Oncologic Emergencies Quiz

Explanation
Dexamethasone is the most appropriate initial management for this patient because the presentation of daily retro-orbital headaches that are worse in the morning, along with severe nausea and vomiting, suggests increased intracranial pressure. The multiple metastatic lesions seen on the MRI indicate that the breast cancer has spread to the brain. Dexamethasone is a glucocorticoid that can help reduce inflammation and edema in the brain, thereby alleviating the symptoms and reducing intracranial pressure. This can provide immediate relief to the patient while further treatment options are considered.

Explanation
The most appropriate initial management for this patient is a 0.9% saline bolus. The patient's altered mental status, orthostatic blood pressure, dry mucous membranes, and laboratory findings of hypercalcemia and elevated creatinine suggest that he is experiencing hypercalcemic crisis, which is a life-threatening condition. Hypercalcemia can cause dehydration and impaired renal function, leading to altered mental status. A 0.9% saline bolus is given to correct the dehydration and increase renal perfusion, which can help lower the serum calcium levels. Furosemide is a loop diuretic that can be used to enhance calcium excretion, but it should be used cautiously and after volume repletion. Pamidronate is a bisphosphonate that inhibits bone resorption and can be used for long-term management of hypercalcemia, but it is not the most appropriate initial intervention in this acute situation. A 0.45% saline bolus is hypotonic and not appropriate for a patient with hypercalcemia and dehydration.

Explanation
The most appropriate therapy for this patient is Vancomycin, piperacillin-tazobactam, and gentamicin. This patient is presenting with a fever and leukopenia, which are concerning for neutropenic fever, a common complication of chemotherapy. Neutropenic fever is often caused by bacterial infections, and the combination of Vancomycin, piperacillin-tazobactam, and gentamicin provides broad-spectrum coverage against both gram-positive and gram-negative bacteria. Amphotericin is an antifungal agent and would not be the first-line treatment for this patient. Therefore, the correct answer is Vancomycin, piperacillin-tazobactam, and gentamicin.

Explanation
The most likely diagnosis for a 71-year-old man with lung cancer who presents with worsening dyspnea is Superior vena cava (SVC) syndrome. SVC syndrome occurs when the superior vena cava, which is responsible for returning blood from the upper body to the heart, becomes obstructed. In patients with lung cancer, the tumor can compress or invade the SVC, leading to symptoms such as dyspnea, facial swelling, and dilated veins in the upper body. This condition can cause significant respiratory distress and is a common complication in patients with lung cancer.

Explanation
Dexamethasone is the most appropriate initial management for this patient because she presents with symptoms of increased intracranial pressure, such as daily retro-orbital headaches that worsen in the morning and vomiting. These symptoms, along with the presence of multiple metastatic lesions on MRI, suggest that the headaches are likely due to brain metastases. Dexamethasone is a corticosteroid that can help reduce inflammation and edema in the brain, alleviating symptoms and improving the patient's quality of life. Biopsy or surgical resection may be considered later for definitive diagnosis and treatment, but initial management should focus on symptom relief.

Explanation
The most likely cause of the patient's electrolyte abnormalities is tumor lysis syndrome. Tumor lysis syndrome occurs when large amounts of tumor cells are destroyed rapidly, leading to the release of intracellular contents such as potassium, phosphate, and uric acid into the bloodstream. This can result in hyperkalemia, hyperphosphatemia, and elevated uric acid levels. Additionally, the increased breakdown of cells can lead to elevated lactate dehydrogenase levels. Acute renal failure and hypercalcemia can also cause electrolyte abnormalities, but the given clinical presentation and laboratory findings are more consistent with tumor lysis syndrome.

Explanation
The most appropriate initial management for this patient is a 0.9% saline bolus. The patient's altered mental status and lethargy may be indicative of dehydration or electrolyte imbalances, which can be addressed by administering IV fluids. A 0.9% saline bolus is commonly used to rapidly expand intravascular volume and correct hypovolemia. This can help improve the patient's mental status and overall condition. Pamidronate is a bisphosphonate used for the treatment of hypercalcemia, which is not indicated in this case. Furosemide is a loop diuretic that may be used to treat fluid overload, but it is not the most appropriate initial management in this patient.

Explanation
The most likely cause of the patient's electrolyte abnormalities is tumor lysis syndrome. Tumor lysis syndrome is a condition that occurs when cancer cells release their contents into the bloodstream, leading to the release of large amounts of potassium, phosphate, and uric acid. This can result in hyperkalemia, hyperphosphatemia, and elevated uric acid levels. Additionally, the elevated lactate dehydrogenase (LDH) is a marker of cell breakdown, further supporting the diagnosis of tumor lysis syndrome. The patient's symptoms of fatigue and malaise are also consistent with this condition.

Explanation
Based on the given information, the most likely diagnosis is Superior vena cava (SVC) syndrome. The patient has distended jugular veins, a plethoric face, venous collaterals on his chest wall, and distant heart sounds. These findings are consistent with SVC syndrome, which occurs when there is obstruction or compression of the superior vena cava, leading to impaired venous return from the upper body. This can be caused by lung cancer, as in this case, due to tumor invasion or compression of the SVC. Pericardial tamponade, constrictive pericarditis, and congestive heart failure do not typically present with these specific findings.

Explanation
The most appropriate therapy for this patient is Vancomycin, piperacillin-tazobactam, and gentamicin. The patient's presentation with fever, fatigue, and a low leukocyte count suggests neutropenic fever, which is a common complication of chemotherapy. Neutropenic patients are at high risk for serious bacterial infections, including sepsis. Therefore, broad-spectrum antibiotics that cover both gram-positive and gram-negative bacteria, such as Vancomycin, piperacillin-tazobactam, and gentamicin, are the most appropriate choice to provide coverage against a wide range of pathogens. Caspofungin and Amphotericin are antifungal agents, which are not indicated in this scenario.