12-phase flow (12)

1. 1FRAME
   Confirm cholestatic jaundice: total bilirubin elevated + direct bilirubin > 1.0 mg/dL (> 17 micromol/L) in infant beyond 2 weeks of age (Fawaz NASPGHAN 2017 PMID 27429428)
   inputs: age_in_days, stool_color_history, total_and_direct_bilirubin
   advance: Direct hyperbilirubinemia confirmed + pediatric hepatology referral initiated
2. 2ENTRY
   Infant > 2 weeks with persistent jaundice + clay-colored / acholic stools + dark urine; failure of physiologic jaundice to resolve (Fawaz NASPGHAN 2017)
   inputs: age_in_days
   advance: Entry trigger captured + direct bilirubin ordered
3. 3CONTEXT
   Age (presentation usually 4-8 weeks; Kasai window < 60 days), birth history, feeding history, stool color cards, family history of liver disease, TORCH risk factors (Fawaz NASPGHAN 2017)
   inputs: weight, gestational_age, feeding_history_breast_vs_formula, family_history_liver_disease, torch_risk_factors
   advance: Context complete + diagnostic workup launched
4. 4RED_FLAGS
   Direct hyperbilirubinemia + acholic stools + hepatomegaly + failure to thrive + coagulopathy + ascites + splenomegaly (signs of established cirrhosis at presentation = late presentation, worse outcome) (Fawaz NASPGHAN 2017; Hartley Lancet 2009)
   inputs: coag_pt_inr
   advance: Severity / late-presentation status assigned
5. 5INITIAL_WORKUP
   Total + direct bilirubin; LFTs (AST, ALT, GGT, alkaline phosphatase); coags (PT/INR); CBC; metabolic panel; alpha-1 antitrypsin level + phenotype; TSH + T4; urinalysis + culture; TORCH workup; sweat chloride; fasting abdominal ultrasound (triangular cord sign) (Fawaz NASPGHAN 2017 PMID 27429428)
   inputs: total_and_direct_bilirubin, lft_ast_alt_ggt_alkphos, coag_pt_inr, cbc_with_diff, alpha_1_antitrypsin_level_phenotype, tsh_t4, urinalysis_culture, torch_workup, sweat_chloride, fasting_abdominal_ultrasound
   actions: workup.pediatric_fever, workup.encephalopathy, panel.lft, panel.cbc, panel.coag, panel.metabolic, panel.thyroid, panel.ua
   advance: Baseline workup complete + pediatric hepatology consultation
6. 6BRANCHING_WORKUP
   HIDA scan with phenobarbital priming 5 mg/kg/day PO × 5 days (no excretion into bowel by 24 h supports BA); MRCP if available; intraoperative cholangiogram (gold standard); liver biopsy (bile-duct proliferation, fibrosis, bile plugs); next-generation sequencing for Alagille / PFIC / other genetic causes (Fawaz NASPGHAN 2017; Hartley Lancet 2009)
   inputs: hida_scan_with_phenobarbital_priming, liver_biopsy
   advance: Diagnostic workup complete + surgical consultation for Kasai consideration
7. 7DIFFERENTIAL
   Biliary atresia (25-40% of neonatal cholestasis) vs Alagille syndrome (JAG1 / NOTCH2) vs progressive familial intrahepatic cholestasis 1/2/3 vs alpha-1 antitrypsin deficiency vs cystic fibrosis vs galactosemia vs tyrosinemia vs neonatal hemochromatosis vs TPN-associated cholestasis vs TORCH infections vs neonatal sepsis with cholestasis (Fawaz NASPGHAN 2017)
   advance: Differential narrowed + surgical decision
8. 8RISK_STRATIFICATION
   Age at Kasai (best outcomes < 60 days; significant decline 60-90 days; very poor > 90 days); polysplenia syndrome (biliary atresia splenic malformation syndrome — BASM); cirrhosis at presentation (Hartley Lancet 2009)
   inputs: age_in_days
   advance: Risk tier documented + surgical timing decision
9. 9TREATMENT
   Step 1: Kasai hepatoportoenterostomy < 60 days of life (surgical mainstay; non_pharm). Step 2: Post-Kasai ursodeoxycholic acid 10-20 mg/kg/day PO BID-TID (max 30 mg/kg/day) for choleresis. Step 3: Fat-soluble vitamin supplementation (vitamin A, D, E, K) per total bilirubin trend (Venkat 2014 PMID 25419594). Step 4: MCT-enriched formula for fat absorption. Step 5: Phenobarbital 5 mg/kg/day PO × 5 days ONLY as HIDA-scan priming (NOT for routine choleresis post-Kasai). Step 6: NO routine post-op steroids (Alonso START 2018 PMID 30244988 — no benefit + growth impairment). Step 7: Liver transplant referral at diagnosis. (Fawaz NASPGHAN 2017; Hartley Lancet 2009)
   inputs: weight
   advance: Kasai performed (or transplant pathway if late presentation) + post-op plan documented
10. 10DISPOSITION
    Admission for diagnostic workup + Kasai surgical evaluation; pediatric liver transplant center transfer (Fawaz NASPGHAN 2017)
    advance: Disposition + transplant-center transfer documented
11. 11MONITORING
    Total bilirubin trend post-Kasai (clears to normal at 3 mo in ~ 60% of Kasai successes per Hartley 2009 Lancet); fat-soluble vitamin levels per total bilirubin (Venkat 2014 PMID 25419594); growth + nutrition; signs of portal hypertension + cirrhosis; cholangitis surveillance (fever + bile-leak post-op) (Fawaz NASPGHAN 2017)
    advance: Monitoring orders documented
12. 12FOLLOWUP
    Pediatric hepatology + transplant team; surgery; nutrition; cholangitis prevention (some centers use prophylactic trimethoprim-sulfamethoxazole post-Kasai); transplant evaluation if total bilirubin remains elevated at 3-6 mo post-Kasai or progressive cirrhosis (Hartley Lancet 2009)
    advance: Follow-up + nutritional support + transplant evaluation plan documented