12-phase flow (10)

1. 1FRAME
   Scleroderma renal crisis (SRC) = acute renin-driven malignant HTN + AKI + MAHA in patient with systemic sclerosis (especially diffuse cutaneous SSc + early disease + recent high-dose steroid). Pathophysiology: scleroderma vasculopathy → glomerular hypoperfusion → renin surge → angiotensin II → severe vasoconstriction + hyperreninemia → microangiopathy. Pharmacology pivot: ACE INHIBITOR FIRST AND CONTINUOUS even as Cr rises (PARADOXICAL — Steen Ann Intern Med 1990 PMID 2403473 changed survival from <10% to >70% at 1 yr); ARB if ACEi-intolerant; CCB for additional control; AVOID glucocorticoid (precipitates SRC). Dialysis if needed (often transient — half recover in 6-24 mo). Route to parent engine for shared HTN-emergency arc; this dossier owns the renin-driven pharmacology + MAHA workup + scleroderma-specific perspective.
   inputs: sbp, dbp, systemic_sclerosis_subtype, creatinine
   advance: SRC criteria met (scleroderma + new HTN + AKI ± MAHA)
2. 2ENTRY
   Recognize SRC criteria — scleroderma diagnosis (especially diffuse cutaneous + early + on steroid) + new SBP ≥150 OR ≥30 mmHg above baseline + AKI + MAHA features; document baseline BP from prior records
   inputs: age, sbp, baseline_BP_documentation
   advance: IV access + ACEi initiated immediately; do not wait for full workup
3. 3CONTEXT
   Scleroderma duration + subtype (diffuse cutaneous = 80% SRC); recent steroid (>15 mg prednisone — Helfrich 1989 PMID 2916497); RNA polymerase III antibody (associated with SRC); prior SRC episode (recurrence ~20%); medications (especially recent steroid pulse, NSAIDs)
   inputs: age, systemic_sclerosis_subtype
   advance: context complete with steroid exposure documented
4. 4RED_FLAGS
   Concurrent stroke (HTN-driven), pulmonary edema (hypertensive cardiomyopathy), severe AKI (oliguria, K elevation), MAHA features (schistocytes, low platelets, low haptoglobin, elevated LDH); critical AVOID — high-dose glucocorticoid (precipitates SRC), nephrotoxic agents (NSAIDs, contrast — minimize)
   inputs: sbp, creatinine
   actions: htn_emergency
   advance: RED flags screened + ACEi initiated
5. 5INITIAL_WORKUP
   CMP + Mg + uric acid (renin/aldosterone if available); CBC with smear (MAHA: schistocytes, thrombocytopenia); haptoglobin + LDH + indirect bili (hemolysis); UA with sediment + UPCR (proteinuria typically mild); plasma renin activity (research-grade); ECG (LV strain, ischemia); CXR (pulm edema); ANA + anti-Scl70 + anticentromere + RNA polymerase III if scleroderma not yet diagnosed
   inputs: creatinine, cbc_with_smear, haptoglobin, ldh, urinalysis_with_active_sediment
   actions: panel.cardiac, panel.renal
   advance: workup documented + ACEi titration initiated
6. 6BRANCHING_WORKUP
   Echo with PASP (PH common in SSc; affects prognosis + treatment); renal biopsy NOT routinely indicated (clinical dx); if dx unclear or atypical → renal biopsy may show classic onion-skin vasculopathy + thrombotic microangiopathy; HRCT chest if interstitial lung disease (ILD) overlap
   inputs: echo_with_PASP, plasma_renin_activity
   advance: PH + ILD assessment + renal biopsy decision made
7. 7TREATMENT
   CAPTOPRIL FIRST: short-acting ACEi for rapid titration. Captopril 12.5 mg PO q4-6h, increase by 12.5-25 mg per dose q4-6h to BP <140/90 (Steen Ann Intern Med 1990 PMID 2403473 — landmark; even if Cr rises, CONTINUE — survival benefit despite acute Cr increase). Once stable transition to longer-acting ACEi (lisinopril, enalapril) for outpatient maintenance. ARB (losartan, valsartan) if ACEi intolerant (cough, angioedema) — though ACEi has the historical efficacy data. ADD CCB (amlodipine 5-10 mg or nicardipine IV) if BP not at target on max-tolerated ACEi. AVOID nitroprusside long-term (cyanide). DIALYSIS if oliguria + uremia + hyperkalemia + volume overload — half of SRC patients eventually recover renal function within 6-24 mo with continued ACEi (Steen JCR 2003 PMID 12867255).
   inputs: sbp, dbp, creatinine
   advance: BP at target on ACEi + Cr trajectory monitored + dialysis decision made
8. 8DISPOSITION
   ICU mandatory for q4-6h BP titration + a-line; nephrology + rheumatology consults; dialysis access if needed; outpatient transition once stable + ACEi tolerated
   advance: ICU bed assigned + nephrology + rheumatology consults booked
9. 9MONITORING
   A-line + q4-6h BP during titration; q4-6h BMP for K + Cr (PARADOXICAL — Cr rise often expected with ACEi in SRC; do not stop unless very severe); CBC with smear daily for MAHA trajectory; haptoglobin + LDH q24-48h; UOP + dialysis access if oliguric; serial echo for cardiac function
   inputs: sbp, creatinine
   actions: panel.renal
   advance: BP at target + Cr stable or recovering + MAHA resolving
10. 10FOLLOWUP
    Lifelong ACEi continuation even on dialysis (renal recovery up to 2 yr); rheumatology follow-up for SSc disease management; dialysis transition if persistent ESRD; renal transplant possible after 2-yr stable course; AVOID future high-dose steroid; cardiac surveillance for chronic HF; pulmonary HTN screen yearly
    advance: lifelong ACEi + rheumatology + nephrology + cardiology surveillance plan in place