12-phase flow (12)

1. 1FRAME
   Confirm acute croup (subglottic — barky cough + inspiratory stridor + hoarseness, URI prodrome, 6 mo-6 yr) vs epiglottitis (supraglottic, drooling, tripod, muffled voice, toxic) / bacterial tracheitis / foreign body / anaphylaxis / retropharyngeal abscess as the dominant diagnosis (AAP/CPS pediatric croup CPG)
   inputs: age
   advance: Croup framing confirmed; epiglottitis / tracheitis mimics noted
2. 2ENTRY
   Trigger captured: barky/"seal-bark" cough ± inspiratory stridor ± hoarseness, typically nocturnal worsening after a 12-48 h URI prodrome (AAP/CPS pediatric croup CPG)
   inputs: age, barky_cough
   advance: Entry trigger captured
3. 3CONTEXT
   Symptom-onset tempo + URI prodrome, prior croup episodes (recurrent/spasmodic), prior intubation / known airway anomaly, immunization status, vitals, meds/allergies — collected keeping the child calm (agitation worsens dynamic subglottic obstruction) (AAP/CPS pediatric croup CPG)
   inputs: symptom_onset_tempo, prior_croup_episodes, known_airway_anomaly_or_prior_intubation, temperature, hr, current_meds_and_allergies
   advance: Context captured without agitating the child
4. 4RED_FLAGS
   Stridor at rest, marked retractions, hypoxia (SpO2 drop = LATE), agitation → fatigue / lethargy, decreasing air entry, dusky/cyanotic, biphasic stridor + toxic (bacterial-tracheitis pivot), poor steroid/epinephrine response → keep child calm, escalate, prepare airway for impending failure (AAP/CPS pediatric croup CPG)
   inputs: stridor_at_rest, work_of_breathing, mental_status, spo2, biphasic_stridor_toxic
   actions: workup.pediatric_fever
   advance: Impending-failure / bacterial-tracheitis red flags screened
5. 5INITIAL_WORKUP
   Croup is a CLINICAL diagnosis — NO routine labs / NO routine imaging. Westley croup score computed inline + at the bedside. AP neck radiograph ("steeple sign") rendered inline ONLY if the diagnosis is uncertain AND the child is stable; poor sens/spec; a normal film does NOT exclude croup; imaging must never delay treatment of a distressed child (AAP/CPS pediatric croup CPG)
   inputs: stridor_at_rest, spo2, ap_neck_radiograph_steeple_sign
   advance: Westley score assigned; clinical diagnosis made
6. 6BRANCHING_WORKUP
   Only if atypical / toxic / poor-response: bacterial-tracheitis pathway → ENT + bronchoscopy + tracheal culture + CBC + renal panel (vancomycin dosing); foreign-body pathway if abrupt afebrile choking; recurrent/atypical (age <6 mo or >6 yr, ≥3 episodes, baseline biphasic stridor, prior intubation) → flag for ENT airway evaluation (AAP/CPS pediatric croup CPG)
   inputs: biphasic_stridor_toxic, tracheal_culture_if_bacterial_tracheitis, prior_croup_episodes
   actions: workup.aspiration_pneumonia
   advance: Atypical/toxic workup done as triggered, or skipped (typical croup)
7. 7DIFFERENTIAL
   Croup vs epiglottitis (drooling + tripod + muffled "hot-potato" voice + toxic + NO barky cough) vs bacterial tracheitis (toxic + biphasic stridor + thick purulent secretions + poor steroid/epinephrine response) vs foreign body (abrupt + afebrile + choking) vs anaphylaxis (urticaria + exposure + angioedema) vs retropharyngeal abscess (neck stiffness + dysphagia) — pivot findings encoded (AAP/CPS pediatric croup CPG)
   inputs: barky_cough, stridor_at_rest, biphasic_stridor_toxic
   advance: Dominant diagnosis assigned
8. 8RISK_STRATIFICATION
   Westley croup score: mild ≤2 / moderate 3-7 / severe ≥8 / impending respiratory failure (lethargy, decreasing air entry, dusky/cyanotic, marked fatigue — recognized clinically independent of the numeric tier) — drives steroid-only vs steroid+epinephrine+observe vs admit vs PICU/airway. pSOFA/qSOFA only as a sepsis adjunct if the bacterial-tracheitis branch is septic — NOT for croup airway timing (AAP/CPS pediatric croup CPG)
   inputs: westley_score, stridor_at_rest, mental_status
   advance: Severity tier assigned
9. 9TREATMENT
   DEXAMETHASONE for ALL severities (0.15-0.6 mg/kg PO/IM/IV single dose, commonly 0.6 mg/kg, max 16 mg; prednisolone 1-2 mg/kg PO alternative; nebulized budesonide 2 mg if vomiting). NEBULIZED EPINEPHRINE (racemic 2.25% 0.5 mL or L-epinephrine 1:1000 0.5 mL/kg, max 5 mL) for MODERATE-SEVERE with a mandatory 3-4 h observation for rebound; may repeat for severe/impending. Humidified O2 + minimal handling + keep calm; escalate to controlled intubation (smaller-than-predicted ETT, most experienced operator, ENT/anesthesia) for impending failure. BACTERIAL TRACHEITIS → empiric vancomycin + 3rd-gen cephalosporin + ENT/bronchoscopy (antibiotics + airway, NOT steroid/epinephrine) (AAP/CPS pediatric croup CPG; Cochrane; Bjornson NEJM)
   inputs: age, weight, westley_score, spo2
   advance: Severity-appropriate regimen + observation/airway plan documented
10. 10DISPOSITION
    Discharge home: mild OR back to mild at 3-4 h post-epinephrine, no stridor at rest, normal SpO2, tolerating PO, reliable caregiver + return precautions. Admit: persistent stridor at rest, hypoxia, ≥2 epinephrine doses, poor PO, unreliable follow-up. PICU: impending failure / repeated epinephrine / intubation / bacterial tracheitis (AAP/CPS pediatric croup CPG)
    inputs: westley_score, stridor_at_rest, spo2
    advance: Disposition documented
11. 11MONITORING
    ED: continuous observation 3-4 h after EACH nebulized-epinephrine dose for rebound, serial Westley score, SpO2, work of breathing. Inpatient/PICU: continuous SpO2, work of breathing, response to therapy, secured-tube monitoring if intubated, bacterial-tracheitis secretion/airway monitoring (AAP/CPS pediatric croup CPG)
    inputs: spo2, work_of_breathing, westley_score
    advance: Observation period completed; trajectory documented
12. 12FOLLOWUP
    Caregiver education (calm child, cool/humidified air comfort measure, course 3-7 d with nocturnal peak), return precautions (stridor at rest, marked retractions, drooling, lethargy, poor intake, cyanosis); recurrent/atypical or subglottic-stenosis flag → ENT / airway (flexible-or-rigid laryngoscopy/bronchoscopy) evaluation; complete antibiotics if bacterial tracheitis; primary-care follow-up (AAP/CPS pediatric croup CPG)
    advance: Education + return precautions + ENT/airway plan (if flagged) documented