A crush injury has occurred when a body part has been subjected to a high degree of force or pressure, usually after being squeezed between two heavy objects.  

The Royal College of Surgeons of Edinburgh’s Faculty of Pre-Hospital Care states: 

“A crush injury is a direct injury resulting from crush. Crush syndrome is the systemic manifestation of muscle cell damage resulting from pressure or crushing”. 

Crush injuries mainly occur on building sites, industrial sites, where objects can fall such as construction areas, storage warehouses and in road accidents. If the blood flow is restricted or impaired for more than 15 minutes, toxins can be released into the rest of the body and cause organ damage. This process is called 'Crush Syndrome' and the patient is at a high risk of death. 

When someone is trapped the heavy object can affect the blood flow to a limb of which is being crushed. When the flow of blood to an area is restricted by a heavy weight, there is the danger of a build-up of toxins within the muscle below the site of the crushing weight. This is a lot like a pond. Fresh water flows and keeps the water from becoming stagnant, creating a natural filter system. When you stop that water flow the water will become toxic.  

The toxins we refer to in our bodies are histamine, lactic acid, potassium, nitric oxide, amongst others that normally circulate in just the right amount. When someone is crushed or trapped these chemicals will build up all with a serious negative effect on the blood chemistry, including vasodilation and intravascular coagulation. The results of which can lead to hyperkalaemia (which may precipitate cardiac arrest), hypocalcaemia, metabolic acidosis, and Acute Kidney Injury. 

So, what should you do if you find someone trapped? 

Firstly, ask how long have they been there? 

For crushing less than 15 minutes: The quicker you release them and treat them the better.  

• Release the weight as quickly as you can. 
• Dial 999 – tell them the person is trapped. 
• Control any bleeding, major and minor.  
• Treat for shock by laying them down, raise their feet in the air. 
  
  For crushing more than 15 minutes: This is a rule heavily debated with the emergency medical field. 
  
  Our advice is:  

• DO NOT release the weight until you have: 
• Dialled 999 - ASK 999 SHOULD YOU MOVE THIS PATIENT? 
• Monitor patient and follow the advice of your 999 Emergency Medical Advisor. 
  
  If the patient is unconsciousness and you cannot protect their airway and breathing, seek advice from the 999 operator they will tell you what to do in that situation. Ensuring the person remains breathing is always the number one priority in any emergency. 

References:

1. St Johns Ambulance, St Andrews First Aid and British Red Cross (2019) First Aid Manual. 12th Edition. Dorling Kindersley. London. p.118

2. Greaves I, Porter K, Smith JE. (2003) “Consensus Statement On The Early Management Of Crush Injury And Prevention Of Crush Syndrome” Journal of the Royal Army Medical Corps. 149: 255-259

3. Aoki N, Demsar J, Zupan B, Mozina M, Pretto EA, Oda J, Tanaka H, Sugimoto K, Yoshioka T and Fukui T. (2007) “Predictive Model for Estimating Risk of Crush Syndrome: A Data Mining Approach”. The Journal of Trauma, Injury, Infection, and Critical Care. April. 62 (4) 940-945