Clinical Summary

Step-by-Step Management

1. Assess Volume Status Immediately

• Look for signs of severe dehydration: dry mucous membranes, reduced skin turgor, sunken eyes, tachycardia, hypotension, prolonged capillary refill.
• Insert IV access (2 large-bore peripheral cannulas).
• Insert a urinary catheter to accurately monitor urine output.

2. IV Fluid Resuscitation (Priority #1)

• Give Lactated Ringer's (Hartmann's) or Plasma-Lyte as the preferred balanced crystalloid. Avoid large volumes of 0.9% NaCl (risk of hyperchloremic metabolic acidosis, which worsens renal vasoconstriction).
• Bolus: 500 mL - 1 L over 15-30 minutes, then reassess.
• Target urine output of >0.5 mL/kg/hour.
• Reassess volume status after each bolus using clinical response or point-of-care ultrasound (IVC collapsibility, bladder volume).
• Once anuric, watch carefully - if the kidneys start responding (oliguria returning), it confirms prerenal etiology and fluid resuscitation is working.

Avoid Hydroxyethyl Starch (HES/pentastarch) - associated with severe kidney injury and increased mortality.

3. Bloods / Baseline Investigations

4. Manage Hyperkalemia (If Present)

• K+ ≤6 mEq/L, no ECG changes: dietary restriction + potassium-binding resin (sodium zirconium cyclosilicate or sodium polystyrene sulfonate).
• K+ >6 mEq/L or ECG changes: this is an emergency - treat immediately:
  • Calcium gluconate 10 mL of 10% solution IV over 5 min - membrane stabilization
  • Insulin 10-20 units IV + Glucose 250 mL of 20% IV over 30-60 min - shifts K+ intracellularly
  • Salbutamol (albuterol) 10-20 mg nebulized - additional K+ shift
  • Sodium bicarbonate - if concurrent severe metabolic acidosis
  • Prepare for emergency dialysis if refractory

5. Manage Metabolic Acidosis (If Present)

• Mild (HCO3 >15): often corrects with fluid resuscitation alone.
• Severe (pH <7.2): IV sodium bicarbonate infusion (monitor for volume overload and rebound alkalosis).
• Refractory acidosis = indication for dialysis.

6. Antiemetic Management (Ongoing Vomiting)

• Ondansetron is safe in renal impairment - it is hepatically metabolized and no dose adjustment is needed for renal failure (unlike metoclopramide which has increased CNS side effects in renal failure).
• The standard IV dose is 4-8 mg every 6-8 hours. If vomiting is ongoing, a repeat dose after 4-6 hours is appropriate.
• Be cautious about QT prolongation: ondansetron prolongs the QT interval. In the setting of AKI with potential electrolyte disturbances (hypokalemia, hypomagnesemia from vomiting), the risk is higher. Check electrolytes and ECG before re-dosing.
• Correct hypokalemia and hypomagnesemia if present (common from vomiting), as these potentiate arrhythmias.
• Alternative if persistent: metoclopramide 10 mg IV (use cautiously; reduce dose in renal failure) or promethazine (use with caution).
• Keep the patient NPO (nil by mouth) temporarily to reduce vomiting stimulus.

7. Nasogastric Tube (If Vomiting Uncontrollable)

8. Monitor for Indications for Urgent Dialysis

• Acidosis (pH <7.1 refractory to bicarbonate)
• Electrolytes (K+ >6.5 mEq/L refractory to medical management)
• Intoxications (not applicable here)
• Overload (pulmonary edema refractory to diuretics)
• Uremia (encephalopathy, uremic pericarditis - friction rub)

9. Nutrition

• Keep NPO initially while vomiting.
• Once vomiting controlled: resume oral hydration with ORS (oral rehydration solution).
• If prolonged NPO: consider NG feeding or IV dextrose-based fluids to prevent catabolism (caloric target 20-30 kcal/kg/day; protein 0.8-1.0 g/kg/day if not on dialysis).

10. Drug Review

• Review ALL medications. In AKI, renally cleared drugs accumulate and dose adjustment is needed for GFR.
• Avoid nephrotoxins: NSAIDs (common over-the-counter in AGE), aminoglycosides, IV contrast agents.
• Avoid ACE inhibitors / ARBs: worsen prerenal AKI.
• Treat the underlying AGE cause if identifiable (e.g., if bacterial: antibiotics per stool culture).

Summary Algorithm

AGE -> Dehydration -> Prerenal AKI -> Anuria
         ↓
    IV Balanced Crystalloid (LR/Hartmann's) urgently
         ↓
    Check K+, ECG → treat hyperkalemia
    Check pH → treat acidosis
         ↓
    Control vomiting (repeat ondansetron, check QTc/electrolytes)
         ↓
    Urine output responding? → continue supportive care
    Urine output NOT responding? → Nephrology consult, consider dialysis

• Brenner and Rector's The Kidney, Intravascular Volume Depletion / AKI due to Diarrheal Diseases
• Washington Manual of Medical Therapeutics, AKI Treatment & Special Considerations
• Brenner's The Kidney, Table 29.7: Supportive Management of AKI
• Harrison's Principles of Internal Medicine 22E, AKI Management