Pediatric Pain and Sedation
I am not a pediatrician. I am an ED doctor. You don’t have to be a genius pediatrician or anesthetist to manage pain well.
The mantra ‘Children are not little adults’ is true to a certain extent but it also serves to frighten generalists like us into being ‘cautious’. Children are small human beings, pain and trauma is both frightening AND painful. You have to treat the anxiety and fear as well as the pain. You will not manage the child’s pain if you don’t manage their anxiety, which is primarily a communication skill.
YOU are the expert in managing acute pain.
Not the anesthetist
Not the pediatrician
Here is your Syllabus:
Differences between children and adults relevant to pain control:
- Airway – nothing relevant
- Breathing – functional residual capacity is close to closing capacity, which means if respiratory drive is depressed, alveoli will close, this means saturations will drop quickly.
- Circulation – greater cardiac output, so agents will get to the central nervous system faster.
Non-pharmacological agents are more important than pharmacological agents.
- YOUR demeanor, what YOU say
- The environment
- Smart phones
- Play Specialists
- Helpful parents
- The minimal amount of monitoring
Your choice of agent will be based on the injury, and what you need to do. You should follow the WHO analgesic ladder but don’t be afraid to start off with high potency agents if the situation warrants it.
|Can load with 20mg/kg|
|Can load with 10mg/kg|
|PO Oramorph||50-200mcg/kg||Works slowly
Probably shouldn’t be used until you are thinking about maintenance.
|Intranasal Diamorphine||0.1mg/kg||Work quickly and very well. Should be your first line for acute severe pain.|
|IV Fentanyl||1-2 mcg/kg|
|Lidnocaine||2mg/kg max 200mg||Nerve blocks and regional techniques are underused in paediatrics. They can make EVERYTHING a lot easier.|
|Lidnocaine with adrenaline||7mg/kg max 500mg|
|Bupivicaine||3mg/kg max 150mg|
|Emla||NA||These all take time to work, and you have to weigh up the ‘stewing time’ versus the variable analgesic affect.|
|IV||1mg/kg +0.5mg/kg top up||It is rare that the top up dose will be useful.|
|IM||2mg/kg + 1mg/kg top up|
|Ketamine for Pain|
Paediatric procedural sedation is a useful skill. It is not difficult. Generally, for children under 12 I will use ketamine, and for children who are older I might use Propofol and Fentanyl depending on what I need to do.
There is a general consensus that paediatric sedation is difficult or risky. It is neither of those things providing you prepare appropriately.
How to sedate a child (in brief):
- Gain Consent
- Weigh the child
- Do an airway assessment
- Have an idea about what size BVM/Circuit you want and what size OPA you want.
- Get a cannula in (if you are giving it IV).
- Have appropriate monitoring in place – a sats probe, and ETCO2 is usually all you really need. They can also be applied AFTER you have given the ketamine.
- Perform sedation in resus or a procedure room with full of anesthetic capability. The room needs to be quiet, calm and dark.
- You will need a nurse/seditionist/procedurist as a minimum
- Give your dose of ketamine
- Perform the procedure. The child may respond to painful stimuli. They will not remember.
- Wait for the child to come back to normal.
Things to know about Ketamine
Ketamine works by non-competitive anatagonism of the NMDA receptor, it also has a poorly understood preference of mu and kappa opioid receptors which is probably how it exerts its analgesic effect.
An IV dose of 1mg/kg (2mg/kg IM) is normally sufficient for anything you might need to do in the ED. Ketamine isn’t like Propofol, it doesn’t have a dose-response effect, you aren’t going to dissociate people further by giving much more (As long as you have got your weight estimation correct)
The most recent meta-analysis I could find for ketamine procedural sedation is from 2016 and including 258 studies and 13 876 children. The incidence of adverse events is below. (https://bmjopen.bmj.com/content/6/6/e011384.info).
The figures below are for ketamine sedation alone.
Intubation – 0.03 per 100
Aspiration – NEVER
Use of BVM – 0.6 per 100
Apnoea 0.5 per 100
Hypoxia 1.8 per 100
Agitation 2.4 per 100
Laryngospasm 0.4 per 100
Vomit 8 per 100
The factors that increased the risk of one of adverse airway events happening are (https://www.ncbi.nlm.nih.gov/pubmed/19201064)
This is taken from a different meta-analysis of 8282 paediatric ketamine sedations.
- Age less than 2 or greather than 13
- Dose of >2.5mg/kg
- Giving an anticholinergic
- Giving a benzodiazepine
- Children sedate like they are when you give the ketamine. If they are chilled, they are likely to stay nice and relaxed during the procedure. If they are hyped up, they will stay hyped up but in a dissociated way.
- If your patient is not sedated enough for the procedure. They will need to go to theatre.
- If there are airway noises, gently re-position and re-assess. Laryngospasm is rare, you are more likely to cause it by jumping in and applying PEEP, or inserting an airway when all that may be required is a chin lift.
- Don’t give more than 1 top up dose of ketamine (EVER).
- If you are putting in a cannula try and do it well before the sedation and allow the child to calm down after it. The cannula is the MOST difficult part of procedural sedation.
- Don’t sedate a child more than once in the ED.
- It Is ‘standard’ practice if doing IM sedation to site a cannula ‘for safety’. As the initial treatments for laryngospasm are airway maneuvers and PEEP, IV access is probably over-complicating things. If you are getting into the situation where you need to give suxamethonium (which can be given IM) you’ll probably be in a position where you need to gain IO access anyway. We quite happily give children large doses of oral opiates without siting a cannula first ’for safety’.
|Median Nerve -half of thumb, half of palm
– Flexor Carpi Radialis + Palmaris longus tendon is identified
– 5 mls of local anaesthetic is instilled lateral or medial to this with care that needle doesn’t cause parasthesiae
|Radial Nerve – radial aspect of dorsum of hand, thumb
– 1-2cm proximal to radial styloid, just underneath tendon of EPB
– s/c injection of 5mls
|Ulnar Nerve – ulnar border of hand and half of ring finger
– locate flexor carpi ulnaris tendon
– inject close to the artery, aspirates to check not in artery
– inject as withdraw to get cutaneous branches [5mls]
Tibial nerve L5-S3 – sole of foot
Insert needle posteriolateraly to post tibial artery at level of medial mal until you hit bone. Aprx 5ml.
Saphenous L3L4 and Superficial Peroneal nerve – dorsum of foot and lateral edge
S/C infiltration just anterior to medial malleolus in a ridge over the front of the leg.
Superficial peroneal nerve – L4-S2 – dorsum of foot
Continue saphenous injection to the lateral malleolus.
Sural Nerve L5-S2 – medial edge, 5th toe
S/C infiltration from achilles to lateral mal
Deep peroneal nerve 1st web space
Between EHL and EDL top of foot. Inject top of foot just medial to EHL tendon. Advance to bone and inject.