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

Abstract

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. 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. 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. 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. 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.