Wilderness Medicine Flashcards
Air embolism typically happens when divers ___________.
hold their breath during ascent or rapidly ascends
When you ascend, the surrounding pressure decreases which causes gases to expand. A large enough expanse can cause air to pass into the large blood vessels. The air can embolize to any part of the body and (causing stroke, MI, and any other type of end-organ dysfunction).
Air embolism typically starts happening ________ after ascending.
10 minutes
A diver starts experiencing confusion at great depth. What’s the likely problem?
Nitrogen narcosis
This happens usually at depths greater than 100 ft
Air embolism typically starts happening ________ after ascending.
10 minutes
A diver starts experiencing confusion at great depth. What’s the likely problem?
Nitrogen narcosis
How do you treat nitrogen narcosis?
Ascent
Black widows typically cause what symptoms?
Abdominal pain
The neurotoxin causes GI muscle spasm.
If a person is hypothermic and pulseless, continue CPR until the core temp is ___________.
32° C or greater
If it is greater than this and they are still dead it is ok to stop CPR from a hypothermia standpoint.
Lightning strikes typically cause what physical exam findings?
Lichtenburg sign
TM ruptures
The main cause of death in hypothermia is ____________.
ventricular arrythmia
People generally start to become altered when core temp drops below what?
90 F
People generally lose all vitals when temperature drops below ____.
75 F
When is someone cold and dead?
- When an arrest happened before the hypothermia, such as a trauma that then led to hypothermia
- When chest is frozen to the point that chest cannot be compressed
- When there is an apparent other cause of death (such as massive trauma)!
You should consider ___________ in all hypothermic arrest patients.
ECMO
People with arrest from hypothermia typically do well on ECMO, even if there has been a long down time and gaps in CPR. There are many reports of hours of CPR that have full recovery.
Defibrillation typically works only above what core temperature?
30 C
In addition to the dead patients who are hypothermic, you should also consider ECMO in ________.
Patients who are altered, hypotensive, have ventricular arrhythmia, or have a core temp less than 28 F
You need to check what lab before sending a hypothermic patient to ECMO?
Potassium
Severe elevations (>12) suggest a poor prognosis.
The wounds from fire ant bites are called __________________.
sterile pustules
These look like bacterial abscesses but do not require antibiotics.
Describe fire ants.
They are small (1/8 - 3/8 of an inch long) and reddish brown in color. There are other types of ants in North Carolina that look like this, though, so it is tough to identify unless they’ve bitten you.
Why is it so important to probe the depth of bite wounds on the head (particularly in children)?
Innocuous-looking wounds can hide skull penetrations that can lead to brain abscesses.
Review the management of sea urchin, jellyfish, and man-of-war stings?
- First, if you are on scene make sure that you are removing the afflicted person from water. If they are in extreme pain and disoriented there is a risk of drowning.
- Second, rinse aggressively with water.
- Third, do a local block to numb the area.
- Fourth, remove the spines.
** Note: warm water baths have the best data suggesting pain control.
A diver experiences vertigo. What is the likely etiology?
Barotitis
Water pressure causes compression of the middle ear which can irritate the vestibular nerve if the Eustachian tube cannot relieve the pressure. Severe barotitis can lead to TM perforation.
Review the grading of frostbite.
There are two grading systems. The old style delineates four degrees of frostbite and the new style merely notes superficial or deep.
Old:
- 1st degree: erythema or blanching without blisters (epidermis only)
- 2nd degree: erythema w/ clear bullae (epidermis to dermis)
- 3rd degree: erythema w/ hemorrhagic bullae (epidermis to subcutaneous tissue)
- 4th degree: necrosis of digits (epidermis to bone, muscle, and tendons)
New:
- Superficial: first and second degree (i.e., erythema +/- clear bullae)
- Deep: third and fourth degree (i.e., hemorrhagic blisters or necrosis)
Brown recluses have what distinctive external feature?
A violin-shaped mark on their posterior cephalothorax
Envemonatioin by coral snakes produces what toxidrome?
Cholinergic
How should you rewarm frostbite?
Immersion bath until the tissue is pliable.
Review the six different types of poisonous snakes in NC.
- Copperheads
- Water moccasins (aka cottonmouths)
- Rattlesnakes (3 different kinds)
- Eastern coral snakes
Importantly, bites from eastern coral snakes can take up to _________ hours to appear.
12
Because of this, people with these bites warrant admission for observation.
Other than local necrosis, what can brown recluse venom cause?
Coagulopathy
Why does exhalation on ascent prevent arterial air embolus during diving?
During ascent, lung volume expands due to the drop in extrathoracic pressure. If a diver does not exhale on ascent, the expanded lung volume must escape through another means. In severe cases, air is compressed into the vascular system into emboli.
Air can embolize to become PEs, STEMIs, or CVAs.
Treat with 100% oxygen, supine positioning, and transfer to a hyperbaric chamber.
Divers should wait how long to fly after a dive?
12-24 hours
