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.

Hypophosphatasia: nonlethal disease despite skeletal presentation in utero (17 new cases and literature review).

Hypophosphatasia (HPP) is caused by deactivating mutation(s) within the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Patients manifest rickets or osteomalacia and dental disease ranging from absence of skeletal mineralization in utero to only loss of adult dentition. Until recently, HPP skeletal disease in utero was thought to always predict a lethal outcome. However, several reports beginning in 1999 emphasized a benign prenatal form of HPP (BP-HPP) where skeletal disease detected in utero had a mild postnatal course. Here we describe prenatal and postnatal findings of 17 additional BP-HPP patients among our 178 pediatric HPP patients. Their findings are compared with those of their siblings with HPP, carrier parents, and others with identical TNSALP mutations. New information concerning 7 previously published BP-HPP patients accompanies a review of the HPP literature. Among our 17 BP-HPP patients, prenatal ultrasound showed normal chest or abdominal circumferences where recorded. Sometimes, poor skeletal mineralization, fetal crowding, and third-trimester improvement were observed. Postnatally, extremity bowing further improved (13 patients). BP-HPP severity postnatally spanned the "infantile" to "odonto" HPP phenotypes, resembling our patients who harbored identical TNSALP mutation(s). Eight had autosomal dominant (AD) and 9 had autosomal recessive (AR) BP-HPP. Fourteen of our 15 mothers were HPP carriers or affected. Of the 41 cumulative BP-HPP patients (24 literature cases meriting a BP-HPP diagnosis since 1996 plus our 17 patients), 63% had AR BP-HPP. Maternally transmitted HPP involved 11 of the 13 total AD BP-HPP probands (p = 0.01), supporting a maternal in utero effect on the baby. Fetal crowding, normal fetal mineralization and chest size, and TNSALP heterozygosity seem to identify BP-HPP. However, bowed fetal long bones with AR HPP, specific TNSALP mutations, or poor skeletal mineralization before the third trimester do not reliably diagnose HPP lethality.