Rectus sheath hematoma complicating low-molecular weight heparin therapy.

Rectus sheath hematoma (RSH) is an uncommon but serious bleeding complication of anticoagulant therapy that has received little attention in the literature. Two cases of RSH among recent admissions to an inpatient medicine service and four archival cases were reviewed. All six patients were on low-molecular weight heparin (LMWH) therapy. Five of the six patients had a creatinine clearance of 40 ml/min or less, and five also had cough. Two patients with the most serious outcome were aged 90 and 92 years. RSH complicating LMWH therapy appears to constitute a clinical syndrome consisting of sudden onset of abdominal pain in the setting of renal insufficiency, advanced age and abdominal straining (e.g. cough). Risk of RSH may be reduced in patients receiving LMWH by assessing renal function, monitoring heparin levels (e.g. when the creatinine clearance is 40 ml/min or less) and adjusting the dose accordingly; by avoidance of abdominal strain (e.g. by treating cough); and by attention to technique when the abdominal wall is used as the injection site. Patients of advanced age may be at particular risk for RSH.