12-phase flow (12)

1. 1FRAME
   Bleed character (hematemesis / melena / hematochezia / occult), onset, volume, hemodynamic state, anchor source (UGI vs LGI vs occult) (Laine 2012; Strate 2016)
   inputs: bleed_character, bleed_onset_time, bleed_volume_estimate, sbp
   advance: bleed characterized + hemodynamic risk classified
2. 2ENTRY
   Associated abdominal pain, retching, syncope/presyncope, jaundice/ascites, bowel-habit change → narrow phenotype (Laine 2012)
   inputs: associated_abdominal_pain, associated_retching_vomiting, syncope_or_presyncope, jaundice_or_ascites, change_in_bowel_habit
   advance: entry presentation captured
3. 3CONTEXT
   Age, sex, cirrhosis/portal HTN, prior GI bleed, NSAID/aspirin, anticoagulant/antiplatelet, prior AAA/aortic graft, pelvic RT, cardiac disease, vitals + temp (Laine 2012; Garcia-Tsao 2017)
   inputs: age, sex, sbp, hr, rr, spo2, temp, cirrhosis_or_portal_htn, prior_ugi_bleed, nsaid_aspirin_use, anticoagulant_antiplatelet_use, prior_aaa_or_aortic_graft, cardiac_disease_demand_ischemia
   advance: context complete
4. 4RED_FLAGS
   Massive bleed with hemodynamic instability; aorto-enteric fistula (prior AAA repair + UGI bleed); ruptured esophagus (Boerhaave); cirrhotic variceal bleed; demand ischemia / type 2 MI; perforated PUD; mesenteric ischemia overlap (Laine 2012; Garcia-Tsao 2017)
   inputs: sbp, hr
   advance: no immediate life-threat OR resuscitation + downstream engine activation
5. 5INITIAL_WORKUP
   CBC + diff, BMP (BUN:Cr ratio), LFT + albumin + INR, PTT, type & cross ≥2-4 units, lactate, hs-cTn (selective), ECG, upright CXR if perforation suspected (Laine 2012; ACG 2023 PMID 36038243)
   inputs: cbc_with_diff, bmp, lft, coags_inr_ptt, type_and_cross, lactate, troponin_hs, ecg_12_lead, upright_cxr
   actions: panel.cbc, panel.renal, panel.lft, panel.coag, panel.cardiac
   advance: initial workup reviewed + risk score assigned
6. 6BRANCHING_WORKUP
   UGI bleed: pre-endoscopy IV PPI + octreotide if cirrhotic + ceftriaxone prophylaxis + EGD within 24 h (Laine 2012; ESGE 2017 PMID 27083250). LGI bleed: hemodynamically stable → colonoscopy within 24 h after prep; unstable + active → CTA + IR embolization (Strate 2016 PMID 24042191). Obscure: capsule endoscopy / push enteroscopy / RBC scan. Suspected aorto-enteric fistula → STAT CTA + vascular surgery.
   inputs: cta_abdomen_for_aef, cta_mesenteric_for_lgib, rbc_scan_for_obscure_bleed
   advance: definitive procedure pathway selected
7. 7DIFFERENTIAL
   UGI phenotypes (Laine 2012): PUD ~30-50%, varices ~10-15%, Mallory-Weiss ~5-10%, esophagitis ~5%, gastritis ~5%, malignancy ~5%, Dieulafoy ~1-3%, aorto-enteric fistula <1% but lethal. LGI phenotypes (Strate 2016): diverticular ~30-40%, angiodysplasia ~5-15%, colitis (ischemic/infectious/IBD) ~10-20%, neoplasm ~10%, hemorrhoidal/anorectal ~10%, post-polypectomy ~5%, radiation proctitis ~3%. Occult: angiodysplasia / NSAID-PUD / malignancy.
   advance: phenotype ranked with pre-test priors
8. 8RISK_STRATIFICATION
   UGI: Glasgow-Blatchford (GBS) ≤1 → low risk outpatient; ≥7 → high risk endoscopy + ICU; pre-endoscopy Rockall (age + shock + comorbidity); AIMS65 (alb<3, INR>1.5, AMS, SBP<90, age>65) — schema-blocked in clinical-tools-registry. LGIB: Oakland score (age, sex, prior LGIB, HR, SBP, Hgb, exam) for outpatient triage — schema-blocked. Forrest classification at endoscopy (Ia spurter → IIc pigmented spot → III clean base) drives endoscopic Rx + rebleed risk (Laine 2012). Cirrhotic: Child-Pugh / MELD overlay (Garcia-Tsao 2017).
   inputs: age, sbp, hr
   advance: risk scores documented
9. 9TREATMENT
   Resuscitation (restrictive Hgb 7 g/dL trigger for stable; 8 g/dL for cardiac comorbidity per Villanueva NEJM 2013); two large-bore IVs; crystalloid then pRBC; massive transfusion protocol if SBP <90 despite 2 L; reverse anticoagulation (4F-PCC for warfarin INR >1.5, andexanet for apixaban/rivaroxaban, idarucizumab for dabigatran, platelets if <50 or on antiplatelet); IV PPI (omeprazole 80 mg bolus + 8 mg/hr OR pantoprazole 80 mg IV) for ALL suspected UGI bleed pending EGD (Laine 2012); octreotide 50 mcg IV bolus + 50 mcg/hr for suspected variceal source (Garcia-Tsao 2017); ceftriaxone 1 g IV daily x 7 days for cirrhotic UGI bleed (SBP prophylaxis); erythromycin 250 mg IV 30-90 min pre-EGD for gastric blood clearance.
   inputs: sbp, cbc_with_diff
   advance: resuscitation initiated; endoscopic / IR / surgical pathway selected
10. 10DISPOSITION
    GBS 0-1 → outpatient EGD if reliable follow-up; GBS ≥7 OR Rockall ≥3 → admit + EGD within 24 h; hemodynamically unstable / massive bleed / variceal bleed / suspected aorto-enteric fistula → ICU + emergent intervention; LGIB unstable + active → CTA + IR; LGIB stable → colonoscopy within 24 h; obscure bleed → admit for capsule / push enteroscopy; cirrhotic variceal → ICU + EGD banding + octreotide + ceftriaxone → route to gi.variceal_bleed.v1.
    advance: disposition assigned + downstream handoff complete
11. 11MONITORING
    Serial vitals q15 min × 1 h then q30 min × 4 h; serial Hgb q4-6h × 24 h then q12-24h; lactate clearance; urine output ≥0.5 mL/kg/h; mental status; serial abdominal exams (perforation watch); telemetry if cardiac comorbidity
    inputs: cbc_with_diff, lactate, sbp
    advance: stability achieved or escalation triggered
12. 12FOLLOWUP
    Discharged low-risk UGI bleed: PPI 8 wks + H. pylori test-and-treat + outpatient EGD ≤2 wks + return precautions; cirrhotic post-bleed: 2° prophylaxis (NSBB + endoscopic surveillance per AASLD); discharge bundle (NSAID deprescribe, alcohol cessation counseling); LGIB diverticular: low-residue diet + outpatient colonoscopy 4-8 wks; H. pylori-positive PUD → triple/quadruple therapy
    advance: discharge bundle prescribed + follow-up scheduled