Spinal Anesthesia in Caesarean Section: Comparison Between Levobupivacaine and Hyperbaric Bupivacaine

Spinal anesthesia is a safe technique, widely used and tested in the gynecological field, so as to be considered the first choice technique in cesarean section, which allows to quickly obtain a valid sensor and motor block. Bupivacaine is one of the most widely used drug for obtaining spinal anesthesia in pregnant women undergoing caesarean section. Bupivacaine is a local anesthetic available as a racemic mixture of its two enantiomers, the R (+)- dextrobupivacaine and the S (-) - levobupivacaine, whose clinical use is widely validated. Racemic bupivacaine is available as a simple or hyperbaric solution, the latter being the most commonly used for spinal anesthesia. Levobupivacaine, which is the pure levorotatory enantiomer of racemic bupivacaine, is a slightly hypobaric solution compared to liquor and has shown less heart and nerve toxicity, probably due to its ability to bind proteins more rapidly, and a greater selectivity towards the sensory component compared to Bupivacaine, presents action and effects better predictable. Its baricity would also offer the advantage of providing a less sensitive block to the position.

Hypotension is one of the most common complications of spinal anesthesia and is particularly relevant in caesarean section because, in addition to the adverse effects on the parturient, it can have repercussions on the fetus through a reduction of placental perfusion.

Some studies have showed a similar incidence of hypotension in patients treated with bupivacaine compared to those treated with levobupivacaine, while others assert an equivalence between the two drugs. In most studies, however, a significantly lower incidence of hypotension and a greater hemodynamic stability were reported in pregnant patients undergoing spinal anesthesia by caesarean section with levobupivacaine.

Being both hyperbaric bupivacaine and levobupivacaine routinely used at the "G. Rodolico" Universitary Hospital of Catania for the spinal anesthesia of pregnant women undergoing caesarean section and being their use decided exclusively at discretion of the treating anesthesiologist, in the light of the discrepant data in the literature about the incidence of hypotension with the two drugs, the main objective of this observational study is to evaluate the hemodynamic effects mediated by levobupivacaine on pregnant women subjected to elective cesarean section and to compare them with those mediated by hyperbaric bupivacaine in an historical court of pregnant women subjected to caesarean section in the period between April 2017 and April 2018. The hemodynamic parameters will be monitored in real time with a non-invasive hemodynamic monitoring system (EV1000® platform + Clearsight® system - Edwards LifeSciences), routinely used in the "G. Rodolico" Universitary Hospital of Catania, allowing to obtain greater accuracy and veracity of the results compared to previous studies conducted on such anesthetics.