Perimortem caesarean birth — structured SAQ (15 marks)

(a) Indication and timing (4 marks)

One mark for the indication, one for the fundal-height threshold, one for the timing, one for stating the maternal purpose and the honest evidence grade. ^[1][5]

• Indication: maternal cardiac arrest that has not responded to correctly performed cardiopulmonary resuscitation, in a woman whose uterus is large enough to compress the great vessels.^[5][6]
• Threshold: a fundus palpable at or above the umbilicus. Gestational age is unknown here and often unreliable in an arrest, so fundal height is the decision tool. Three finger-breadths above the umbilicus clearly meets it.^[5][6]
• Timing: begin the hysterotomy at 4 minutes from arrest, aiming to deliver by 5 minutes. She arrested two minutes ago, so I would be preparing now and cutting in two minutes.^[1][5]
• Purpose and evidence: the procedure is performed for maternal benefit; a surviving baby is a secondary gain. The 4-minute rule originated as a physiologically reasoned expert recommendation from Katz and colleagues in 1986 and has never been tested in a randomised trial. It is a target for urgency, not a deadline after which the procedure becomes futile — survival with good neurology is reported far beyond it.^[1][3][7]

(b) Physiological basis (3 marks)

One mark each for any three of the following four mechanisms. ^[1][2]

• Relief of aortocaval compression. The gravid uterus flattens the inferior vena cava against the spine; chest compressions already generate only a fraction of normal cardiac output, and obstructed venous return reduces that further.^[1][5]
• Redistribution of cardiac output. The term uterus receives a large share of maternal cardiac output; emptying it returns that flow to the brain and heart.^[2][6]
• Improved ventilation. Reduced intra-abdominal pressure un-splints the diaphragm and improves compliance, which matters because pregnancy shortens the safe apnoea time.^[6][8]
• Fetal oxygen delivery. It ceases with the maternal circulation, so neonatal outcome tracks the arrest-to-delivery interval closely.^[3][7]

Credit for citing Katz 2005: in 12 of 18 cases with documented haemodynamics, delivery preceded the return of maternal pulse and blood pressure, and in no case did the mother deteriorate because of the operation. ^[2]

(c) Conduct of the procedure (5 marks)

One mark each for location, equipment and anaesthesia, incision, delivery and packing, and continuation of resuscitation. ^[5][6]

• Location: in the emergency department, where she lies. Do not transfer to theatre — transfer costs minutes and degrades compressions.^[5][6]
• Equipment and anaesthesia: a scalpel is the only essential instrument; ideally a dedicated pack with scalpel, large scissors, forceps, cord clamps and swabs. No anaesthetic agent is required in cardiac arrest, and no consent is needed; state aloud that the anaesthetist will give anaesthesia if circulation and awareness return. Skin preparation and draping must not delay the incision.^[6][8]
• Incision: a midline vertical skin incision from just below the umbilicus to the pubic symphysis is fastest for most operators; enter fascia and peritoneum in as few passes as possible, extending bluntly where safe. A transverse incision is acceptable if that is genuinely faster for the operator.^[6][7]
• Uterus and delivery: a vertical or low transverse hysterotomy started with the scalpel and extended with scissors or fingers, protecting the fetus; deliver the fetus and then the placenta and hand the baby to a separate neonatal team.^[6][5]
• Resuscitation continues throughout: chest compressions, ventilation, rhythm checks, drugs and defibrillation are uninterrupted, and manual left uterine displacement continues until the baby is out. Pack the uterus and abdomen; expect a nearly dry field until circulation returns.^[5][6]

(d) Immediate care of both patients (3 marks)

One mark for continued maternal resuscitation, one for anticipating haemorrhage at return of circulation, one for the neonatal plan. ^[6][4]

• Mother: continue the advanced life support algorithm and treat the cause — here, traumatic haemorrhage, so blood products, damage-control surgery and the massive haemorrhage protocol. Delivery improves the physiology; it does not treat the pathology.^[5][6]
• Anticipate torrential bleeding the moment spontaneous circulation returns. Have uterotonics, blood and the massive haemorrhage protocol running before the incision; transfer to theatre for definitive haemostasis and formal closure once she is stable enough to move; then intensive care with targeted temperature management.^[6][4]
• Baby: a separate neonatal resuscitation team receives the baby at its own resuscitaire, assesses for hypoxic-ischaemic encephalopathy and refers for therapeutic hypothermia if criteria are met. Neonatal survival is documented at extremely preterm gestations and after prolonged maternal resuscitation.^[7][8]
• Then document the time of arrest, time of incision, time of delivery, personnel and findings; arrange a staff debrief, a family conversation and an incident review.^[8][4]