Which of the following conditions affects partial thromboplastin time?

Which of the following conditions affects partial thromboplastin time?

A 28-year-old black man with sickle cell disease presents to the emergency department with abdominal pain, chest pain, and shortness of breath. His dyspnea evolved over 36 hours after a visit with his niece and nephew. His history is significant for approximately 2 emergency department visits or hospital admissions per year for painful crises. Three years ago, he spent 4 weeks in the hospital after an episode of acute chest syndrome. He has been taking hydroxyurea but only intermittently because of financial concerns. His pulse is 116 beats per minute and regular, his blood pressure is 138/76 mm Hg, his respiratory rate is 18 breaths per minute, and his temperature is 38.3°C. Pulse oximetry shows 91% oxygen saturation with room air and 93% with 4 L of oxygen by nasal cannula. His lungs have scattered inspiratory crackles in the right midlung field. His spleen is not palpable. The remainder of the physical examination findings are normal. Diagnostic testing results are shown in Table 9.Q4. A chest radiograph shows a right middle and upper lobe air space infiltrate. The patient is given supplemental oxygen, adequate pain control, and intravenous antibiotics. Which of the following should you now order?

A 45-year-old man presents with deep vein thrombosis of the right femoral vein. Three months ago, he received a diagnosis of systemic lupus erythematosus (SLE). In addition to confirming SLE, laboratory testing also documented the presence of a lupus anticoagulant (LAC). There is no family history of venous thrombosis. Current medications include hydroxychloroquine. Laboratory testing shows normal results for a complete blood cell count and for tests of liver and kidney function. Special coagulation testing confirms the persistence of an LAC. What is the most reasonable duration of warfarin anticoagulation for this patient?

At her annual physical examination, an asymptomatic 68-year-old woman has lymphocytosis (32 × 10^9/L) with a normal hemoglobin level and platelet count. On examination, she has 1-cm lymphadenopathy in the cervical region and no palpable liver or spleen enlargement. A peripheral blood smear shows identically appearing mature lymphocytes with smudge cells. Flow cytometry of the peripheral blood lymphocytes shows a monoclonal B population with dim expression of λ light chain and CD20 that is positive for expression of CD5, CD19, and CD23. Which of the following is the best next step in her management?

A 73-year-old woman presented to the emergency department with new-onset back pain, confusion, and constipation over the past week. Her past medical history is significant only for hypertension. On examination, she is slightly pale with slow cognition and point tenderness over the lumbar spine. Plain films of the lumbar spine show osteolytic lesions in L2, L3, and L5. Laboratory values are as follows: hemoglobin 9.3 g/dL, leukocyte count 4.6 × 10^9/L with a normal differential count, platelet count 230 × 10^9/L, creatinine 1.6 mg/dL, total calcium 13.1 mg/dL, albumin 3.6 g/dL, and total protein 9.1 g/dL. What is the most likely diagnosis?