Historically, a common belief about the spinal anesthesia
in patients with severe preeclampsia is causing severe hypotension and decreasing uteroplacental perfusion which prevents the widespread use of spinal anesthesia in preeclampsia. After recent studies, comparing general and regional anesthesia risk-benefit considerations strongly favor neuraxial techniques over general anesthesia for cesarean delivery in the setting of severe preeclampsia as long as neuraxial anesthesia is not contraindicated [31
]. Two small prospective studies by Wallace et al. [33
] and Sharwood-Smith et al. [34
] have shown that the hemodynamic effects of spinal anesthesia were similar to those seen with epidural anesthesia in severely preeclamptic patients; Visalyaputra et al. [35
] have shown that the incidence of hypotension was more frequent in the spinal group than in the epidural group (51% versus 23%) in a large population. But they also showed hypotension was easily treated in all patients. They conclude that the results of this large prospective study support the use of spinal anesthesia for cesarean delivery in severely preeclamptic patients.
Berends et al. [36
] conducted a prospective trial among 30 patients whom were randomised into three groups: epidural anesthesia with prophylactic fluid loading (EA-F), combined spinal epidural anesthesia with prophylactic fluid loading (CSE-F), or combined spinal epidural anesthesia with prophylactic ephedrine (CSE-V). They concluded that combined spinal and epidural anesthesia (CSE) is a safe alternative to conventional epidural anesthesia in severe preeclamptic women and that the prophylactic use of ephedrine is effective and safe to prevent and treat spinal hypotension after combined spinal and epidural anesthesia for Cesarean section in severe preeclamptic women. However, the small study sample means that the conclusions from this study should be viewed with caution.
Karinen et al. [37
] studied a prophylactic crystalloid bolus before spinal anesthesia in preeclamptic patients mean central venous pressure increased significantly after preload, but decreased to baseline shortly after induction of spinal anesthesia. Visalyaputra et al. [35
] and Sharwood-Smith et al. [34
] showed the transient impact of IV fluid boluses on CVP. Prophylactic phenylephrine infusions have not been studied in the setting of uteroplacental insufficiency, and there is insufficient evidence to suggest their evidence-based use in the preeclamptic population [31
An important absolute contraindication for neuroaxial anesthesia is coagulation disorders. As discussed earlier preeclampsia is commonly responsible for thrombocytopenia occurring in the 2nd and 3rd trimester. Sharma et al. [38
] used thromboelastography and showed that platelet count >100 × 103/mm3
there were no abnormalities of coagulation detectable. They also concluded severe preeclamptic women with a platelet count <100,000/mm3
are hypocoagulable when compared to healthy pregnant women and other preeclamptic women. Orlikowski et al. [39
] have measured platelet count, bleeding time and thrombelastography (TEG) variables and the correlation between these variables in 49 pregnant patients presenting with pre-eclampsia or eclampsia. They figured out in the patients with severe thrombocytopenia a platelet count of 75 × 103/mm3
should be associated with adequate haemostasis. Taken together in the absence of other coagulation abnormalities, the risk of haemotoma associated with neuroaxial anaesthesia with platelet counts >75 × 103/mm3
is very low. There is no proposed data for a “safe” platelet count. Based on a consensus statement from the AmericanSociety of Regional Anesthesia [40
] many anesthesiologists require a platelet count of at least 75,000 or 80,000/μL (and, if the platelet count is <150,000/μL, normal partial thromboplastin [PTT] and prothrombin [PT] times) before initiating spinal anesthesia in patients with severe preeclampsia. The ASA practice guidelines advise that “the use of a platelet count may reduce the risk of anesthesia-related complications” in preeclampsia. The Association of Anaesthetists of Great Britain & Ireland, The Obstetric Anaesthetists’ Association Regional Anaesthesia UK evaluated relative risks related to neuroaxial blocks in obstetric patients with abnormalities of coagulation; they formed 4 groups of relative risks in idiopathic trombocytopenic pregnants. They grouped patients with Platelet count >75 × 103/mm3
within 24 h of block in normal risk and platelet count <75 × 103/mm3
in increased risk group [41
As emphasized by practice guidelines from the American Society of Anesthesiologists (ASA) and American College of Obstetricians and Gynecologists (ACOG), neuraxial anesthetic techniques, when feasible, are strongly preferred to general anesthesia for preeclamptic parturients.