How to do a Cervical Block or Paracervical Block
The arteries come in at the 3 and 9 O clock position as in the diagram. Don’t inject there, if you do, you will be injecting lidocaine into the blood streams! Instead, inject above at the site of the tenaculum in the image below and at the 6 o’clock position and the paracervical block sites in the image below. Use a longer needle that has a larger bore, like 20 gauge needle so that it’s easy to inject. Then advance the needle and then inject as you pull out. When you anesthetize well, you will see blanching of the cervix in the area you have injected.
Aspirate before injecting to avoid injecting into a vessel. You can inject at the 10, 12, 2, 4, 6, and 8 o’clock positions. Stay away from the 9 and 3 o’clock positions.
The following image comes from the AAFP article cited below.
Sources
Am Fam Physician. 1999 Jun 1;59(11):3069-3076.