Lactic Acidosis: This condition is characterized by an elevated anion gap due to increased lactic acid levels, often resulting from tissue hypoperfusion or hypoxia, which can also explain the hypotension. Normal BUN and creatinine levels suggest that the kidneys are not the primary source of the issue.

Diabetic Ketoacidosis (DKA): Although DKA typically presents with hyperglycemia and ketosis, it can cause an elevated anion gap metabolic acidosis. Hypotension can occur due to dehydration. Normal BUN and creatinine might be seen early in the disease process.
Ethylene Glycol or Methanol Poisoning: These toxic ingestions can lead to an elevated anion gap metabolic acidosis. Hypotension can be present due to the toxic effects on the cardiovascular system. Early in the course, BUN and creatinine might still be normal.

Sepsis: Sepsis can cause lactic acidosis due to tissue hypoperfusion, leading to an elevated anion gap. It is crucial to consider sepsis due to its high mortality rate if not promptly treated. Hypotension is a key feature of septic shock.
Cardiogenic Shock: Similar to sepsis, cardiogenic shock can result in lactic acidosis due to inadequate tissue perfusion. The hypotension in this scenario is due to the heart's inability to pump effectively.

Ketoacidosis due to Starvation: Prolonged fasting or starvation can lead to ketoacidosis, which might present with an elevated anion gap. However, this condition is less likely to cause significant hypotension compared to other diagnoses.
Isopropyl Alcohol Toxicity: While isopropyl alcohol ingestion can cause a metabolic acidosis, it typically does not result in an elevated anion gap to the same extent as other alcohols like methanol or ethylene glycol. However, it can still lead to significant hypotension and should be considered in the appropriate clinical context.