Differential Diagnosis for 70-year-old Female with Vomiting

Given the laboratory results and clinical presentation of a 70-year-old female with vomiting for 3 days, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • C. Renal insufficiency: The elevated BUN (48 mg/dL) and creatinine (2.1 mg/dL) levels strongly suggest renal insufficiency. The patient's vomiting could lead to dehydration, which in turn can cause a prerenal acute kidney injury, exacerbating renal insufficiency.

• Other Likely Diagnoses

  • B. Diabetes: Although the glucose level is slightly elevated (109 mg/dL), it's not definitively diagnostic of diabetes mellitus without further testing (e.g., HbA1c). However, diabetes can lead to renal insufficiency and could be a contributing factor.
  • Dehydration: Not explicitly listed but implied through the clinical presentation of vomiting. Dehydration can lead to electrolyte imbalances and exacerbate renal insufficiency.

• Do Not Miss Diagnoses

  • Severe Electrolyte Imbalance: Although the sodium, potassium, and chloride levels are within relatively normal limits, the magnesium level is slightly low (1.8 mg/dL), and phosphate is low (2.5 mg/dL). Severe electrolyte imbalances can be life-threatening and require prompt correction.
  • Gastrointestinal Obstruction: A condition that could cause vomiting and potentially lead to severe dehydration and electrolyte imbalances if not promptly addressed.

• Rare Diagnoses

  • A. Hepatitis: The liver enzymes (AST 27 U/L, ALT 19 U/L, Alk Phos 74 U/L) are not significantly elevated, making hepatitis a less likely diagnosis based on the provided laboratory results.
  • Other Endocrine Disorders: Although not directly suggested by the laboratory results, other endocrine disorders could potentially cause vomiting and electrolyte disturbances, but they would be less common and require specific diagnostic testing to confirm.