Keeping Casualties Warm

 Last month, we posted about ‘The UMBLES’. The purpose… to raise awareness that it might be getting into summertime in the UK, but in medicine, particularly for traumatic injuries, we always need to be aware that however warm we might be, our casualty can get cold... very quickly. The UMBLES were shared courtesy of World Extreme Medicine | B Corp Certified and they’re a fun and easy to remember way to help identify the early signs of hypothermia.

Stumbles: Slower movement, loss of control over movement, stiffness in extremities

🗣 Mumbles: Slurred, slow or incoherent speech, sleepiness, confusion

🤝 Fumbles: Slow reaction time, dropping objects, poor coordination

😤 Grumbles: Change in behaviour, expressing a negative attitude, paradoxical undressing

🚑 Crumbles: Life threatening, unable to walk, deteriorating consciousness, decreasing heart and respiratory rate, cardiac arrest.

Human bodies are actually designed to be great at losing heat and a bit rubbish at staying warm! So being able to identify hypothermia is really useful for our patients (and ourselves), but why is it so important and rather than treating it, what can we do to prevent it in the first place?

Firstly, let’s take a look at why patients can be too cold in the first place:

Blood or fluid loss: Blood (or fluid) loss due to trauma injuries, burns or surgery trigger a spiralling process that reduces body temperature see below.

Low body weight/BMI: Having less body fat can reduce insulation, making you more sensitive to the cold.

Poor circulation: Restricted blood flow can prevent heat from reaching the extremities, leading to feeling cold. Conditions such as Reynaud’s, diabetes and peripheral artery disease are among the medical culprits for this, but trauma can be a cause too.

Thyroid problems: an underactive thyroid gland, which helps to regulate temperature, can cause someone to feel cold

Vitamin deficiencies: Lack of iron or vitamin B12 can contribute to anaemia and reduced blood flow, leading to feeling cold.

Medications: Some medications can cause sensitivity to cold.

Anxiety or panic attacks: Fear or anxiety can trigger a cold sensation. Lack of sleep: Not getting enough rest can disrupt your body's temperature regulation.

Dehydration: Dehydration can affect body temperature regulation. Skipping meals: Not eating enough can lower metabolism and reduce heat production.

Brain: Occasionally, feeling cold might be due to damage or a tumour in the part of the brain that controls temperature, the Hypothalamus.

Many of the issues above could cause someone to feel cold, rather than being hypothermic from a clinical perspective. Separating the two are really important and some can be addressed by simple lifestyle improvements such as eating and drinking regularly and healthily, getting enough sleep and managing stress triggers.

Much of this we can manage ourselves or keep an eye on our crew and colleagues to make sure they are aware of the risks as well. Some issues mentioned relate to chronic or serious medical conditions which you may not be aware of until someone’s health worsens, or something critical happens.  But by far the biggest risk for a medic onboard is if a trauma patient gets too cold.

Clinical hypothermia is classed as a temperature of 35 degrees or lower and at this temperature, there are a series of dangerous processes that happen in the body.

1. Hypothermia - disrupts the normal blood clotting process and leads to coagulopathy. It can also lead to heart arrhythmias.

2. Coagulopathy - is a disturbance in the body’s ability to clot blood. In a hypothermic patient, the blood’s ability to clot is reduced and it can lead to uncontrolled bleeding.

3. Acidosis - is when the blood pH increases above normal levels (readings of below pH 7.35) due to poor tissue perfusion caused by a lack of oxygen and blood flow. This reduces the function of coagulation factors in the blood and stops it clotting, which can make hypothermia worse.

4. Hypocalcaemia - blood loss causes low calcium levels. This lowers the pH further (greater acidosis), which in turn increases the time for a clot to form. This 4-way process is known, rather dramatically, as the Trauma Diamond of Death! But that’s no exaggeration. As you can see, all 4 elements are interrelated and create a downward spiralling effect where each component of the triad can worsen the others, creating a negative feedback loop which could be fatal for your patient. 

Hypothermia disrupts the coagulation cascade, making it harder for blood to clot. Hypocalcaemia and Acidosis make this even worse. The result is poor perfusion leading to tissue and organ damage. It can be extremely challenging to reverse this process and the patient may deteriorate rapidly. So, what can you do to prevent it? Especially if you find yourself in a remote or difficult environment with limited resources?

Control Bleeding - stopping the bleed should be your first priority once your approach is safe. Early Intervention - recognise the risks for trauma patients in particular. It’s essential to think about keeping someone warm, even when the ambient temperature seems OK. Acting earlier can improve outcomes. If you’re the responder, you’re likely to be feeling very warm due to the stress of the situation and even in a tropical climate, trauma patients can get cold quickly. Wind chill and wet skin and clothes (if they have been in the water) add a further complication. Seek Help - access your telemedicine provider sooner rather than later.

A major bleed may require an immediate medevac and correcting the triad will take a team of healthcare professionals with advanced treatment options. If you are in a position where resuscitation is needed, there are adjustments required to shocks and drug therapy. What can you do? If we find ourselves caring for a trauma patient onboard, there are some simple steps that can help to keep them warm and reduce the risk of the trauma triad kicking in… which is of course better for everyone involved.

Here’s our suggestions: If possible, move the patient to a warm, sheltered location If not, create shelter from any breeze and cover to protect from rain Replace wet clothing with dry layers, cover the top of the head Cover with blankets or whatever warm items you have available Foil blankets are great, but they only reflect back existing heat and you need a layer between the foil and the patient

Self heating blankets should not go directly on the skin Make sure you insulate from the ground. This may require some small amount of movement, but the benefits of keeping them warm outweigh the risks Offer sips of warm (not hot), sweet drinks if they’re able to swallow but no alcohol! They need the sugar for energy as being cold uses up stores Handle gently Monitor temperature with a tympanic (ear) thermometer

Remember your ABCs, after addressing any major haemorrhage Body heat from another person can be considered if needed You can still carry out your top to toe secondary survey in full with a bit of fancy blanket folding magic! We hope you’ve enjoyed this blog and picked up a few tips on why someone might get cold, how to keep a patient warm and why it’s so important in the bigger picture of managing trauma onboard. The key thing to remember is that however warm you might feel, the patient can get cold much more quickly than you might imagine.

Resources: Resus Room Podcast: https://www.theresusroom.co.uk/hypothermia-2/

TSG Associates Article: https://www.tsgassociates.co.uk/news/item/the lethal-triad-and-how-to-address-it If you’d like to follow an expert - Jorgen Melau: https://www.linkedin.com/in/jmelau