Module 7

Local anaesthetic and the periprostatic block

Practical pain control: where the needle goes, safe doses, and recognising toxicity.

Good local anaesthetic is the difference between a calm awake biopsy and a miserable one. It is also a genuine safety skill. Let us cover both the comfort and the caution.

MRI slices live

The raw multi-parametric scan.

3D reconstruction live

Segmented gland, zones and lesion as a rotatable model.

Beside-patient spatial teaching future spatial workflow

Future spatial-computing workflows for placing the anatomy model in clinical space.

01 Making it tolerable 3 min

Half of pain control is not pharmacological. Talk the patient through each step, raise a small skin wheal first, and inject slowly. Rushed, silent injecting hurts more.

Comfort basics Warn, wheal, inject slowly. Communication is part of the anaesthetic.

You know the simple things that make an awake biopsy tolerable.

A simple, non-drug way to reduce biopsy pain?

02 The periprostatic block 4 min

The key target is the periprostatic nerve supply, around the base of the gland and near the neurovascular bundles. For transperineal work you also infiltrate the perineal skin and track, and sometimes the apex.

Key point Numb the perineal route and the periprostatic nerves at the base. That covers most of the discomfort.

You know where the local anaesthetic actually needs to go.

The key deep target for the block is what?

03 Safe doses 4 min

Local anaesthetic is safe within limits and dangerous beyond them. For lidocaine, a rough ceiling is around 3 mg/kg plain, or about 7 mg/kg with adrenaline. Keep a running total, and be especially careful in small or elderly patients.

Always track the total Exceeding the maximum dose risks systemic toxicity. Do the sum, do not eyeball it.

You understand that dose limits are a real safety boundary, not a formality.

Why keep a running total of the lidocaine used?

04 Spotting LAST 4 min

LAST, local anaesthetic systemic toxicity, is rare but serious. Early warning signs are neurological: perioral tingling, a metallic taste, ringing in the ears, agitation or confusion. It can progress to seizures and cardiac collapse.

If you suspect it: stop injecting, call for help, manage the airway, and follow the lipid emulsion (Intralipid) protocol.

Act early Perioral tingling or a metallic taste during injection is LAST until proven otherwise. Stop and call for help.

You can recognise and begin to manage LAST. End of Module 7.

An early sign of local anaesthetic systemic toxicity?

That is Module 7. You can make a biopsy comfortable and recognise the rare but serious complication.

Next: Specimen handling and the histology interface →