Differential Diagnosis

The patient's laboratory results show a potassium level of 4.3 mmol/L, creatinine of 1.12 mg/dL, sodium of 132 mmol/L, and an estimated glomerular filtration rate (eGFR) of 52 mL/min/1.73m^2. Based on these values, the following differential diagnoses can be considered:

• Single Most Likely Diagnosis
  • Chronic Kidney Disease (CKD): The patient's eGFR of 52 indicates a reduced kidney function, which is a hallmark of CKD. The slightly elevated creatinine level also supports this diagnosis. CKD can lead to various electrolyte imbalances and is a common condition in patients with kidney dysfunction.
• Other Likely Diagnoses
  • Dehydration: The patient's sodium level is slightly low, which could be indicative of dehydration. Dehydration can also lead to a decrease in eGFR and an increase in creatinine levels.
  • Diuretic Use: The use of diuretics can lead to electrolyte imbalances, including low sodium levels, and can also affect kidney function, leading to a decrease in eGFR.
• Do Not Miss Diagnoses
  • Acute Kidney Injury (AKI): Although the patient's eGFR is not severely decreased, AKI is a potentially life-threatening condition that requires prompt diagnosis and treatment. The patient's creatinine level is slightly elevated, which could be indicative of AKI.
  • Adrenal Insufficiency: The patient's low sodium level could be indicative of adrenal insufficiency, which is a life-threatening condition if left untreated.
• Rare Diagnoses
  • Tubulointerstitial Disease: This is a rare condition that affects the tubules and interstitium of the kidneys, leading to kidney dysfunction and electrolyte imbalances.
  • Renal Tubular Acidosis: This is a rare condition that affects the kidneys' ability to regulate acid-base balance, leading to electrolyte imbalances and kidney dysfunction.

It is essential to note that a thorough medical history, physical examination, and additional laboratory tests are necessary to confirm the diagnosis and rule out other potential causes.