Maternal collapse and resuscitation in pregnancy — structured oral station (12 minutes)

Opening prompt — "The staff are standing at the end of the bed. Go."

Model response: ^[1][2]

• "I would say loudly: this is a maternal cardiac arrest, put out the arrest call and the obstetric emergency call, I am the team leader."
• "Get her flat on a firm surface — on the floor if the bed will not do — and check breathing and pulse for no more than ten seconds. Gasping is not breathing; if there is no pulse I start compressions immediately."^[2]
• "Compressions at 100 to 120 per minute, depth 5 to 6 cm, hands on the centre of the sternum a little higher than usual because the heart is displaced upward in pregnancy. At 31 weeks her fundus is above the umbilicus, so I want one person doing continuous manual left uterine displacement from the outset."^[5][6]
• "Bag-valve-mask with 100% oxygen and early intubation by the most experienced airway operator — she is obese and 31 weeks, so I expect a difficult airway and I want that declared in advance."^[1][3]
• "Two large-bore cannulae above the diaphragm or humeral intraosseous access. Attach the defibrillator. Start the clock aloud, and state that if there is no output at four minutes I will perform a perimortem caesarean here."^[2][8]
• "Roles: leader, compressions, airway, uterine displacement, drugs and access, scribe. And someone to call the neonatal team."^[3]

Examiner is listening for: taking the room verbally, flat not tilted, displacement, the higher hand position, access above the diaphragm, and the four-minute commitment named as a time. ^[1][6]

Probe 1 — "Why not tilt her? I was taught 15 to 30 degrees left lateral."

• "Tilt does relieve aortocaval compression, but it comes at a cost: on a tilted patient you cannot generate the same compression force or depth, and the systematic review of maternal positioning together with manikin studies of tilt methods show exactly that degradation."^[6]
• "Manual left uterine displacement achieves the same decompression with the patient flat, so you keep compression quality. That is why current guidance is displace, do not tilt."^[1][2]

Probe 2 — "Work through your reversible causes for this woman."

Structure earns the mark. Give the framework, then personalise it. ^[1]

• "Four H: hypoxia — she was admitted with breathlessness; hypovolaemia, which in obstetrics means haemorrhage until proven otherwise, revealed or concealed; hypo- or hyperkalaemia and metabolic causes; hypothermia, unlikely here."^[1]
• "Four T: thrombosis — pulmonary embolism is very high on my list in an obese 41-year-old at 31 weeks admitted with breathlessness; tamponade; toxins, so I would check her drug chart for magnesium, opioids and any recent local anaesthetic; tension pneumothorax."^[1][7]
• "Obstetric causes: haemorrhage, amniotic fluid embolism, eclampsia, and complications of anaesthesia. She is not in labour and has had no block, so anaesthetic causes are less likely here — but in the UK CAPS cohort sixteen of sixty-six arrests were caused solely by obstetric anaesthesia, and twelve of those women were obese, so I never dismiss it reflexively."^[4][1]
• "My working diagnosis is massive pulmonary embolism until proven otherwise, and I would consider thrombolysis during CPR with prolonged resuscitation afterwards."^[9][1]

Probe 3 — "What investigations do you want, and when?"

• "Nothing delays the resuscitation. In the first ten minutes only point-of-care tests: a blood gas with lactate, potassium, glucose and haemoglobin, and bedside ultrasound between compression cycles for tamponade, right heart strain and free intraperitoneal fluid."^[9][1]
• "Waveform capnography is my compression-quality monitor and my earliest sign of return of spontaneous circulation. A persistently very low end-tidal carbon dioxide tells me my compressions are inadequate or she is not salvageable."^[9][2]
• "In parallel to the laboratory: full blood count, coagulation with fibrinogen, cross-match, electrolytes, calcium and liver function. Computed tomography and echocardiography come after return of spontaneous circulation, not before."^[1][9]

Probe 4 — "Give me your drug doses."

• "Unchanged by pregnancy. Adrenaline 1 mg intravenously every 3 to 5 minutes; amiodarone 300 mg intravenously after the third shock with a further 150 mg if needed; defibrillation at standard energies, which is safe for the fetus."^[2][9]
• "Cause-specific: magnesium sulfate 4 g intravenously over 5 to 15 minutes then 1 g/h for eclampsia; calcium gluconate 1 g intravenously for magnesium toxicity; adrenaline 0.5 mg intramuscular for anaphylaxis; 20% lipid emulsion 1.5 mL/kg as a bolus then 0.25 mL/kg/min for local anaesthetic systemic toxicity; naloxone 400 micrograms intravenously for opioid toxicity."^[1][7]

Probe 5 — "Four minutes, no output. What are you doing?"

• "I am performing a perimortem caesarean birth here on the ward, aiming to deliver by five minutes. At 31 weeks her fundus is well above the umbilicus."^[8][2]
• "This is a maternal resuscitation manoeuvre. It relieves aortocaval compression, redistributes uterine blood flow to her brain and heart, and improves ventilation."^[8][1]
• "No anaesthetic, no consent, no move to theatre. A scalpel is the only essential instrument. Compressions and uterine displacement continue until the baby is out, and the neonatal team receives the baby at a separate resuscitaire."^[1][3]
• "In CAPS the median interval from collapse to perimortem caesarean was 3 minutes in survivors and 12 minutes in those who died. That number is why I commit to the time out loud."^[4]

Probe 6 — "When would you stop?"

• "It is my decision as team leader, made explicitly with the team rather than by drift. I would weigh the cause and whether it is reversible, the duration of arrest, the response to treatment of reversible causes, the end-tidal carbon dioxide, and whether extracorporeal support is realistically available."^[9][1]
• "If she has a potentially reversible cause such as massive pulmonary embolism and I have thrombolysed her, I would continue resuscitation for at least 60 to 90 minutes before considering stopping."^[9]
• "I would say out loud what I am thinking, invite the team to disagree, then state the decision and the time, and I would speak to the family myself."^[3][1]

Probe 7 — "Her sixteen-year-old daughter is in the corridor. She has seen everything."

Rapport and respect are separately scored. Demonstrate them, do not describe them. ^[1]

• Ask a named senior midwife to stay with her continuously; do not leave a child alone with what she has seen.
• Go to her, sit at her level, use her mother's name. "I am one of the doctors looking after your mum. Her heart has stopped and our team is doing everything we can to restart it. I know how frightening this looks."
• Ask who else should be called and make sure that happens.
• Offer honesty in small pieces, check what she has understood, and promise to come back. Never say "she will be fine."
• Afterwards, ensure formal family support and a documented follow-up conversation.^[1][4]

Probe 8 — "What happens in your unit tomorrow?"

• "A structured team debrief, separate from the clinical handover, and psychological support offered to everyone in the room including the ward staff who found her."^[3][1]
• "An incident report and a maternal near-miss or mortality review, and coronial notification if she died."^[1][4]
• "Then the systems question: were the arrest trolley, the perimortem caesarean pack and the roles where they should have been? Units that drill this achieve shorter collapse-to-delivery intervals, so the timings go back into the simulation programme."^[3][4]