Pudendal and paracervical blocks are single-injection nerve blocks that are commonly used during obstetric and gynecologic procedures. These blocks are typically administered by an obstetrician or gynecologist, rather than an anesthesiologist, and are simple to perform.
Pudendal and paracervical blocks are single-injection, or single-shot, nerve blocks that involve a one-time injection of local anesthetic adjacent to the nerve or plexus for pain relief. The duration and density of the block depends upon the dose, concentration, and pharmacology of the chosen local anesthetic.
Transvaginal Pudendal Nerve Block
A pudendal nerve block provides anesthesia to the lower vagina, vulva, and surrounding tissues, with some relaxation of the pelvic floor. Blocking the pudendal nerve with an injection of local anesthetic is used for vaginal deliveries and for minor surgeries of the vagina and perineum. The pudendal nerve provides the majority of sensations and functions of the external genitals, the urethra, the anus, and the perineum. It also controls the external anal sphincter and the sphincter muscles of the bladder.
Pudendal nerve blocks are still used for certain obstetric and gynecologic indications, but they have been displaced by an increase in the use of neuraxial anesthesia (such as epidurals or spinals), especially in the context of treatment for pain in the second stage of labor. The procedure, however remains a useful tool for urgent or emergent deliveries when quick pain control and analgesia are indicated.
Your doctor may use this block when you undergo the following procedures:
- Operative vaginal deliver (forceps or vacuum)
- Episiotomy repair
- Office-based vaginal procedures
What does this procedure involve
The doctor will use two fingers to feel along the inner left wall of the vagina to locate a boney protuberance called the ischial spine. Using a special needle, pain medication can be injected into the nerve root located in this area. The process is repeated on the right side. This will numb the perineum and lower part of the vagina.
Paracervical Nerve Block
Paracervical blocks can provide excellent anesthesia for procedures that involve cervical dilation, uterine aspiration, or instrumentation of the uterus. The paracervical block is not recommended for loop electrosurgical excision procedure (LEEP) procedures because it may not be as dense on the surface of the cervix.
Your doctor may use this block when you undergo the following procedures:
- LEEP (loop electrosurgical excision procedure)
- IUD (intrauterine device) insertion
- Hysteroscopy (diagnostic, polypectomy, myomectomy, IUD removal)
- Colposcopy
- Cervical Biopsy
- Endometrial ablation
What does this procedure involve
There are a variety of techniques to perform a paracervical block. Each surgeon develops a preferred technique. In a basic paracervical block, anesthetic medication is injected into the upper and lower portions of the cervix. Typical medications are Lidocaine and Mepivacaine. This technique works quickly to numb the cervix.
More complex procedures require a deeper paracervical block to provide anesthesia to the cervix and upper uterus. There are many techniques. The doctor will inject medication in different areas of the cervix to allow the anesthetic to be absorbed into the surrounding nerve bundles. The procedure is done slowly to avoid injecting into any blood vessels. After the injections are complete, the surgeon will wait 10-15 minutes to allow it to take effect before proceeding with other procedures.
