Enviromental Flashcards
What is the temp range for hypothermia:
1. Mild
2. Moderate
3. Severe
- 32-35 degrees
- 29-32 degrees
- < 29 degrees
Describe mild (32-35 degrees) hypothermia (6)
- thermogenesis still possible
- Shivering
- Apathy
- Ataxia
- Dysarthria
- Tachycardia
Describe moderate (29-32 degrees) hypothermia (6)
- Progressive failure thermogenesis
- No shivering
- Altered mental state
- Muscular rigidity
- Bradycardia
- Hypotension
Describe severe (<29 degrees) hypothermia (6)
- Adopt temp of surrounding enviroment
- Signs of life almost undetectable
- Coma
- Fixed/dilated pupils
- Areflexia
- Profound bradycardia and hyptension
What is a J wave
Deflection at J point
Which leads can J waves be seen the best?
Lead II
V3-6
Describe frostnip (3)
- Short lived, superficial freezing
- Rapid response to warming
- No swelling
Describe superficial frostbite (3)
- Superficial layers only
- Clear blisters 24-48 hours after injury
- Tissue below remains pliable and soft
Describe deep frostbite (4)
- Full thickness
- Blood filled blisters 1-3 weeks later
- Underlying tissue woody and stony
- Bad prognosis, loss of digits likely
How should frostbite be managed immediately? (4)
- Splint area and wrap in loose, dry clothing
- Don’t warm unless you can continue to
- Rewarm at 40-42 degrees initially
- Analgesia (re-warming very painful)
When should surgery be performed on frostbite?
Delayed
What is the most useful discriminating factor in the pre-hospital environment for the severity of heat illness?
Altered mentation after 30 mins cooling
What is:
- exertional heat illness
- non-extertional heat illness
- Increased work leads to increased heat production
- Inability to compensate for enviromental change
What is the WBGT (heat)?
Wet Bulb Globe Temperature - heat stress index
When does the American College of Sports Medicine suggest cancelling an event?
WBGT > 28 degrees C
What is the initial management of heat illness? (3)
- Cool first, transfer later
- Immersion in ice water is gold standard
- Aim to cool to 38.5 degrees - 39 degrees C to avoid hypothermia
What are the 5 types of heat illness?
What is the underlying mechanism that makes heat stroke different from heat exhuastion?
SIRS response leading to multi-organ failure with encephalopathy predominating
What biochemical abnormalities can be seen in heat stroke? (6)
What the two main groups of snakes?
- Vipers
- Elapids
Where are vipers found?
Americas/Africa/Europe
Where are elapids found?
SE Asia, Australia, PNG
How long should snake bites be observed for?
24 hours - can be delayed
What type of snake is a cobra?
Elapid
How do you treat suspected envenomation?
- pressure immobilisation (> lymph/venous pressure)
- Anti-venom
- Neostigmine if paralysis due to cobra/death adder and no anti-venom
What types of spider are poisonous? (3)
- Lactrodectus (black widow, red back spider)
- Funnel web spider
- Recluse spiders
What are the effects of venomous spider bites?
Mainly local but can be systemic
What are the effects of scorpion bites in:
- US/OZ
- N. Africa, S + C America and ME
- Local affects only
- Can lead to systemic effects resembling a cathecholamine surge
What types of jellyfish have systemic effects?
Box and Portuguese Man of War
How do you treat Jellyfish envenomation?
- Box jellyfish - rinse with vinegar + anti-venom
Other jellyfish
2. Wash in sea/saline water to remove remaining nematocysts
3. Then immerse in hot water
Describe pressure immobilisation post envenomation? (4)
- Dont remove trousers as can increase venom through bloodstream
- Pressure bandage from below wound as high as possible with minimal movement of leg
- Apply splint to immobilise joint above/below bite
- Restrict walking
What is:
1. Immersion
2. Submersion
- Airway above water
- Airway below water
Following submersion what occurs initially?
Patient will swallow water preferentially until urge to breath takes over
Following submersion how long does
1. Resp movement
2. Cardiac output
COntinue for?
- 1 min
- 2 mins
(approx)
How cold does water need to be to lead to a ‘cold shock response’?
< 15 degrees
What is the ‘cold shock response?’
Involuntary gasp (2-3L) and uncontrollable hyperventilation for around 90 secs
Therefore decreased time to aspirate lethal amount of water
What is the lethal amount of water aspirated in:
1. Sea water
2. Fresh water
- 1.5L
- 3 L
What is the consequence of submersion in water < 6 degrees C?
- Selective brain cooling from aspiration
- successful resus can increase from after 30mins to 90 mins
What are the good prognostic indicators in drowning (9)?
- Submersion <10mins
- Tw (water temp) < 10 degrees and patient temp <33-35 degrees
- Time to BLS < 10 mins
- Early ROSC
- Child
- No aspiration
- Spontaenously breathing
- PH > 7.1 and blood glucose < 11.2
- Neurologically intact at hospital
What is the strongest predictor of prognosis in drowning?
Submersion > 10 mins
> 25 mins nearly 100% mortality (unless very cold water)
Describe the 3 zones in water rescue and the PPE that should be worn
- Hot = in/on water + full PPE
- Warm = < 3m from waters edge + full PPE
- Cold = safe
What is the recommendation for non-specialist water rescue options? (3)
Talk
Reach
Throw
In drownings what should trigger prolonged resus? (4)
- Submersion < 30mins (Tw >6 degrees) or <90mins (Tw <6 degrees)
- Possibility of air pocket
- Intermittently submerged ie. life jacket
- Signs of life
In prolonged immersion what should the initial management be? (3)
- conscious, encourage patients to continue fighting for survival
- if semi/un conscious then remove horizontal from water to avoid circum-rescue collapse
- prioritise oxygenation ( <10% shockable) how AED not c/i in wet enviroments
What should we consider in ALS following a drowning? (5)
- 5 rescue breaths and ALS if no response
- I+V
- OG tube
- May need high PEEP
- Consider ECMO
What considerations should be made with post drowning patients? (4)
- Ignore ‘foam at mouth; and give oxygen
- Consider PHEA and PEEP 10-15cmH20
- Vasopressors and cautious fluids
- Treat as ‘wet head injury’ i.e. neuroprotection
What 3 criteria need to be met to discharge a drowning from scene?
- No foam at mouth
- No resp distress and normal resp exam
- Safety net
What does SCUBA stand for?
Self Contained Underwater Breathing Apparatus