From the Guidelines
The patient needs immediate treatment for dehydration, acute kidney injury, and hypernatremia, and the most appropriate initial step is to start with IV fluid resuscitation using 0.9% normal saline at 150-200 mL/hour, as suggested by the most recent and highest quality study 1.
Patient Assessment
The elevated BUN/Cr ratio of 31.3 suggests prerenal azotemia, while the high sodium (156 mEq/L) indicates significant hypernatremia. The elevated anion gap (18) suggests metabolic acidosis.
- Correct sodium slowly at no more than 8-10 mEq/L per 24 hours to avoid cerebral edema.
- Identify and treat the underlying cause, which may include excessive fluid losses, inadequate intake, or diabetes insipidus.
- Temporarily hold potentially nephrotoxic medications like NSAIDs, ACE inhibitors, and ARBs, as recommended by 1 and supported by 1.
Renal Function and Disease Management
The patient's GFR of 49.2 indicates stage 3 chronic kidney disease, which requires follow-up after resolving the acute issues.
- Consider nephrology consultation if renal function doesn't improve within 24-48 hours with fluid resuscitation.
- Monitor serum creatinine and potassium levels for the development of increased creatinine or changes in potassium, as suggested by 1.
Treatment and Management
- Use the RIFLE criteria to classify the severity of acute renal failure, as described in 1.
- Consider the use of continuous renal replacement therapy (CRRT) if the patient's condition worsens, with a minimum dose of 35 mL/kg/hour, as recommended by 1.
- Monitor fluid status, urine output, and electrolytes every 4-6 hours to adjust treatment as needed.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Patient's Laboratory Results
The patient's laboratory results show:
- BUN: 47
- Cr: 1.5
- BUN/Cr ratio: 31.3
- Sodium: 156
- Potassium: 4.4
- Chloride: 117
- CO2: 21
- Anion gap: 18
- Calcium: 9.9
- GFR: 49.2
Possible Interventions
Based on the patient's laboratory results, possible interventions include:
- Fluid resuscitation with balanced electrolyte solutions instead of 0.9% saline to reduce the risk of metabolic acidosis and impaired renal function 2, 3
- Avoiding excessive sodium and chloride intake to prevent hypernatremia and acute kidney injury 4
- Using buffered solutions to reduce the occurrence of renal failure and metabolic acidosis 5
- Considering the use of balanced electrolyte solutions for fluid resuscitation in patients with severe sepsis or diabetic ketoacidosis 6, 3
Key Considerations
Key considerations for the patient's treatment include:
- The patient's high sodium level (156) and high chloride level (117) may indicate hypernatremia and metabolic acidosis
- The patient's low GFR (49.2) may indicate impaired renal function
- The use of 0.9% saline for fluid resuscitation may exacerbate hypernatremia and metabolic acidosis
- Balanced electrolyte solutions may be a better choice for fluid resuscitation to reduce the risk of metabolic acidosis and impaired renal function 2, 3