Anesthesia Management for Severe Preeclampsia During Cesarean Delivery
Primary Recommendation
Neuraxial anesthesia (spinal or epidural) is the preferred anesthetic technique for cesarean delivery in severe preeclampsia, with spinal anesthesia being particularly advantageous when no epidural catheter is already in place. 1, 2, 3
Pre-Anesthetic Assessment and Preparation
Coagulation Status Evaluation
Check platelet count and coagulation studies immediately before the procedure in severe or fulminating preeclampsia or HELLP syndrome, as platelet counts can decrease rapidly in these circumstances 1
Neuraxial anesthesia can be performed if platelet count is >75,000/mm³ with normal coagulation studies and a non-rapidly declining trend 1
If platelet count is <100,000/mm³, obtain a coagulation screen; if normal, regional anesthesia down to 75,000/mm³ is reasonable depending on the rate of decrease 1
If platelet count is <75,000/mm³ or coagulation is abnormal, general anesthesia is indicated 1
Hemodynamic Optimization
Insert central venous catheter to assess intravascular volume status, as severe preeclampsia patients are often hypovolemic despite appearing edematous 1
Administer fresh frozen plasma if coagulopathy is present and surgery is urgent 1
Transfuse platelets immediately before surgery if count is <50,000/mm³ to achieve >50,000/mm³ 1
Blood Pressure Control
Initiate antihypertensive therapy before anesthesia if systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg persisting >15 minutes 1, 4, 5
Target blood pressure <160/110 mmHg or diastolic around 85 mmHg 4, 5
First-line agents include IV labetalol or oral nifedipine 4, 5
Continue hydralazine infusion if already initiated to prevent eclampsia or intracranial hemorrhage 1
Neuraxial Anesthesia Technique Selection
Spinal Anesthesia (Preferred When No Epidural Catheter Present)
Spinal anesthesia is the preferred choice for cesarean delivery in severe preeclampsia when there is no indwelling epidural catheter and coagulation parameters are acceptable. 2, 3
Advantages:
- Severe preeclampsia patients experience less frequent and less severe spinal-induced hypotension compared to healthy parturients 2
- Provides rapid, reliable, dense anesthesia with lower failure rate than epidural 3
- In a randomized trial, only 1/11 spinal patients had mild pain versus 7/10 epidural patients requiring additional analgesia 3
- Mean ephedrine requirement was similar between spinal (5.2 mg) and epidural (6.3 mg) groups 3
Technical Considerations:
- Use pencil-point spinal needles to minimize postdural puncture headache risk 1
- Hypotension, when it occurs, is typically easily treated, short-lived, and not associated with adverse outcomes 2
Epidural Anesthesia
- Consider epidural anesthesia if an epidural catheter is already in place for labor analgesia 1
- May provide more gradual onset with potentially less hypotension than spinal, though this advantage is minimal in severe preeclampsia 2, 3
- Higher failure rate requiring supplemental analgesia or conversion to general anesthesia 3
Combined Spinal-Epidural
- Provides rapid onset of spinal with epidural catheter backup for prolonged surgery or postoperative analgesia 1
- Consider when labor duration may exceed spinal duration or operative delivery is possible 1
Continuous Spinal Anesthesia
- May be considered as an alternative when epidural cannot be established, particularly in morbidly obese patients 6
- Allows titration of local anesthetic dose to minimize hemodynamic changes 6
General Anesthesia (When Neuraxial Contraindicated)
Indications:
- Platelet count <75,000/mm³ with abnormal coagulation 1
- Coagulopathy (elevated PT/PTT, low fibrinogen) 1
- Emergency delivery requiring immediate intervention
- Patient refusal or failed neuraxial technique
Technique:
Rapid sequence induction with careful attention to attenuating hypertensive response to intubation is essential. 1
- Administer fentanyl 5 µg/kg IV before intubation to attenuate hypertensive response 1
- Induction: thiopentone 5 mg/kg (or propofol equivalent) 1
- Muscle relaxation: succinylcholine 1.5 mg/kg for intubation 1
- Maintenance: atracurium 0.6 mg/kg for neuromuscular blockade 1
- Ventilation: 50% nitrous oxide with 0.5% isoflurane in oxygen 1
Critical Pitfalls:
- General anesthesia carries significant risks including difficult airway, pulmonary aspiration, and severe hypertensive response to intubation 1
- Severe preeclampsia patients may have airway edema making intubation more difficult 1
Intraoperative Hemodynamic Management
Hypotension Management
- Preeclamptic patients require less vasopressor support than healthy parturients due to increased systemic vascular resistance 2
- Treat hypotension with small boluses of phenylephrine or ephedrine 1
- Avoid excessive fluid administration as these patients are at risk for pulmonary edema 1
Hypertension Management
- Continue antihypertensive infusions throughout surgery 4
- Avoid combining magnesium sulfate with calcium channel blockers due to severe hypotension risk 5
Monitoring Requirements
Intraoperative:
- Continuous arterial blood pressure (invasive monitoring if severe instability) 1
- Central venous pressure 1
- Continuous ECG 1
- Pulse oximetry 1
- Urinary output 1
Postoperative (First 24 Hours):
- High-dependency unit monitoring for at least 24 hours postoperatively 1
- Continue blood pressure, CVP, urinary output, ECG, and oxygen saturation monitoring 1
Magnesium Sulfate Considerations
- Administer magnesium sulfate for seizure prophylaxis in severe preeclampsia with neurological signs or symptoms 4, 5, 7
- Monitor deep tendon reflexes, respiratory rate, and urine output to prevent magnesium toxicity 5
- Do not combine with calcium channel blockers due to severe hypotension risk 5
Special Circumstances
HELLP Syndrome
- Check platelet count and coagulation studies immediately before any neuraxial procedure, as rapid deterioration can occur 1
- Consider platelet transfusion if count <50,000/mm³ 1
- General anesthesia may be necessary if coagulopathy is severe 1
Emergency Situations
- If immediate delivery is required and coagulation status unknown, proceed with general anesthesia 1
- Rapid assessment of platelet count and coagulation is essential but should not delay life-saving intervention 1
Key Clinical Pitfalls to Avoid
Do not delay neuraxial anesthesia based on outdated concerns about hypotension in severe preeclampsia - these patients actually experience less hypotension than healthy parturients 2, 3
Do not perform neuraxial anesthesia without recent (<6 hours for mild/moderate, immediately before for severe/HELLP) platelet count and coagulation studies 1
Do not use ACE inhibitors or ARBs perioperatively - these are absolutely contraindicated in pregnancy 5
Do not over-resuscitate with fluids - severe preeclampsia patients are at high risk for pulmonary edema despite appearing hypovolemic 1
Do not use sodium nitroprusside except as last resort - it crosses the placenta and can cause fetal cyanide toxicity 7, 8
Do not assume epidural is safer than spinal - evidence shows spinal provides superior analgesia with similar hemodynamic profiles in severe preeclampsia 3