Randomised high- and low-dose heparin prophylaxis in patients undergoing thoracotomy for benign and malignant disease: effect on thrombo-elastography.

BACKGROUND Both cancer patients and patients undergoing surgery are thought to be at an increased risk of thrombo-embolic events. Consequently, low-molecular-weight heparin (LMWH) is administered to all such patients perioperatively. There is a lack of consensus in guidelines regarding the timing of administration and the dosage of thromboprophylactic agents. Studies have shown that thrombo-elastography (TEG) is a useful test in assessing global haemostatic function, and has been validated in monitoring the dosage of LMWH. In this study, we assess the coagulation status of patients undergoing thoracic surgery with TEG, and the effectiveness of administered LMWH for thromboprophylaxis. METHODS Thirty patients with primary lung cancer (LC) and 30 with benign lung disease (BL) were studied prospectively. Patients were randomised to receive subcutaneous LMWH 40 mg once or twice per day perioperatively. Their coagulation status was monitored with TEG preoperatively and postoperatively for 3 consecutive days. RESULTS Preoperative TEG parameters (k time, alpha angle and maximum amplitude (MA)) were within the normal range in both the LC and BL groups. Preoperative r time was prolonged in both the groups, but with no significant difference between the two groups (p>0.05). Postoperatively, r time was prolonged in some patients receiving LMWH twice daily, suggesting a possible adequate thromboprophylaxis in these patients only. CONCLUSION This study demonstrates that the majority of patients with LC are not hypercoagulable. We also showed that LMWH once or twice a day might not provide sufficient thromboprophylaxis. We advocate screening for patients demonstrating hypercoagulable states and ensuring adequate thromboprophylaxis in this group of patients with careful monitoring.