Sedation for transport

One of your colleagues, Andy, has been lucky enough to grab a ticket to a prestigious international conference to be held in Dublin. He is thinking about taking his children but wonders how to keep them happy on the long international flight. He wonders if you have any tricks up your sleeve for keeping children calm during transit.

Bottom line

There are a range of short-term sedation options that encompass all routes – oral, intranasal and intravenous

Children under 15kg, requiring sedation for MRI, should receive chloral hydrate according to NICE guidelines

There is little consensus on the most effective sedative agent for older children though, given enough time, a number of distraction techniques have been proven to help

Sedating antihistamines, whilst useful for travel sickness, may cause paradoxical excitability

Travelling with children can be fraught with danger. Here we consider some of the options for what is essentially procedural sedation where the procedure is safe transportion of the patient. The journey may be short (to the MRI scanner), moderate (to another hospital) or potentially never-ending (to another country).

The short journey

Occasionally unsettled children need to leave the comfort of the ward or Emergency Department environment for some special investigations. One of the more common destinations is the MRI suite. For some ideas on how to be best prepared to transport a critically unwell patient then take a look at this video.
The majority of patients, however, are not critically unwell but do have to be able to lie still for up to 45 minutes at a time.

The ‘No Sedation’ approach

MRI scanners can be scary and noisy places for children (and adults too) and so preparing children by use of visualisation and simulation may reduce distress if time allows. This is not appropriate for the more emergent case or for younger children.

Other forms of psychological distraction therapy such as the use of guided imagery, hospital clowns, play therapists or dogs have also been shown to reduce anxiety.

The ‘Oral Medication’ approach

Chloral hydrate

Chloral hydrate is a hypnotic agent that precedes the advent of barbiturates and benzodiazepines. It has been the ‘go-to’ agent for oral sedation for many years with quoted doses ranging from 75-100mg per kilogram. Whilst it is certainly useful for children less than 48 months old, it becomes much less effective as the child becomes older. As with most sedative agents it may produce a paradoxical response – the child becomes hyperactive rather than sedated – and this occurs in approximately 6% of cases. It may also cause nausea and vomiting (4%) as well as mild respiratory depression (4%).

Pentobarbital

Pentobarbital, at doses of up to 5mg per kg, has a faster onset and achieves higher sedation scores than chloral but with the downside of an increased risk of paradoxical reactions and a longer duration of sedation. It is not routinely used in Australian practice.

Midazolam

As chloral is less effective as the child gets older, the current UK NICE guidelines suggest the following oral regime:

Weight < 15kg – chloral hydrate
Weight > 15kg – midazolam

One study found that although chloral hydrate was effective more than 90% of the time, midazolam was only effective in 18% of cases!

The ‘Intra-Nasal Medication’ approach

Midazolam

This quick-acting benzodiazepine can be used (via mucosal atomiser) device can be used at doses of 0.15 to 0.45 mg per kilogram. See Tim Horeczko’s post in the Pediatric Emergency Playbook for more details.

Dexmedetomidine

Dexmedetomidine is a potent alpha-2-agonist that is often used as an intravenous sedative agent in the ICU setting. As a tasteless, odourless liquid with rapid onset via the intranasal route, it has been shown to provide a safe and effective means of sedation that avoids intravenous access. Less rescue medication is required at doses of 4 mcg per kilogram.

The ‘IV Medication’ approach’

Using intravenous medication for MRI sedation pushes the child into the realms of general anaesthesia with the need for much more rigorous physiological monitoring. This should only be done in conjunction with the anaesthetic department.

Midazolam

At doses of between 0.1 to 0.6mg per kg

As with both the oral and intranasal approach, the most common adverse event is hypoxia which is easily reversed using simple airway manoeuvres.  

Propofol

As a rapidly acting anaesthetic agent with a relatively short offset time, a continuous infusion will be needed to keep a child still for a 45-minute scan. This places them at risk of complications such as airway obstruction, hypoxia and hypotension.

There are a number of documented factors that increase the need for sedation.  They include:

Previously failed sedation

Potential for failed sedation

Perceived medical risk

The moderate journey

With a lot of us not working in specialist paediatric centres, some children have to be transferred out to the local centre of excellence for further clinical input. If your hospital does not have a paediatric surgeon then the six-year-old with possible appendicitis may have to travel some distance down the road to receive definitive care. Most children will be fine with this journey.

Whilst we can counter the emetogenic effects of a lot of things we do, it can be hard to offset the near-universal nausea induced by car journeys. Australian Prescriber has a great review on motion sickness in children here. All the tricks that parents know such as focusing on the horizon, keeping the window open and lining your stomach with a light meal are not appropriate for inter-hospital transfer.

The ‘Medical’ Approach

Antihistamines

Remember that sedating antihistamines are not benign drugs and there have been case reports of fatalities when OTC antihistamines have been used to treat colds and snuffly noses. In Australia and New Zealand, they require a prescription for use in children under 2 years of age. Their anticholinergic effects include drowsiness, dry mouth and blurred vision as well as the bane of every parent, paradoxical excitability.

Promethazine (Phenergan) and dimenhydrinate (Dramamine and Gravol) are approved for use in Australia, whereas diphenhydramine (Benadryl) is commonly used overseas.

Non-sedating antihistamines are ineffective.

The ‘Alternative’ approach

Ginger, acupressure wristbands and other alternative therapies are as effective as placebo in managing motion sickness in children.

The international flight

Those of us with small children understand the complexities of international travel. It has to be planned with near-military precision – encompassing a shared mental model between parents, multiple checklists and closed-loop communication.

The ‘Over The Counter’ approach

Whilst travel sickness is less of a problem on long-haul flights many parents swear by sedating antihistamines such as promethazine to ease their (and their fellow travellers’ burden). Again it is important to remember the potential paradoxical reaction and test out the medication well in advance

Why shouldn’t neonates fly?

We know that even healthy children will become relatively hypoxic at altitude. There is a theoretical risk that relative surfactant deficiency may lead to worsening V/Q mismatch and critical hypoxia in flight.

The problem is only half over when you arrive though as children find the concept of time zones a little harder to master than their parents and so they will be wide awake at three in the morning.

Weighing up the pro and cons with the full support of his partner he decides to go to the conference without his family on the proviso he brings some nice gifts back with him.

References

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Frankville DD, Spear RM, Dyck JB. The dose of propofol required to prevent children from moving during magnetic resonance imaging. Anesthesiology. 1993 Nov;79(5):953-8.

Greenberg SB, Faerber EN, Aspinall CL, Adams RC. High-dose chloral hydrate sedation for children undergoing MR imaging: safety and efficacy in relation to age. AJR. American Journal of Roentgenology. 1993 Sep;161(3):639-41.

Malviya S, Voepel-Lewis T, Eldevik OP, Rockwell DT, Wong JH, Tait AR. Sedation and general anaesthesia in children undergoing MRI and CT: adverse events and outcomes. British Journal of Anaesthesia. 2000 Jun 1;84(6):743-8. Full text here

Malviya S, Voepel‐Lewis T, Tait AR, Reynolds PI, Gujar SK, Gebarski SS, Petter Eldevik O. Pentobarbital vs chloral hydrate for sedation of children undergoing MRI: efficacy and recovery characteristics. Pediatric Anesthesia. 2004 Jul 1;14(7):589-95.

Rosenberg DR, Sweeney JA, Gillen JS, Kim J, Varanelli MJ, O’HEARN KM, Erb PA, Davis D, Thulborn KR. Magnetic resonance imaging of children without sedation: preparation with simulation. Journal of the American Academy of Child & Adolescent Psychiatry. 1997 Jun 30;36(6):853-9. Full text here

Sammons H, Choonara I, Alotaibi B. Midazolam for imaging procedural sedation in children: A systematic review. Archives of Disease in Childhood. 2015 Jun 1;100(6):e1-.

Stauffer WM, Konop RJ, Kamat D. Traveling with infants and young children part I: anticipatory guidance: travel preparation and preventive health advice. Journal of Travel Medicine. 2001 Sep 1;8(5):254-9.

Tug A, Hanci A, Turk HS, Aybey F, Isil CT, Sayin P, Oba S. Comparison of Two Different Intranasal Doses of Dexmedetomidine in Children for Magnetic Resonance Imaging Sedation. Pediatric Drugs. 2015 Dec 1;17(6):479-85.

Viggiano MP, Giganti F, Rossi A, Di Feo D, Vagnoli L, Calcagno G, Defilippi C. Impact of psychological interventions on reducing anxiety, fear and the need for sedation in children undergoing magnetic resonance imaging. Pediatric Reports. 2015 Feb 24;7(1). Full text here