Infections increase the risk of central venous catheter-related thrombosis in adult acute myeloid leukemia.

Introduction: Central venous catheters (CVC) related thrombosis (CRT) represents a well known complication in patients with acute myeloid leukemia (AML) receiving intensive chemotherapy but the efficacy of antithrombotic prophylaxis still remains controversial.

Patients And Methods: We analyzed 71 consecutive AML patients whose CVC was inserted before each chemotherapy cycle for an overall number of 106 CVC placements. In 47/106 insertions, a prophylaxis with 100 IU/kg/day low molecular weight heparin (LMWH) was administered for 7 days after CVC insertion and additional 7 after CVC removal. This unconventional dose of LMWH, although higher than usual, appeared adequate for a short-course approach. LMWH was delivered regardless of the platelet (PLT) count once provided that it should have been maintained above 20 x 10(9)/L by transfusions.

Results: Of 106 insertions, we observed 19 (18%) episodes of CRT, 58 (54%) of sepsis and 50 (47%) infections of CVC-exit site with no difference between LMWH and no-LMWH group. Occurrence of CRT was significantly associated with CVC-exit site infections (14/19, p=0.01) and sepsis (16/19, p=0.005) with no difference between LMWH and no-LMWH group. In multivariate analysis, both CVC-exit site infections and sepsis were confirmed to be independent risk factors for CRT development.

Conclusion: Our retrospective study, although based on a small sample size, suggests that the occurrence of CVC-exit site infections and neutropenic sepsis following chemotherapy significantly increases the risk of CRT in AML, independently from the use of LMWH prophylaxis.