Category 1 caesarean section with severe pre-eclampsia and falling platelets
A 34-year-old woman (BMI 42 kg/m²) at 36 weeks' gestation presents with severe pre-eclampsia. Blood pressure is 168/108 mmHg despite labetalol 200 mg twice daily and nifedipine 20 mg modified release. She has frontal headache and visual scotomata. Platelets are 78 ×10⁹/L and falling from 112 two days ago; ALT 180 U/L, creatinine 110 µmol/L, uric acid 480 µmol/L. Cardiotocography shows a prolonged fetal deceleration, and the obstetric team calls a category 1 caesarean section. Airway assessment: Mallampati 3, mouth opening 3 cm, thyromental distance 6 cm, neck circumference 42 cm, no beard. She is 158 cm tall and weighs 105 kg. She has no other medical history and no allergies. Intravenous magnesium sulphate has been started. The anaesthetic room is 30 seconds from the theatre, and a difficult airway trolley is available.
1. Choose and justify the anaesthetic technique for this category 1 caesarean section, addressing the platelet count, the airway, and fetal urgency.
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This is a conflict between the risk of neuraxial haematoma and the risk of a difficult general anaesthetic. The platelet count is 78 ×10⁹/L, which is above the commonly used obstetric neuraxial threshold of about 70 ×10⁹/L, but it is falling and the ALT is raised, suggesting possible HELLP syndrome. I would check fibrinogen and look for clinical bleeding; if fibrinogen is normal and there is no coagulopathy, a single-shot spinal is reasonable and avoids airway instrumentation in an obese patient with a Mallampati 3 airway.
Technique: hyperbaric bupivacaine 0.5% 2.5 mL plus fentanyl 15 µg, with left uterine displacement, oxygen, and immediate availability of general anaesthesia. I would avoid an epidural catheter because of the falling platelet count. If the platelet count is below 70 ×10⁹/L, fibrinogen is low, or there is clinical bleeding, I would proceed to general anaesthesia with a difficult airway plan and two experienced anaesthetists.
The decision must be made in seconds, not minutes. Fetal bradycardia is an indication for urgency, but the mother's safety remains the priority. A spinal that is likely to fail or a general anaesthetic that is likely to be difficult are both dangerous; the chosen technique should be the one with the lowest combined risk in experienced hands.
2. If general anaesthesia is required, outline your induction and maintenance plan, including blood pressure control and neonatal considerations.
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Preparation: preoxygenate for 3 minutes in a ramped position, attach standard monitoring and capnography, ensure two suction units, video laryngoscope, bougie, and a second anaesthetist. Give sodium citrate and ranitidine if not already given.
Induction: rapid sequence with propofol 1.5–2 mg/kg (reduce if hypovolaemic) and suxamethonium 1.5 mg/kg, with cricoid pressure if it does not worsen the view. Intubate with the video laryngoscope, confirm with capnography, and secure the tube.
Maintenance: sevoflurane 0.8–1.0 MAC in oxygen/air, fentanyl 1–2 µg/kg, and magnesium as prescribed. Avoid high-dose opioids because of neonatal respiratory depression. Control blood pressure with labetalol 20–50 mg IV or hydralazine 5–10 mg IV in small aliquots; avoid ergometrine. After delivery, give oxytocin 5 IU slowly IV, and have neonatal resuscitation ready. The main risks are failed intubation, aspiration, severe hypertension on laryngoscopy, and uterine atony.
3. Describe your postoperative analgesia and monitoring plan, including thromboprophylaxis after a neuraxial block.
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After a spinal, I would use multimodal analgesia: regular paracetamol, cautious tramadol or a low-dose fentanyl PCA, and avoid NSAIDs because of the renal impairment and low platelets. Intrathecal morphine 100 µg could be used if the platelet count is stable and there is appropriate ward monitoring, but respiratory depression risk must be considered.
Monitoring: level 2 care for at least 24 hours with hourly observations, strict fluid balance, blood pressure control, magnesium toxicity checks, and daily platelets, LFTs, creatinine, and haemoglobin. Watch for HELLP progression, pulmonary oedema, and eclampsia.
Thromboprophylaxis: use mechanical prophylaxis initially. After a single-shot spinal, LMWH can usually start 4–6 hours later if there is no traumatic tap; after a bloody tap, delay to 12 hours and document the decision. With platelets of 78 ×10⁹/L and falling, I would discuss the dose and timing with haematology and avoid prophylactic LMWH until the platelet trend and bleeding risk are clearer.