Burns

Over 175000 patients visit the emergency department every year with a burns injury in the UK. Burns can be life threatening in the acute phase and severely affect quality of life in the chronic phase with scarring and sometimes even loss of limbs and body parts. Care in the first hours can have a massive impact on the long term outcome, so here is the facts on burns! 

FIRST AID:

If you approach a burns patient outside of hospital adopt the SAFE approach first always.
SAFE: Shout for help, Assess scene (is it safe?), ensure its Free from danger before you approach, Evaluate the casualty (ABCDE)). Pay particular attention to the A for Airway in your primary and secondary surveys and look for signs of inhalation injury (listed below).

After you have done a general assessment of the patient with ABCD, remove any clothing and jewellery around the injury unless they are stuck to the wound, then leave it. 

Manage the burn with the 3 C's:

COOL CALL COVER

Cool the burn with normal running tap water for at least 20 minutes, the water should be around 15 degrees. Cooling is beneficial up to three hours after the burn. The rule is to cool the burn but warm the patient! so make sure the rest of the patient is well covered up, you must prevent hypothermia at all costs. Don't use ice. 

Call an ambulance. 

Cover the injury, use loose clingfilm, on the face you should use wet gauze instead. 

EXAMINATION AND HISTORY:

The severity of a burn is judged by the percentage total body surface affected (%TBSA) and the depth of the burn.

3 methods for Judging %TBSA: 
- Wallaces rule of nines (adults, picture below)
- Lund and Bowder chart (accounts for age differences)
- Number of hands (Area of palmar surface of hand is equal to1%)
Include all burnt areas in the surface area but NOT very superficial burns, with no blistering and only red and dry.

Judging depth of burn, four levels of depth:
(-Superficial (dry, red and painful, normal capillary refill)
-Superficial dermal (erythematous, small blistering, moist, painful, brisk capillary refill)
-Mid-dermal (dark pink, blistered, sluggish capillary refill, dull sensation)
-Deep-dermal (blotchy red, may be blisters still, no refill, no sensation)
-Full thickness (white or black, eschar often present, no refill and insensate)

This system has largely superceded the degrees system but is roughly the same:
superficial dermal=first degree burn
mid-dermal and deep dermal= second degree burn
full thickness= third degree burn
note that deep dermal and full thickness burns will not heal!

You should pay pay aprticular attention to signs of impending airway obstruction; hoarseness, stridor, snoring and smoke induced inhalation injury which can result in airway oedema and obstruction. So look for signs of burns to mouth, nose, face, singed nasal hairrs, carbonacous sputum. 

If any of the burns are circumferential in nature, they could act as a tourniquet with scarring and tissue swelling underneath. This could lead to limb ischemia or even respiratory compromise if the chest wall is involved. You need to look out for this! To preserve the limb the patient may need an 'echarotomy' a surgical incision of the burnt tissue to allow the tissue to expand. 

FLUIDS:

Loss of water from the burnt area and generalised oedema caused by systemic inflammation can cause a life threatening hypovolemia and organ failure.
Start fluids with all burns greater than 15% TBSA using m-Parkland formula below
and aim for a urine output of 0.5ml per kg body weight.
Remember inhalation burns also lead to fluid losses! (you cannot see the extent of internal burns).

The Modified Parkland Formula:
-give 3-4ml Hartmanns solution per kg body weight per %TBSA over 24hours (half given over first 8hours, over half given over next 16hours).

Dilutional hyponatremia is common and so is hyperkalemia with extensive muscle damage. Electrocution burns can cause rhadbomyolysis and myoglobinuria. You may need to increase the fluid resuscitation to prevent acute tubular necrosis from kidney myogobin overload.

MANAGEMENT and pearls:

Inhalation injury management:
-establish patent airway early and consider intubation early. oxygenate and ventilate. Get arterial blood gases and CO levels.

Get tetanus status

Gastroparesis is common and you should consider inserting a NGT.

Patients are often in pain and emotional distress so give IV analgesia early. Consider opioids as first line (titrated to effect).

Avoid antiseptics and dress wounds with non-adherent dressings and gauze, applie covering bandge very loosely. In a first aid setting clingfilm works very well.
-Paraffin gauze and silver sulfadiazine cream, covered with gauze and bandage.

Consider non-accidental injury and abuse, (does the pattern of injury fit the story).

Antibiotics not indicated in early care

Children: start fluids with 10% TBSA burns and aim for urine output of 1ml per kg body wt.

When to refer to a burns specialist/burns centre:

• Any chemical or electrical burn
• Any burn to face, perineum/genitalia, hands and feet
• TBSA greater than 25% second degree burn
• All full thickness burns

Main complications of full thickness/third degree burns:

• Infections, sepsis
• Tetanus
• Hypothermia
• Hypovolemia

Chemical burn management:

-Brush off any powder first, flush the area with copious amounts of water for 20-30minutes. Note duration of exposure and whether chemical is acid or base. 

Surgical management:

(generally by  a plastic surgeon or burns specialist)

Dressing, Escharotomy, Escharectomy, Flaps, Graft

-late escharectomy has better aesthetic outcomes but early escharotomy may be necessary for circulation or ventilation problems. 

Sources:

-Emergency medicine secrets 6th edition Dr Vincent Markovchick 2016

-Student BMJ January 2016 volume 24

-Lecture notes Prof Klinger Humanitas University 2016 and seminar 2015

How to stay well this winter, a short video by the NHS choir explaining exactly that.

The chart-topping @Choir_NHS are here to help everyone to #StayWellThisWinter – show your support and share their song! pic.twitter.com/VHlwVJR49R

— NHS Choices (@NHSChoices) December 5, 2016

What did I learn today? 3

Back from England after taking the SJT exam, learnt alot today.

• You cant be a person and doctor.
• Italy yesterday had a referendum to change the constitution, a move by Prime minister Renzi to overcome the political gridlock that makes passing laws so difficult in Italy. The vote ended 60:40 in favour of the NO vote.  A result alongside the election of a far right prime minister in Austria and Brexit, could further push the eurozone into the shadows. 
• When to order a CT when the GCS is normal after a minor head injury, follow the 'Avoid Driving if you Get SSmashed And Vomit' rule. 
• Some native Indian foxes explain the concept of mindfullness and how it, works. 
• It might be better to diagnosis someone with 'ACL tear 90%' or 'Congestive heart failure 55%' with a percentage indicating our diagnostic certainty. First10EM talks about diagnostic uncertainty and how it might help prevent misdiagnosis and the alarming frequency that provisional diagnoses become permanent diagnoses. 
• People are happier when they talk to strangers
• By April 2018 the UK could see a sugar tax, a law capable of preventing 3.7milllion people from getting obese. The debate is this spring and will take around a year to take full effect. 

Forensic medicine: Gun Shot Wounds

Depending on where you are working, gun shot wounds (GSWs) may be a rarity or so common that almost everyday you will see a patient with a GSW in the emergency room. GSWs generally have a bad prognosis with a high incidence of gangrene and anaerobic infection. On top of that there is likely to be a criminal investigation regarding the shooting, so knowledge of how to describe a lesion and preserve evidence is incredibly important. 

When talking about GSWs you first need to consider the construction of the bullet and the mechanics of gunfire. Projectiles are most often made of lead and may be jacketed or not, the jacket is often made of an alloy like brass (copper and zinc alloy). Here in Italy, unjacketed projectiles are illegal.

The bullet contains the projectile, jacket and a small amount of gunpowder which produces the explosion behind which propels the projectile.  The gunpowder usually contains the following chemicals; Barium, Antimony and Lead. These chemicals are what forensics pathologists look for when they look for evidence, they can sometimes even type the gun with knowledge of the chemical ratio.

On pressing the trigger there is a small explosion and most of the gunpowder is burnt to produce gas, however some powder will not burn and be fired along with the projectile.

So when the bullet exits the muzzle of the gun, gas and small fragments of unburnt powder also exits the gun like a kind of small pepper spray, there is also residue and grease from the barrel that is fired along with everything else.

A shotgun bullet is slightly different in that the projectile is actually a collection on small pellets (the shot) as the pellets leave the barrel of the gun they spread out so a GSW from a close range shotgun shot (it forms a large hole) is different to a long range shotgun shot (many small holes).

Bullets may penetrate the body and may exit or stop within the body. They can ricochet off bone and some are actually made to bounce more in the body cavities (nasty). The bullet entry hole is usually much bigger than the actual bullet because as the bullet travels through the air it spins and oscillates (again some are designed to do this more, for more damage). It can sometimes be very difficult to tell the difference between the entrance and exit wound because of this. Bullets may even break and leave multiple exit wounds from a single a entry point or multiple entries. Usually an entrance wound is a round discontinuation with no loss of tissue. The residues from the gun will be on the skin surface around the entrance wound. Its important to use tape or a stub to collect the residue from the skin surface. In fact you should keep anything used to clean the wound and the victims clothes as well as they will contain very important residue.

There are four things you can see with a GSW and it depends on the distance of the victim from the gun.

•        Entry/exit wound

•        Tattooing

•        Smoke stains

•        Burns.

At long distance there will be only the entry and exit wounds from the bullet. As the victim is closer to the attacker tattooing can be seen caused by small pieces of unburnt gunpowder that produce small black spots (penetrating skin) or red spots (excoriations).

At even closer range the smoke from the gun can produce smoke stains on the skin, colouring the skin around the entry wound black. At even closer range than this the flame from the gunshot can burn the skin.

All these residues are collected and mapped and compared often with shooting experiments to determine firing range and gun type (each gun has its own distinct pattern of residue spread).

If the gun is fired at point blank on contact with the skin, a so called contact wound is produced. This is often stellate in shape, the flaps are caused by the pressure of air as it escapes around the gun, it can look like a blunt force injury so be careful in your description.

If the bullet penetrates a flat bone it can be easy to spot the entry and exit side from bevelling of the bone edge (the bone will be bevelled on the exit side of the bone and diameter of the hole as the entry side has a smaller diameter to the exit side. Exit wounds can be very messy and may sometimes look like a blunt force injury, sometimes if the victim is against a surface where the bullet exits eg. A wall, material from the wall behind can be found in the wound. 

In terms of treatment, GSWs must be treated with thorough debridement and delayed primary suture in the same way as battle injuries (future post). It must never be closed straight away! The debridement should be extra thorough taking extra care to remove fragments of clothing and soil from the wound. 

Clinically you can divide GSWs into low velocity and high velocity injuries. Low velocity injuries can cause little soft tissue damage as long as they remain stable (remember that oscillation and cartwheeling of the bullet will cause more damage). High velocity injuries act like a small explosion and many tissue planes are separated providing easy access for infections. There is often foreign material in the wound further enhancing chance of infection. 

Mean Arterial Pressure (MAP)

I'm currently studying shock, its a huge subject and incredibly important topic in medicine. It doesn't matter what kind of doctor you are, you need to be able to deal with shock. MAP is very relevant in the state of shock.

MAP a great indicator of the perfusion pressure of the organs. Its kind of like an average blood pressure, so if its low there isn't much blood reaching the vital organs. As we all know, blood pressure has two components a systolic and diastolic component. So its not so easy to work out MAP or 'average' blood pressure.

There are some formulas that help (DBP = diastolic blood pressure, SBP = systolic blood pressure):

MAP = DBP + 1/3 (DBP-SBP)

MAP = 2/3 DBP + 1/3 SBP

There are many and quick search of wikipedia or on google will easily come up with many different formules, the two above are the simplest. (note: DBP - SBP is also called the Pulse Pressure).

A normal MAP in a healthy subject is around 90mmHg or in the range 70-110mmHg,
In the treatment of shock we are trying to get the MAP to around 65mmHg or maintaining it there.
(this is because a MAP above 60mmHg is considered enough to perfuse the organs. thus below 60mmHg you should start worrying about organ ischemia).

First Aid Saves lives! part one Airways

Just got back from a mandatory first aid course at work, being a medical student and having done first aid courses before, it was easy to think I already knew it all. I was surprised at how much I learnt from the experience. 
The first thing I learnt was some shocking statistics;

• Two thirds of people in the British public couldn't save a life in the event of an emergency.
• over a quarter of people who said they knew first aid would of done the wrong thing in an emergency (for example if someone was choking they would put their fingers in the persons throat to relieve the obstruction (pushing the obstruction further down))
• In the UK, less than one in ten will survive a heart attack while in Norway over 25% will, most likely due to the fact most people in Norway are able to perform CPR (First aid training being mandatory in Norwegian schools). 

I'll try an give a concise summary here about what was covered. also big thanks to Actual First Aid for the excellently run course. 

When approaching an emergency or an unconscious individual the mnemonic to use is:

DR ABC

D is for Danger. 

First, make sure its safe to approach, we dont want to generate another casualty for the ambulance to deal with. A classic example would be a car crash situation and oncoming traffic, a second crash?

R is for Response

You need to determine if the casualty is conscious, check this by asking a simple question."are you ok", perhaps they cannot respond verbally, so ask "can you open your eyes". if there is no response, you should call for help and contact the emergency services and move onto ABC. 

A is for Airway

The tongue is an incredible muscle, unlike the muscles in your arms and legs, the tongue is only attached at one point. The picture below highlights the tongue (purple) and its singular attachment at the bottom of the mouth in a cadaver. When someone loses consciousness the tongue relaxes completely and falls back slightly covering up the airway (not the thin route to the airway in the cadaver).(By the way its impossible to swallow your tongue, just try it).

The airway can be opened by gently tilting the head back by applying pressure to the forehead with your hand. HOWEVER, its possible in many situations that the casualty may have sustained a spinal or cervical spinal neck injury. In this case movements of the head and neck are to be avoided if there is any suspicion of neck injury. So how do you open the airway?
The best way to open the airway in this case would be by dislocating the jaw and bringing the jaw forward the so called 'jaw thrust' maneuver.
This is performed by placing three fingers behind the angle of the jaw close to the ear and with your thumbs applying pressure to the cheek bones below the eye, you pull the jaw forward and out so that the head doesn't move. (the movement of the jaw, pulls the attached tongue forward as well, allowing air to pass).

B is for Breathing
not breathing? you should consider CPR see part two...

C is for Circulation
no pulse? you should consider CPR see part two...