9. Analgesia for circumcision Flashcards
I want you to imagine I am the mother of a 2-year-old boy due to come
into hospital for circumcision.
I am very worried that he will suffer with pain after the operation.
Can you explain to me how you will prevent this?
‘I can appreciate your concern.
We tend to use a combination of techniques for pain relief, which keep the children comfortable after the operation.
The first thing we will do, once he is asleep,
is to put an injection of local anaesthetic into the base of his penis.
This usually provides good pain relief for up to 12 hours after the operation.
In addition to this, we have a variety of other pain relief options available.
We would start with simple paracetamol
followed by the addition of something stronger like ibuprofen or voltarol.
Local anaesthetic gel (lignocaine) can also be smeared onto the wound
regularly to cover the first 24–36 hours.
These measures provide good pain relief and can be administered by you at home.
It can be a bit sore at home for a few days,
but the medicines I have mentioned will keep him comfortable.
In the rare event that something stronger was needed,
we may use morphine liquid to drink but we would keep
him in hospital if that were the case.’
How can you assess post-operative pain in children?
An assessment of pain can be made by experienced staff
with the use of routine monitoring
(HR, BP and respiratory rate)
together with behavioural assessment techniques
(e.g. child withdrawn or lashing out).
It is important to repeat the assessments and listen to the parents.
In older children (>4 years),
one can use numerical pain-rating scales or
visual scales like the face self-reporting scale,
providing they have been understood pre-operatively.
What is the nerve supply to the penis?
The nerve supply to the penis is derived from
the pudendal nerve (S2–4) which gives off the
dorsal nerve of the penis bilaterally.
These run deep to Buck’s fascia
and are just lateral to the
dorsal arteries and veins bilaterally.
They supply the distal two-thirds of the penis.
Ventral branches from the dorsal nerves supply the frenulum.
The genitofemoral and ilioinguinal nerves may
also provide some sensory supply at the base.
Once the child is asleep and being monitored by a second anaesthetist,
how do you perform a penile block?
The dorsal nerves are blocked with injections of
0.5% plain bupivacaine either side of the midline deep to Buck’s fascia.
The volume would be 1ml + 0.1 ml/kg (max dose 2 mg/kg).
This ensures that the local anaesthetic passes
posteriorly to block the ventral branches supplying the frenulum.
Bilateral blocks are necessary because there is a midline septum,
which may prevent spread from a single injection.
The risk of vascular injury is also reduced.
Could you use a caudal?
Yes.
To estimate the volume and dose required,
the regime of Armitage may be employed. Using 0.25% plain bupivacaine,
the volume is based on the weight and the level to be blocked.
Lumbo-sacral block up to L1 – 0.5 ml/kg
Block up to T10 – 1 ml/kg
Block up to T6 – 1.25 ml/kg
What problems might be associated with a caudal?
Dural tap
Failure
IV injection
Hypotension (rare in children)
Urinary retention
Motor weakness necessitating overnight stay in hospital
