Differential Diagnosis for a 4-week-old Male Infant with Hypoplastic Left Heart Syndrome
- Single most likely diagnosis:
- Sepsis: The infant's symptoms of fever (38.3 C), tachycardia (175/min), tachypnea (70/min), and hypoxia (pulse oximetry 80% on room air) are highly suggestive of sepsis, a common and serious complication in post-surgical patients, especially those with complex congenital heart disease.
- Other Likely diagnoses:
- Cardiac failure: Given the patient's history of hypoplastic left heart syndrome and recent palliative heart surgery, cardiac failure is a plausible diagnosis, as the infant may be experiencing decreased cardiac output or fluid overload.
- Respiratory infection: The symptoms of tachypnea, tachycardia, and hypoxia could also indicate a respiratory infection, which is a common complication in infants with congenital heart disease.
- Gastroesophageal reflux disease (GERD): The episode of vomiting could be related to GERD, which is common in infants, especially those with congenital heart disease.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Cardiac tamponade: Although less likely, cardiac tamponade is a life-threatening condition that can occur after cardiac surgery, and the distant heart sounds and hypotension (80/40 mm Hg) make it a diagnosis that should not be missed.
- Pulmonary embolism: Although rare in infants, pulmonary embolism can occur, especially in patients with central venous catheters or recent surgery, and would be catastrophic if not recognized and treated promptly.
- Rare diagnoses:
- Coronary artery thrombosis: This is a rare but potentially life-threatening complication that can occur after cardiac surgery, especially in patients with complex congenital heart disease.
- Myocardial ischemia: Myocardial ischemia can occur in infants with congenital heart disease, especially after cardiac surgery, and would require prompt recognition and treatment to prevent long-term damage.