The impact of perioperative oxidative stress on pulmonary complications of liver transplant patients

Abstract

Objective To explore the impact of perioperative oxidative stress on pulmonary complications of patients who underwent orthotopic liver transplantation(OLT). Methods Thirty-five patients (30 males and 5 females with age ranging from 24 to 65 years old and median age of 46 years old) who underwent OLT from March 2008 to January 2009 in the Third Affiliated Hospital of Sun Yat-sen University were enrolled in this prospective study. The informed consents of all patients were obtained and the ethical committee approval was received. The patients were kept general anesthesia with tracheal intubation, and the breathing parameters were regulated to maintain the end-tidal CO2 partial pressure at 30 to 40 mm Hg (1 mm Hg=0.133 kPa) . Modified piggyback OLT was performed on the patients. The incidence of pulmonary complications within 1 month after operation was observed. The patients were divided into 2 groups: the group without pulmonary complication (no-complication group) and the group with pulmonary complication (complication group) . Oxidative stress indexes such as serum malondialdehyde(MDA) level, superoxide dismutase(SOD) and the total antioxidant capacity(T-AOC) were recorded at the time point of post-anesthesia(T1), 1 h after liver reperfusion(T2), 3 h after reperfusion(T3) and 24 h after reperfusion (T4). Clinical data of patients in two groups were compared using t test or χ2 test. Serum MDA level, SOD, T-AOC in two groups were compared using Wilcoxon rank sum test. Results Twenty-three out of 35 patients in complication group suffered pulmonary complications after the operation, including 16 cases of pneumonia, 1 case of atelectasis, 1 case of pleural effusion, 2 cases of pneumothorax combined with pneumonia, and 3 cases of pneumonia combined with pleural effusion. No pulmonary complications were observed in 12 cases in no-complication group. There were no significant differences in the preoperative clinical data between two groups(P>0.05). Compared with no-complication group, the serum MDA level in complication group increased evidently at the time point of T2, T3(Z=-2.190,-2.798; P<0.05), T-AOC increased evidently at the time point of T4 (Z=-2.798, P<0.05) . The maximum variation value of perioperative serum MDA level in complication group increased significantly (Z=-2.016, P<0.05) . Besides, compared with no-complication group, the serum SOD level in complication group decreased evidently at the time point of T2 (Z=-2.224, P<0.05) . The maximum variation value of perioperative serum SOD level in complication group reduced significantly (Z=-2.120, P<0.05) . Conclusions The perioperative oxidative stress of OLT patients are obvious. Patients with severe oxidative stress may be more likely to suffer early pulmonary complications after OLT. Key words: Liver transplantation; Oxidative stress; Lung; Postoperative complications; Malondialdehyde; Superoxide dismutase; Total antioxidant capacity