INFLUENCE OF HEPARIN THROMBOPROPHYLAXIS ON PLASMA LEUKOCYTE ELASTASE LEVELS FOLLOWING LOBECTOMY FOR LUNG-CARCINOMA

Recent in vitro studies and animal investigations indicate that plasma leucocyte elastase (PLE) can dissolve pulmonary structural proteins, such as elastin, and produce lesions in the lung similar to that seen in adult respiratory distress syndrome (ARDS) and emphysema. In contra st, heparin strongly inhibits PLE and protects elastin from elastolysi s. On the basis of these findings, PLE levels were monitored in 24 pat ients with non-small cell lung carcinoma (NSCLC) undergoing lobectomy. Ten patients from Killingbeck Hospital (Group 1) received 5000 IU sub cutaneous (s.c.) heparin commenced 2 h prior to surgery and continued at 8 h intervals until the patient was fully ambulatory. Fourteen pati ents from Bradford Royal Infirmary (Group 2) received no heparin as st andard policy. There was no significant difference in pre-operative PL E levels between groups. The post operative PLE levels in both groups increased significantly (P < 0.02) on the first post operation day(POD ). However, PLE levels of Group 2 were 25 to 53 times higher than thos e of Group 1 at each postoperative interval (first, third, and seventh POD) respectively (0.002 < P < 0.02). There was no difference in bloo d loss between groups (P = 0.17). These results indicate that post ope rative PLE activity is elevated in NSCLC patients following lobectomy and s.c. heparin administration as thromboprophylaxis may inhibit PLE activity post operatively without increasing blood loss. Therefore, he parin may have a role to play in protecting lung tissue against the pu lmonary lesions caused by proteolytic activity of PLE, and theoretical ly reduce post-operative complications, such as ARDS or emphysema.