12-phase flow (12)

1. 1FRAME
   Acute deliberate or accidental cyclic-antidepressant overdose; the engine exists to time-critically detect and reverse sodium-channel cardiotoxicity, seizures, and refractory hypotension [ACMT 2024]
   inputs: agent_and_dose, time_since_ingestion
   advance: Cyclic agent overdose framed; deterioration window (peak risk 1–6 h) understood
2. 2ENTRY
   Recognize ingestion history, wide QRS / terminal R in aVR on ECG, or the anticholinergic-plus-seizure/coma/hypotension cluster [Boehnert & Lovejoy NEJM 1985; Goldfrank 2024]
   inputs: age
   advance: Trigger present (history, ECG, or toxidrome)
3. 3CONTEXT
   Capture specific agent, estimated mg/kg dose, co-ingestants (ethanol/benzo/SSRI/antipsychotic), time since ingestion, home QT-prolonging/serotonergic meds, pediatric exploratory vs intentional [ACMT 2024]
   inputs: weight_kg, agent_and_dose, time_since_ingestion, home_qt_prolonging_meds
   advance: Agent, dose estimate, co-ingestants, and timeline captured
4. 4RED_FLAGS
   QRS >100 ms (seizure risk) / >160 ms (ventricular-arrhythmia risk), terminal R in aVR >3 mm, R/S aVR >0.7, seizure, coma, hypotension, ventricular dysrhythmia, refractory acidosis — any one mandates resuscitation-bay management and serum alkalinization [Boehnert & Lovejoy NEJM 1985; Liebelt 1995]
   inputs: qrs_duration_ms, sbp, mental_status_gcs
   actions: calc.news2
   advance: Cardiotoxicity / CNS red flags screened; alkalinization started if any positive
5. 5INITIAL_WORKUP
   12-lead + continuous ECG, ABG/VBG, CMP (Na/K/HCO3/Cr/glucose), lactate, CBC, APAP + salicylate + ethanol co-screen, UDS, β-hCG, CK (rhabdomyolysis from seizures), CXR if intubated; TCA assays are confirmatory only and do not guide therapy [ACMT 2024; Goldfrank 2024]
   inputs: ecg_12_lead, arterial_ph, bicarbonate, sodium, potassium, acetaminophen_level, salicylate_level
   actions: workup.tca_overdose, panel.cardiac, panel.metabolic, panel.abg, panel.tox_screen
   advance: ECG + acid-base + electrolytes + co-ingestant screen resulted
6. 6BRANCHING_WORKUP
   Wide-complex tachycardia → distinguish TCA sodium-channel blockade from VT/SVT-with-aberrancy/hyperkalemia [workup.wide_complex_tach]; new seizure → exclude alternative causes [workup.first_seizure]; toxic-alcohol HAGMA confounder if osmolar/anion gap unexplained [workup.toxic_alcohols]
   inputs: ecg_12_lead
   actions: workup.wide_complex_tach, workup.first_seizure, workup.toxic_alcohols
   advance: Branch diagnostics queued; sodium-channel pattern confirmed as the dominant driver
7. 7DIFFERENTIAL
   Differentiate from other sodium-channel-blocking xenobiotics (Class IA/IC, diphenhydramine, bupropion, propranolol, carbamazepine, cocaine), pure anticholinergic toxidrome, sympathomimetic toxidrome, serotonin syndrome, hyperkalemia, and primary VT [Goldfrank 2024; ACMT 2024]
   advance: TCA confirmed as the principal contributor to the cardiotoxicity / toxidrome
8. 8RISK_STRATIFICATION
   Boehnert & Lovejoy thresholds — QRS >100 ms (≈one-third seize), QRS >160 ms (≈half develop ventricular arrhythmia); terminal R in aVR >3 mm and R/S aVR >0.7 predict toxicity; persistent tachycardia / coma / acidosis stratify severity and ICU disposition [Boehnert & Lovejoy NEJM 1985; Liebelt 1995]
   inputs: qrs_duration_ms, sbp, mental_status_gcs
   actions: calc.news2
   advance: ECG-based risk tier assigned; ICU vs monitored-bed disposition decided
9. 9TREATMENT
   Airway/breathing first (RSI for coma, with hyperventilation to support pH); hypertonic sodium bicarbonate 1–2 mEq/kg IV boluses titrated to QRS <100 ms + arterial pH 7.50–7.55, then infusion; benzodiazepines first-line for seizures; isotonic fluids then norepinephrine for hypotension; IV lipid emulsion for refractory cardiovascular collapse; VA-ECMO as last-line bridge; AVOID Class IA/IC/III antiarrhythmics, flumazenil, and physostigmine [Goldfrank 2024; ACMT 2024]
   inputs: qrs_duration_ms, arterial_ph, sbp
   advance: Alkalinization active with QRS narrowing; seizure/hypotension controlled; rescue tiers staged
10. 10DISPOSITION
    ICU for any QRS prolongation, seizure, hypotension, dysrhythmia, AMS, or ongoing NaHCO3 infusion; medical clearance only if asymptomatic with normal serial ECGs and normal mental status at ≥6 h post-ingestion; psychiatry for intentional ingestion [ACMT 2024]
    advance: Disposition assigned (ICU vs monitored bed vs medically cleared for psych)
11. 11MONITORING
    Continuous telemetry + serial 12-lead ECG (QRS / terminal-R-aVR trend), ABG q1–2h during active alkalinization, K+ q2h (alkalinization-driven hypokalemia), arterial pH ceiling 7.55, neuro checks q1h, capnography if intubated, watch for delayed deterioration and post-bolus re-widening [Goldfrank 2024]
    inputs: qrs_duration_ms, arterial_ph, potassium
    actions: panel.cardiac, panel.abg
    advance: QRS normalized, hemodynamics stable off vasopressors, no seizures, alkalinization weaned without re-widening
12. 12FOLLOWUP
    Psychiatry safety plan and means-restriction counselling for intentional ingestion, PCP medication reconciliation (limit TCA dispensed quantity / switch to safer agent), social work, neurology if anoxic injury, cardiology if persistent conduction abnormality [ACMT 2024]
    advance: Safety plan, prescribing review, and follow-up documented