Differential Diagnosis
- Single most likely diagnosis
- Malignant pleural and pericardial effusions: Given the patient's history of lung cancer, the presence of pleural and pericardial effusions on CTA is highly suggestive of malignant involvement of these spaces, which can cause progressive weakness, shortness of breath (SOB), and persistent tachycardia due to impaired cardiac function and possible cardiac tamponade.
- Other Likely diagnoses
- Anemia exacerbation: The patient is here for transfusion, indicating anemia, which can cause progressive weakness and SOB. The transfusion and magnesium repletion may help alleviate these symptoms.
- Chemotherapy-related cardiomyopathy: The patient's history of chemotherapy for lung cancer increases the risk of cardiomyopathy, which can lead to heart failure symptoms such as SOB and weakness.
- Hypomagnesemia: The patient is pending magnesium repletion, suggesting hypomagnesemia, which can cause weakness, SOB, and cardiac arrhythmias.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cardiac tamponade: Although the CTA showed pericardial effusion, cardiac tamponade is a life-threatening condition that requires immediate attention. The patient's persistent tachycardia and SOB increase the suspicion for this condition.
- Pulmonary embolism (despite negative CTA): While the CTA was negative for PE, it is essential to consider this diagnosis, especially in a patient with cancer, as PEs can be occult or not visible on initial imaging.
- Sepsis: The patient's weakness, SOB, and tachycardia could be indicative of sepsis, particularly in an immunocompromised patient undergoing chemotherapy.
- Rare diagnoses
- Superior vena cava syndrome: Although less likely, the patient's history of lung cancer and presence of pleural and pericardial effusions increase the risk of superior vena cava syndrome, which can cause SOB and weakness.
- Pneumopericardium: This rare condition, where air enters the pericardial space, can cause cardiac tamponade and should be considered in a patient with lung cancer and pericardial effusion.