Chloroprocaine Spinal Anesthesia for Cervical Cerclage (CP Spinal)

This study aims to determine whether or not spinal anesthesia with the local anesthetic drug, chloroprocaine, wears off faster than the local anesthetic drug, bupivacaine, and results in faster discharge from the post-anesthesia care unit after surgery.

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.

Patients in BUP group will receive hyperbaric 0.75% bupivacaine 9 mg (1.4 ml), with fentanyl 15 mcg (0.3 ml), with saline (0.3 ml) to bring the volume to ~ 2 ml

The mean difference between groups in time between the end of spinal injection (t IT) to time for no motor block (t motor), i.e. tIT - T motor. Motor block will be assessed using the Bromage scale: Bromage Scale I = free movement of the legs and feet = no block II = able to flex knees, with free movement of feet = partial (33%) block III = unable to flex knees, but with free movement of the feet = almost complete (66%) block IV = unable to move legs or feet = complete block (100%)

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)

Submission will be made by December, 2020. Publication availability is to be determined by the peer review process. Once published, the data should be available indefinitely.

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Hejtmanek MR, Pollock JE. Chloroprocaine for spinal anesthesia: a retrospective analysis. Acta Anaesthesiol Scand. 2011 Mar;55(3):267-72. doi: 10.1111/j.1399-6576.2010.02371.x.

Lee A, Shatil B, Landau R, Menon P, Smiley R. Intrathecal 2-Chloroprocaine 3% Versus Hyperbaric Bupivacaine 0.75% for Cervical Cerclage: A Double-Blind Randomized Controlled Trial. Anesth Analg. 2022 Mar 1;134(3):624-632. doi: 10.1213/ANE.0000000000005653.