Severe preeclampsia with rapidly falling platelets requiring category-1 caesarean delivery
A 34-year-old nulliparous woman at 36+4 weeks' gestation is admitted with severe preeclampsia. Blood pressure is 168/112 mmHg on a labetalol infusion of 20 mg/h; she has a persistent headache, visual scotomata and 3+ proteinuria. Laboratory results show platelets 78 x 10^9/L, which was 156 x 10^9/L 30 hours earlier; aspartate aminotransferase 186 U/L; creatinine 1.1 mg/dL; low haptoglobin; fibrinogen 2.4 g/L; international normalised ratio 1.1. She has no bruising, bleeding or history of coagulopathy and takes no antiplatelet or anticoagulant drugs. The fetal tracing now shows recurrent late decelerations with a baseline of 165 beats/min, and the obstetrician requests a category-1 caesarean delivery. Airway examination is unremarkable, but she has 2+ pitting oedema of the face and has gained 12 kg in three weeks. Intravenous access is in place and a magnesium sulphate infusion has just started.
1. Would you choose neuraxial anaesthesia or general anaesthesia, and how does the platelet trend influence your decision?
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The decision turns on the rate of fall, not the absolute number alone. A platelet count of 78 x 10^9/L with normal platelet function and no other coagulopathy is generally accepted as compatible with neuraxial blockade, but this count has halved in 30 hours, which is characteristic of HELLP progression; the count at the time of the needle is likely to be lower than 78, and coagulation may deteriorate further over the next few hours. I would send an immediate repeat full blood count and fibrinogen, and use viscoelastic testing if available.
If the repeat count is stable at 70 x 10^9/L or above with a normal fibrinogen and no clinical bleeding, I would perform a single-shot spinal with a 25-27 G pencil-point needle: a small, atraumatic needle carries a much lower haematoma risk than an epidural catheter, and it avoids the obstetric airway, which is oedematous and a recognised high-risk intubation. Hyperbaric bupivacaine 2.2-2.4 mL with fentanyl 15 mcg, titrated, with a phenylephrine infusion running.
If the count has fallen below 70 x 10^9/L, or I cannot get a result within the timeframe demanded by the category-1 fetal indication, I would proceed to general anaesthesia, accepting the difficult-airway and hypertensive-response risks in exchange for avoiding a spinal haematoma in a patient with a rapidly evolving coagulopathy. This is a shared decision to document explicitly.
2. Describe your induction and intraoperative haemodynamic management if general anaesthesia is required.
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Preoxygenate for 3 minutes with left uterine displacement and a working suction. Assume a difficult airway: videolaryngoscope ready, a 6.0-6.5 mm tube, and a plan for failed intubation that avoids multiple attempts in an oedematous airway.
Induction: thiopentone 5 mg/kg or propofol 2-2.5 mg/kg (reduce the dose if she is hypovolaemic), with suxamethonium 1.5 mg/kg or rocuronium 1.2 mg/kg, and cricoid pressure. Blunt the pressor response to laryngoscopy with an alfentanil 10-20 mcg/kg bolus or remifentanil 1 mcg/kg, accepting that both cross the placenta and can cause neonatal respiratory depression, so the paediatric team must be present and ready. Aim to keep systolic pressure below 160 mmHg before laryngoscopy without allowing a fall of more than 20-25% from baseline, because uteroplacental perfusion is pressure-dependent.
Have phenylephrine 50-100 mcg boluses and an infusion prepared, plus labetalol or hydralazine drawn up for surges. Magnesium potentiates neuromuscular blockade, so reduce relaxant doses and use quantitative monitoring; it also causes vasodilatation and worsens hypotension after induction.
After delivery, give oxytocin 3 IU slowly over at least one minute rather than a 5 IU bolus, then 10 IU/h, because bolus oxytocin causes profound tachycardia and hypotension. Ergometrine is contraindicated because of hypertension. Maintain normocapnia and normothermia, and check arterial blood gases and platelets if bleeding is more than expected.
3. What are your postoperative analgesia and monitoring priorities?
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Analgesia: if a spinal was performed, intrathecal morphine 100-150 mcg gives excellent, prolonged analgesia without the need for systemic opioids, but she must be monitored for respiratory depression and pruritus on the ward. If general anaesthesia was used, use a fentanyl patient-controlled analgesia with no background infusion, regular paracetamol, and avoid non-steroidal anti-inflammatory drugs because of the thrombocytopenia and renal impairment. Wound infiltration with local anaesthetic is a useful adjunct.
Monitoring priorities:
- Repeat platelets, liver enzymes and fibrinogen every 6-12 hours, because HELLP can worsen for up to 48 hours after delivery; watch for right upper quadrant pain, which may signal hepatic infarction or subcapsular haematoma.
- Neurological observations every hour for at least 24 hours: if a neuraxial technique was used, new back pain, motor weakness or sensory level change mandates urgent magnetic resonance imaging and neurosurgical referral for possible spinal haematoma.
- Continue magnesium sulphate for 24 hours with hourly reflexes, respiratory rate and urine output, and treat toxicity with calcium gluconate.
- Blood pressure control with labetalol or nifedipine, aiming below 150/100 mmHg, and fluid restriction to about 80 mL/h to reduce the risk of pulmonary oedema.
- Thromboprophylaxis with compression stockings initially; low-molecular-weight heparin must be timed against any neuraxial procedure.