Description
This session will delve into complex and high-risk cases of Acute Kidney Injury (AKI) encountered in intensive care units. Through real-world scenarios, we will explore diagnostic dilemmas, evolving clinical presentations, and management strategies in critically ill patients. The discussion will highlight key decision points, including fluid management, use of nephrotoxic drugs, and the timing of renal replacement therapy. Attendees will gain practical insights into balancing life-saving interventions with kidney protection in dynamic ICU environments.
Summary Listen
- AKI matters significantly in the ICU, with up to 50% of patients experiencing it, leading to high mortality (60-70%) and progression to chronic kidney disease in one-third of survivors. AKI is defined by creatinine increases (≥0.3 mg/dL within 48 hours or ≥1.5 times baseline within 7 days) or decreased urine output (<0.5 mL/kg/hour for 6 hours). Early detection is crucial, as creatinine changes lag behind GFR decline.
- Reliance solely on creatinine levels can be misleading due to factors like low muscle mass, fluid overload, and chronic illness. Clinical assessment and tools like the Renal Angina Index (RAI) are essential for early risk stratification. The RAI considers risk factors (sepsis, ventilation) and injury markers (creatinine increase, volume overload) to predict severe AKI.
- In septic shock, after ruling out obstruction, assess volume status and review medications. Bedside volume assessment, using passive leg raises, IVC ultrasound, or carotid Doppler, is crucial. Urine indices (FENa, FEUrea, urine sodium, microscopy) aid in differentiating pre-renal from intrinsic AKI. Remember FENa is unreliable in patients on diuretics.
- Fluid management in ICU balances resuscitation and overload risk, aiming for euvolemia. Avoid chloride-rich fluids. Overhydration (>10% baseline weight) increases mortality. Monitor cumulative fluid balance rather than focusing solely on daily urine output.
- The furosemide stress test can predict AKI progression. A dose of 1 mg/kg IV (1.5 mg/kg if already on furosemide) with urine output <200 mL in 2 hours indicates a high risk of dialysis need. Early vs. late RRT initiation hasn't shown mortality reduction.
- Absolute indications for dialysis include pH <7.1, potassium >6.5 with arrhythmia, intoxication, pulmonary edema, and uremic encephalopathy. RRT modalities include SLIT, intermittent hemodialysis, and CRRT. CRRT is preferred for hemodynamically unstable patients. CRRT dosing is 20-25 mL/kg/hour.
- Anticoagulation during CRRT involves heparin or citrate. Citrate is preferred in bleeding risk patients but requires monitoring of ionized and total calcium. Complications of CRRT include metabolic acidosis/alkalosis, addressed by adjusting exit flow.
- In septic-induced AKI, stabilize MAP and manage fluids. Septic AKI pathogenesis involves inflammation, thrombosis, and tubular injury. Manage hypertension during CRRT by maintaining MAP >65, avoiding ultrafiltration, and titrating vasopressors. Filter life is extended by maintaining blood flow >120 mL/min.
- Adjust antibiotic dosing during CRRT due to increased clearance. Be aware of nephrotoxins like NSAIDs, contrast, aminoglycosides, antivirals, and vancomycin. Hepatorenal syndrome is a diagnosis of exclusion; manage volume carefully.
- AKI can recur, transitioning into acute kidney disease (AKD) between days 7-90. AKD increases the risk of CKD. Early nephrology involvement is critical. Key quality indicators include daily monitoring of urine output and creatinine, avoidance of nephrotoxic medications, and discharge planning with nephrology follow-up.
- Special populations like burn patients require aggressive fluid resuscitation and are prone to rhabdomyolysis. Treat rhabdomyolysis with aggressive hydration and urine alkalinization. COVID-19 can cause AKI via cytokine storm and tubular injury. The ICU toolkit includes bedside ultrasound, nephrotoxin checklists, and RAI calculators.
Sample Certificate
About the Speakers
Dr. Ahmed Sabry
Director of Nephrology, Hayat National Hospitals, Saudi Arabia
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