Continuous Infusion versus Intermittent Intravenous Heparin Injection Ef-fect on Coagulation State after Peripheral Vascular Surgery

Thromboembolism is one of the major surgery complications with high rates of mortality and morbidity. We compared effects of two methods of heparin administration (continuous vs. intermittent) on coagulation state after peripheral vascular surgery. This randomized clinical trial was conducted on 120 patients underwent peripheral vascular surgery in Alzahra University Hospital in Isfahan, Iran. Patients randomized to receive continuous (750 u/kg/24h, n = 60) or intermittent (150 u/kg/4h, n = 60) heparin infusion. In the continuous infusion group, PTT was checked every six hours, and in the intermittent group PTT was checked 10 min after each dose and then 1 min before the following dose. Platelets counts, hemoglobin, hematocrit, and bleeding were precisely monitored. The two groups were similar in age, gender, concurrent disease, and type of surgery. Thrombosis was occurred in 18.3% and 3.3% of the patients in the continuous and intermittent heparin infusion groups respectively (P < 0.05). PTT greater than 58.5 s was seen in 20% of the patients in continuous group versus 6.6% of the patients in intermittent heparin infusion groups (P < 0.029). No cases of heparin induced thrombocytopenia or active bleeding was occurred, but decreasing in platelets counts was observed in one patient (1.6%) in each group. The intermittent heparin infusion has better outcomes compared with continuous infusion in preventing thrombosis after peripheral vascular surgery. Future studies with larger sample sizes and longer follow-ups are required before recommendation of this strategy for prevention of thrombosis after surgeries.