›Potassium > 6.5 mmol/L with ECG changes
›Fluid overload causing respiratory compromise
›Severe metabolic acidosis
›Bicarbonate < 10 mmol/L unresponsive to bicarb therapy
›Uremic encephalopathy
›Modality selection
›Peritoneal dialysis — preferred in children < 10 kg
›Avoids large venous access in small children
›Continuous gentle fluid removal
›Continuous renal replacement therapy — hemodynamically unstable
›CVVH or CVVHDF
›Flow rate 20 to 25 mL/kg/hour
›Intermittent hemodialysis — hemodynamically stable adults
›4-hour sessions as needed
›Acute hypertensive emergency
›Nicardipine IV
›5 mg/hour initial infusion
›Titrate by 2.5 mg/hour every 5 to 15 minutes
›Maximum 15 mg/hour
›Labetalol IV
›0.25 mg/kg IV bolus — maximum 20 mg per dose
›Infusion 0.5 to 3 mg/kg/hour
›Avoid in bradycardia or heart block
›Hydralazine IV — alternative in children
›0.2 to 0.6 mg/kg IV per dose
›Onset 10 to 20 minutes
›Oral antihypertensive maintenance
›Amlodipine PO
›Adults 5 to 10 mg daily
›Children 0.1 to 0.3 mg/kg/day
›Avoid ACE inhibitors and ARBs acutely
›Hyperkalemia risk in AKI
›May use in recovery phase for proteinuria reduction
Treatment of aHUS — complement inhibition
›Eculizumab — anti-C5 monoclonal antibody
›First-line therapy for complement-mediated aHUS
›Class I recommendation
›Initiate without waiting for genetic test results
›Dosing — adults
›Induction: 900 mg IV weekly for 4 weeks
›Maintenance: 1200 mg IV every 2 weeks from week 5 onward
›Dosing — pediatric weight-based
›5 to < 10 kg: 300 mg weekly x 1, then 300 mg every 3 weeks
›10 to < 20 kg: 600 mg weekly x 1, then 300 mg every 2 weeks
›20 to < 30 kg: 600 mg weekly x 2, then 600 mg every 2 weeks
›30 to < 40 kg: 900 mg weekly x 2, then 900 mg every 2 weeks
›>= 40 kg: adult dosing
›Mandatory pre-treatment meningococcal vaccination
›MenACWY and MenB vaccines required
›If urgent initiation before vaccination, prophylactic penicillin V or amoxicillin
›Ravulizumab — longer-acting C5 inhibitor
›Alternative to eculizumab — 8-week dosing interval after loading
›Same efficacy and safety profile
›Preferred for long-term maintenance due to convenience
›Loading dose based on weight, then maintenance every 8 weeks
›Duration of complement inhibition
›Complement factor mutation — indefinite therapy usually required
›Anti-factor H antibody mediated — immunosuppression may allow discontinuation
›Trial of discontinuation only with specialist guidance
Plasma exchange — selected indications
›Plasma exchange role in HUS
›Not first-line for STEC-HUS — no proven benefit
›Use if TTP cannot be excluded pending ADAMTS13
›Empirical plasma exchange for severe undifferentiated TMA
›Bridging therapy for aHUS when eculizumab unavailable
›Fresh frozen plasma 30 to 40 mL/kg exchange
›Daily exchanges until eculizumab available
›Contraindications and risks
›Citrate toxicity — hypocalcemia
›Sepsis risk from central access
›Not a substitute for eculizumab in aHUS
›Contraindicated agents in STEC-HUS
›Antibiotics
›Fluoroquinolones and TMP-SMX increase Shiga toxin release
›Multiple meta-analyses confirm HUS risk increase
›Class I recommendation to avoid
›Antimotility agents
›Loperamide, diphenoxylate, opioids
›Reduce colonic STEC excretion
›Increase neurological complication risk
›NSAIDs
›Worsen AKI
›Avoid in all phases of HUS