Should spinal anesthesia be used for caesarean delivery in a patient with preeclampsia,? Spinal anesthesia was once considered contraindicated because the ensuing hypotension would compromise uteroplacental blood flow. This has not been supported by evidence, and indeed spinal anesthesia is a reasonable treatment method. Dr. Vanessa G. Henke, Department of Anesthesia, Stanford University School of Medicine, Stanford, California and colleagues recently reviewed the controversy in their manuscript “Spinal Anesthesia in Severe Preeclampsia” in this month’s Anesthesia & Analgesia.
What is the evidence that shows hypotension is not an issue when spinal anesthesia is used for patients with severe preeclampsia?
In one study, hypotension risk and need for ephedrine for preeclampsia patients was less than for healthy patients. In that study, mean gestational age and fetal weight were significantly lower in the severely preeclamptic group so aorto-caval compression could have been less in the preeclamptic patients. In a second study, there were similar findings and similar issues as with the first study. In a third study, normotensive and preeclamptic patients gestational age was controlled and hypotension risk and need for ephedrine use was less in the patients with preeclampsia compared to normotensive patients.
Is spinal anesthesia as safe as epidural anesthesia for patients with severe preeclampsia?
A rigorous multicenter randomized, controlled trial that involved 100 severely preeclamptic parturients, showed that although hypotension was greater after spinal anesthesia compared to epidural anesthesia, the differences were most likely not clinically significant.
When should spinal anesthesia be considered for patients undergoing caesarian delivery?
Spinal anesthesia should be considered, in an emergency, if there is no epidural catheter in place, and if there is a contraindication to a neuraxial technique (coagulopathy or eclampsia with persistent neurologic deficits).
Why is general anesthesia problematic for patients with preeclampsia?
Although the absolute risk of general anesthesia is low, patients with preeclampsia who receive general anesthesia can become hypertensive. The risk of difficult or failed laryngoscopy and intubation is greater in preeclampsia patients compared with normotensive patients, perhaps because of greater pregnancy associated swelling of pharyngeal and glottis tissue.
How can risk of hypotension after spinal anesthesia be lowered?
Fluid management or prophylactic phenylephrine infusions have not specifically been studied in this population. Hypotension due to spinal anesthesia is dependent on dose of spinal anesthetic. Hypotension after a combined spinal-epidural is less than after a single shot spinal anesthetic, although combined spinal anesthesia has not been compared with spinal anesthesia in patients with severe preeclampsia.
How should hemodynamics be monitored in patients with preeclampsia?
There’s no evidence to show that invasive hemodynamic monitoring improves outcome in patients with severe preeclampsia.
Does coagulopathy affect risk of spinal/epidural anesthesia?
Smaller needles are used for spinal anesthesia, so risk of hematoma may be less. There’s no specific rule for a safe platelet count, yet many feel that the platelet count should be at least 75,000 /µl and partial thromboplastin and prothrombin should be normal if the platelet count is < 150,000 /µl before spinal anesthesia is used.
Read the article in its entirety for much more detail on this subject.
OpenAnesthesia has a discussion on anesthesia for caesarean delivery.