Pre-Hospital Management of Burns.  
Part 2 - Special Cases

In the previous article we looked at the assessment and treatment of thermal burns which represent the vast majority of burns we will be exposed to.  In industrial or high-hazard environments there is a greater incidence of more specific burns, notably chemical, electrical and cryogenic burns.

Chemical burns

Chemical burns cause cellular damage by chemical reaction rather than heat.   Chemical burns can be caused by over 25,000 different chemicals (1) but can be broadly separated into acid or alkaline

Strong acids with a pH of 2 or less, such as hydrochloric acid, cause coagulative necrosis to form a tough leathery eschar at the point of skin contact. While extremely painful, this allows for some protection of structures deep to the necrotic site.  Irrigation should be maintained for at least 30 minutes.

Alkalis break apart cell structures, loosening tissues through liquefaction necrosis. The result is a poor barrier to chemical penetration and deeper, ongoing burns.  Alkali burns are deeper and therefore generally more severe than acid burns.  Irrigation could take hours to reach mitigation of an alkali. (1)

 Whilst this is relevant for evaluating your first aid needs analysis if your organisation works with acids and alkalis, if the contaminant is unknown, do not waste time trying to neutralise it:

Treatment

• Protect yourself from contamination

• Brush away dry powders

• Prompt irrigation is the most effective treatment for burns; patients who receive irrigation within 10 minutes had a 5-fold decrease in full-thickness injury and a 2-fold decrease in length of hospital stay. (2)

• Irrigate the area with low pressure, high volume water. The water does not need to be sterile, but it should be cool and copious.

• Prioritise:

1. Nose and mouth

2. Eyes

3. Hands

4. Rest of the body

• Identify the substance from the container or MSDS

Water will react with some acids as the acid dissociates to produce hydrogen ions which react further with the water producing an exothermic reactions which can generate significant heat - this is why the casualty should be drenched with water rather than 'lightly sprinkled'.

Where there is no water:

If your First Aid Needs Analysis suggests a risk of acid or alkali burn, where there is NO water, Diphoterine® should be considered as part of your Medical kit.  

Diphoterine is an amphoteric irrigating agent for the treatment of chemical burns, which can, impressively, neutralise both acids and alkalis, can be used in the eyes and is non-toxic.   A retrospective study has shown that it is able to neutralize pH values to a reasonable degree but without significant difference in the time to healing, the length of hospital stay, or need for surgery (3).   As such the primary treatment of both acid and alkali burns if water is available remains as copious irrigation in the first instance followed by Diphoterine if available.  

Specific Chemicals

The following advice is specifically for industries where these chemicals are present and where the specific treatments should be made available.   If the chemical cause is unknown, the First Aid treatment is always irrigation with water.

Elementary metals
Alkali metals such as lithium, sodium, potassium, or magnesium react with water and oxygen– in these instance fragments should be removed from the skin using tweezers and the wound covered with mineral oil (4)

Hydrofluoric Acid
The two mechanisms that cause tissue damage are corrosive burn from the free hydrogen ions and chemical burn from tissue penetration of the fluoride ions.

Fluoride ions penetrate and form insoluble salts with calcium and magnesium.  Soluble salts also are formed with other cations but dissociate rapidly.  Consequently, fluoride ions are released and further tissue destruction occurs.

Systemic toxicity occurs secondary to depletion of total body stores of calcium and magnesium, resulting in enzymatic and cellular dysfunction, and ultimately in cell death.   The majority of deaths result from cardiac arrhythmias that were precipitated by hypocalcaemia and consequent hyperkalemia (5)

Treatment is typically prompt irrigation followed by topical Calcium Gluconate gel applied every 30 mins in the first instance and then 4 hourly.  A clinical indicator is relief of pain. (6)   Immediate irrigation with HexaFlourine® has improved outcomes (7).

Phenol / Carbolic acid
Phenol is extremely poisonous and corrosive. It can be absorbed across intact skin. Since phenol has a local anaesthetic effect, it may cause extensive tissue damage before the casualty feels any pain.  As such, prompt treatment of individuals exposed to phenol is essential.

Following irrigation, swab the affected area with Polyethylene Glycol 300 (PEG)

Electrical burns

Electrical burns present hidden dangers of internal damage which may not be reflected in the severity – or absence of - surface wounds; electricity entering the body will continue to cause damage to internal structures.

• Domestic electricity is considered low voltage (230V in the UK). Low voltage electrocutions can cause minor burns at entry and exit points but can cause heart arrhythmias and respiratory failure.

• High Voltage electrocution (> 10,000V) are associated with 4th degree burns, loss of limb, and fatal arrhythmias.

• Arc burns occur when electricity arc from the source across an air gap into the casualty – injury pattern is essentially a blast injury, and although momentary, the heat the casualty is exposed to can exceed 2,400oc

• Electrocutions over 70,000V are considered unsurvivable.

Treatment

This is an exercise in scene safety.   The treatment for the burn is the same as for thermal burns however, this should only be attempted once the danger has been remove or isolated.

Cardiac arrest should be pre-empted and prompt defibrillation should be anticipated.

Cryogenic burns & Frostbite

Frostbite and cryogenic burns present as a white or yellow, waxy skin.  Immediate rewarming in a water between 37°C and 40 °C is recommended. (8-10)  Adherence to this narrow temperature range is important; rewarming at lower temperatures is less beneficial to the tissue survival, whilst rewarming at higher temperatures may compound the injury by producing a burn wound. Rewarming should be continued for 15–30 minutes until thawing is complete.

Do Not:

• Attempt to rewarm too quickly.

• Rub or massage the affected area.

• Do not allow the casualty to drink alcohol or smoke – both reduce peripheral blood supply.

• Frozen tissue is relatively robust compared to recently thawed tissue. In a remote environment only rewarm the tissue if you are certain the tissue is not likely to re-freeze (e.g. at altitude). If this is not possible, it is better to evacuate the casualty with frostbite and rewarm the tissue later (11).

References

1. Tintinalli, Judith E. (2010). Emergency Medicine: A Comprehensive Study Guide. New York: McGraw-Hill Companies. pp. 1374–1386.
   

2. Leonard LG; Scheulen JJ; Munster AM (1982) “Chemical burns: effect of prompt first aid” Journal of Trauma. 22(5):420-3
   

3. Zack-Williams SDL, Ahmed Z, Moiemen NS (2015) “The clinical efficacy of Diphoterine® in the management of cutaneous chemical burns: a 2-year evaluation study”. Annals of Burns Fire Disasters. Mar 31; 28(1): 9–12.
   

4. Robinett AD, Shelton B, Dyer SK(2010) “Special Considerations in Hazardous Materials BurnsOriginal Research Article” The Journal of Emergency Medicine, Vol 39 - 5, November 2010, Pages 544-553
   

5. McIvor ME (1987) “Delayed fatal hyperkalaemia in a patient with acute fluorine intoxication”. Annals of Emergency Medicine. 16(10): 1165-7
   

6. McKee D, Thoma A, Bailey K, Fish J. (2014) “A review of hydrofluoric acid burn management”. Plastic Surgery (Oakville). 22(2): 95–98.
   

7. Burgher F, Mathieu L, Lati E, Gasser P, Peno-Mazzarino L, Blomet J, Hall AHH, Maibach HI(2011) “Part 2. Comparison of emergency washing solutions in 70% hydrofluoric acid-burned human skin in an established ex vivo explants model” Cutaneous and Ocular Toxicology. Jun; 30(2): 108–115.
   

8. Malhotra MS, Mathew L. (1978) “Effect of rewarming at various water bath temperatures in experimental frostbite”. Aviation, Space and Environmental Medecine. 1978;49:874–876.
   

9. C. Sever, E. Ulkur, F. Uygur, B. Celikoz(2008) Hand burn caused by Freon gas”. Burns, 34, pp. 1210–1212
   

10. Sever C, Kulahci Y, Acar A, Duman H. (2010) “Frostbite Injury of Hand Caused by Liquid Helium: A Case Report”. Eplasty. 10: e35.
    

11. McIntosh SE, Opacic M, Freer L, Grissom CK, Auerbach PS, Rodway GW, Cochran A, Giesbrecht GG, McDevitt M, Imray CH, Johnson EL, Dow J, Hackett PH, (2014) "Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite: 2014 Update". Wilderness & Environmental Medicine. 25, S43–S54 (2014)