A 68-year-old man is admitted with a left lower lobe pneumonia and is started on antibiotics. He has a long history of diabetes, hypothyroidism, hypercholesterolemia, and hypertension. He also has diabetic retinopathy, peripheral neuropathy, and nephropathy. He has an arterio-venous fistula placed for a possible dialysis. Medications are insulin, furosemide, atorvastatin, metoprolol and levothyroxine. After having his blood drawn for some laboratory studies today, he bleeds persistently. Laboratory studies show: His baseline creatinine level is between 3.2-3.5 mg/dL. Which of the following is the most likely cause of his bleeding?

Question

A 68-year-old man is admitted with a left lower lobe pneumonia and is started on antibiotics.  He has a long history of diabetes, hypothyroidism, hypercholesterolemia, and hypertension.  He also has diabetic retinopathy, peripheral neuropathy, and nephropathy.  He has an arterio-venous fistula placed for a possible dialysis.  Medications are insulin, furosemide, atorvastatin, metoprolol and levothyroxine.  After having his blood drawn for some laboratory studies today, he bleeds persistently.  Laboratory studies show:  His baseline creatinine level is between 3.2-3.5 mg/dL.  Which of the following is the most likely cause of his bleeding?

Quizplus · Accepted Answer

Abnormal hemostasis is a common manifestation seen in patients with chronic renal failure. Abnormal bleeding and bruising are characteristic of uremic coagulopathy. Nowadays, ecchymoses and epistaxis are the only major bleeding manifestations seen due to the advent of dialysis; however, gastrointestinal bleeding, hemopericardium, subdural hematoma, and bleeding from surgical or invasive sites can still occur due to uremic coagulopathy. The pathogenesis is multifactorial, but the major defect involves platelet-vessel wall and platelet-platelet interaction. Several uremic toxins have been implicated in the pathogenesis of platelet dysfunction seen in chronic renal failure (CRF), the chief among which is guanidinosuccinic acid. Activated partial thromboplastin (aPTT), prothrombin (PT), and thrombin times (TT) are generally normal. Bleeding time (BT) is reflective of platelet function, and is usually prolonged. The platelet count is normal, but there is platelet dysfunction that causes bleeding. A number of agents such as desmopressin (DDAVP), cryoprecipitate, and conjugated estrogens have been used to correct the coagulopathy in uremic patients. DDAVP increases the release of factor VIII:von Willebrand factor multimers from endothelial storage sites. (Choices A, C, D, and E) Disseminated intravascular coagulation (DIC), factor VIII deficiency, consumptive coagulopathy, and thrombocytopenia are not common causes of bleeding in uremic patients. Furthermore, this patient's normal platelet count makes the diagnosis of DIC unlikely. Educational objective: Platelet dysfunction is the most common cause of abnormal hemostasis in patients with chronic kidney disease. PT, PTT, and platelet count are normal. Bleeding time is prolonged. DDAVP is usually the treatment of choice, if needed. DDAVP increases the release of factor VIII:von Willebrand factor multimers from endothelial storage sites. Platelet transfusion is not indicated because the transfused platelets quickly become inactive. *Extremely high yield question for USMLE!!!

A 68-Year-Old Man Is Admitted with a Left Lower Lobe