Pudendal Nerve Block

Last updated 20.09.12

 

Definition

-  Analgesic nerve block of pudendal nerve

 

Features

-  Transperienal or transvaginal approaches

-  7ml LA bilaterally = 14ml + 6ml perineal infiltration = 20ml total

-  5-10min to effect

-  Lasts 20-60min+

 

Indications

-  Labour

-  Instrumental delivery

-  Episiotomy

-  Perineal repair

-  Perineal surgery

 

Contraindications/Precautions

-  Bleeding diathesis

-  Localised infection

 

Equipment

-  LA: 1% Lidocaine 20ml

-  25G needle

-  20cm 20-22g pudendal needle with guide

-  10ml syringe

-  Sterile gloves

-  Chlorhexadine

 

Needle

 

Procedure

-  Prep equipment

-  Wash hands, don gloves

-  Lithotomy position

-  Transvaginal

-  Position 2nd & 3rd fingers over ischial spine

-  Place needle tip 1cm anteriomedial to ischial spine

-  Advance needle 1cm

-  Aspirate to confirm not intravascular

-  Inject 7ml LA

-  Transperineal

-  Skin prep with Chlorhexadine

-  Penetration of site 2.5cm posteriomedial to ischial tuberosity

-  LA into injection site (wheal) with 25G needle

-  Insert pudendal needle at perpendicular to skin

-  Insert finger into rectum or vagina to guide needle towards ischial spine (dependant on space)

-  Aspirate to confirm not intravascular

-  Inject 3-4ml LA then advance 1cm, repeat aspiration then inject a further 4ml LA

-  Repeat on contralateral side

-  Confirmation by loss of anal wink test

 

Location

 

Injection

 

Complications

-  Maternal haematoma: vaginal, retroperitoneal, ischorectal

-  Rectal puncture

-  Nerve trauma

-  Needle stick injury

-  Fetal injection

 

 

 

References

 

Pic (Insertion) & Info: eMedicine Transvaginal Pudendal Nerve Block

Pic (Location): painspa.co.uk/treatments/pudendal-nerve-block

Pic (Needle): my.supplychain.nhs.uk/catalogue/product/ftr016