Differential Diagnosis for a 65-year-old Male Patient
Single Most Likely Diagnosis
- Gastrointestinal bleeding: The patient's history of falling hemoglobin levels since the incident, abdominal pain, and the use of diclofenac (a nonsteroidal anti-inflammatory drug known to cause gastrointestinal irritation and bleeding) strongly suggest gastrointestinal bleeding as the most likely diagnosis. The stress of the initial injury and the subsequent use of dexamethasone and diclofenac could exacerbate the risk of gastrointestinal complications.
Other Likely Diagnoses
- Intra-abdominal hemorrhage: Given the patient's recent history of trauma (self-inflicted wound) and the presence of abdominal pain, an intra-abdominal hemorrhage could be a possible cause of the patient's symptoms, especially if there were any internal injuries sustained during the incident.
- Stress ulcer: The use of dexamethasone and the physical stress from the injury could lead to the development of stress ulcers, which might cause gastrointestinal bleeding.
Do Not Miss Diagnoses
- Splenic injury or rupture: Although less common in the context provided, any form of abdominal trauma could potentially lead to splenic injury, which might not be immediately apparent but could lead to severe consequences if missed.
- Hemorrhage from other internal sites: Given the initial trauma, there's a possibility of bleeding from other internal sites that might not be immediately obvious, such as the liver, kidneys, or major vessels.
- Infection or sepsis: The patient's condition could be complicated by infection, especially if the wound became infected or if there was internal contamination. Sepsis would be a critical condition not to miss due to its high mortality rate.
Rare Diagnoses
- Angiodysplasia or vascular malformations: Although rare, these conditions could cause gastrointestinal bleeding, especially in older adults. However, they would be less likely given the acute presentation following trauma and medication use.
- Other rare causes of gastrointestinal bleeding: Conditions like Dieulafoy's lesion, gastric antral vascular ectasia (GAVE), or portal hypertensive gastropathy are rare but could be considered if common causes are ruled out.