hirudin and Obesity--Morbid

The case of a patient with confirmed heparin-induced thrombocytopenia (HIT) and anticoagulation failure undergoing catheter-directed thrombolysis (CDT) with alteplase and bivalirudin for extensive thrombosis is reported.. A 48-year-old, morbidly obese Caucasian woman was admitted to a trauma-surgical intensive care unit (TSICU) after a motor vehicle accident. The patient suffered aortic and renal lacerations, multiple rib and spinal fractures, pleural effusion, bilateral subdural hematomas, and cerebral edema. An inferior vena cava (IVC) filter was placed on hospital day 3, and prophylactic enoxaparin was initiated. The patient was diagnosed with HIT on hospital day 10. Systemic bivalirudin was initiated, and the patient was transitioned to therapeutic fondaparinux on hospital day 13. The patient continued to improve and was transferred from the TSICU to a step-down unit a few days later; the IVC filter remained in place. On hospital day 20, the patient developed respiratory distress and was transferred back to the TSICU. Computed tomography angiography was performed and revealed a questionable pulmonary embolism and distended IVC and iliac veins. Lower-extremity Doppler ultrasound revealed extensive thrombosis. On hospital day 21, the patient underwent CDT with alteplase and bivalirudin infusions through two CDT sheaths for approximately 36 hours, after which most of the thrombus had dissipated. The IVC filter and drug administration sheaths were removed. After the procedure, the patient received bivalirudin and was later transitioned to warfarin.. A 48-year-old woman with HIT and anticoagulation failure possibly due to the presence of an IVC filter was successfully treated with CDT using alteplase and bivalirudin.

Topics: Anticoagulants; Catheterization; Female; Fibrinolytic Agents; Heparin; Hirudins; Humans; Middle Aged; Obesity, Morbid; Peptide Fragments; Recombinant Proteins; Thrombocytopenia; Thrombolytic Therapy; Tissue Plasminogen Activator

To report the use of subcutaneous lepirudin in an obese patient with heparin resistance.. A 34-year-old morbidly obese male (weight 145 kg) presented with hypoxia on postoperative day 1 following a sigmoid colectomy. A continuous unfractionated heparin infusion was started for a suspected pulmonary embolism. Doses were escalated without therapeutic activated partial thromboplastin time (aPTT) response and an antithrombin (AT) level was obtained. The AT level was reported as 78% (reference range 85-120%). Computed tomography angiography ruled out pulmonary embolism and lepirudin 50 mg administered subcutaneously twice daily was started (serum creatinine 1.3 mg/dL) for prevention of venous thromboembolism. The resulting aPTT values were therapeutic (63 and 60 sec, reference range 24-34, therapeutic heparin range 55-85). The dose was adjusted to 25 mg twice daily. aPTT values were 35 and 48 seconds. His serum creatinine increased to 1.6 mg/dL and minor bleeding was noted. The dose was decreased to 25 mg once daily, with resulting aPTT values of 31, 39, and 41 seconds. The patient was discharged to home without development of venous thromboembolism, as confirmed by duplex ultrasonography.. Commonly administered anticoagulants, such as unfractionated heparin, low-molecular-weight heparins, and fondaparinux, exert their effect by complexing with AT and thrombin (Factor IIa), activating AT and preventing thrombin from exerting coagulation effect. Without AT present, these drugs have little effect on inhibiting the coagulation cascade. Lepirudin is a synthetic irreversible direct thrombin inhibitor and does not rely on AT to exert its anticoagulation action. It can be given subcutaneously and is eliminated primarily by the kidneys. Dosage adjustments for both renal function and obesity need to be considered and aPTT should be monitored.. In obese patients or those with heparin resistance, subcutaneous lepirudin can be monitored and the regimen adjusted based on aPTT values. Further studies are warranted to maximize efficacy and define dosing.

Topics: Adult; Anticoagulants; Critical Care; Dose-Response Relationship, Drug; Drug Resistance; Heparin; Hirudins; Humans; Injections, Subcutaneous; Male; Obesity, Morbid; Partial Thromboplastin Time; Recombinant Proteins; Venous Thromboembolism