Bicarbonate Epidural Injection in Emergency Caesarian
Status:
Completed
Trial end date:
2021-02-26
Target enrollment:
Participant gender:
Summary
During labor, pain is systematic. In France, epidural analgesia is the gold standard to fight
pain.
Sometimes, emergency situations involve the maternal or fetal prognosis and require an
emergency fetal extraction by caesarean. When an effective epidural analgesia is in place, an
injection of adrenaline lidocaine converts this epidural analgesia into an epidural
anesthesia allowing a surgical procedure. Sometimes, the time required to set up the
anesthesia cannot be expected and a general anesthesia is performed.
Local anesthetics used during epidural analgesia have Pka between 7.8 and 8.1. In solution,
local anesthetics exist in two forms: an un-ionized form and an ionized form. The non-ionized
form is liposoluble and crosses the lipid membranes to reach the site of intracellular
action. The non-ionized form conditions the time taken to install anesthesia.
When the pH of the solution is equal to Pka, un-ionized and ionized form are present in equal
quantity. Commercial local anesthetic solutions have acidic pH and so contained a majority of
ionized form. Alkalinization of local anesthetics solution should bring the pH closer to pKa
and therefore to favor a greater proportion of non-ionized form.