Desert Scenario 1

Scenario

You have been leading a group of three people and have been hiking 18-20 miles a day for just over a week in the deserts of Jordan. It’s been hard and hot as anticipated, but not scorching hot. You’ve found water every day. This afternoon you hike a steep sun-drenched sandstone ridge in a mountainous area. One of your group has been lagging behind regularly and eventually stops and sits on the edge of the ridge. He looks pasty white and sweaty and says he feels awful.

Your scene size-up is brief: no hazards, one patient who looks sick and sat down.

First of all, what are the dangers of this environment? How could problems be avoided?

- Mountain: Falls from ridges, loose rocks, falling rocks, tough terrain prone to accidents – proper boots, try to follow clear tracks, use poles to test floor

- Desert: Heat, dust storm, absence of water – have portable shelter/face and airway protection

- 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

What are the risks/issues of this scenario?

- Ridge edge, not much space – others in dangers

- Tough terrain, patient evac difficult

- Very remote, help might not be near

- Risk of exposure if unable to move the shade/shelter

What do you want to know about this patient?

- Name and age – Navi – 27

- Signs and symptoms – Feels weak and lethargic, confused unsure of time of day, muscle cramps, headache and fatigue, nauseas – these all started a couple days ago and have just gotten worse.

- Allergies – none

- Medications – none

- Past medical history ­– no significant hx

- Last ins and outs – Been eating as much as everyone else when camp is made, expedition meals, lost one of their water bottles and so has only been having managing 1L ration before having to refill.

- 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 Met group in Jordan, they live here and is visiting them for this hike.

o Nothing of note remembered, it’s just hard work, not felt like this before.

o Using suncream, wearing hat and covering skin.

o Finding it difficult to sleep and rest because bed is not comfy.

o Don’t know how long has been walking but another group member says 8 hours today so far

o Kit is substantially heavier than the others as they have the tent and camping stove etc.

Perform A-E

The patient agrees to your assessment, has a sound airway, is breathing without distress, is dressed in trousers and tight long sleeve t-shirt – both polyester, is obviously not bleeding, has a strong radial pulse, and is on dry ground on another hot day. A member explains he thinks he has grown increasingly ill over the last few days and he isn’t sure if he should continue to their planned rest site.

- Alert and Orientated - alert and oriented to person, place but showing some signs of confusion with regards to time of day and how long they have been walking

- Pulse 110 bpm

- Respiration 24 rpm

- Temperature 37.9 C

- BP 90/64 mmHg

- O2 sats 98%

Skin feels warm and sweaty

What are the important signs and symptoms?

- Confusion

- Tachycardic and tachypnoeic

- High temp

- Low blood pressure

- Fatigued and weak

- Headache

- Muscle cramps

From initial thoughts what do we think is going on? What could contribute to this casualty’s issues?

- Heat exhaustion due to slow onset, patient background (healthy and young) and history of exertion

- Un-breathable clothes

- Lack of water

- Heavy pack

- Exertion and lack of acclimatisation

How would you treat?

7 R’s

- 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 – Is this necessary for this patient? Or do they just need rest?

How would you prevent this from happening in the first place?

- Wear proper clothing

- Distribute packs evenly

- Shorten distance/hike to more reasonable hike

- Allow time for acclimatisation

- Allow for proper rest breaks

- 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.