The effect of blood pressure on hematoma formation with perioperative Lovenox in excisional body contouring surgery

Background: Prophylactic use of low molecular weight heparin (LMWH) has been shown to be efficacious in decreasing thromboembolism. LMWHs are associated with increased rates of bleeding. Objective: We reviewed perioperative blood pressure dynamics for patients who experienced hematomas while undergoing body contouring procedures while receiving enoxaparin (Lovenox), compared with similar patients who did not have development of a postoperative hematoma. Methods: A retrospective chart review was performed examining 2 patient groups: 10 patients who experienced a hematoma after excisional body contouring surgery with perioperative Lovenox; and 10 similar patients with respect to sex, surgery type, massive weight loss status, and Lovenox administration, who did not have a hematoma. Preoperative and postoperative blood pressures were recorded, as were blood pressures during the last 2 hours of surgery. Mean arterial pressures (MAPs) were calculated for all time points, and mean intraoperative MAP was statistically compared with preoperative and postoperative MAP, for the two groups. Results: The mean preoperative MAP for each group was the same (97.5 mm Hg vs 95.8 mm Hg; P = .61). The mean MAP for the last 2 hours of each case was significantly lower in the hematoma group (66.7 mm Hg vs 82.4 mm Hg; P < .0001), and a higher mean postoperative MAP reached significance in the hematoma group (96.3 mm Hg vs 88.5 mm Hg; P = .05). Both the difference between intraoperative and preoperative blood pressure (30.7 mm Hg vs 13.4 mm Hg; P < .0001) and between intraoperative and postoperative blood pressure (29.6 mm Hg vs 7.0 mm Hg; P < .0001) were increased in the hematoma group versus the non-hematoma group. Conclusions: Many patients undergoing excisional body contouring surgery are at risk for VTE and may need perioperative chemoprophylaxis. However, maintaining a normal intraoperative blood pressure and vigilance in recognizing and treating postoperative hypertension may reduce the hematoma rate seen with perioperative administration of LMWH.