In a patient with severe preeclampsia and markedly elevated creatinine undergoing cesarean section, what is the optimal anesthesia technique?

Neuraxial Anesthesia with Spinal Technique Preferred for Cesarean Section in Severe Preeclampsia with Elevated Creatinine

Neuraxial anesthesia, specifically spinal anesthesia, is the optimal choice for this patient with severe preeclampsia and creatinine >400 μmol/L undergoing cesarean section, provided platelet count is ≥75,000/mm³ and coagulation studies are normal. 1

Pre-Anesthetic Assessment Algorithm

Immediate laboratory evaluation is critical:

• Check platelet count and coagulation studies (PT/INR, aPTT) immediately before the procedure, as platelet counts can decrease rapidly in severe preeclampsia and HELLP syndrome 1
• If platelet count is >75,000/mm³ with normal coagulation studies and non-rapidly declining trend, proceed with neuraxial anesthesia 1
• If platelet count is <75,000/mm³ or coagulation is abnormal, general anesthesia is required 1
• If platelet count is between 75,000-100,000/mm³, verify the trend is stable or rising, not rapidly falling 1

Blood Pressure Control Before Anesthesia

Initiate antihypertensive therapy before inducing anesthesia if systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg persisting >15 minutes 1

• Target blood pressure to <160/110 mmHg or diastolic around 85 mmHg 1
• This reduces the risk of cerebrovascular complications during the sympathetic blockade of neuraxial anesthesia 1

Neuraxial Technique Selection

Spinal anesthesia is preferred when no epidural catheter is already in place 2, 1:

• Provides rapid, reliable onset of surgical anesthesia 2
• Use pencil-point spinal needles to reduce post-dural puncture headache risk 2
• Combined spinal-epidural (CSE) offers backup epidural catheter for prolonged surgery or postoperative analgesia, though it increases time to skin incision 2

If an epidural catheter is already in place from labor, use incremental epidural dosing 2, 1

Critical Hemodynamic Management During Spinal Anesthesia

The elevated creatinine indicates severe preeclampsia with renal involvement, making these patients particularly vulnerable to both hypotension and fluid overload:

• Avoid excessive fluid preloading, as severe preeclampsia patients are at high risk for pulmonary edema despite appearing hypovolemic 1
• Start prophylactic phenylephrine infusion at 0.6 μg/kg/min immediately after spinal injection to prevent hypotension while minimizing interventions 3
• Alternative: norepinephrine infusion at 0.05 μg/kg/min (efficacy ratio 11-12:1 compared to phenylephrine) 3
• Titrate vasopressor to maintain systolic BP within 20% of baseline, as maintaining near-baseline BP optimizes uteroplacental perfusion 4

Monitoring Requirements

Continuous invasive arterial blood pressure monitoring is strongly recommended given the severe preeclampsia with renal dysfunction 1:

• Central venous pressure monitoring helps assess intravascular volume status, as these patients are often hypovolemic despite edema 1
• Continuous ECG, pulse oximetry, and urinary output monitoring 1
• Monitor for signs of pulmonary edema throughout the procedure 1

Magnesium Sulfate Considerations

Continue magnesium sulfate for seizure prophylaxis if already initiated 1:

• Monitor deep tendon reflexes, respiratory rate (>12/min), and urine output (>30 mL/hour) to prevent magnesium toxicity 1
• Magnesium potentiates neuromuscular blockade if general anesthesia becomes necessary 1

When General Anesthesia Is Required

General anesthesia is indicated if:

• Platelet count <75,000/mm³ or abnormal coagulation studies 1
• Profound fetal bradycardia, severe hemorrhage, or other obstetric emergency requiring immediate delivery 2

If general anesthesia is necessary:

• Perform rapid sequence induction with careful attention to attenuating hypertensive response to intubation 1
• Administer fentanyl 5 µg/kg IV before intubation to blunt the hypertensive response 1
• Be prepared for difficult airway management, as preeclampsia causes airway edema 1

Common Pitfalls to Avoid

• Do not delay checking coagulation studies in severe preeclampsia—platelet counts can drop precipitously within hours 1
• Do not administer large fluid boluses to prevent hypotension, as this increases pulmonary edema risk in patients with renal dysfunction and capillary leak 1
• Do not rely on baseline platelet counts from earlier in labor—recheck immediately before the procedure 1
• Do not use fixed-dose phenylephrine regimens without titration, as they result in more hemodynamic instability than weight-based dosing 3, 5