Systemic Effects of Subcutaneous Heparin Use in Otolaryngology Patients

OBJECTIVES: To describe a population of otolaryngology patients who developed systemic anticoagulation from pharmacologic deep vein thrombosis prophylaxis using subcutaneous low-dose unfractionated heparin and describe associated adverse events and identify risk factors for this occurrence. STUDY DESIGN: Retrospective case series with chart review. SETTING: Single-institution, academic tertiary care center. SUBJECTS AND METHODS: Patients who developed prolonged partial thromboplastin times from routine administration of subcutaneous low-dose unfractionated heparin postoperatively were retrospectively identified during a 16-month period. Data regarding demographics, disease characteristics, laboratory values, associated complications, and risk factors were collected and analyzed. RESULTS: Five patients, all with head and neck cancer, postoperatively developed prolonged partial thromboplastin time levels with prophylactic subcutaneous low-dose unfractionated heparin. All had body mass index ≤ 20 kg/m(2) and received 5000 units of subcutaneous low-dose unfractionated heparin 3 times daily. Four had impaired renal function. Adverse events included 5 postoperative wound hematomas, an emergent reintubation, and a case of persistent mucosal bleeding. These bleeding complications accounted for 25% of all bleeding complications in otolaryngology patients during the same period. CONCLUSION: Unanticipated systemic effects of subcutaneous low-dose unfractionated heparin can cause significant morbidity in surgically treated patients with head and neck cancer. From this case series, risk factors appear to include subcutaneous low-dose unfractionated heparin 3 times daily dose frequency, low body mass index, and renal dysfunction. For this at-risk patient population, a protocol is needed to minimize both deep vein thromboses and complications of prophylactic therapy.