Spinal anaesthesia for caesarean section in a patient with pre-eclampsia

Technique choice: Neuraxial anaesthesia is preferred over general anaesthesia in pre-eclampsia because it avoids the pressor response to laryngoscopy, avoids airway manipulation in a patient with oedema and a potentially difficult airway, and allows the mother to be awake for delivery. The main concern is thrombocytopenia: a platelet count of 88 × 10⁹/L is generally considered acceptable for neuraxial block in many guidelines (often a threshold of 75–80 × 10⁹/L is used when the count is stable and there is no other coagulopathy), but I would confirm the count is not falling rapidly, check for bruising or bleeding, and document the risk discussion. If there were any doubt, general anaesthesia would be the alternative.

Preventing hypotension:

• Preload with a balanced crystalloid (e.g., 500 mL) but avoid excessive fluid in pre-eclampsia because of the risk of pulmonary oedema.
• Start a prophylactic phenylephrine infusion (e.g., 25–50 µg/min) before or immediately after the block, titrated to blood pressure.
• Use a modest spinal dose (e.g., hyperbaric bupivacaine 2.0–2.5 mL plus fentanyl 15–25 µg) to achieve a block adequate for surgery but not excessive spread.
• Position with left uterine displacement, monitor blood pressure every minute for the first 10 minutes, and treat systolic < 100 mmHg or a fall > 20% from baseline promptly.
• Have ephedrine available for bradycardia with hypotension, and be ready to convert to general anaesthesia if the block fails or the fetal condition deteriorates.

Recognise: This is spinal-induced hypotension with a high block and vagal response - a common cause of nausea and vomiting in this setting. The block at T4 is adequate for surgery but the sympathetic block is causing vasodilation and bradycardia.

Immediate steps:

1. Call for help and tell the obstetrician to pause.
2. Left uterine displacement and tilt the table to relieve aortocaval compression.
3. Oxygen by face mask at 6–10 L/min, and check the airway and ventilation.
4. Vasopressor: give a bolus of phenylephrine 50–100 µg IV, repeated as needed; if there is significant bradycardia, use ephedrine 5–10 mg IV instead.
5. Fluid: give a 250–500 mL crystalloid bolus, watching for pulmonary oedema in this pre-eclamptic patient.
6. Reassess blood pressure every minute; if it does not respond, consider a further vasopressor bolus or infusion and exclude a high block (check hand grip and breathing).
7. Anti-emetic once stable (e.g., ondansetron 4 mg IV) and reassure the mother.

If the block ascends further with difficulty breathing or loss of consciousness, secure the airway and consider general anaesthesia. Document the event and the response.

Monitoring:

• Continue regular blood pressure and heart rate observations, at least hourly initially, because pre-eclampsia can worsen or resolve after delivery; watch for signs of pulmonary oedema (breathlessness, crackles, falling saturation).
• Monitor urine output and fluid balance carefully.
• Check postoperative haemoglobin and platelets if there is bleeding or a falling count.
• Continue magnesium sulphate if it was started for seizure prophylaxis, with monitoring of respiratory rate, reflexes, and urine output.

Analgesia:

• Intrathecal morphine (e.g., 100–200 µg) given with the spinal provides 12–24 hours of analgesia; monitor for respiratory depression, sedation, and itching.
• Regular paracetamol and a non-steroidal anti-inflammatory agent (if renal function and platelets allow) as adjuncts.
• Avoid intramuscular injections if the platelet count is low; use oral or intravenous routes.
• Encourage early mobilisation once the block has worn off, with thromboprophylaxis as per protocol.

Safety: Document the spinal level, the hypotension event, and the response. Ensure the mother is reviewed by the obstetric team and that the neonatal team is aware of the fetal bradycardia at delivery.