What is the most appropriate therapy for a patient with acute kidney injury, hyperkalemia, and oliguria, unresponsive to furosemide, in the setting of septic shock and acute respiratory distress syndrome?

From the Guidelines

The most appropriate therapy for this patient is to begin continuous renal replacement therapy (CRRT). This 77-year-old woman has developed acute kidney injury (AKI) in the setting of septic shock and ARDS, with clear indications for renal replacement therapy including severe hyperkalemia (6.4 mEq/L), metabolic acidosis (bicarbonate 12 mEq/L), oliguria (30 mL/h) unresponsive to diuretics, and volume overload evidenced by elevated central venous pressure and pulmonary edema on chest radiograph. CRRT is preferred over intermittent hemodialysis in hemodynamically unstable ICU patients as it provides gradual, continuous fluid removal and solute clearance without causing significant blood pressure fluctuations, as suggested by the Surviving Sepsis Campaign guidelines 1. Peritoneal dialysis would be inadequate for the severity of her condition and could worsen respiratory status by increasing intra-abdominal pressure. Continuing current management is inappropriate given her life-threatening hyperkalemia and fluid overload. Switching to bumetanide would be ineffective as she has already demonstrated diuretic resistance. CRRT will help correct electrolyte abnormalities, remove fluid, improve acid-base status, and potentially improve oxygenation by reducing pulmonary edema while maintaining hemodynamic stability during ongoing treatment for septic shock. The most recent guidelines from the Kidney Disease: Improving Global Outcomes (KDIGO) conference also support the use of CRRT in hemodynamically unstable patients with AKI, with a recommended effluent volume of 20-25 ml/kg per hour 1.

Some key points to consider in this patient's management include:

• The importance of timely initiation of RRT in patients with severe AKI and life-threatening complications such as hyperkalemia and fluid overload
• The choice of RRT modality, with CRRT being preferred in hemodynamically unstable patients
• The need for careful monitoring and adjustment of RRT parameters to achieve optimal fluid and solute clearance
• The importance of considering the patient's overall clinical status and prognosis when making decisions about RRT initiation and continuation.

Overall, the use of CRRT in this patient is supported by the available evidence and guidelines, and is likely to improve her outcomes by correcting life-threatening electrolyte and fluid abnormalities, and maintaining hemodynamic stability during ongoing treatment for septic shock.

From the Research

Patient Assessment

The patient is a 77-year-old woman with acute kidney injury, septic shock, and acute respiratory distress syndrome. She has been hospitalized for 2 days and has received 3600 mL of Ringer's lactate solution. Her current medications include norepinephrine, ceftaroline, levofloxacin, and dexmedetomidine.

Laboratory Results

The patient's laboratory results show:

• Creatinine: 3.4 mg/dL (300.6 µmol/L)
• Electrolytes:
  • Sodium: 134 mEq/L (134 mmol/L)
  • Potassium: 6.4 mEq/L (6.4 mmol/L)
  • Chloride: 100 mEq/L (100 mmol/L)
  • Bicarbonate: 12 mEq/L (12 mmol/L)
• Urine output is 30 mL/h and unresponsive to escalating doses of intravenous furosemide.

Appropriate Therapy

Based on the patient's condition and laboratory results, the most appropriate therapy is:

• A: Begin continuous renal replacement therapy (CRRT), as the patient has acute kidney injury and is hemodynamically unstable, with a high creatinine level and low urine output 2, 3, 4. CRRT is commonly used to provide renal support for critically ill patients with acute kidney injury, particularly those who are hemodynamically unstable 2. The optimal timing of initiating CRRT in septic shock patients with acute kidney injury is within 16.5 hours after AKI onset 5.

Key Considerations

• The patient's condition, including septic shock and acute respiratory distress syndrome, requires close monitoring and aggressive treatment.
• CRRT is a preferred treatment for acute kidney injury in intensive care units (ICUs) throughout much of the developed world 3.
• The patient's high creatinine level, low urine output, and hemodynamic instability make CRRT a suitable treatment option 2, 4.