A patient with acute exacerbation of chronic obstructive pulmonary disease (COPD) demonstrates hypercapnia and respiratory acidosis on arterial blood gas analysis. Which of the following ventilatory strategies is most appropriate for managing the patient's respiratory failure?

Correct Answer: D

Rationale: In a patient with acute exacerbation of COPD who presents with hypercapnia and respiratory acidosis, the most appropriate ventilatory strategy is invasive mechanical ventilation with a lung protective strategy. This involves using lower tidal volumes and limiting plateau pressures to prevent ventilator-induced lung injury.

Correct Answer: A

Rationale: Thrombotic thrombocytopenic purpura (TTP) is a rare but serious condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurological abnormalities, fever, and renal dysfunction. The classic pentad of symptoms includes fever, neurologic changes, renal impairment, thrombocytopenia, and microangiopathic hemolytic anemia. The presence of petechiae, purpura, and mucosal bleeding along with thrombocytopenia, elevated serum creatinine, and schistocytes on peripheral blood smear are consistent with TTP. In TTP, there is usually a deficiency of ADAMTS13 (a von Willebrand factor-cleaving protease) leading to excessive platelet adhesion, aggregation, and microthrombi formation within small blood vessels. Treatment typically

Correct Answer: D

Rationale: Multiple myeloma is a plasma cell neoplasm characterized by the presence of abnormal monoclonal plasma cells in the bone marrow, which produce a monoclonal spike on serum protein electrophoresis. The clinical presentation of weakness, bone pain, and recurrent infections is typical of multiple myeloma. Anemia can result from bone marrow infiltration by the abnormal plasma cells, hypercalcemia is due to bone destruction and release of calcium, renal insufficiency can result from hypercalcemia and protein deposition in the kidneys, and the monoclonal spike in serum protein electrophoresis indicates the presence of a monoclonal protein. Waldenström macroglobulinemia, Hodgkin lymphoma, and chronic lymphocytic leukemia do not typically present with the classic tetrad of findings seen in multiple myeloma.

Correct Answer: C

Rationale: The patient is presenting with sudden onset weakness and numbness on one side of the body, along with difficulty speaking and understanding speech, which are typical symptoms of a stroke. Imaging revealing an acute infarction involving the left middle cerebral artery territory is consistent with an ischemic stroke. Ischemic stroke occurs when there is a blockage in a blood vessel supplying blood to the brain, leading to a lack of oxygen and nutrients to the affected area, resulting in neurological deficits. This is in contrast to an intracerebral hemorrhage, which is caused by bleeding into the brain tissue, or a subarachnoid hemorrhage, which involves bleeding into the space surrounding the brain. A transient ischemic attack (TIA) is a temporary episode of neurological dysfunction caused by a brief blockage of blood flow to a part of the brain, usually resolving within 24 hours. In this case, the presentation and imaging findings are most

Correct Answer: D

Rationale: A subarachnoid hemorrhage is characterized by bleeding within the subarachnoid space, the area between the arachnoid mater and the pia mater surrounding the brain. Patients typically present with a sudden-onset severe headache, altered mental status, and focal neurological deficits due to the mass effect of the blood in the subarachnoid space. Imaging, such as a CT scan, can confirm the presence of the hemorrhagic lesion. Ischemic stroke results from a blockage in the blood vessels supplying the brain, leading to tissue infarction and neurological deficits. Subdural hematoma is a collection of blood between the dura mater and the arachnoid mater, commonly seen following head trauma. Intracerebral hemorrhage involves bleeding within the brain tissue itself, often leading to focal neurological deficits.