12-phase flow (12)

1. 1FRAME
   Onset (acute vs subacute vs chronic; episodic vs persistent), character (bilious vs feculent vs bloody vs projectile), timing (postprandial vs morning vs cyclic) — anchors DDx (Quigley 2013 PMID 29407306)
   inputs: vomiting_onset_duration, vomiting_character_bilious_bloody_fecal, vomiting_timing_postprandial_morning
   advance: pattern characterized
2. 2ENTRY
   Associated abdominal pain (location), diarrhea, fever, headache/photophobia, chest symptoms, vertigo — DDx-narrowing features
   inputs: associated_abdominal_pain, associated_diarrhea, associated_fever, associated_headache_photophobia, associated_chest_symptoms, associated_vertigo_dizziness
   advance: phenotype-defining features captured
3. 3CONTEXT
   Age, sex, pregnancy status, vitals, prior abdominal surgery, DM/insulin, chronic steroid/adrenal, chemo/opioid/cannabis use, migraine history, CAD/diabetic/elderly/female (atypical ACS), cirrhosis (PMID 23589549; PMID 25584725; PMID 28209253; PMID 25965476)
   inputs: age, sex, sbp, hr, rr, spo2, temp, pregnancy_status_lmp, prior_abdominal_surgery_bowel_obstruction, diabetes_meds_insulin, chronic_steroid_or_adrenal_insufficiency, chemo_radiation_within_5_days, opioid_use_chronic_or_acute, migraine_history, cad_diabetic_elderly_female
   advance: context complete
4. 4RED_FLAGS
   Surgical abdomen (peritonitis, perforation, ischemia, obstruction with strangulation); ICH/SAH/mass (vomiting + headache + focal neuro); atypical ACS (vomiting + chest/diaphoresis); adrenal crisis (vomiting + hypotension + steroid history); DKA/HHS (vomiting + hyperglycemia); ectopic pregnancy with rupture; UGIB (hematemesis/coffee-ground)
   inputs: sbp, associated_abdominal_pain, associated_headache_photophobia, associated_chest_symptoms, vomiting_character_bilious_bloody_fecal
   advance: no immediate life-threat OR emergent intervention activated
5. 5INITIAL_WORKUP
   CBC, BMP (glucose, anion gap, K, Na, BUN/Cr), LFT + lipase, urine pregnancy (mandatory women 10-55), UA (ketones, nitrites), lactate (if septic appearance), troponin (if atypical ACS), beta-hCG quant (if pregnant), ECG, CXR (if perforation/aspiration suspected), abdominal X-ray series (SBO suspicion)
   inputs: cbc_with_diff, bmp_glucose_anion_gap, lft_lipase, urine_pregnancy_test, urinalysis, lactate_venous, troponin_hs, ecg_12_lead, cxr_pa_lateral, abdominal_xray_upright_supine
   actions: panel.cbc, panel.renal, panel.lft, panel.cardiac, panel.inflammation
   advance: initial workup reviewed + phenotype narrowed
6. 6BRANCHING_WORKUP
   SBO: CT abdomen with contrast → gi.small-bowel-obstruction.core.v1. Appendicitis: CT or US (peds/pregnancy) → gi.acute-appendicitis.core.v1. Pancreatitis: lipase + CT severity → gi.acute-pancreatitis.core.v1. Cholecystitis: US RUQ → gi.acute-cholecystitis.core.v1. DKA: pH/HCO3 + ketones → endo.dka.core.v1. HHS: glucose + osm → endo.hhs.core.v1. Adrenal crisis: ACTH-stim + cortisol → endo.adrenal-crisis.core.v1. Migraine: clinical + neuroimaging only if red flags → neuro.migraine.core.v1. Raised ICP: NCCT → neuro engines. Pregnancy: TVUS + beta-hCG quant → ob. Atypical ACS: ECG + troponin → cardio.nstemi.core.v1 / cardio.stemi.core.v1. Vertigo: HINTS exam → symptom.vertigo.v1. CHS: clinical + cessation
   inputs: ct_abdomen_pelvis_iv_contrast, us_abdomen_ruq, tvus_pregnancy, ncct_head, beta_hcg_quant
   advance: definitive pathway selected
7. 7DIFFERENTIAL
   Acute self-limited (~60-70%): viral gastroenteritis (Norwalk, rotavirus), food poisoning, food intolerance. Surgical abdomen: SBO, appendicitis, pancreatitis, cholecystitis, mesenteric ischemia, perforation. Metabolic: DKA, HHS, adrenal crisis, uremia, hyperCa. Neuro: migraine, raised ICP, ICH, SAH, vertigo (central/peripheral). Pregnancy: morning sickness, hyperemesis, molar, ectopic. Cardiac: atypical ACS (diabetic/elderly/female). Drug-induced: chemo, opioids, antibiotics. Functional: cyclic vomiting, cannabinoid hyperemesis, functional dyspepsia, gastroparesis. Vestibular. Toxic ingestion (acetaminophen, salicylate, ethanol, methanol)
   advance: phenotype ranked with pre-test priors
8. 8RISK_STRATIFICATION
   qSOFA (sepsis), SIRS, lactate clearance for volume-depleted septic; Alvarado for appendicitis (schema-blocked); Ranson/BISAP/APACHE-II for pancreatitis (schema-blocked); HEART for atypical ACS phenotype (wired calc.heart); PE Wells/PERC if vomiting + pleuritic chest (calc.wells_pe / calc.perc — though PE less common with isolated emesis)
   actions: calc.heart, calc.wells_pe, calc.perc
   advance: risk scores documented
9. 9TREATMENT
   Volume + electrolyte resuscitation (IV NS or LR; correct K early in vomiting alkalosis). Antiemetics: ondansetron 4-8 mg IV (caution QTc), metoclopramide 10 mg IV (avoid in obstruction), prochlorperazine 5-10 mg IV, droperidol 0.625-1.25 mg IV, promethazine 12.5-25 mg IV. Pregnancy: pyridoxine + doxylamine first-line; ondansetron second (RCOG NVP PMID 25584725). DKA/HHS: insulin + K + fluids (route endo). Adrenal crisis: hydrocortisone 100 mg IV stat + fluids (route endo.adrenal-crisis.core.v1). Migraine: IV metoclopramide/prochlorperazine ± dihydroergotamine ± sumatriptan + diphenhydramine to prevent EPS. Surgical abdomen: NPO, NG decompression, fluids, antibiotics, surgical consult. CHS: hot showers, capsaicin cream, cessation. Atypical ACS: ASA + heparin + cath route (cardio.nstemi / cardio.stemi). UGIB: PPI + variceal protocol if cirrhotic
   inputs: sbp, bmp_glucose_anion_gap, pregnancy_status_lmp
   advance: definitive intervention initiated
10. 10DISPOSITION
    Discharge: viral gastroenteritis tolerating PO + stable vitals + adequate hydration; resolved migraine; mild pregnancy NVP with home antiemetics. Observation: persistent vomiting with mild dehydration; cyclic vomiting episode resolving; CHS post-cessation. Ward: SBO non-operative trial, pancreatitis mild, cholecystitis pre-op, adrenal crisis stabilized, HHS, hyperemesis with electrolyte derangement. Telemetry: atypical ACS, severe DKA. ICU: shock (septic, hemorrhagic, adrenal, ACS), severe pancreatitis (organ failure), mesenteric ischemia post-op, severe HHS with AMS. OR: appendicitis, complicated cholecystitis, perforation, strangulated SBO, ectopic rupture
    advance: disposition assigned + downstream handoff complete
11. 11MONITORING
    Vitals q1-4h, I/O, K/Na/BUN/Cr q4-6h while vomiting; glucose q1h in DKA; lipase trend in pancreatitis; ECG monitoring if ondansetron + electrolyte derangement (QTc); fetal monitoring if pregnant; serial abdominal exam in surgical phenotype
    inputs: sbp, hr, bmp_glucose_anion_gap
    advance: stability achieved or escalation triggered
12. 12FOLLOWUP
    Outpatient GI for cyclic vomiting / functional / gastroparesis / IBS overlay; OB for hyperemesis; endocrine for adrenal insufficiency / chronic DM; cardiology for atypical ACS post-cath; neurology for migraine prevention; addiction support for CHS / opioids; chemotherapy team for CINV optimization
    advance: discharge bundle prescribed + follow-up scheduled