warfarin and Osteomyelitis

Here we describe an 8-year old male child with homozygous sickle cell disease who presented with left parietal skull bone infarction and, during his stay in hospital, developed a right femoral deep vein thrombosis (DVT), both uncommon complications of the disease. He initially presented with severe headache and generalised tenderness of the calvarium, which did not respond to simple analgesics. Scalp swelling in and around the left frontal (including left orbit) and parietal regions developed 24 h after presentation. The differential diagnosis included incipient stroke, acute sickle bone crisis and osteomyelitis, with a possible complication of epidural haematoma, or orbital compression syndrome. An initial exchange blood transfusion did not lead to appreciable reduction in opiate requirements. Significant symptomatic relief was attained only after a second exchange transfusion. The DVT developed at the site of catheterisation (right femoral vein), and this was treated with maximal doses of enoxaparin followed by warfarin. The child is now well and off anti-coagulants. In this article we present a review of the literature and discuss possible mechanisms of these complications in our patient.

Topics: Anemia, Sickle Cell; Anticoagulants; Catheterization; Child; Diagnosis, Differential; Edema; Enoxaparin; Exchange Transfusion, Whole Blood; Femoral Vein; Headache; Humans; Infarction; Male; Osteomyelitis; Parietal Bone; Stroke; Thrombophilia; Thrombophlebitis; Warfarin

A 79-year-old man with a history of deep vein thrombosis and pulmonary embolism received anticoagulation therapy with warfarin 5 mg daily for 8 months. He was diagnosed with osteomyelitis and underwent partial metatarsal resection of his right foot. After surgery, antibiotics were initiated, including ertapenem sodium 1 g intravenously every 24 hours, vancomycin 1400 mg intravenously every 24 hours, and rifampin 300 mg by mouth twice daily. Achieving a therapeutic level of anticoagulation was difficult despite escalating doses of warfarin, because of the interaction with rifampin. A 5- to 6-fold increase in warfarin dose was prescribed to reach therapeutic international normalized ratios (INRs), but even these increases were insufficient to maintain his INR in the therapeutic range. After rifampin was discontinued, warfarin doses were gradually reduced over the next 2 months. When concurrent warfarin-rifampin therapy is necessary, vigilant monitoring is imperative and significant increases in warfarin doses are likely.

Topics: Aged; Antibiotics, Antitubercular; Anticoagulants; Drug Administration Schedule; Drug Interactions; Drug Monitoring; Humans; International Normalized Ratio; Male; Nursing Assessment; Osteomyelitis; Postoperative Care; Pulmonary Embolism; Rifampin; Risk Assessment; Venous Thrombosis; Warfarin

An increasingly reported entity, Lemierre's syndrome classically presents with a recent oropharyngeal infection, internal jugular vein thrombosis and the presence of anaerobic organisms such as Fusobacterium necrophorum. The authors report a normally fit and well 17-year-old boy who presented with severe sepsis following a 5-day history of a sore throat, myalgia and neck stiffness requiring intensive care admission. Blood cultures grew F. necrophorum and radiological investigations demonstrated left internal jugular vein, cavernous sinus and sigmoid sinus thrombus, left vertebral artery dissection and thrombus within the left internal carotid artery. Imaging also revealed two areas of acute ischaemia in the brain, consistent with septic emboli, skull base (clival) osteomyelitis and an extensive epidural abscess. The patient improved on meropenem and metronidazole and was warfarinised for his cavernous sinus thrombosis. He has an on-going left-sided hypoglossal (XIIth) nerve palsy.

Topics: Adolescent; Anti-Infective Agents; Anticoagulants; Cranial Fossa, Posterior; Fever; Fusobacterium Infections; Fusobacterium necrophorum; Humans; Hypoglossal Nerve Diseases; Jugular Veins; Lemierre Syndrome; Male; Meropenem; Metronidazole; Osteomyelitis; Pharyngitis; Sepsis; Thienamycins; Treatment Outcome; Warfarin

This article describes a case of a 26-year-old man presenting with left knee pain of 1 week's duration, fever, and acute onset of shortness of breath the day of admission. An arthrocentesis of the knee joint was grossly positive for methicillin-resistant Staphylococcus aureus. A left lower extremity venous duplex showed thrombosis of the superficial femoral, popliteal, posterior tibial, peroneal, and gastrocnemius veins. Pulmonary computed tomography-angiography was positive for acute pulmonary emboli. Initial management consisted of anticoagulation, intravenous antibiotics, and 2 arthroscopic irrigation and debridement procedures. After a normal transesophageal echocardiogram, a diagnosis of septic knee-induced deep venous thrombosis (DVT) of the left lower leg with subsequent septic pulmonary emboli was established. The patient was discharged to a long-term care facility for a 6-week monitored course of intravenous antibiotics. His DVT and pulmonary emboli were managed successfully with oral warfarin. Two months after his initial presentation, the patient returned with acute worsening knee pain. A knee arthrocentesis was unremarkable; however, radiographic imaging revealed fulminant osteomyelitis of the distal femur. He has since undergone open arthrotomy with excisional irrigation and debridement and is on a chronic oral antibiotic regimen. Sparse pediatric literature has shown an association between musculoskeletal sepsis and thrombosis. Only 1 case of septic knee-induced DVT exists in the adult literature, and it was not associated with pulmonary emboli. Our case provides evidence that DVT must be considered by the treating physician as a possible and devastating complication of septic arthritis.

Topics: Adult; Anti-Bacterial Agents; Anticoagulants; Arthritis, Infectious; Debridement; Femur; Humans; Injections, Intravenous; Knee Joint; Male; Methicillin-Resistant Staphylococcus aureus; Osteomyelitis; Staphylococcal Infections; Therapeutic Irrigation; Venous Thrombosis; Warfarin