What is the immediate management for a patient presenting with a nephrology emergency, such as acute kidney injury or severe electrolyte imbalance?

Immediate Management of Nephrology Emergencies

For patients presenting with acute kidney injury or severe electrolyte imbalances, immediately assess for life-threatening complications requiring urgent dialysis (hyperkalemia >6.5 mEq/L with ECG changes, severe acidosis pH <7.2, pulmonary edema refractory to diuretics, or uremic encephalopathy) and initiate aggressive fluid resuscitation with 0.9% saline while avoiding potassium-containing solutions. 1

Initial Assessment and Stabilization

Identify Life-Threatening Complications Requiring Immediate Dialysis

The following are absolute indications for urgent renal replacement therapy, regardless of GFR level 1:

• Severe hyperkalemia (>6.5 mEq/L) with ECG changes or resistant to medical management 1
• Refractory pulmonary edema not responding to diuretics 1
• Severe metabolic acidosis (pH <7.2) refractory to medical treatment 1
• Uremic encephalopathy with altered mental status, seizures, or coma 1
• Uremic pericarditis 1
• Crush syndrome with severe rhabdomyolysis and AKI 1

Immediate Fluid Resuscitation Protocol

For patients with AKI, particularly in crush injury or volume depletion:

• Start 0.9% normal saline at 1 liter/hour immediately upon patient contact 2, 3, 1
• Avoid potassium-containing fluids (such as Lactated Ringer's) as potassium levels may increase markedly even with intact renal function 3, 1
• Avoid starch-based fluids which are associated with increased rates of AKI and bleeding 2, 3
• Reduce infusion rate by at least 50% after 2 hours if patient stabilizes 2, 3

Critical Laboratory Assessment

Obtain immediately 2, 1:

• Serum potassium - most urgent electrolyte to assess 1
• Arterial blood gas - to evaluate acidosis 1
• Creatinine and BUN/urea 1
• Complete blood count 1
• ECG if hyperkalemia suspected 1

Management of Specific Emergencies

Severe Hyperkalemia (>6.5 mEq/L)

If ECG changes present (peaked T waves, widened QRS, loss of P waves):

1. Administer calcium gluconate 1000-2000 mg IV immediately for cardiac membrane stabilization 4

   • Dilute to 10-50 mg/mL concentration 4
   • Infuse at maximum rate of 200 mg/minute in adults, 100 mg/minute in pediatrics 4
   • Monitor ECG continuously during administration 4

2. Initiate urgent hemodialysis if hyperkalemia is refractory to medical management 1

   • Hemodialysis provides rapid potassium clearance 2
   • Multiple daily treatments may be required in hypercatabolic states 2

Persistent AKI Management

When AKI persists beyond 48 hours:

• Reassess the underlying etiology - consider additional causes beyond the initial diagnosis 2
• Measure kidney function precisely using timed urine creatinine clearance (best available estimate in steady state) 2
• Do NOT use eGFR equations - these are inaccurate in acute settings 2
• Re-evaluate hemodynamic and volume status 2
• Assess adequacy of kidney perfusion 2
• Consider nephrology consultation if etiology unclear or subspecialist care needed 2

Volume Overload with Pulmonary Edema

If diuretics fail to resolve pulmonary edema:

• Initiate urgent hemodialysis for fluid removal 1
• Monitor for signs: dyspnea, crackles, hypoxemia, hypertension 1
• Provide supplemental oxygen as needed 1

Severe Metabolic Acidosis (pH <7.2)

If acidosis is refractory to medical management:

• Initiate urgent dialysis 1
• Bicarbonate administration may be considered but is not superior to fluid resuscitation alone in crush injury 2
• Large bicarbonate doses may worsen hypocalcemia in crush syndrome 2

Special Considerations for Crush Injury/Rhabdomyolysis

Early aggressive fluid resuscitation is critical to prevent crush syndrome and AKI 2, 3:

• Begin fluid resuscitation before extrication if possible 2, 3
• Infuse 3-6 liters of 0.9% saline depending on clinical condition 2
• Monitor for compartment syndrome using the "6 Ps": pain, paresthesia, paresis, pain with stretch, pink color, pulselessness 3
• Watch for dark urine indicating myoglobinuria 3
• Early dialysis may be necessary for hyperkalemia and rhabdomyolysis management 1

Mannitol Controversy

• Mannitol has theoretical benefits (diuretic, antioxidant, vasodilatory properties) 2
• However, evidence shows little extra benefit over crystalloid resuscitation alone 2
• Mannitol is potentially nephrotoxic and requires close monitoring often impossible in disaster settings 2

Dialysis Access and Modality

For urgent dialysis initiation:

• Establish central venous access - preferably right internal jugular vein to preserve future access sites 1
• Avoid subclavian vein as it compromises future permanent access 1
• Intermittent hemodialysis is first-line for most urgent situations 2, 1
• Continuous renal replacement therapy indicated only in hemodynamically unstable patients 1
• Peritoneal dialysis is a viable alternative in children or when other modalities unavailable 1

Monitoring During Treatment

For Calcium Gluconate Administration

• Measure serum calcium every 4-6 hours during intermittent infusions 4
• Measure every 1-4 hours during continuous infusion 4
• Monitor vitals and ECG continuously 4

For AKI Patients

• Monitor electrolytes, acid-base status, and kidney function to detect early complications 3
• Reassess every 30 minutes to 1 hour in first 24 hours for compartment syndrome in crush injuries 5
• Watch for signs of infection: increasing pain, redness, warmth, swelling, purulent drainage 3

Critical Pitfalls to Avoid

• Do NOT delay dialysis when absolute indications present - hyperkalemia with ECG changes or pulmonary edema are immediately life-threatening 1
• Do NOT use potassium-containing fluids in AKI or crush injury 3, 1
• Do NOT mix calcium gluconate with ceftriaxone - can form fatal precipitates, especially in neonates 4
• Do NOT elevate limbs if compartment syndrome suspected - worsens ischemia by reducing perfusion pressure 5
• Do NOT underestimate closed crush injuries - they can be misleading and initially belie severity 5
• Failure to recognize crush injury early misses the narrow window when intensive fluid resuscitation prevents AKI 3

When to Consult Nephrology

Immediate consultation indicated for 2:

• Unclear etiology of AKI requiring subspecialist evaluation
• Need for urgent dialysis initiation
• Persistent AKI beyond 48 hours
• Complex electrolyte disturbances
• Consideration of renal replacement therapy