POSTOPERATIVE LUNG INJURY AND OXIDATIVE DAMAGE IN PATIENTS UNDERGOINGPULMONARY RESECTION

Postpneumonectomy pulmonary oedema (PPO) complicates a significant num ber of thoracic surgical procedures involving lung resection and in it s extreme form is indistinguishable from the acute respiratory distres s syndrome. This study investigated the possibility that ischaemia-rep erfusion (I-R) injury contributes to PPO via the production of damagin g reactive oxygen species. In a prospective, observational, comparativ e study, patients undergoing pneumonectomy, lobectomy, or wedge resect ion or open lung biopsy were investigated for perioperative changes in lung function indicative of lung injury and changes in plasma indices of oxidative damage. Significant percentage perioperative falls in pl asma protein thiol levels (-17.9+/- 7.0% for pneumonectomy, -24.3+/-5. 5% for two-lobe lobectomy and -10.2+/-2.2% for one-lobe lobectomy, p<0 .05) and rises in plasma protein carbonyl levels (26.2+/-10.5% for pne umonectomy, p<0.05, 9.8+/-7.0% for two-lobe lobectomy and 5.0+/-3.7% f or one-lobe lobectomy) were identified, but not in patients undergoing biopsy or wedge resection. Plasma myeloperoxidase levels rose in all groups, but not significantly. The carbon monoxide transfer coefficien t (Kco) fell significantly in patients undergoing lobectomy (p<0.05) b ut not in those undergoing wedge resection, lung biopsy or pneumonecto my. Changes in markers of oxidative protein damage occurred in patient s undergoing lung resection, although the gas transfer coefficient fel l significantly only following lobectomy. Oxidative-damage occurs duri ng pulmonary resection, although associated effects on gas exchange ar e seen only after lobectomy.