What are the presentation and management of a 35-year-old female with severe Acute Kidney Injury (AKI)?

Presentation and Management of Severe AKI in a 35-Year-Old Female

A 35-year-old female with severe acute kidney injury (AKI) will typically present with oliguria or anuria, fluid overload, electrolyte abnormalities, and uremic symptoms, requiring immediate evaluation and management to prevent mortality and long-term kidney damage.

Clinical Presentation

Common Symptoms and Signs

• Decreased urine output (<0.5 mL/kg/h for ≥12 hours in stage 2 or <0.3 mL/kg/h for ≥24 hours in stage 3 AKI) 1
• Fluid overload manifestations:
  • Peripheral edema
  • Pulmonary edema with dyspnea
  • Elevated jugular venous pressure
• Uremic symptoms:
  • Nausea and vomiting
  • Altered mental status (confusion, drowsiness)
  • Seizures in severe cases
  • Uremic frost (rare)
• Electrolyte disturbances:
  • Hyperkalemia (may present with muscle weakness, cardiac arrhythmias)
  • Metabolic acidosis (Kussmaul breathing)
  • Hyperphosphatemia
  • Hypocalcemia

Laboratory Findings

• Elevated serum creatinine (≥3 times baseline or increase to ≥4.0 mg/dL) 1
• Elevated BUN
• Electrolyte abnormalities:
  • Hyperkalemia
  • Metabolic acidosis (decreased bicarbonate)
  • Increased anion gap
• Urinalysis may show:
  • Hematuria or proteinuria (in glomerular diseases)
  • Muddy brown casts (in acute tubular necrosis)
  • Normal sediment (in prerenal or hepatorenal syndrome) 2

Diagnostic Approach

1. Initial Laboratory Workup 1:

   • Serum creatinine and BUN
   • Complete blood count with differential
   • Serum electrolytes with calculated anion gap
   • Urinalysis with microscopy
   • Urine chemistry (sodium, creatinine)

2. Imaging:

   • Renal ultrasound to rule out obstruction 1
   • Consider non-contrast CT scan if obstruction is suspected 1

3. Determine AKI Etiology - categorize as:

   • Prerenal: Volume depletion, sepsis, heart failure, liver disease
   • Intrinsic renal: Acute tubular necrosis, glomerulonephritis, vasculitis
   • Postrenal: Urinary tract obstruction 2, 1

4. Assess AKI Severity using KDIGO classification 1:

   Stage	Creatinine Criterion	Urine Output Criterion
   1	Increase ≥0.3 mg/dL in 48h or 1.5-1.9× baseline	<0.5 mL/kg/h for 6-12h
   2	2.0-2.9× baseline	<0.5 mL/kg/h for ≥12h
   3	≥3.0× baseline or increase to ≥4.0 mg/dL or RRT initiation	<0.3 mL/kg/h for ≥24h or anuria for ≥12h

Management

Immediate Interventions

1. Volume Status Assessment and Management:

   • Use central venous pressure monitoring, arterial blood pressure monitoring, and inferior vena cava echocardiography to assess volume status 3
   • For hypovolemia: Administer isotonic crystalloids 1
   • For fluid overload: Consider diuretics and fluid restriction to 2L daily 1

2. Discontinue Nephrotoxic Medications 2, 1:

   • NSAIDs
   • ACE inhibitors/ARBs
   • Aminoglycosides
   • Contrast agents
   • Adjust medication doses based on renal function

3. Treat Underlying Causes:

   • For infection/sepsis: Appropriate antibiotics and source control
   • For obstruction: Urgent decompression via percutaneous nephrostomy or retrograde ureteral stenting 1
   • For hepatorenal syndrome: Vasoconstrictor therapy plus albumin 2

4. Manage Electrolyte Abnormalities:

   • Hyperkalemia: Calcium gluconate, insulin with glucose, sodium bicarbonate, potassium binders, dialysis if severe
   • Metabolic acidosis: Sodium bicarbonate if severe

Advanced Management

1. Renal Replacement Therapy (RRT) indications 2, 1:

   • Refractory hyperkalemia
   • Severe metabolic acidosis
   • Volume overload unresponsive to diuretics
   • Uremic symptoms (encephalopathy, pericarditis)
   • Certain toxin ingestions

2. Nutritional Support:

   • Ensure adequate caloric intake
   • Protein restriction may be necessary in severe uremia without RRT
   • Monitor and correct electrolyte abnormalities

3. Hemodynamic Management:

   • Maintain adequate mean arterial pressure to ensure renal perfusion 1
   • Consider vasopressors if needed to maintain blood pressure

Special Considerations for Young Female Patients

1. Consider specific etiologies more common in young women:

   • Autoimmune diseases (lupus nephritis, vasculitis)
   • Pregnancy-related complications (preeclampsia, HELLP syndrome)
   • Thrombotic microangiopathies (TTP, HUS, aHUS)
   • Drug-induced nephrotoxicity

2. Pregnancy testing should be performed in all women of childbearing age

Monitoring and Follow-up

1. Daily monitoring of:

   • Serum creatinine and electrolytes
   • Fluid balance
   • Urine output

2. Post-AKI Follow-up 2, 1:

   • Evaluate kidney function 3 months after AKI episode
   • Screen for development of chronic kidney disease
   • Adjust medications as kidney function recovers
   • More frequent monitoring if eGFR remains <45 mL/min/1.73m²

Prognosis

• Severe AKI (Stage 3) is associated with significantly increased mortality risk 1
• Risk of progression to chronic kidney disease is high following severe AKI 2
• Long-term consequences include cardiovascular morbidity and mortality 4

Common Pitfalls to Avoid

1. Delayed recognition of AKI - monitor high-risk patients closely
2. Inadequate volume assessment - both under-resuscitation and fluid overload can worsen AKI
3. Continued use of nephrotoxic medications - perform medication reconciliation daily
4. Failure to identify and treat the underlying cause - comprehensive evaluation is essential
5. Delayed nephrology consultation - consider early involvement for severe AKI

Remember that early intervention is crucial to prevent progression of AKI and reduce mortality risk in this young patient.