334.1 🎓 醫孞生版

334.1.0.1 📌 䞀頁重點

334.1.0.1.1 Management Principles

334.1.1 Address Underlying Cause

  • Pre-renal: volume resuscitation (crystalloid; albumin in HRS), treat HF, hold ACE/ARB/NSAIDs/diuretics if appropriate
  • ATN: supportive, no specific therapy
  • AIN: hold offending drug + corticosteroids if severe
  • GN: immunosuppression (Ch339)
  • Post-renal: relieve obstruction (foley, ureteric stent, nephrostomy)
  • Drug-induced: discontinue, alternative agent, dose adjustment
  • Sepsis: antibiotics + source control + hemodynamic support

334.1.2 Supportive Care

Volume Management: - Hypovolemic: IV fluids (isotonic crystalloid first-line; albumin in select - HRS, hypoalbuminemia) - Euvolemic / hypervolemic: diuretics + fluid restriction - Decongestion in CRS

Electrolyte Management: - Hyperkalemia: most urgent (Ch334 details) - Acid-base: bicarb if severe metabolic acidosis - Hyper-/hypocalcemia, hyperphosphatemia - Sodium dyscrasia

Acid-Base: - Sodium bicarbonate IV for severe acidosis - Mainly when pH < 7.20 or severe - BICAR-ICU trial: bicarb benefits in severe metabolic acidosis + AKI

Nutrition: - Maintain adequate calories - Protein restriction NOT routinely recommended (KDIGO) - Adequate protein for catabolism (1.2-1.5 g/kg/d if on RRT)

Drug Dosing: - Adjust for renal function - Avoid nephrotoxins - Monitor levels (vancomycin, aminoglycoside, digoxin)

DVT Prophylaxis: - Standard with renal-adjusted dosing

334.1.3 Avoid Nephrotoxins

  • NSAIDs
  • Aminoglycosides if alternatives
  • Contrast (if needed: minimize, hydrate)
  • ACE/ARB acutely (resume when stable)
334.1.3.0.1 Renal Replacement Therapy (RRT)

334.1.4 Indications (AEIOU Mnemonic)

A — Acidosis: - Severe metabolic acidosis refractory to medical management - pH < 7.1 typical threshold

E — Electrolyte: - Hyperkalemia refractory (K > 6.5 or rapidly rising) despite medical therapy - Severe hypercalcemia (rare) - Severe hyperphosphatemia

I — Ingestion: - Removable toxins: - Methanol, ethylene glycol - Lithium - Salicylates - Metformin (in severe lactic acidosis) - Theophylline (charcoal hemoperfusion historically) - Aluminum, vancomycin (some), barbiturates

O — Overload (Volume): - Pulmonary edema refractory to diuretics - Diuretic-resistant volume overload

U — Uremia: - Encephalopathy - Pericarditis (uremic) - Bleeding (uremic) - Severe nausea, vomiting

334.1.5 Timing of RRT

  • STARRT-AKI (2020): accelerated vs standard timing — no mortality benefit
  • AKIKI (2016): similar
  • IDEAL-ICU (2018): similar
  • Practice: initiate based on need, not just numbers
334.1.5.0.1 RRT Modalities

334.1.6 Intermittent Hemodialysis (IHD)

Principle: rapid solute removal across semi-permeable membrane

Setting: hemodynamically stable (limited use in shock)

Typical Session: 3-4 hours - 3x/week chronic - More frequent acute

Vascular Access: - Central venous catheter (CVC): emergent - Internal jugular > femoral > subclavian - Tunneled (long-term) vs non-tunneled (acute) - AV fistula (chronic) — preferred - AV graft (alternative)

Pros: - Rapid clearance - Cost-effective - Outpatient feasible

Cons: - Hemodynamic instability - Disequilibrium syndrome (especially first sessions) - Vascular access complications

334.1.7 Continuous Renal Replacement Therapy (CRRT)

Principle: continuous slow removal (24/7)

Modalities: - CVVH (continuous veno-venous hemofiltration): convective - CVVHD (continuous veno-venous hemodialysis): diffusive - CVVHDF (continuous veno-venous hemodiafiltration): both - SCUF (slow continuous ultrafiltration): fluid removal only

Setting: hemodynamically unstable, ICU

Pros: - Hemodynamic stability - Gradual fluid removal - Better for cerebral edema (less disequilibrium)

Cons: - Slower clearance - Resource intensive - Anticoagulation required - Cost

Anticoagulation: - Heparin (systemic) - Citrate regional (preferred when feasible — reduces bleeding; monitor Ca, alkalosis, citrate accumulation) - No anticoagulant (saline flushes)

334.1.8 Sustained Low-Efficiency Dialysis (SLED) / PIRRT

Hybrid: 6-12 hour daily sessions Pros: less hemodynamic stress than IHD, less resource than CRRT Cons: intermediate of both

334.1.9 Peritoneal Dialysis (PD)

Acute Use: - Rare in adult AKI (US, Europe) - More common in low-resource settings - Pediatric AKI

Chronic (Ch336 details)

334.1.9.0.1 Specific Management Issues

334.1.10 Anticoagulation in RRT

  • IHD: usually heparin (low-dose); citrate if bleeding risk
  • CRRT: heparin or citrate; citrate preferred for bleeding/HIT

334.1.11 Citrate Anticoagulation Complications

  • Hypocalcemia (citrate binds Ca)
  • Metabolic alkalosis
  • Citrate accumulation (liver failure)
  • Hyperglycemia
  • Monitor: ionized Ca, total Ca, gap (total/ionized ratio), pH

334.1.12 Dialyzability of Drugs

  • Antibiotics often need dose adjustment + supplementation
  • Vancomycin: timed administration
  • Aminoglycoside: usually post-HD

334.1.13 Fluid Removal Targets

  • Tailored to clinical status
  • 100-300 mL/h CRRT typical
  • More aggressive with overt overload
334.1.13.0.1 Outcomes + Recovery

334.1.14 Mortality

  • AKI requiring RRT: 30-50% in-hospital mortality
  • ICU AKI: variable
  • Late mortality: ↑

334.1.15 Renal Recovery

  • 70-80% recover renal function (variable)
  • Some progress to CKD or ESRD
  • Predictors of poor recovery: severity, age, comorbidities, repeated episodes

334.1.16 Long-Term Surveillance

  • Post-AKI clinics emerging
  • Periodic eGFR + UACR monitoring
  • CKD prevention strategies
  • Avoid further nephrotoxins
  • ACE/ARB, SGLT2i may slow progression in some
334.1.16.0.1 Special Populations

334.1.17 COVID-19 AKI

  • 20-30% of hospitalized COVID
  • Multifactorial
  • CRRT often needed
  • Citrate vs heparin controversial

334.1.18 Sepsis-AKI

  • Most common ICU cause
  • Often resolves with sepsis treatment
  • KDIGO standard supportive

334.1.19 Cardiorenal Syndrome

  • Diuretic resistance common
  • ADVOR (acetazolamide), TACTICS-HF (tolvaptan)
  • Ultrafiltration (UNLOAD positive, CARRESS-HF mixed)
  • LVAD considerations

334.1.20 Hepatorenal Syndrome

  • Terlipressin + albumin (FDA 2022)
  • ICU norepinephrine + albumin
  • Liver transplant
  • TIPS for selected

334.1.21 ESKD on Transplant List

  • Different from de novo AKI
  • Coordinated with transplant team

334.1.21.1 🩺 床邊速查

  • AKI principles: address cause + supportive + RRT when indicated
  • RRT indications (AEIOU): Acidosis, Electrolyte (K), Ingestion, Overload, Uremia
  • IHD: stable patient, 3-4 hr sessions
  • CRRT: unstable (shock), continuous; CVVH/D/HDF; citrate preferred for bleeding/HIT
  • STARRT-AKI 2020 / AKIKI / IDEAL-ICU: no benefit early RRT vs need-based
  • HRS: terlipressin + albumin (FDA 2022)
  • Citrate complications: hypoCa, alkalosis, citrate accumulation (liver failure)
  • Post-AKI: ↑ CKD risk; surveillance important