12-phase flow (12)

1. 1FRAME
   Confirm GERD scope: typical reflux symptoms amenable to empiric PPI vs refractory GERD vs Barrett surveillance (ACG 2022 Katz)
   inputs: ppi_trial_history
   advance: pathway assigned: empiric, refractory, or Barrett
2. 2ENTRY
   Recognize heartburn, regurgitation, dysphagia, chronic cough, or non-cardiac chest pain as GERD trigger (ACG 2022 Katz)
   inputs: heartburn_frequency
   advance: symptom trigger confirmed
3. 3CONTEXT
   Age, sex, BMI, smoking, symptom duration, PPI history, family history of esophageal cancer, current medications (ACG 2022 Katz; AGA 2024 Barrett)
   inputs: age, sex, bmi, duration_symptoms, ppi_trial_history, current_meds
   advance: context captured
4. 4RED_FLAGS
   Screen for alarm symptoms: dysphagia, odynophagia, unintentional weight loss, GI bleeding, iron-deficiency anemia, recurrent vomiting — all mandate EGD (ACG 2022 Katz)
   inputs: alarm_symptoms
   advance: alarm symptoms present (EGD path) or absent (empiric PPI path)
5. 5INITIAL_WORKUP
   CBC if alarm symptoms; empiric PPI trial 8 weeks is first-line diagnostic-therapeutic maneuver for typical symptoms without alarms (ACG 2022 Katz)
   inputs: cbc
   actions: panel.cbc
   advance: empiric PPI started or EGD ordered
6. 6BRANCHING_WORKUP
   EGD for alarm symptoms (post-test malignancy/stricture probability crosses test threshold — empiric PPI loop contraindicated), refractory GERD (failed 8 wk PPI BID), Barrett screening; ambulatory pH-impedance OFF PPI is the reference standard — acid exposure time (AET) >6% = conclusive pathological reflux, <4% normal, 4-6% inconclusive (Lyon Consensus 2.0); AET <4% + negative symptom-association → functional heartburn/reflux hypersensitivity (route away from acid-suppression escalation/surgery); HRM if motility disorder or pre-fundoplication (Lyon Consensus 2018 PMID 29437910; ACG 2022 Katz PMID 34807007)
   inputs: egd, ph_impedance, hrm
   actions: workup.dyspepsia, workup.dysphagia, workup.achalasia
   advance: EGD findings classified (erosive, NERD, Barrett, eosinophilic) or functional overlay identified
7. 7DIFFERENTIAL
   Erosive esophagitis (LA grade A-D), NERD, Barrett esophagus +/- dysplasia, eosinophilic esophagitis, functional heartburn, achalasia, rumination (ACG 2022 Katz; Lyon Consensus 2018)
   advance: phenotype assigned
8. 8RISK_STRATIFICATION
   LA grade A-D for erosive esophagitis (C/D = severe, high Barrett risk, mandates repeat EGD); Barrett segment length + dysplasia grade drives surveillance interval and EAC progression risk — NDBE ~0.2-0.5%/yr, LGD ~0.5-1%/yr, HGD ~6-7%/yr to esophageal adenocarcinoma (AGA Barrett surveillance guidance)
   advance: severity/Barrett risk documented
9. 9TREATMENT
   Standard-dose PPI ×8 wk heals erosive esophagitis ~85-90% (LA A-B) vs H2RA ~50%; step-up/step-down; H2RA for mild/on-demand; vonoprazan (PCAB) non-inferior to lansoprazole and superior for severe LA C/D + maintenance (PHALCON-EE Laine Gastroenterology 2023 PMID 36228734); RFA achieves ~80-90% complete eradication of dysplastic Barrett; fundoplication vs esomeprazole comparable 5-yr remission, surgery superior for regurgitation (LOTUS); deprescribe PPI at 8 wk if no Barrett/refractory/erosive C-D (ACG 2022 Katz PMID 34807007)
   inputs: ppi_trial_history
   advance: treatment plan initiated
10. 10DISPOSITION
    Outpatient for all non-alarm GERD; urgent EGD referral for alarm symptoms; GI referral for refractory, Barrett, surgical candidacy (ACG 2022 Katz)
    advance: disposition set
11. 11MONITORING
    PPI step-down attempt after 8 wk; Barrett surveillance EGD intervals (no dysplasia q3-5yr, LGD q6-12mo, post-ablation q3mo then annually) (AGA 2024 Barrett; ACG 2022 Katz)
    advance: monitoring cadence set
12. 12FOLLOWUP
    Symptom reassessment at 8 wk; lifestyle reinforcement (weight loss, head-of-bed elevation, avoid late meals); long-term PPI safety counseling (bone, Mg, C. diff) (ACG 2022 Katz; NICE 2024)
    advance: follow-up scheduled