Dorsal penile nerve block

Preferred anesthetic

• Lidocaine 1% plain (10 mg/mL) is commonly used.
• Do not use epinephrine-containing local anesthetic for routine penile blocks.
• Bupivacaine 0.25% plain (2.5 mg/mL) can provide longer analgesia but has greater cardiotoxicity risk. Use cautiously, particularly in infants.

Maximum total doses

• Lidocaine 1% = 10 mg/mL
• Bupivacaine 0.25% = 2.5 mg/mL

Technique: dorsal penile nerve block

1. Position supine. Prep the penis and base with antiseptic; use sterile gloves.
2. Palpate the pubic symphysis and penis base.
3. Use a small needle, usually 25-30 G.
4. Insert at the 10 o'clock position at the base of the penis, just lateral to the dorsal midline.
5. Advance carefully toward the pubic symphysis while staying superficial to avoid the corpora and dorsal vessels.
6. Aspirate. If no blood, inject slowly.
7. Repeat at the 2 o'clock position.
8. Wait 5-10 minutes and test anesthesia before the procedure.

Typical injection volumes

• Neonate: lidocaine 1% 0.2-0.4 mL per side. Keep within 3 mg/kg total.
• Child: lidocaine 1% about 0.1 mL/kg per side, adjusting so the total calculated maximum is never exceeded.
• Adult: often 2-3 mL of 1% lidocaine per side. Use the minimum effective volume, commonly 4-6 mL total.

Alternative: penile ring block

1. Insert superficially at the base of the penis.
2. Infiltrate subcutaneously around the circumference, avoiding the ventral midline/urethra and avoiding intravascular injection.
3. Do not create a tight, high-pressure ring.

Typical volumes

• Neonate: lidocaine 1% 0.6-0.8 mL total subcutaneously around the base.
• Child/adult: titrate a small total volume, commonly 3-8 mL of 1% lidocaine, while remaining below the weight-based maximum.

Example calculation

• 3 mg/kg × 3.5 kg = 10.5 mg maximum
• 1% lidocaine = 10 mg/mL
• Maximum total volume = 1.05 mL

Do not proceed or stop if

• Allergy to the anesthetic
• Infection at injection site
• Unclear penile anatomy, significant hypospadias, major edema, or bleeding disorder without appropriate planning
• Aspiration yields blood
• Symptoms of LAST occur: tinnitus, metallic taste, circumoral numbness, agitation, seizures, arrhythmia, or cardiovascular collapse. Stop injecting, call for help, manage airway/seizures, and use lipid emulsion according to institutional LAST protocol.

Adult dorsal penile nerve block

Indications

Local anesthetic and dose

• A commonly used adult regimen is lidocaine 1%, 2 mL at 10 o'clock and 2 mL at 2 o'clock, total 4 mL = 40 mg.
• If longer analgesia is needed, bupivacaine 0.25%, 2 mL per side may be used, or a small lidocaine-bupivacaine mixture according to local policy.
• Use plain anesthetic, without epinephrine, for this block.

Landmark technique

Equipment

• 25-27 G needle, 1.5 inch needle usually adequate
• 5 or 10 mL syringe
• Plain local anesthetic
• Antiseptic, sterile gloves, gauze
• Resuscitation and LAST treatment equipment available

Steps

1. Position the patient supine. Explain the procedure and obtain consent.
2. Prep and drape the penis and suprapubic area. Gently hold the penis caudally.
3. Identify the base of the penis and pubic symphysis.
4. At the penile base, insert the needle at the 10 o'clock position, just lateral to the dorsal midline and immediately distal to the inferior pubic ramus.
5. Advance about 0.5 cm in a slightly medial and caudal direction, aiming to pass through superficial fascia while avoiding the dorsal neurovascular bundle and corpora.
6. Aspirate. If no blood is obtained, inject 2 mL of 1% plain lidocaine slowly.
7. Repeat at the 2 o'clock position with another 2 mL.
8. Massage gently if desired, wait 5-10 minutes, then test sensation before beginning the procedure.

If frenular/ventral anesthesia is needed

Ring block alternative

• Infiltrate subcutaneously around the penile base using 5-8 mL total of 1% plain lidocaine, in divided aliquots.
• Avoid a high-pressure circumferential injection and do not inject deeply into the corpora or toward the urethra.
• Keep the full calculated dose below the maximum.

Safety points

• Aspirate before every aliquot and inject slowly.
• Avoid injection into the dorsal vein/arteries, corpora cavernosa, or urethra.
• Use extra caution or seek senior/anesthesia input in severe liver disease, low body weight, significant cardiac disease, or when other local anesthetics/sedatives have been given.
• Stop immediately if toxicity occurs: perioral numbness, metallic taste, tinnitus, agitation, seizures, bradyarrhythmia, or hypotension. Manage under a local-anesthetic systemic toxicity protocol, including lipid emulsion when indicated.