AB194. 104. Timing of low molecular heparin administration and effect on breast haematoma formation

Background: NICE guidelines recommend prophylactic low molecular heparin (LMWH) administration in all patients undergoing elective surgery. Studies show that LMWH should be administered at least peri-operatively to have optimal prophylactic benefit (O'donnell and Weitz, 2003, Collins et al., 1988). In breast surgery, conflicting evidence regarding optimum timing of administration of venous thromboembolism (VTE) prophylaxis exists, with some studies reporting an association between pre-operative administration and wound haematoma formation. Local guidelines recommend pre-operative LMWH administration. Aims: (I) compare current practices relating to LMWH administration to local guidelines and; (II) to determine whether timing of administration impacted rates of post-operative haematoma formation

Methods: All patients who underwent breast surgery during a 1-year period in a University Hospital were identified. Timing of administration of LMWH was recorded for all patients and compared to local guidelines. The incidence of post-operative haematoma was recorded in all patients. Statistical analysis was performed to determine if timing of LMWH administration, or other demographic factors influenced rate of haematoma formation.

Results: A total of 300 patients underwent breast surgeries in the 1-year period. Preliminary data indicate that 20% patients received LMWH pre-operatively, 55% post-operatively and 25% received none. The 0.005% of patients to date developed post-operative haematomas.

Conclusions: These data indicate that adherence to local guidance of pre-operative LMWH is poor, as in the majority of cases LMWH was administered post-operatively.

Keywords: Low molecular weight heparin; administration; prophylaxis; surgery