The effect of epidural ropivacaine on arterial oxygenation and intrapulmonary shunt during one-lung ventilation
- VernacularTitle:硬膜外阻滞对全麻单肺通气期间肺内分流和氧合的影响
- Author:
Yi FENG
;
Ying SUN
;
Baxian YANG
- Publication Type:Journal Article
- Keywords:
Respiration, artifical;
Anesthesia, epidural;
Anesthesia, general;
Respiratory function tests;
Pulmonary circulation
- From:
Chinese Journal of Anesthesiology
1994;0(03):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the effect of of thoracic epidural block on arterial oxygenation and intrapulmonary shunt during one-lung ventilation(OLV).Methods Twenty-four ASA class I - Ⅱ patients undergoing prolonged periods of OLV during elective general thoracic surgery were divided into two groups: general anesthesia group(GA)(n=12) and general anesthesia + epidural block group(GE, n = 12). The patients were premedicated with only scopolamine 0.3mg. Radial artery was cannulated and Swan-Ganz catheter placed via right internal jugular vein under local anesthesia. Epidural block was performed at T7-8or T8-9 and a catheter was inserted and advanced in the epidural space cranially for 3.5-4 cm. General anesthesia was induced with propofol l.5mg?kg-1, fentanyl 3?g?kg-1 and vecuronium 0.1 mg?kg-1. Right or left-sided double-lumen endobronchial tube was placed blindly and the correct position was determined by a combination of unilateral clamping and unclamping and auscultation of the lungs. In GA group anesthesia was maintained with continuous infusion of propofol (150-200 ?g?kg-1?min-1 ) and intermittent IV boluses of fentanyl and vecuronium. BIS was maintained at 45-50. In GE group anesthesia was maintained with infusion of propofol(80 - 120 ?g?kg-1?min-1 ) and epidural block (a loading dose of 0.5% ropivacaine 7-9ml followed by epidural infusion of 0.5% ropivacaine 3-5 ml?h-1) .The patients were mechanically ventilated. VT = 8-10 ml?kg-1, FiO2 = 1, I: R = 1:1.5 and respiratory rate was adjusted to maintain PET CO2 at 35-45 mm Hg. During OLV the above parameters were maintained. ECG, HR, MAP, MPAP, CVP, continuous cardiac output, BIS and TOP were continuously monitored during operation. Blood samples were taken from radial artery and S-G catheter for blood gas analysis at following intervals: (1) during spontaneous breathing when the patients was a wake (baseline); (2) when the patient was placed in lateral position and the two lungs were being ventilated for 30 min(TLV 30 I) ; (3) 5,15, 30 and 60 minduring the course of OLV; (4) the two lungs were ventilated again for 30 min (TLV 30II) andQs/Qt was calculated. Results Venous admixture increased significantly after induction of anesthesia and during mechanical ventilation and increased further during OLV as compared with the baseline(P
