Desert Scenario 2
Scenario and notes
Type of resource:
You are part of a 2 vehicle convoy through the Sahara desert on route to an archaeological dig 3 days into the desert through difficult terrain. At some point into the journey one of the vehicles tire bursts causing rapid deceleration resulting in the 2ndvehicle colliding into the back of it. There are minor casualties that you sort, but both vehicles are out of action.
Someone has radioed for help and has been told the soonest they can be there in 2 days as helicopter help in unavailable. You have limited supplies and the only shelter is the shade of the cars. Towards the end of day 2, one member of the group who complained of feeling ill the night before has again complained of feeling ill.
First of all, what are the dangers of this environment? How could problems be avoided?
- Desert: Heat, dust storm, absence of water – have portable shelter/face and airway protection, have reserves and extra supplies in case of emergency.
- Spiders, scorpians, centipedes, snakes can be found in cracks and crevices – cover skin, wear protective boots, research common fauna and flora and if possible have vaccines/anti-vemon/emergency numbers for specialists/known location of suitable tertiary care centres
- Exposure: Deserts can be incredible hot during the day but very cold at night, hypothermia is also a risk. Adequate shelter and layers would avoid this.
- Location: Dunes are constantly shifting, roads are covered, no obvious land marks – GPS for location is a must.
What are the risks/issues of this scenario?
- Limited supplies/resources/shelter – dehydration + hyper/hypothermia
- No immediate help
- Difficult to find location
- Potential bites/stings if not raised off sand
What do you want to know about this patient?
- Name and age – Bruce – 56
- Signs and symptoms – Initially very anxious but deteriorated and now hard to get a sensible response, dizzy, nauseous, sun-burn, headache, vomiting, stopped sweating.
- Allergies – none
- Medications – Ramipril (increases risk of heat illness), Amitriptyline (increases risk of heat illness), Cetirizine (increases risk of heat illness)
- Past medical history – Hypertension, IBS, couple of itchy bug bites
- Last ins and outs – Been eating and drinking very little as limited supplies and feels sick. Probably only 1 small cup of water today and the day before.
- Events leading up to now e.g. any injuries, any experiences like this before, how have you found each day, how are they sleeping etc.
o Got drowsy in the sun and fell asleep with no shelter
o Woke up feeling dizzy and gradually got worse
o Tried to take shelter from the sun in car shadow but felt like couldn’t cool down
o Been in the sun most of the day trying to help fix what they can of the car but got so bad, had to sit down
o Was sick a number of times and now cant get a proper response
Patient has a sound airway, is breathing, is dressed in trousers and tight long sleeve t-shirt – both polyester, is obviously not bleeding, on dry hot ground on another hot day. A member explains he has grown increasingly ill over the last hour and is growing increasingly concerned. Whilst helping with the car, he kept mistaking objects for other things, mumbling to himself, and saying things that didn’t make sense.
- Delirious – mumbling and not orientated
- Pulse 120 bpm
- Respiration 22 rpm
- Temperature 38.2 C
- BP 85/62 mmHg
- O2 sats 98%
Skin feels warm and dry, looks red and sore
What are the important signs and symptoms?
- Impaired consciousness
- Tachycardic and tachypnoeic
- Very High temp
- Low blood pressure
- Vomiting, nauseous and dizziness
From initial thoughts what do we think is going on? What could contribute to this casualty’s issues?
- Heat stroke due to prolonged exposure and measurable increase in temp. Cannot prove tissue damage yet though. Plus sun burn.
- Un-breathable clothes
- Lack of water
- Not much shelter from sun
- Some of his medications can increase risk of heat illness.
How would you treat?
- Recognise signs and symptoms – if in doubt, treat as heat injury
- Rest casualty in shade – get rest of group under cover and drinking water
- Remove all clothing – strip to underwear
- Resuscitate – Maintain ABC
- Reduce temp ASAP – Evaporative cooling and IV fluids
- Rehydrate – Oral or IV fluids (1L of saline or dextrose saline a 5’C for heatstroke and 12’C for heat exhaustion – 2L of IV fluids usually sufficient)
- Rush to hospital – evacuate all heat casualties – essential for this patient as serious heat illness present
How would you prevent this from happening in the first place?
- Ensure emergency reserves in case of vehicular failure
- Keep in shade at all times or makeshift shade from equipment in car
- Flag symptoms as soon as they appear before they get worse
What other heat problems could occur?
- Heat syncope – fainting on standing in the heat due to blood pooling in the legs and increased flow in skin. Treat with rest in cool area and oral fluids and consider potential for heat illness.
- Heat oedema – mild swelling of limbs during first days of exposure, plasma volume increases to allow for increased blood flow to skin.
- Heat cramps – may occur in salt depleted individuals or those unaccustomed to exercise in heat. Salt supplementation helps prevent these. If individual is well, no association with heat illness.
- Miliaria rubra (prickly heat) – intense itchy prickly or burning rash that arises in skin waterlogged from excess perspiration. Pores become blocked with debris and inflamed, producing many tiny blisters on red skin. Prevent by wearing loose airy cotton clothing and taking regular cool showers. Treat with frequent cool water, dabbing dry to prevent further damage and application of talcum powder. Histamines may help with sleep.
- Sunburn – reduces thermoregulatory capacity of skin and central thermoregulation. Protect from significant heat until burn has healed.
- Fungal infections – common in moist skin folds such as groin, breast folds, hot damp feet. Apply antifungal powder and clean skin and keep dry.
How do we thermoregulate?
In normal environments the body loses heat through radiation, conduction, convection and evaporation. Once the environmental temperature rises above 35’C it is impossible to lose heat through conduction, convection, or radiation. Therefore, our ability to survive and function in higher temperatures depends on our ability to sweat.
Sweating allows the body to lose heat at any environment temperature through evaporation, but evaporative heat loss can only occur if the body is hydrated, and the air is not saturated with water vapour. Sweating is most efficient then in hot, dry deserts.
Difficult travel – will needs considerable reserves of fuel, food, and water are essential to ensure safety in event of bad weather, mechanical failure or navigational problems.
Dust storms – develop with little warning in any arid/semi-arid environment. Take form of advancing wall of dust/debris many miles long and several thousand feet high. Can appear from any direction but generally follow winds. Most pass within an hour, but some may persist for several hours. High winds can destroy tents and strip campsites. Health risks include suffocation from dust inhalation and extremely low visibility both on roads and in the air, leading to disorientation and risk of serious accident.
Flora + Fauna – Snakes and scorpions live in deserts and may enter discarded footwear or containers. Plants in arid areas can have thorns, tough spiny surfaces, or serrated leaves.