Effects of inhaled aerosolized different doses of lidocaine on lung injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass

Abstract

Objective To evaluate the effects of inhaled aerosolized different doses of lidocaine on lung injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Thirty ASA physical status Ⅱ or Ⅲ patients of both sexes,aged 18-58 yr,weighing 35-70 kg,undergoing elective cardiac valve replacement with CPB,were randomly divided into 3 groups (n =10 each) using a random number table:control group (group C),lidocaine 100 mg group (group L1) and lidocaine 200 mg group (group L2).Anesthesia was induced with iv injection of midazolam,etomidate,fentanyl and vecuronium.The patients were endotracheally intubated and mechanically ventilated.The aemsolized normal saline 10 ml,2％ lidocaine 5 ml + saline 5 ml and 2％ lidocaine 10 ml were inhaled in C,L1 and L2 groups,respectively,starting from 10 min after induction.At 10 min after induction (T0),1 and 10 min after opening of vena cava (T1,2),and the end of CPB (T3),blood samples were collected from the left radial artery (LRA) and right atrium (RA) for determination of plasma interleukin8 (IL-8),tumor necrosis factor-α (TNF-α) and malondialdehyde (MDA) concentrations (using ELISA) and the expression of CD11 b on polymorphonuclear leukocytes (by flow cytometry).Blood samples were collected from the left radial artery at T0,immediately after beginning of CPB,at T3 and at 2 and 6 h after termination of CPB for blood gas analysis.The oxygenation index (OI),respiratory index (RI) and dynamic lung compliance (Cdyn) were calculated.Results Compared with group C,the ratio between IL-8 concentration in LRA and in RA (concentration of IL-8LRA/RA) was significantly decreased at T2,3,the concentration of MDALRA/RA was decreased at T3 (P ＜ 0.05),no significant change was found in the expression of CD11bLRA/RA at each time point (P ＞ 0.05),and RI was decreased at T3 in L1 and L2 groups (P ＜ 0.05).There were no significant differences in the concentration of IL-8LRA/RA,TNF-αLRA/RA and MDALRA/RA,expression of CD11bLR A/RA,RI,OI and Cdyn at each time point between group L2 and group L1 (P ＞ 0.05).Conclusion Aerosolized lidocaine inhalation can attenuate lung injury and improve lung function in patients undergoing cardiac valve replacement under CPB by reducing inflammatory responses and lipid peroxidation in lung tissues. Key words: Lidocaine; Metered dose inhalers; Extracorporeal circulation; Respiratory distress syndrome, adult