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 lowdose 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.

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.

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/m₂ 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.