Anesthetic Management of Preeclampsia for Cesarean Section: Regional vs. General Anesthesia


Introduction and Context


What is the scope of hypertensive diseases in pregnancy?
Hypertensive diseases of pregnancy complicate about 5 to 10 percent of pregnancies. In the last 25 years,
the incidence has increased by about 25 percent.

Why does maternal morbidity or mortality occur in these cases?
Maternal morbidity or mortality occurs because of delayed diagnosis and inadequate treatment of hypertension
and its associated complications.

What is the core debate topic presented?
The debate is on the anesthetic management of preeclampsia parturients for cesarean delivery, specifically
whether it should be regional anesthesia or general anesthesia.


Dr. Gurudatt's Argument: Regional Anesthesia is Ideal


What was the historical perspective on anesthesia for hypertensive disorders?
About 30 years ago, postgraduates were taught that for any hypertensive disorders of pregnancy, one should
always go for general anesthesia. This changed in the mid-1990s when clinical trials demonstrated the safety
of neuroaxial anesthesia.

What is a significant development in obstetric anesthesia practice?
The confirmation of the safety of neuroaxial anesthesia for labor and cesarean delivery in women with
preeclampsia is one of the most important developments in the past 25 years in obstetric anesthesia practice.

What are the major advantages of neuroaxial anesthesia?
The major advantages are the control of hypertension and the avoidance of the need for airway management.

What do official guidelines and task forces recommend?
  • The American College of Obstetricians and Gynecologists states that neuroaxial anesthetic techniques, when feasible, are strongly preferred to general anesthesia for preeclamptic parturients.
  • The American Society of Anesthesiologists task force encourages early epidural catheter placement in laboring preeclamptic patients to secure a means of delivering neuroaxial anesthesia, avoiding the risks of general anesthesia in case an emergency cesarean is required.
  • Recent guidelines for managing severe preeclampsia recommend neuroaxial anesthesia over general anesthesia for cesarean section to reduce maternal morbidity.

What are the key advantages of regional anesthesia?
Advantages include avoiding airway instrumentation, providing effective analgesia/anesthesia while minimizing
maternal and neonatal sedation, allowing for neuroaxial morphine to provide postoperative analgesia, and
allowing the patient to be present for the birth of her child.

What are the different neuroaxial anesthetic techniques available?
The techniques available are spinal anesthesia, epidural anesthesia, or a combined spinal-epidural (CSE) technique.

What was the historical concern with spinal anesthesia in preeclampsia?
Earlier, there was concern that precipitous spinal anesthesia-induced hypotension, superimposed on pre-existing
uteroplacental hypoperfusion, could be a real problem.

What does current evidence show about spinal anesthesia-induced hypotension in preeclamptic patients?
Strong evidence from as early as the 1950s and many subsequent trials have demonstrated that preeclampsia
actually attenuates spinal anesthesia-induced hypotension. Preeclamptic parturients experience less frequent
and less severe hypotension and require smaller doses of vasopressors than normotensive controls after spinal
anesthesia.

Is spinal anesthesia appropriate for severe preeclampsia?
Yes, data taken together suggests that the use of spinal anesthesia for cesarean delivery in women with severe
preeclampsia is appropriate. Studies show stable hemodynamic status in preeclamptic mothers with little effect
on cardiac output and afterload.

Can neuroaxial anesthesia be considered in stable eclamptic mothers?
In stable eclamptic mothers (GCS 14, no recent seizures treated with magnesium sulfate, no organ failure),
neuroaxial analgesia or anesthesia can be considered. Studies have found no difference in maternal and neonatal
outcomes compared to general anesthesia.

What about the risk of epidural hematoma in thrombocytopenic patients?
The incidence of epidural hematoma has been found to be very low in obstetric anesthesia practice, even in studies
done with thrombocytopenic parturients. In emergent situations with a non-reassuring airway, the risk-benefit ratio
may favor a single-shot spinal with a thin-gauge needle over general anesthesia, despite extreme thrombocytopenia.

What are the limited indications for general anesthesia?
Indications for general anesthesia are few and include coagulopathy, sustained fetal bradycardia with a reassuring
maternal airway, severe ongoing maternal hemorrhage, and absolute contraindications to the neuroaxial technique.

What are the concerns with general anesthesia in these patients?
Concerns include:
  • Difficult airway
  • Hypertensive response to intubation and extubation, leading to risk of stroke
  • Aspiration risk and pulmonary edema
  • Myocardial ischemia
  • Prolongation of non-depolarizing muscle relaxant effects due to magnesium sulfate
  • Polypharmacy and effects on the neonate
Studies in low and middle-income countries found GA is associated with increased complications in women with preeclampsia.

How significant is the failed intubation rate in obstetrics?
The failed intubation rate in obstetric patients is almost eight times higher than in non-obstetric surgical
populations. Even with modern advances, the incidence can be about 1 in 443, with maternal mortality occurring at a
rate of 1 death per 90 failed intubations. Desaturation during airway management occurs twice as often in patients
with hypertensive disorders.

What is the relationship between general anesthesia and stroke in preeclamptic women?
General anesthesia for cesarean delivery is associated with an increased risk of stroke compared with neuroaxial
anesthesia in preeclamptic women. The hypertensive response to intubation and extubation can cause significant
spikes in blood pressure, and the neuroendocrine response for GA is much higher than with epidural.


Dr. Baburaj's Argument: The Case for General Anesthesia


What are the potential problems associated with spinal or epidural anesthesia?
  • Hypotension: Sudden, severe hypotension can occur due to extensive sympathectomy in the setting of low intravascular volume and vasoconstriction.
  • Spinal Epidural Hematoma: In emergencies, patients may have borderline coagulation profiles, placing them at risk for hematoma and subsequent paraplegia.
  • Cerebral Edema: Patients with severe preeclampsia or eclampsia may be drowsy and unable to protect their airway, making regional anesthesia unsuitable.
  • Consent: Patients may give consent under pressure after hearing about GA complications.
  • Difficulty in Positioning: Obese patients with edema make needle placement difficult, leading to multiple attempts and larger needles.
  • Inadequate or High Levels: A block may be too low, requiring conversion to GA, or too high, causing respiratory compromise.
  • Prolonged Surgery: If surgery is prolonged, spinal anesthesia may require supplementation with GA.

In which clinical scenarios is general anesthesia the only option?
GA is the only option when there is an immediate threat to the life of the mother or fetus, such as cord prolapse,
abruption, or maternal cardiorespiratory distress.

What are the advantages of general anesthesia in these specific situations?
Advantages include:
  • No fear of hypotension, bradycardia, or spinal hematoma.
  • Better control of airway and respiration in a sedated or drowsy patient.
  • No issues with inadequate or too high block levels.
  • Patient comfort (can lie supine with left uterine tilt).
  • No post-dural puncture headache (PDPH), unnecessary bed rest, or hydration.
  • No time constraints on the surgeon.

How can the risks of general anesthesia be managed?
  • Hemodynamic response: Can be controlled with titrated doses of induction agents, opioids, vasodilators, and beta-blockers.
  • Difficult airway: Can be managed with confidence using all gadgets, adhering to protocols (Plan A, B, C, etc.), and having an experienced assistant.
  • Drug titration: Using monitors (ECG, BIS, NMT) to give titrated doses, avoiding overdose, delayed recovery, and awareness.
  • Post-operative pain: Can be managed with multimodal analgesia.
  • Venous thromboembolism: Can be managed with proper gadgets and early mobilization.


Rebuttal and Cross-Examination


Dr. Gurudatt's Rebuttal: How does he counter the concern about drastic falls in blood pressure?
He reiterates that trials show hardly any fall in blood pressure in preeclamptic patients due to high circulating
catecholamine levels and an increased vascular response, which outweighs the sympathetic block.

How does Dr. Gurudatt address the concern about patients on magnesium sulfate?
He points out that magnesium sulfate poses more problems for GA (prolonging muscle relaxants) than for regional
anesthesia, and its effects are harder to monitor routinely.

What is Dr. Gurudatt's view on performing spinal anesthesia in an emergency?
Even in an emergency with a non-reassuring airway, a "rapid sequence spinal" can be attempted to prevent the high
risks associated with general anesthesia.

Dr. Baburaj's Supplement: How does he view the hypotension risk in an emergency scenario?
In a dire emergency with pre-existing dehydration and intravascular volume depletion, there is a very high chance of
hypotension occurring with regional anesthesia, which could worsen placental circulation.

What is Dr. Baburaj's main concern regarding epidural hematoma?
Despite the low reported incidence, if a patient lands in paraplegia, it is a major disaster. If there is any doubt
about coagulopathy, he would definitely go for GA to avoid that risk.


Specific Clinical Scenarios and Consensus


In a preeclamptic with a platelet count >=70,000, is the number alone sufficient to proceed with regional anesthesia?
(Dr. Gurudatt) No, it depends on the trend of the platelet count. If the trend shows a decrease, a one-hour-previous
count is ideal. Other coagulation parameters (PT/INR) are also needed. If these are normal, an epidural or CSE can be performed.

How should anticoagulant use change the management strategy for regional anesthesia?
(Dr. Gurudatt) For elective procedures, oral anticoagulants should be stopped and switched to parenteral if needed.
For parenteral anticoagulants, one must wait appropriate time intervals (e.g., 12 hours for prophylactic LMWH, 24
hours for therapeutic LMWH, 6 hours for unfractionated heparin) before a block. In an emergency on anticoagulants,
one must correct coagulopathy and proceed with GA, as a neuroaxial block is contraindicated.

For a patient on a magnesium sulfate infusion undergoing GA, should the infusion be stopped?
(Dr. Baburaj) No, magnesium sulfate is the gold standard for managing preeclampsia and should be continued. During
GA, drugs must be titrated according to response with proper monitoring, as magnesium can potentiate anesthetics and neuromuscular blockers.

Would you advocate platelet transfusion for a patient with a count of 50,000 and no bleeding history?
(Dr. Baburaj) No, he would not advocate platelet transfusion in this case. (Dr. Gurudatt) He agrees and would
consider spinal anesthesia if there are no other contraindications.

What are the key consensus points from the discussion?
  • Place an early neuroaxial catheter for labor analgesia to avoid GA and airway instrumentation.
  • Neuroaxial anesthesia is safe; any hypotension is minimal and amenable to vasopressors.
  • A platelet count greater than 70,000-75,000 is a reasonable threshold for neuroaxial anesthesia.
  • General anesthesia is a choice when there is a lack of time (emergency) or coagulopathy.
  • During GA, avoid acute increases in blood pressure to prevent cerebral complications.
  • For intravascular volume management, use co-loading (around 85 ml/kg), not pre-loading.
  • Vigilance is needed in the immediate post-operative period to prevent complications.

What are the medicolegal implications of choosing one technique over another?
(Dr. Baburaj) In a court of law, if a complication occurs after regional anesthesia in a patient with abnormal
coagulation, the question will be closed: was it advisable? All experts would say no. If in doubt about coagulation
status or urgency, it's safer to choose GA for defensive practice. (Dr. Gurudatt) Following textbooks, guidelines,
and advisories, and having good communication and counseling with the patient, should support you in a medicolegal situation.