus of lower lobe of the operated side. The patients were mechanically ventilated (FiO2= 100%, VT = 8 ml?kg-1 , RR = 10-15 bpm, I: E = 1:2). PaCO2 was maintained at 30-35 mm Hg. Anesthesia was maintained with 1.5%-2.0% isoflurane and intermittent Ⅳ boluses of fentanyl and vecuronium. BP, HR, CVP, SpO2, PETCO2 and airway pressure were monitored during operation. Blood samples were taken simultaneously from radial artery and central vein for blood gas analysis before induction of anesthesia when the patients were lying supine and breathing spontaneously (T0), after the lungs on both sides were ventilated for 30 min in lateral position (T1) and 30 min after OLV (group A) or lower lobe bronchus was blocked off (group B) in lateral position (T2). Qs/Qt was calculated (blood from central vein was used instead of mixed venous blood from pulmonary artery) . Blood concentrations of TXB2 and 6-k-PGF1 were determined by radioimmunoassay at T0, T1 and T2. Results There was no significant difference in demographic data between the two groups. At T2 the airway pressure in group A was significantly higher than that in group B. At T2 PaO2 was significantly higher in group B than in group A. Qs/Qt was significantly increased at T1 and T2 as compared to the baselines in both groups. Qs/Qt was significantly increased at T2 compared to that at T1 in group A only, while there was no significant difference between Qs/Qt at T1 and T2 in group B. The TXB2 concentration at T2 was significantly increased as compared to that at T0 and T1 in group A and was significantly higher than that at T2 in group B. Conclusion Lower lobe bronchus blockade was superior to OLV in terms of Qs/Qt and PaO2 during esophagus cancer resection.