Analgesia and Procedural Sedation Module

Cite this article as:
Team DFTB. Analgesia and Procedural Sedation Module, Don't Forget the Bubbles, 2020. Available at:
https://doi.org/10.31440/DFTB.27063
TopicAnalgesia and procedural sedation
AuthorLauren Shearer
DurationUp to 2 hours
Equipment requiredNone
Outline
Pre-reading
Case: pain assessment and the analgesic ladder
Pain assessment and the analgesic ladder: discussion
Case: other analgesic considerations
Other analgesic considerations: discussion
Advanced case: entonox sedation + adjuncts
Entonox sedation + adjuncts: discussion
Advanced case: ketamine sedation
Ketamine sedation: discussion
Simulation
Quiz
References
  • Pre-reading
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline for sharing admission criteria.

Lily, 4 years old, presents to the ED with her mother after falling from a scooter whilst in the park. She is holding her arm and not using it. There is no obvious gross deformity.

How would you do a pain assessment in this age category?

What would be the optimum analgesia choice based on a severe pain score?

What other methods or non-pharmacological adjuncts can be used?

When should we reassess the pain?

Pain scores

See RCEM Pain in Children – Best Practice Guidance for a guide on how to assess pain.

Consider different assessment tools:

  • FLACC (Face, legs, activity, cry, and consolability)
  • Wong Baker Faces
  • Visual analogue scale

Analgesic ladder

See the analgesic ladder (RCEM guidance above and the WHO pain ladder).

Adjuvants should be considered in all steps of the ladder.

Bottom of the ladder is the most commonly used paracetamol (at 15mg/kg/dose) and non-steroidal anti-inflammatory drugs (NSAIDs). Paracetamol is an antipyretic and weak analgesic. It is used for the treatment of mild pain and fever associated with a sore throat or illness. But we should avoid oligo-analgesia and use the right drug for the right kind of pain.

Moving up the ladder are weak opioids like codeine. Codeine (an inactive compound of morphine) is no longer recommended for the management of acute moderate pain, particularly in children under 12 years with obstructive sleep apnoea or for post tonsillectomy procedures. Codeine must be metabolised by the cytochrome P450 enzyme 2D6 to the active compound, morphine, to relieve pain. Poor metabolisers of codeine may metabolise only up to 15% of the morphine concentration, receiving little or no analgesia from codeine. Ultra rapid metabolisers may metabolise up to 50% more morphine than normal metabolisers – which is potentially life threatening.

Children with moderate to severe pain should receive opioids together with non opioids. Morphine, oxycodone, hydromorphone are all active compounds that do not require the enzyme conversion to provide analgesia. Fentanyl, a synthetic opioid, has few, if any cardiovascular side effects. This is in contrast to morphine which may exacerbate hypotension with its vasodilatory effects. So in haemodynamically unstable children, fentanyl may be the preferred choice for acute pain management.

What about IN fentanyl?

It’s easy to use, it’s needle-less, and decreases the overall need for utilisation of IV or IM routes which is a positive change in parent and patient satisfaction. It bypasses first pass metabolism permitting rapid and predictable bioavailability (compared with oral and intramuscular routes) and offers direct CSF delivery via the nose- brain pathway route

The maximum volume of IN medication permitted is 1ml per nostril and in cases of nasal trauma or septal defects, IN Fentanyl of course cannot be used. Rule of thumb, the IN dose is 2-3 times the IV dose.

Administer intranasal medications in the sniffing position. Lie the patient flat with occiput posterior, put patient in the sniffing position, seat the mucosal atomizing device cushion in the nostril, aim toward the pinna of the ear, and shoot fast – you have to push the drug as fast as you can to atomize the solution.

IN medication can be used for sedation, anxiolysis, pain control and seizure management. A 2014 Cochrane review on intranasal fentanyl concluded that it can be an effective analgesic for children aged 3 years and above with acute moderate to severe pain. Studies have demonstrated INF to result in decreased time to medication administration and equivalent pain control when compared to IV morphine, oral morphine or IV Fentanyl. IN Fentanyl (1.5mcg/kg) has become an excellent alternative to morphine in the ED, it has a greater safety profile and is easily available in the ED.

What about IN Ketamine?

How does it compare to IN Fentanyl? One study demonstrated a similar pain reduction in children with moderate to severe pain from an isolated limb injury in the Paediatric ED, although the sample size was small and there was no comparator or placebo group. Adverse effects were more frequent with ketamine; however, these were all relatively mild (drowsiness and dizziness). Also, practically speaking, pain control doses for the IN Ketamine route at 1mg/kg mean that volumes for most children weighing above 10kg will exceed 1ml per naris if the ketamine concentration 10mg/ml is used.

What about IN Dexmedetomidine?

An alpha-2 receptor agonist (like clonidine), does not markedly decrease blood pressure. Dexmedetomidine targets receptors in the CNS and spinal cord, and so it provides deep sedation, with very minimal blood pressure effects. It induces a sleep-like state. In fact, EEGs done under dex show the same pattern as seen in stage II sleep. Dexmedetomidine is safe, if titrated, and does not depress airway reflexes or respiration. Dose is 2.5 mcg/kg IN, and can add another 1 mcg/kg if needed. The downside is that it can last 30 minutes or more, but it may be a good choice for an abdominal ultrasound or CT head.Inflicting Pain with an IV to relieve pain is not something that makes sense to young children. IN medication offers pain relief prior to getting intravenous access and can even obviate the need for IV access if definitive care such as a cast, suturing, reduction of bony injuries can be done during the duration of action of the IN medication.

Consider non-pharmacological adjuncts

It is important these are thought about in conjunction with pharmacological techniques. These include:
Play specialists

  • Distraction techniques
  • Music
  • Games
  • Don’t forget the Bubbles

Immobilisation of injuries

Environment

  • Right people
  • Right place  
  • Right time

Parental/carer anxiety

Neonates

Sucrose, and non-nutritive sucking interventions exert analgesic effects independent of the opioid pathway. Swaddling/facilitated tucking (preterm) and skin to skin care significantly increase B-endorphin levels.

Rocking/holding neonates and breastfeeding during minor procedures have all been shown to decrease objective measures of pain such as heart rate and crying.

Reassess

Pain should be assessed on arrival and then monitored throughout their time in the emergency department and if appropriate beyond. Children in moderate and severe pain should have their pain reassessed within 60 minutes of receiving analgesia.

Frank, 8-years-old, was playing in the street with friends and fell over. He cut his knee on some broken glass and sustained a 4 cm laceration over his patella. An x-ray shows no foreign body and no fractures. The knee is swollen and the laceration requires suturing. On pain assessment he is reporting mild pain.

What are your initial considerations?

What are the options for cleaning and closing?

Don’t forget oral analgesics (as above) and a full assessment for other injuries.

LAT gel (lidocaine, adrenaline and tetracaine)

  • Unsuitable for under 1s
  • Takes 20-30 minutes to work
  • Skin will blanch when ready
  • Max dose: 2 mls for 1 -3 year; 3 mls for >3 years
  • Not for use on: mucous membranes; extremities; wounds >8 hours old
  • Can be used in conjunction with local anaesthetic infiltration
  • Max dose not to exceed 5mg/kg

Local anaesthetic infiltration

  • Inject slowly to reduce pain
  • Small gauge needle to reduce pain
  • Doses: 3mg/kg lidocaine

Other topical agents (not for this case specifically):

EMLA cream (lidocaine 2.5% and prilocaine 2.5%) is effective at numbing the tissue below intact skin to a depth of 6-7mm if left on for 30-60 min but does cause vasoconstriction which can be problematic if looking to cannulate.

LMX4, a topical liposomal 4% lidocaine cream like EMLA has full effectiveness by 30 minutes.

Environment

  • Play specialist
    Distraction techniques appropriate to age
  • Preparation of the child and area
  • Quiet setting
  • Parental/carer involvement
  • Using appropriate language

Freddie, 9 years old, attends the emergency department after falling from the monkey bars. He has sustained a displaced and angulated supracondylar fracture. He has some tingling at the fingers in the ulna distribution and therefore requires urgent manipulation. You decide to use nitrous oxide.

Do you need any pharmacological adjuncts?

What about non pharmacological?

What other considerations should be made?

Nitrous oxide – mechanism

Nitrous oxide provides anaesthesia, anoxiolysis and some mild amnesia but offers limited analgesia. Administration of analgesic supplements is recommended. Many papers including the FAN study demonstrate the safety and efficacy of co-administering intranasal fentanyl. Other analgesics can also be safely used.

Delivery methods

There are two methods of delivering nitrous oxide, piped nitrous oxide and Entonox. Piped nitrous oxide can provide variable concentrations and can be titrated to response, whereas entonox is a fixed 50/50 mix of nitrous and oxygen and comes in canisters. The canister is set up with a demand value that needs to be overcome with a deep breath; this can be difficult for under 5’s.  You should see onset of effect in 30-60 seconds with the peak effect at 2-5 minutes. Offset of effects is similar at 2-5minutes, 100% oxygen should be applied during this time post procedure to avoid diffusion hypoxia.

Side effects

Side effects are minor and transient but include:

  • Nausea
  • Vomiting (6-10% children receiving 50% dose). Increases incidence with higher dose, longer duration and concurrent opioid use. Consider prophylactic antiemetic if child has history of nausea or vomiting.
  • Dizziness
  • Nightmares

Contraindications

Nitrous oxide diffuses through tissues more rapidly than nitrogen alone and can expand in air containing spaces within the body, so it is contraindicated in:

  • Pneumothorax
  • Pneumocephalus
  • After diving
  • Gastrointestinal obstruction

Nitrous oxide inactivates the vitamin B12 dependent enzyme, methionine synthase and can deplete the B12 stores.  Therefore caution is advised in those at risk of vitamin B12 deficiency (vegetarians, patients with gastrointestinal disorders and those taking regular H2 receptors and proton pump inhibitors)

Monitoring and staffing

Despite the absence of use of intravenous sedative drugs, it is best practice to manage this patient in a high dependency setting, with monitoring including; respiratory rate, heart rate and oxygen saturations and at least 2 members of staff where one’s job is entirely focused on the sedation and monitoring of the child.

Guided imagery

Guided imagery would work well in this setting with a trained practitioner.  This is a process where a variety of techniques can be used such as simple visualisation, story telling, direct suggestion imagery and fantasy exploration to elicit a physical response such as a reduction in pain, stress or anxiety.

Lola, 2 years old, has fallen in the playground and sustained a laceration to the forehead. Lola had an ice cream after the incident in an attempt to settle her. She has no past medical history and was born at term. Can she have procedural sedation in the department? What are the considerations?

What drugs do you need for the sedation? Should you use any adjuncts with the ketamine? Are there any emergency drugs you should have available?

There are no contraindications and you decide to go ahead with ketamine sedation, during the procedure whilst full monitoring in place the CO2 trace is lost.  What is your structured approach to management of this scenario?

Contraindications

A through pre sedation assessment is required to assess ASA grade, examine airway anatomy and illicit any contraindications listed below

Fasting

Multiple studies have shown that fasting does not reduce the risk of aspiration or increase the risk of adverse events and the 2020 updated guidelines for ketamine sedation in the ED have echoed this. They advised that the fasting state should be considered in relation to the urgency of the procedure, but recent food intake should not be considered a contraindication to ketamine use. 

Setting

RCEM states the procedure should be carried out in an area with immediate access to full resuscitation facilities; three practitioners should be present throughout, one for the sedation, one for the procedure and one for monitoring and assistance. The updated 2020 guidance has included capnography in the mandatory monitoring required along with heart rate, ECG, blood pressure, respiratory rate and oxygen saturations. While there is no evidence that shows that capnography reduces the incidence of adverse events, there are studies that show capnography decreased the incidence of hypoxia and respiratory events. 

Pre-oxygenation

Oxygen should be given prior to the procedure if possible and during to reduce the time to de-saturation should an adverse event occur.

Ketamine

Ketamine is a NMDA receptor antagonist. It is a dissociative anaesthetic, a potent analgesic and amnesic. Ketamine induces a trance like state, often with the eyes open. It maintains the airway reflexes and maintains cardiovascular stability.

The RCEM accepted dose is 1mg/kg over 60 seconds. A rate of 60 seconds reduces the incidence of adverse events such as laryngospasm. A top up dose of 0.5mg/kg can be used if necessary. Onset is within 1 minute and will elicit a horizontal nystagmus and a loss of response to verbal stimuli. The HR, BP and RR may increase slightly. Sedation will wear off after 20 minutes and full recovery should occur by 60-120 minutes. RCEM no longer advise the use of IM ketamine as they suggest it is safer to have IV access available from the start of the procedure should an adverse event occur.

Adjuncts

Midazolam: a 2018 BestBets review looking at 6 studies including 2 RCTs has shown that prophylactic benzodiazepines do not significantly decrease the incidence of emergence delirium and they in fact can increase the risk of adverse events, so they should not routinely be given prophylactically. However, midazolam can be used to treat severe emergence, especially in older children. (Aliquots of IV 0.05-0.1mg/kg can be given)

Atropine: atropine was previously used prophylactically to reduce secretions however there is no evidence to support its routine use to prevent laryngospasm or other adverse airway events and again it may increase the rate or adverse events. (Green et al)

Ondansetron: may be appropriate for patients at high risk of vomiting due to ketamine’s emetogenic properties. High-risk groups include those with previous nausea/vomiting during sedation/anaesthesia, older children, those who have received opioids or where ketamine is given intramuscularly. Caution should be used in those at risk of long QT.

Emergency drugs: RCEM suggests key resuscitation drug dose calculations should be done prior to the procedure and these should be accessible, however, no specific drugs are recommended. We suggest that WETFLAG dosing should be done along with the dose calculated for suxamethonium (1.5mg/kg for RSI).

Complications

Complications are rare with ketamine. A recent study by Bhatt et al in 2017 (6,760 patients across 5 sites in Canada) looking at propofol, ketamine, propofol/ketamine and ketamine/fentanyl, ketamine alone recorded the lowest serious adverse events at 0.4%. Green et al (2009) showed a 1% risk of noisy breathing requiring airway repositioning, a 0.3% risk of laryngospasm and 0.02% risk of intubation being required.

The capnography trace is there to provide early warning of potential or impending airway and respiratory adverse events. A loss of capnography trace indicates apnoea or obstruction. First check the equipment and monitoring is still in place then check for chest wall movement. If the chest wall is not moving then there is central apnoea. If there is chest wall movement there is obstruction. Airway manoeuvres will relieve obstructive apnoea but will not relieve laryngospasm.

10-year-old boy fell from the top of the climbing frame, landed awkwardly on his left ankle. Primary survey shows no other injuries except obvious deformity of the left ankle.

Scenario

Summary: procedure appropriate for sedation – post procedure simple airway issues due to obesity

Faculty required: operator/Voice of patient/Nurse in scenario

Vitals: HR 120, BP 105/60, Sats 99%, RR 20, ETCO2 4.2, ECG NSR

To establish…

Neurovascular compromise of the foot, CRT delayed

PMH: nil

BH: term, nil complications

DH: nil

NKDA, UTD with immunisations

Last ate 2 hours prior

Candidate should…

  • Check full medical history
  • ASA status
  • Airway assessment (loose tooth, excess body fat)
  • Ensure appropriate setting (RESUS)
  • Appropriate equipment and monitoring (ECG, EtCO2, Sats, HR, RR, BP, suction, tilting table, resuscitation facilities)
  • Describe consent
  • WETFLAG calculations plus emergency drug calculations
  • Choice of appropriate drugs and dosing for sedation
  • Ensure appropriate staff
  • Pre-oxygenation
  • Checks patient during procedure

Post procedure end tidal CO2 trace is lost (due to obesity)

  • Checks equipment
  • Chest wall movement
  • Simple patient positioning and airway manoeuvre opens the airway and CO2 trace returns  
  • Describes post procedure monitoring

Learning points

  1. Emphasis on appropriate preparation
  2. Systematic approach to adverse events and when to anticipate them

Question 1

When should you assess a child’s pain and document a pain score in the emergency department when they present with an injury?

A: Wait until the child is seen by a doctor before assessing pain

B: At triage

C: Immediately after giving oral analgesia

D: Within 60 minutes of receiving analgesia for moderate and severe pain

E: When the child or the child’s parents informs you they are in pain

Answer 1

The correct answer is B + D.

A child’s pain should be assessed on arrival in the emergency department, and should be treated appropriately in a timely manner (within 20 minutes for moderate and severe pain). Pain should also be re-evaluated within 60 minutes of receiving analgesia for moderate and severe pain. This process should be repeated for all subsequent doses of analgesia. Reviewing pain should take into account peak of onset for the analgesia given; as such oral analgesics will not work immediately.

Question 2

Which of the following predict possible airway difficulties in children?

A: C-spine immobilisation

B: Premature birth requiring NICU

C: Trisomy 21

D: Mouth breathing or frequent drooling

E: Reduced mouth opening

Answer 2

All are true.

A through pre assessment prior to sedation should be done to elicit any potential complications and also decide on appropriateness of sedation in the emergency department.

A formal airway assessment should include:

  • Mouth opening
  • Assessment of dentition for loose and protruding teeth
  • Tongue size
  • Presence of soft tissue masses in the mouth
  • Mandible size
  • Neck mobility
  • Tempero-mandibular joint mobility

A review of the child’s medical history should also include, congenital abnormalities, birth complications, previous complications during anaesthetics or sedation, noisy breathing, sleep issues and concurrent upper respiratory tract infections.


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Author: Team DFTB Someone has to do the work around here and who better than the DFTB house-elves .

2 Responses to "Analgesia and Procedural Sedation Module"

  1. Avatar
    Anna Thomas 2 months ago .Reply

    This is a great review – thanks!

    Just to point out that under ketamine sedation adjuncts – midazolam, I think you mean ’emergence delirium’ not just ’emergence’.
    Thanks

    • Avatar
      Andrew Tagg 2 months ago .Reply

      It’s amazing how just one word makes a difference. Fixed – thanks, Anna

      ~ Andy

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