Differential Diagnosis for 43-year-old Male with Acute Pain Abdomen
Single most likely diagnosis
- Postoperative Sepsis with Delirium: The patient's symptoms of acute pain abdomen, disorientation, agitation, and hallucinations (seeing snakes on walls) 2 days after surgery for appendicitis, along with fever (39°F) and tachycardia, strongly suggest a postoperative infection leading to sepsis. The delirium could be a result of the systemic inflammatory response syndrome (SIRS) associated with sepsis.
Other Likely diagnoses
- Postoperative Wound Infection: Given the recent surgery, a wound infection could be causing the patient's fever, tachycardia, and abdominal pain. However, the presence of disorientation and hallucinations suggests a more systemic issue.
- Intra-abdominal Abscess: This could be a complication of the appendicitis surgery, leading to fever, abdominal pain, and potentially systemic symptoms if the abscess is large or leaking.
- Medication-induced Delirium: Certain medications used in the postoperative period, such as opioids or anticholinergics, can cause delirium. However, the presence of fever and tachycardia suggests an infectious cause is more likely.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningitis or Encephalitis: Although less likely given the postoperative context, central nervous system infections can present with fever, disorientation, and hallucinations. Missing these diagnoses could be fatal.
- Pulmonary Embolism: Postoperative patients are at increased risk for venous thromboembolism. While the symptoms don't directly suggest PE, it's a condition that could lead to sudden deterioration and death if not recognized and treated promptly.
- Adrenal Insufficiency: This could be a cause of hypotension and shock in a critically ill patient, especially if the patient has been on long-term steroids. However, the presentation would typically include hypotension, which is not mentioned.
Rare diagnoses
- CNS Vasculitis: A rare condition that could present with neurological symptoms including hallucinations, but would be unusual in this postoperative context without other systemic symptoms of vasculitis.
- Toxins or Poisoning: Certain toxins can cause hallucinations and systemic symptoms, but there's no indication in the scenario that the patient has been exposed to such substances.
- Porphyria: A group of rare disorders that can cause abdominal pain, neurological symptoms, and psychiatric disturbances. However, the acute onset in a postoperative setting makes this less likely.