Postpartum Haemorrhage & Shock — OSCE Practice Questions (Finals Level)

🏥 OSCE Station Stem

Scenario: A 28-year-old primigravida delivers vaginally at 39 weeks after a prolonged labour augmented with oxytocin. Shortly after delivery of the placenta she begins to bleed heavily. Her midwife calls you urgently. On arrival, she looks pale and clammy. BP 88/50 mmHg, HR 128 bpm, RR 28/min, urine output 8 mL/hr. She is confused and distressed.

SECTION 1 — DEFINITIONS & EPIDEMIOLOGY

Model Answer: Primary (early) PPH is defined as a cumulative blood loss of ≥1000 mL (or any amount causing signs/symptoms of haemodynamic instability) within 24 hours of delivery. The traditional definition was >500 mL after vaginal delivery, but this is now considered insufficient as uncomplicated deliveries often lose this much without compromise.

— Swanson's Family Medicine Review; Textbook of Family Medicine 9e

Model Answer: Bleeding occurring from 24 hours to 12 weeks after delivery. Most common cause is infection; retained placental fragments and subinvolution of the placental site are also causes.

Model Answer: PPH complicates 1 in 20 to 1 in 100 deliveries. It has increased ~26% in the US largely due to rising rates of uterine atony. Haemorrhage leading to blood transfusion is the leading cause of severe maternal morbidity in the US, followed by DIC.

— Swanson's Family Medicine Review

SECTION 2 — CAUSES (THE "4 Ts")

Model Answer:

1. Uterine overdistension (polyhydramnios, multiple gestation, macrosomia)
2. High parity (grand multiparity)
3. Rapid or prolonged labour
4. Use of oxytocin for induction/augmentation
5. Intraamniotic infection (chorioamnionitis)
6. Use of uterine-relaxing agents (e.g. tocolytics, halogenated anaesthetic agents)

— Textbook of Family Medicine 9e

Model Answer: Prolonged labour + oxytocin use → both directly increase risk of uterine atony (the most common cause of PPH). Primigravida also means inexperience of the uterine muscle with coordinated contraction.

SECTION 3 — SHOCK CLASSIFICATION

Model Answer: The patient has Class III–IV shock:

This patient: HR 128, BP 88/50 (decreased), RR 28, urine output 8 mL/hr, confused → Class III (borderline IV). Requires immediate crystalloid + blood products.

— Sabiston Textbook of Surgery

Model Answer: The shock index (HR ÷ SBP) is a better early predictor of shock than systolic BP alone. Healthy young women can maintain blood pressure through compensatory vasoconstriction even after significant blood loss — hypotension is a late sign. By Class III shock, 30–40% of blood volume is already lost.

— Current Surgical Therapy 14e

SECTION 4 — IMMEDIATE MANAGEMENT

Model Answer:

Airway: Ensure patent. Give high-flow O₂ via non-rebreather mask — enhances cellular oxygen delivery.

Breathing: Monitor SpO₂ (especially if carboprost used later — causes O₂ desaturation).

Circulation:

• Call for help — senior obstetrician, anaesthetist, haematologist, blood bank
• Two large-bore IV cannulae (14–16G); obtain blood for FBC, crossmatch ≥4 units, coagulation (PT, APTT, fibrinogen, FDPs), U&E
• IV fluids — warmed crystalloid initially; escalate to blood products (packed RBCs, FFP, platelets, cryoprecipitate per massive haemorrhage protocol)
• Catheterise and monitor urine output hourly
• Lie flat, keep warm

Uterus (specific to obstetric cause):

• Bimanual uterine massage — identify atony (boggy, non-contracted uterus)
• Fundal massage while giving uterotonic agents

— Textbook of Family Medicine 9e; Schwartz's Principles of Surgery

Model Answer:

• FBC (Hb, platelets)
• Crossmatch ≥4 units pRBC
• Coagulation screen — PT, APTT, fibrinogen, fibrin degradation products (DIC screen)
• U&E (renal perfusion)
• Group and save if not already done
• Bedside USS — retained products of conception (heterogeneous intrauterine mass with vascularity on Doppler)

SECTION 5 — UTEROTONIC AGENTS (HIGH-YIELD)

— Roberts & Hedges' Clinical Procedures in Emergency Medicine; Textbook of Family Medicine 9e

Model Answer:

1. Second-line uterotonic — ergometrine (unless hypertensive) or carboprost (unless asthmatic)
2. Intrauterine tamponade — Bakri balloon or Foley balloon catheter (leave 24–36 hrs)
3. If these fail → surgical intervention

SECTION 6 — SURGICAL OPTIONS

Model Answer (escalating order):

1. Uterine tamponade — Bakri balloon, Jada vacuum device (>90% success for atony), Foley catheter balloon
2. B-Lynch compression suture — brace suture compressing uterine walls (at caesarean section)
3. O'Leary sutures — uterine artery ligation (sutures placed around uterine artery branches + myometrium)
4. Hypogastric (internal iliac) artery ligation — reduces pulse pressure to uterus; must ligate ≥3 cm distal to bifurcation to avoid posterior division
5. Uterine artery embolisation — interventional radiology (if haemodynamically stable)
6. Caesarean/postpartum hysterectomy — definitive; most common indications: atony, placenta accreta, uterine rupture

— Schwartz's Principles of Surgery

SECTION 7 — SPECIFIC SCENARIOS

Model Answer: A firm fundus with continuing haemorrhage points away from atony. Systematically examine for:

• Vaginal/cervical lacerations — common, need good lighting and exposure to identify; usually easy to repair with sutures
• Retained placental fragments — manual exploration of uterus; curettage if RPOC confirmed
• Uterine rupture — requires immediate laparotomy
• Uterine inversion — may be occult; vaginal examination; requires urgent manual replacement (grasp uterus in palm, push firmly back into abdomen; may need IV magnesium sulfate 0.25 mg for uterine relaxation); rapid IV fluids as can cause immediate shock
• Coagulopathy — if venipuncture sites oozing, check DIC screen

— Textbook of Family Medicine 9e

Model Answer: Placenta accreta = chorionic villi abnormally adherent to myometrium (no Nitabuch's layer). Increta = invasion into myometrium. Percreta = through serosa/into adjacent organs (e.g. bladder).

Risk factor: previous uterine scar + placenta praevia (rates of accreta 11%, 40%, 61% with 1, 2, 3 previous caesarean scars respectively). Causes massive haemorrhage at delivery of placenta. Management often requires caesarean hysterectomy with massive transfusion protocol.

— Schwartz's Principles of Surgery

SECTION 8 — PREVENTION

Model Answer: AMTSL involves:

1. Oxytocin administration before/at delivery of placenta (promotes delivery of placenta, reduces atony)
2. Controlled cord traction
3. Early cord clamping

AMTSL reduces PPH by approximately two-thirds. It is the single most effective intervention to prevent PPH.

— Textbook of Family Medicine 9e

SECTION 9 — RAPID-FIRE SAQs

KEY EXAMINER TIPS

• Don't say ">500 mL" as your definition — the current definition is ≥1000 mL + haemodynamic instability. Examiners will probe this.
• In the shock table, note that BP remains normal in Class I and II — tachycardia and narrowed pulse pressure come first.
• Always mention calling for senior help early and a multidisciplinary team (obstetrician, anaesthetist, haematologist, blood bank).
• Tranexamic acid (TXA) is increasingly tested — give within 3 hours of delivery, 1 g IV; a second 1 g IV dose can be given if bleeding continues after 30 min or restarts within 24 hours (WOMAN trial).
• For ergometrine: the key contraindication is hypertension — vasoconstriction causes severe BP spike.