Abdominal Trauma

The abdomen is the third most injured body part in children, after the head and the chest.

There is a medscape e-learning module here, and a good pdf overview here, here, and another overview here with a summary on page 13. There is some discussion around a case here and some good CT images here. There is an excellent summary about abdominal trauma in children here, which introduces us to some guidelines for careful imaging in children.The anaesthetists at Lewisham wrote a very thorough overview here. There's a good summary of common injuries and their management here.

There is a good CT scan with some SAQs from the PMJ here.

Anatomical differences in children:
- The abdomen is square and becomes more rectangular as the child matures.
- Muscles are thinner, so there is less protection for underlying structures.
- Ribs are more flexible so they are less effective at energy dissipation, so less effective at protecting the upper abdominal structures.
- Solid organs are comparatively larger so are at more risk for injury.
- Attachments are more elastic.
- The intestine is not fully attached within the peritoneal cavity so is more vulnerable to injury due to sudden deceleration and/or abdominal compression.
- The bladder is more exposed.
- Children's spines are exposed to chance fractures, especially if they are restrained with a lap belt only.
- Abdominal distension from aerophagia is common
- Hypothermia is more likely

Clinical Features
The Seatbelt Sign
The seat belt sign is a good indicator of serious injury. In one review, 78% of patients with a seat belt contusion had intra-abdominal injuries, although all children with injuries also had abdominal pain - not just a seat belt sign.
Lap belts are designed to be worn at or below the anterior superior iliac spine level. In smaller children the belts are in the wrong place, and children can move out of them very easily. The introduction of booster seats has helped to improve this. You are up to 3 times more likely to be injured if you are not properly restrained.

Haematuria
The most common indication for abdominal imaging after trauma in children is reported to be haematuria. Non–urinary tract injury is observed more frequently than urinary tract injury in children with haematuria and asymptomatic hematuria is a low-risk indicator for abdominal injury.

80% of injuries are from blunt mechanism.

Holmes 2012 - decision Rules
Holmes looked at children with blunt torso trauma, and suggested some decision rules for when we should be CTing these patients. The paper has been reviewed on PEMLit. He has listed seven factors that make the injury low risk:

Most patients I've seen with trauma do complain of some abdominal pain -so maybe one or two CTs might be saved! This has a 99.9% negative predictive value.

If we do CT it's pretty good at picking up pathology.  If the patient is stable, ultrasound and serial observation is probably sufficient. There's a suggestion of an algorithm here. In a verbal patient, normal obs, normal examination and no abdominal pain is a pretty good indicator of no abdominal injury.

Electrocution in Children

Electrocution is surprisingly common, although rates of lightening strike are decreasing. Given that they should be well aware of the dangers of electricity, I was surprised that electricians and people who work with electricity are most likely to be affected. Electrocutions could affect people in hospital as well as out of hospital, and as the old adage goes, prevention is better than cure. It's not just high voltage electrocutions that cause problems, as a 33 year old with a domestic electrocution found.

If you look hard enough, you can find plenty of information online about electrocution. The AHA has a very thorough article online and EnlightenMe and LITFL have cases on the injuries associated with electrocution.
I know it's not FOAM, but the eLfH e-learning site has a fantastic e-learning module about electrical burns. It tells you a lot about those things that you always wondered about, but weren't quite sure about, and I'd really recommend completing it if you can.

So, lets get started.

Electrocution: death as a result of exposure to electric current

Electrical injury: Tissue damage as a result of exposure to electrical current

Electrical shock: The violent response to electric current exposure often characterised by involuntary muscle contraction.

1000 people per year are estimated to die from exposure to electricity each year. In 2005, there were 11 work related electrocutions and 119 serious injuries in the workplace. Electrical injuries follow a bimodal age distribution pattern - children younger than six, and in early adulthood.


The ability of an electrical current to cause morbidity and mortality is dependent on six different factors:
- Magnitude of the current
- Voltage of the electrical source
- Resistance of tissue types involved - (bone has the most resistance)
- Duration of exposure
- Type of current
- Current pathway

There are two main types of electricity that might cause us injury - low tension and high tension.
 
Low Tension

• <300 Volts 
• at 50hz  
• Alternating current  (AC)
• Domestic (110V in the US and Canada; 220V in Europe, Australia and Asia).
• Can cause VF
• Theoretical risk of late VF if shock travels through the thorax
  May cause tetanic skeletal muscle contractions - stopping people from letting go from the electricity source. Because AC current is repetitive it also increases the likelihood of current flow through the heart during the relative refractory period of the cardiac cycle which can precipitate ventricular fibrillation.
• Intraoral burns are common in young children (toddlers who explore electrical cables by placing them in their mouth). Conduction may be aided by electrolyte rich saliva. Delayed haemorrhage is a recognised feature. 
  Prevention is always important, and ROSPA have lots of advice (and lots of leaflets) about how to make your home safer.

High Tension

• >1000 Volts
• Lightening strikes and overhead power cables.
• Direct current
• May cause asystole, complete heart block and QT prolongation. 
• Keraunoparalysis - transient limb weakness, rarely lasting more than a few hours. Upper limbs > lower limbs. 
• Lightening strikes - mortality of 30%
• extensive autonomic stimulation - hypertension, tachycardia and nonspecific electrocardiographic changes
• brain haemorrhages, oedema and nerve injury.
• Lichtenberg’s flowers 
• Transient, fernlike erythematous floral pattern that develops on the skin
• Fades in 24 - 36 hours 

This type of electricity simultaneously depolarises the entire myocardium. This normally stops the heart completely, but sometimes the heart sorts itself out again and starts working normally again (it has intrinsic cardiac automaticity). This type of electricity also causes thoracic muscle spasm making it very difficult to breathe. Secondary hypoxic cardiac arreast is likely! Victims are most likely to die if they experience immediate respiratory or cardiac arrest and no treatment is provided - if treatment is provided at scene, results are often good. 
DC exposure is single, and often throws the victim away. A direct strike is uncommon, and often splashes sideways from an object or a victim may be holding on to a struck object.

Treatment

• Early basic life support and defibrillation if needed
• Airway:
• Secure the airway early (airway burns likely)
• C-Spine Control:
• Especially if DC current - may have been ejected
• Breathing:
• AC current may paralyse thoracic muscles
• Circulation:
• Hypovolaemia from concurrent injuries likely
• ECG - assess for presence of sinus rhythm, and remember to check the QT interval
• Cannulate in a limb not involved in the current pathway 
• There may be damage to vascular structures that will stop systemic circulation
• Disability: 
• Look for entry and exit burns
• Cool burns as appropriate 
• Remove smouldering clothes, shoes and belts. 
• Exposure: 
• Look for compartment syndrome (if you don't look you won't see!)
• Bloods for:
• FBC, U&E (hyperkalaemia secondary to rhabdomyolysis likely)
• Phosphate
• Calcium
• CK
• Group and Save
• Role of troponins is unclear 
•  Check hearing
• Risk of ruptured ear drums from lightening (Oxford Handbook of Emergency Medicine)
• Urinalysis - check for blood
• Observe
• Six hours of being asymptomatic
• Send home
• Asymptomatic patients with 
• domestic and minor low voltage burns
• normal ECG
• no history suggestive of arrhythmia
• no myoglobinuria
• Admit
• Children who bite electrical flexes
• risk of delayed bleeding
•  All patient with high voltage conduction injuries, or abnormalities found.
• Follow Up 
• Delayed cataract formation 
• Neuropsychiatric problems
• Compartment syndrome advice

The management of burns is important - we'll cover this later!

Venous Access in Children

Intravenous Cannulation
 Most of us are skilled at gaining IV access in adults, but get a bit more concerned when we need to bleed or cannulate a small child. Here's a few tips I've picked up on the way...

Preparation and Distraction

• Get all your stuff ready and open before you start. This means the rustling isn't off putting.
• If the child is big enough, sit them on a parent's knee, and position the hand behind them, so they can't see what is going on. 
• Distraction is really important - parents are excellent at this. They might use an iphone, Where's Wally, or singing of Nursery Rhymes.
• Go in to the room feeling positive and as though you WILL succeed - children pick up on the vibes.
  
• Ametop or Emla cream is very helpful if you have time.
• Babies still feel pain - sucrose can be helpful. 
• If you don't have time for Ametop to work, remember cold spray can be helpful. 
• Analgesic gas can also be very useful - using it also distracts the child!

Technique
There are plenty of excellent resources demonstrating a good technique.

• Medscape
• Royal Children's Hospital
• You Tube

From personal practice, I think the most important steps are distraction (otherwise you have a wriggling child), confidence, and holding the skin really really taut before attempting the cannulation.
What are your tips?

Intraosseous Cannulation
IO is a new idea in adult trauma, but has been used in children for a while. There's a great article on IO in trauma here. There are many methods of gaining IO access in children and despite them all seeming as good as each other in adults,  EZ-IO seems better and quicker in children, with low complications... Whether your department uses a Cook needle or a gun type device like the EZ IO make sure you know how to use it, and which needle to use. Most devices use a pink needle for children.

Although it doesn't alter flow rates, the site you chose for IO access is really important in children, as you don't want to damage their growth plates. These guidelines have clear location pictures reminding us of where the growth plates are. EZ - IO have a clear powerpoint with guidelines too. 

1. Tibia
   Find the flat anteromedial surface of the tibia one- to two-finger breadths below the level of the tibial tuberosity is the preferred site.
   Position the leg with the knee slightly bent and semi-externally rotated. Place a sandbag or towel roll under the leg for support.
2. Ankle
   One- to two-finger breadths proximal to the medial malleolus, sufficiently posterior to avoid the saphenous vein.
   Externally rotate the leg.
   Use only as last choice in young children
3. Humerus
   1 cm above the surgical neck (where the bone juts out)

• Clean the area
• Insert the IO
• After you have inserted the IO, you need to unscrew the needle from the stylet, and dispose of the needle. If you forget to unscrew the needle your IO won't work!
• Secure the IO 
• Consider  flushing with local anaesthetic.
• Aspirate bone marrow for analysis (and remember to let the lab know).
• Attach extension tubing to the IO. This means you can easily access the IO without repeatedly moving the IO.

Keep practicing when ever you can on the non-poorlies, and then when you need to gain IV or IO access in a poorly patient, you'll have no problems.

Drowning

Drowning and near drowning is a fascinating area. As a dinghy sailor, I regularly teach about drowning on our first aid courses, but as we sail on top of the water and not in the water, I've still never seen it! If you get a chance to watch the Cold Water Casualty video, it is well worth a watch. The Royal Yachting Association has a good summary about cold shock, hypothermia and drowning. The RNLI provides some UK statistics. Drowning is specifically mentioned in the cardiac arrest competencies, and in HAP11 Environmental emergencies (an adult competency).

WHO provides us a statistical summary about drowning, and Update in Anaesthesia provides a very thorough overview as does BMJ best practice, LITFL, EP monthly and the AHA.

There is an e-learning module on drowning here and here. Unless you are a Paramedic you're unlikely to have access to the former, and there are so many alternative resources out there I wouldn't subscribe. Enlighten me has an excellent CEMPedia article on drowning  and an adult case.


Statistics
Drowning is the process of experiencing respiratory impairment from submersion/immersion in liquid. In 2000, there were 409,272 deaths from unintentional drowning worldwide, decreasing slightly in 2004 to an estimated 388 000. 150 people drown in the UK coast every year - and 80% of these are male. Drowning is the second highest cause of death from injury, after road traffic injuries.

Young children are at risk as they are unaware of the dangers and less able to escape from water once submerged.

Things Drowning Causes
There are four main problems drowning causes:

• Hypothermia and Cold Water Shock
  Not everyone drowns in warm water! Hypothermia causes its own special problems. The most relevant problem is that blood gets diverted in to the core of the body - causing chilly blood outside, and warm blood inside. When you start to mix the warm and chilly blood, the body gets a bit confused - and arrhythmias can occur.
  Cold shock can happen at any water temperature below fifteen degrees - the average UK water temperature is twelve degrees.
• Associated injuries
  Remember to think about what people injured when they drowned themselves - neck and c-spine injuries are common.
  Awareness of injuries will be low because of natural adrenaline, and vasoconstriction in the extremities.
• Water aspiration
  As you hit the water, before the diving reflex is triggered, you get a gasp reflex (as you do when you first get in a really cold swimming pool!). If you enter turbulant water, as waves crash overhead you are even more likely to inhale some water. Aspiration of even small amounts of water significantly impairs gas exchange. The water dilutes and inactivates surfactant, so alveoli are prone to collapse. The water can also cause direct lung injury.
• Post rescue Collapse
  Loss of hydrostatic pressure of water on the body results in loss of peripheral resistance and venous pooling. Patients should be extricated from the water in a horizontal position.
• Post Drowning Infection
  Some people contract infections after drowning. Swamp water might cause fungal infection (aspergillosis)- so think about it in your poorly patients. Stagnant water with rat urine may cause Weil's disease (Leptospirosis). There are many case reports (1 2 3) about pneumonia after drowning - but there is still no evidence for prophylactic antibiotics.

Investigations
- ABG if significant history of submersion as saturations may not be reliable.
- CXR
- ECG - look closely for a prolonged QTc.
- Core temperature measurement
- Electrolytes and BM
- Blood culture in patients with significant aspiration

Treatment

• ABCD approach
• For children, no modifications to the resuscitation sequence are recommended.
• If intubation needed, ventilate using an ARDS protocol. 
• Observe for  at least six hours.
• After discharge, written discharge advice is well received by families. 
• There is no evidence to support giving prophylactic antibiotics on discharge.

The airway in children

Before we started to think about how to recognise a problematic airway, it is useful to think about the airway of a child, and how this differs from adults.

This page has a nice summary. It's written for anaesthetists so has more information than we'll need to know (hopefully!).There's a very good summary here and here, with some practical suggestions.

LITFL has not let us down, and they also have an excellent summary together with some management tips. e-LfH has a module about stridor.

There is a very thorough powerpoint presentation all about the difficult airway in children here. The pictures are well placed, and makes you realise that children really aren't just little adults.

Basically, children are much more likely to have difficult airways, and have a high anterior larynx. There are lots of pictures that demonstrate these differences really well:



http://www.ceu-emt.com/images/childadultupperair.gif

This is a really good overview, with every difference labelled on a very clear picture.

http://www.revcolanest.com.co/en/la-via-aerea-pediatrica-algunos/articulo/90149961/


There is a nice little case based e-learning module on doctors.net here:
http://www.doctors.net.uk/ecme/wfrmNewIntro.aspx?moduleid=1562
It is a useful reminder of some of the common, and not so common, airway problems in children. 

Ventilate - which ever way you can!

Online Tutorials

There are quite a few places that offer free online tutorials if you are appropriately registered.

• Medline: Anaphylaxis Tutorial
  This is very American, but contains lots of good information. It is a useful overview of the clinical features, and the physiological features. 

• Doctors.org.uk Anaphylaxis Module
  This is a quick but effective case based tutorial on anaphylaxis. It includes a case from a child, and was a very useful over view.
  
  
• BMJ Learning
  There are no BMJ learning modules on anaphylaxis in children.
  
• Enlighten Me
  OSCE Assessment form - this is really useful as it emphasises what you need to know for each different "level" of knowledge.
  Case Study - a four year old with difficulty breathing needs your help...
  CEMPaedia - all about anaphylaxis
  Knowledge Bank - if it all goes wrong, what happens when your patient arrests? Mostly about big people - but a mention of a 16 year old.