12-phase flow (12)

1. 1FRAME
   Acute obstetric emergency — full-thickness disruption of uterine wall before or during delivery; spectrum from complete rupture (extrusion of fetal parts / placenta into peritoneal cavity; obstetric catastrophe) to incomplete rupture / dehiscence ("uterine window"; serosa intact; often asymptomatic intraoperative finding). Partition by VBAC status (TOLAC / primary unscarred / planned repeat cesarean) + prior incision type (LTCS / classical / T-incision / prior rupture / myomectomy) + labor status (spontaneous / induced / no labor) + maternal-fetal stability + future-fertility-desired. Distinguishes from abruption (unscarred uterus / placental separation), AFE (intravascular embolic), PAS (placental adherence overlap).
   inputs: gestational_age_weeks, tolac_vs_planned_repeat_cesarean
   advance: VBAC status + incision type + labor stage + maternal-fetal stability tier tagged
2. 2ENTRY
   Recognise via Category III FHR in TOLAC (~ 70% sensitive marker per Ridgeway AJOG 2004 PMID 14990414) + severe breakthrough abdominal pain on epidural + loss of presenting part on exam + cessation of contractions + maternal hemodynamic compromise. Differential includes placental abruption (unscarred), AFE (sudden cardiopulmonary collapse), pulmonary embolism, eclamptic seizure, surgical emergencies (appendicitis, cholecystitis). Misoprostol use in VBAC is preventable rupture trigger — care-quality M&M event.
   inputs: fetal_heart_rate_baseline, labor_induction_or_augmentation_agent
   advance: Pre-test clinical probability for rupture documented
3. 3CONTEXT
   Prior incision type (LTCS / low-vertical / classical / T-incision / prior rupture / prior myomectomy), inter-pregnancy interval from prior cesarean, labor status (spontaneous / oxytocin / PGE2 / misoprostol-CONTRAINDICATED / Foley), PAS status, macrosomia, multiple gestation, advanced maternal age, grand multiparity, Rh status, future fertility desire.
   inputs: prior_cesarean_incision_type, tolac_vs_planned_repeat_cesarean, labor_induction_or_augmentation_agent, inter_pregnancy_interval_since_prior_cesarean, prior_myomectomy_or_other_uterine_surgery, placenta_accreta_spectrum_status, macrosomia_or_multiple_gestation, maternal_rh_status, maternal_hr, maternal_rr, maternal_spo2, fetal_heart_rate_baseline
   advance: Risk-factor profile + incision-type cohort + maternal-fetal stability tier captured
4. 4RED_FLAGS
   Category III FHR (sudden bradycardia, prolonged decelerations, sinusoidal) + loss of presenting part / station change + maternal hemorrhagic shock (SBP < 90, MAP < 65, HR > 120, lactate > 2) + severe breakthrough abdominal pain on epidural + cessation of contractions + hematuria → IMMEDIATE EMERGENT CESAREAN (door-to-incision target < 18-30 min; Landon NEJM 2004 PMID 15598960). Concealed intraperitoneal rupture hemorrhage can mask hypovolemia — high index of suspicion. Misoprostol use in VBAC = preventable rupture; care-quality M&M event.
   inputs: maternal_bp, maternal_hr, fetal_heart_rate_baseline
   actions: protocol.septic_shock
   advance: Maternal-fetal stability tier set; emergent-cesarean decision documented; OR + anesthesia + neonatology activated
5. 5INITIAL_WORKUP
   Maternal CBC (Hgb + platelets — falling Hgb without visible bleed = concealed rupture hemorrhage), type + screen / crossmatch ≥ 2 units PRBC (MTP-ready if unstable), coag panel (PT/INR, aPTT, fibrinogen), CMP, lactate, Kleihauer-Betke (FMH quantification + RhoGAM dose-adjustment if Rh-negative). Bedside obstetric ultrasound (fetal viability + placental location for PAS / previa ddx + free intraperitoneal fluid clue). Continuous fetal monitoring (Category I/II/III) until OR.
   inputs: maternal_cbc_with_diff, maternal_type_and_screen_or_crossmatch, maternal_coagulation_panel_pt_inr_aptt_fibrinogen, maternal_metabolic_panel, maternal_kleihauer_betke_test, bedside_obstetric_ultrasound
   actions: panel.cbc, panel.coag, panel.renal
   advance: Labs drawn; type + screen up; bedside US performed; fetal monitoring established; OR + anesthesia + neonatology activated
6. 6BRANCHING_WORKUP
   Repeat coag at 1-2 h if active bleeding (DIC trajectory); intraoperative findings define rupture vs dehiscence + extent; cystoscopy if hematuria for bladder-dome involvement; maternal echocardiogram if AFE-mimic features (sudden hypoxia + DIC at delivery); blood culture if post-op fever / sepsis features (chorio overlap).
   inputs: maternal_lactate
   advance: DIC trajectory + intraoperative findings + sepsis-overlap evaluation completed
7. 7DIFFERENTIAL
   Placental abruption (unscarred uterus / placental separation; painful bleeding common to both — abruption is in unscarred uterus, rupture is in scarred uterus / myometrial disruption), amniotic fluid embolism (sudden hypoxia + hypotension + DIC at delivery; intravascular embolic vs mechanical rupture; can co-present), pulmonary embolism (sudden hypoxia ± hypotension; no uterine signs), placenta accreta spectrum (placental adherence + rupture overlap; intraoperative finding), surgical emergencies (appendicitis, cholecystitis — typically less acute), eclamptic seizure (HTN + proteinuria; tonic-clonic).
   advance: Mimics excluded or co-managed
8. 8RISK_STRATIFICATION
   Complete vs incomplete rupture + maternal hemodynamic stability + fetal status (Category I/II/III) + GA + incision type + future-fertility-desired + PAS overlap. Drives emergent-cesarean timing (< 30 min) + intraoperative repair-vs-hysterectomy decision (small tear + stable + fertility-desired → repair; extensive damage / unstable / PAS / no fertility → hysterectomy). Stratifies subsequent-pregnancy risk (recurrence 6-32% → no TOLAC; elective cesarean 36-37 wk).
   inputs: maternal_bp, maternal_hr, fetal_heart_rate_baseline, gestational_age_weeks, prior_cesarean_incision_type
   actions: calc.qsofa, calc.sirs
   advance: Rupture type + delivery-urgency tier + repair-vs-hysterectomy decision documented
9. 9TREATMENT
   EMERGENT CESAREAN (door-to-incision < 18-30 min from rupture diagnosis; Landon NEJM 2004 PMID 15598960). MASSIVE TRANSFUSION (EBL > 1500 mL or DIC): 1:1:1 PRBC:FFP:platelets; cryoprecipitate if fibrinogen < 200 mg/dL; tranexamic acid 1 g IV within 3 h of birth (WOMAN 2017 PMID 28456509); norepinephrine for refractory hypotension; ICU. INTRAOPERATIVE DECISION: uterine repair if small tear + stable + fertility-desired; HYSTERECTOMY if extensive damage / devitalised edges / unstable / continued bleeding / no fertility / PAS overlap. Bladder repair if dome involved. POST-DELIVERY UTEROTONICS for atony (oxytocin first; methylergonovine if no HTN; carboprost if no asthma; misoprostol acceptable post-delivery). RHOGAM if Rh-negative. NEONATAL: emergent NICU; cooling protocol within 6 h if sustained fetal hypoxia → HIE risk (AAP Neonatal Encephalopathy 2014).
   inputs: gestational_age_weeks, maternal_rh_status, future_fertility_desire, prior_cesarean_incision_type
   advance: Emergent cesarean executed; rupture managed (repair vs hysterectomy); RhoGAM dosed if Rh-negative; neonate stabilised + NICU activated if indicated
10. 10DISPOSITION
    OR for emergent cesarean; ICU for massive transfusion / DIC / shock / post-hysterectomy; OB step-down if stable post-repair; mother-baby unit postpartum if uncomplicated; NICU for compromised neonate with HIE pathway if indicated. Postpartum-hemorrhage continued surveillance (rupture is a major hemorrhage source → routes to ob.postpartum-hemorrhage.core.v1).
    inputs: maternal_bp, maternal_spo2
    advance: Maternal level of care set; neonatal pathway initiated; postpartum-hemorrhage surveillance activated
11. 11MONITORING
    Intrapartum / intraoperative: continuous EFM until delivery, maternal vitals q5-15 min, A-line if unstable, serial Hgb + coag q1-2 h while active, fluid balance. Postpartum: vitals q15 min × 2 h then q1 h × 4 h then q4 h × 24 h, fundal tone q15 min × 2 h then q1 h × 4 h (atony surveillance), lochia + uterine tenderness, repeat CBC + coag q4-6 h until stable, urine output, mental status, wound check. ICU: continuous arterial line + central venous catheter, lactate q2-4 h, daily SOFA + cultures, CAM-ICU, VTE prophylaxis once stable.
    inputs: maternal_bp, maternal_hr, maternal_cbc_with_diff, maternal_coagulation_panel_pt_inr_aptt_fibrinogen
    actions: panel.cbc, panel.coag
    advance: Maternal stable + Hgb stable × 6 h + appropriate lochia + responsive newborn evaluation
12. 12FOLLOWUP
    6-wk postpartum visit + rupture-specific anticipatory guidance: recurrence 6-32% in subsequent pregnancy (ACOG PB 205 2019); preconception MFM mandatory; elective cesarean at 36-37 wk for next pregnancy; NO TOLAC in subsequent pregnancy; close 3rd-trimester surveillance for warning signs; thrombophilia / PAS workup if recurrent; addiction medicine if substance use; IPV referral if trauma-related; smoking cessation; HTN surveillance if HTN-driven; mental health screen (EPDS + PCL-5 for peripartum-PTSD given catastrophic event); contraception counseling; immunization audit; newborn outpatient 24-48 h post-discharge peds visit + HIE-cooling follow-up + developmental tracking for first year if hypoxic exposure.
    advance: Postpartum visit complete; future-pregnancy counseling delivered with no-TOLAC + elective cesarean 36-37 wk plan; addiction / IPV / HTN referrals placed; newborn high-risk followup arranged