Chloroprocaine Spinal Anesthesia for Cervical Cerclage (CP Spinal)

This will be a prospective, randomized, double blind clinical trial. Subjects will be ASA I and II women ≥18 yrs old with a singleton pregnancy in the 1st or 2nd trimester of pregnancy undergoing cervical cerclage with spinal anesthesia. Patients will be randomly allocated to the chloroprocaine (CP) or bupivacaine group (BUP). Patients will receive spinal anesthesia with either chloroprocaine 50 mg with fentanyl 15 mcg or bupivacaine 9 mg with fentanyl 15 mcg.

Bupivacaine is the most common local anesthetic used for cervical cerclage with spinal anesthesia. Bupivacaine is safe and has been preferred over other medications such as lidocaine, because it is associated with a low incidence of a complication from spinal anesthesia known as "transient neurologic symptoms" - a condition where pain and cramping in the buttocks and lower extremities can be experienced for several days. Bupivacaine is a long-acting local anesthetic agent and therefore has the disadvantage of a prolonged anesthetic recovery that may last a few hours.

Chloroprocaine is a local anesthetic with a fast onset and short duration that may be used for spinal anesthesia for ambulatory procedures. Chloroprocaine is currently used at the research institution for spinal anesthesia for ambulatory surgical patients, especially for lower extremity orthopedic procedures such as knee arthroscopy, as well as for pregnant patients.

Inclusion criteria

• ASA I and II women
• 18-45 yrs old
• Singleton pregnancy
• Cervical cerclage 1st or 2nd trimester of pregnancy undergoing with spinal anesthesia
• Height 150 - 180 cm
• BMI ≤ 40 kg/m2.

Exclusion criteria

• Any contraindication to neuraxial anesthesia (history of neurologic disease (e.g., multiple sclerosis, spinal stenosis, central or peripheral neuropathy)
• Pre-existing/chronic back pain
• Ester local anesthetic allergy, PABA allergy
• History of atypical cholinesterase (CP is metabolized by cholinesterase)