Chapter 11: Concepts of Care for Patients With Common Environmental Emergencies

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Okay, let's unpack this.

When we think about environmental emergencies,

you know, it's easy to jump straight to huge disasters.

Big floods, massive storms.

The big dramatic stuff.

Exactly.

But the sources we're digging into today really focus on those acute common situations.

The kind of things clinicians actually see pretty often.

Summer heat waves, winter cold snaps, someone getting bitten on a hike or getting sick way up high on a mountain.

That's spot on.

For this deep dive, we're basically synthesizing the absolute must -know clinical points from a key chapter covering these environmental emergencies.

So the mission really is to give you a clear kind of structured understanding of the underlying physiology,

what signs to look for the clinical cues and crucially, the immediate, sometimes life -saving actions you need to take for conditions that mess with thermal regulation, tissue integrity and pain.

Right, and as we go through this stuff, it's interesting how a couple of clinical priorities just keep surfacing again and again in the source material.

It really flags two core concepts.

Tissue integrity, keeping skin and deeper tissues healthy and pain management.

Those run through almost everything we're gonna talk about.

They absolutely do.

And it's also worth just quickly noting the chapter points out that certain groups, older adults, people of color, folks with lower incomes, people dealing with chronic illnesses, they often bear the brunt of these emergencies more heavily.

Factors sometimes tied into bigger issues like climate change, sadly.

Yeah, that's an important context to keep in mind.

So let's start things off on the hot side of the thermometer.

Heat -related illnesses, they become a lot more common once the temperature gets above, let's say, 95 Fahrenheit, that's 35 Celsius.

And the risk really shoots up if the humidity climbs over 80%.

When you're thinking risk factors, look for things affecting fluid balance.

Older age is a big one, higher risk of dehydration.

Also certain meds like diuretics, ACE inhibitors, even some anti -cholinergics.

And substance use can play a role too.

Oh, and obviously people working or exercising hard outdoors.

Okay, so before we get to the really scary one, heat stroke, there's its precursor.

Heat exhaustion, that's more about dehydration, right?

Heavy sweating, not enough fluid and electrolyte replacement.

Exactly, that's the core issue there.

Dehydration from sweating buckets and not taking in enough of the right stuff.

So what does that look like?

How does the patient present?

Clinically, they just look unwell.

Kind of flu -like symptoms, headache, feeling weak, maybe nauseous, might even vomit.

They can look clammy.

And importantly, they're usually still sweating a lot.

Still sweating, okay, and their temperature.

Their core body temp might be up a bit, but it hasn't totally run away yet, like in heat stroke.

Gotcha, so the immediate action alert here is pretty specific then, what do we do?

First things first, stop the activity, get them somewhere cool right away, use cooling packs, stick them on the neck, chest, groin area, and then rehydration.

But here's the key thing, you want sports drinks or those oral rehydration solutions?

Not just water.

Right, avoid plain water.

It can actually make things worse by diluting their sodium too much worse in hyponatremia.

And definitely, absolutely no salt tablets.

They're notorious for irritating the stomach.

Ah, good to know.

Okay, so what happens if that progresses?

Or if someone just gets hit with a massive heat load right off the bat, that's when we get to heat stroke.

That's when you hit heat stroke.

And this is where the body's own temperature control system, the thermoregulation center just fails completely.

Core temperature can rocket past 104 Fahrenheit, 40 Celsius.

This is a full -blown medical emergency.

Is all heat stroke the same though?

I think our source mentioned different types.

It does make a distinction, yeah.

You've got exertional heat stroke, that comes on suddenly.

Think athletes, soldiers, people doing really intense work, especially if they aren't used to the heat, not acclimatized.

Then there's classic heat stroke, sometimes called non -exertional.

This creeps up more slowly, often affects older folks, maybe someone's stuck in a hot apartment without AC during a heat wave.

But for either type, what's the absolute key sign?

The thing that screams stroke, not just exhaustion.

Mental status changes.

That's the hallmark.

Confusion, delirium, maybe even seizures or coma.

That tells you the brain itself is suffering thermal injury.

Even if they're still sweating?

Even if they're still sweating.

Sometimes they are, sometimes they aren't.

But if their mental status is altered, you have to assume heat stroke.

And diagnostics, anything specific we look for?

Yeah, labs can help.

Elevated cardiac troponin I, CTNI, that can show up early and actually helps predict how severe the damage might be, the risk of multi -organ problems down the line.

Wow, okay, so interventions have gotta be fast and aggressive, right?

Absolutely.

Rapid cooling is priority number one.

If you can get them into cold water immersion immediately, the chapter stresses that's the best method, hands down.

And if that's not possible, like out in the field?

At the scene.

Strip off their clothes, douse them with cool water, fan them like crazy, ice packs to the big blood vessel areas, armpits, groin, neck, even the scalp.

And again, nothing by mouth.

Too risky for vomiting and aspiration.

Right, and in the hospital?

In the hospital.

Keep that aggressive cooling going.

Be ready for intubation if needed.

Start 4V fluids, ideally cooled saline if you have it.

You need continuous core temperature monitoring, usually rectal.

And when do you stop cooling?

You stop active cooling when the core temp gets down to about 102 Fahrenheit, which is 39 Celsius.

You don't wanna overshoot and make them hypothermic.

Makes sense.

And there's another critical point here, isn't there?

Something about fever meds.

Yes, absolutely critical.

Do not give aspirin or any other antipyretics, Tylenol, ibuprofen, none of them.

Wait, why not?

They reduce fever, don't they?

They reduce fever when it's caused by infection, where the body intentionally raises its set point.

Keat stroke isn't that.

It's a system failure, an uncontrolled overheating.

Antipyretics just don't work, and they might even cause harm, like worsening potential clotting problems that can happen with heat stroke.

Ah, okay, that's a crucial distinction.

And shivering, if they start shivering while you're cooling them.

You have to stop the shivering immediately, usually with meds like benzodiazepines as prescribed.

Shivering generates heat, which completely defeats the purpose of everything you're trying to do.

Okay, so we've covered the dangers of getting too hot.

Let's clip to the other extreme.

What happens when the body gets too cold?

We're talking hypothermia now, right?

Defined as core temp below 95 Fahrenheit.

Correct, core body temp below 95 degrees Fahrenheit or 35 degrees C.

Risk factors here include things like being malnourished, older age again, trauma can predispose people, certain psychiatric meds, phenethiazines are mentioned, and definitely alcohol.

Alcohol makes you colder, it feels warm going down.

It feels warm because it causes vasodilation, especially in the skin.

Blood rushes to the surface, so you feel warm, but you're actually losing core heat much faster to the environment, a dangerous trick.

And heat loss gets way worse with wind chill and especially with wet clothing.

The source specifically calls out cotton,

avoid it in the cold, it just holds moisture against the skin.

Right, cotton kills, they say in the outdoors community.

Okay, so how do we manage hypothermia?

Does it depend on how cold they are?

Absolutely, it's categorized by severity.

Mild is 90 to 95 Fahrenheit, moderate 82 .4 up to 90, and severe is anything below 82 .4 Fahrenheit.

So for mild cases?

For mild, you can often use passive rewarming, just warm blankets, dry clothes, get them out of the cold, or active external rewarming like heating blankets, warm air blowers.

But you have to watch their skin carefully with those.

You can give them warm drinks to high -carb, to non -alcoholic, non -caffeinated.

Okay, but for moderate and severe, sounds like things get trickier.

Yeah, now we're in the critical rescue zone.

These patients are really unstable, super high risk for cardiac arrest, specifically ventricular fibrillation.

So the absolute rule is handle them gently, no rough movements, no jostling, keep them flat, supine.

And their metabolism is all slowed down, right?

That affects meds.

Hugely, metabolism is so sluggish and unpredictable when you're that cold.

This leads to a fascinating, really important point about medications.

The drug caution rule, holding 50 tens, why that specific temperature, 86 degrees Fahrenheit, 30 C?

Right, below about 86 degrees Fahrenheit or 30 degrees, drugs aren't metabolized effectively.

So you can give a standard dose.

It circulates, but doesn't really work.

Maybe it accumulates.

Then as you warm them up, their metabolism suddenly kicks back in, and boom, you get a flood of that drug hitting the system all at once.

Potential toxicity, especially cardiac side effects.

So generally you hold most IV meds, except maybe vasopressors if needed for blood pressure, until they're warmer than 86 degrees Fahrenheit.

Wow, okay.

And for the really severe cases below 82 .4 degrees air height, the source says we should actually avoid active external rewarming.

No heating blankets for them, why not?

It sounds counterintuitive, right?

But it's because of something called aftirdrop.

Daffordrop?

Yeah.

If you warm the skin really aggressively, the blood vessels in the arms and legs dilate.

All that cold, acidic blood that was kind of trapped out there in the periphery, rushes back to the heart and central organs.

This can cause the core temperature to drop even further, paradoxically, right when you're trying to warm them.

And that sudden drop can trigger V -fib, fatal.

So what do you do for severe hypothermia?

For severe cases, the treatment of choice is active internal or core rewarming.

The best methods involve extracorporeal rewarming.

Extracorporeal, meaning outside the body, like running their blood through a warmer.

Exactly, things like cardiopulmonary bypass or even hemodialysis, you're directly warming the blood itself, warming the core from the inside out.

It's much faster, much safer, and avoids that dangerous aftirdrop.

Okay, moving from overall body temp to localized cold injury, frostbite.

That's actual tissue freezing.

Right, and you gotta distinguish frostnip, which is superficial, might be painful, skin looks pale, but there's no actual tissue damage.

It's reversible from true frostbite.

Frostbite gets graded, usually I through four.

Can you describe the grades a bit?

Grade one is superficial, maybe some numbness, redness.

Grade two, you start seeing blisters, usually clear or milky fluid.

There's some deeper involvement, partial thickness necrosis starts.

Grade three, blisters might be hemorrhagic, deeper freezing, full thickness damage.

And grade fourth is the worst goes down into muscle, even bone.

High risk of gangrene often leads to amputation.

You can't always tell how bad it is right away.

That's a key point.

The true extent of the damage often only becomes clear after you've thawed the tissue.

Things can look deceptively okay initially.

So intervention, what's the move?

Someone comes in with a frozen hand or foot.

First, what not to do.

Never use dry heat, like a hairdryer, or putting it near a fire, and never rub or massage the area.

You'll cause more tissue damage.

Okay, no rubbing, what do we do?

The standard is rapid rewarming.

You use a circulating water bath kept precisely between 99 degrees to 102 degrees FSM.

That's 37 degrees to 39 degrees C.

Needs to be circulating water to maintain the temperature evenly.

And that hurts, right?

Oh, intensely painful.

Rewarming frostbite is agony.

So you need aggressive pain management, usually IV opiates.

Often ibuprofen is given too, not just for pain, but because it might help reduce some of the secondary tissue injury from inflammation.

Okay, after they're rewarmed, what's the focus?

Post -rewarming, you handle the part very gently,

elevate it to a deuce swelling, and you monitor really closely hourly for compartment syndrome.

Compartment syndrome again.

That's a big risk here too.

Huge risk.

The thawing tissue swells up inside the fascial compartment, which doesn't stretch, pressure builds, cuts off blood flow.

The signs are that rapidly worsening pain, pain out of proportion, pain not relieved by the opiates, and numbness or tingling, paresthesias.

It's a surgical emergency if it happens.

And don't forget, tetanus prophylaxis, that damaged tissue is prime real estate for bacteria.

Okay, let's shift gears from temperature to, well, things getting into the body.

Bites and stings.

Starting with snake bites.

The source focuses on the two main poisonous families in North America, right?

Pit vipers and coral snakes.

That's right, pit vipers include rattlesnakes, copperheads, cotton mouths.

Coral snakes are the other main group.

And there's that rhyme for coral snakes.

How does it go?

Red on yellow kilafelo.

It refers to the order of the colored bands.

In the US species, if the red band touches the yellow band, it's likely the venomous coral snake.

Doesn't apply everywhere in the world, but useful here.

So, someone gets bitten, what's the absolute first thing you do?

Nursing priority number one.

Get them away from the snake to a safe area.

Then encourage rest.

Keep them as still and calm as possible.

Movement speeds up venom circulation.

Makes sense.

Immediately remove any tight clothing, watches, rings, jewelry near the bite before swelling starts because it will swell.

And importantly, don't waste time trying to catch the snake.

If you can snap a quick photo from a safe dildance, great, might help ID later, but don't risk another bite.

What's the biggest immediate danger from the venom itself?

For many venomous snakes, especially some pit vipers and coral snakes, the most significant life threat is airway compromise and respiratory failure.

So, maintaining the airway is paramount.

And you absolutely need to contact poison control immediately.

They guide the anti -venom therapy type, dose administration, that's essential.

Okay, what about smaller critters?

Arthropods, spiders, scorpions, bees, wasps.

Yeah, those can cause trouble too.

Black widows, brown recluses have specific venoms causing different symptoms.

Scorpions, depending on the species.

And of course, bees and wasps.

With bees and wasps, the main concern is usually allergy,

right?

Anaphylaxis.

It can range from just local pain and swelling to full -blown life -threatening anaphylaxis.

Remember, honeybees sting once and leave their stinger.

Wasps, hornets, yellow jackets can sting multiple times.

So the action alert here is pretty clear.

If someone has a known severe allergy, they must carry their prescription epinephrine auto -injector at all times and know how to use it.

Also, if someone gets stung a lot, the source mentions maybe more than 50 stings, they need to be seen in an ER setting anyway, even without an allergy, because the sheer volume of venom can cause toxic effects systemically.

Okay, good point.

Lastly in this section,

lightning injuries.

That's a massive electrical event.

Huge voltage, but incredibly brief contact time often leads to what's called a flash -over phenomenon, where the current travels over the surface of the body rather than deep through it.

Being wet increases the risk significantly.

And they get those weird marks, right?

Yeah, the distinctive feathering or branching patterns on the skin.

They're called Lichtenberg figures or sometimes coronagraphic markings.

They look dramatic, but they're not actually burns.

It's more like an electron shower pattern on the skin.

Fascinating.

Now, triage in a lightning strike situation like a mass casualty, there's a specific rule here, isn't there?

It's kind of counterintuitive.

It really is.

In most mass casualty incidents, you prioritize those with vital signs, those who are breathing.

But with lightning, the rule is reversed.

The first priority is to treat those who appear dead, those in cardiopulmonary arrest.

Why is that?

Because lightning often causes immediate cardiac arrest, but the heart rhythm can sometimes spontaneously return after a short period.

However, the respiratory center in the brain can stay shut down for much longer.

So people die from lack of breathing, even if their heart restarts.

If you start CPR and rescue reading immediately, you have a decent chance of saving them.

And critically, rescuers are not at risk of being shocked by touching the victim.

The charge is gone instantly.

Got it.

Start CPR on the apparently lifeless victims first and in the hospital.

In the hospital, assume spinal injury until proven otherwise they might have been thrown by the blast effect or fallen.

So, spinal stabilization first.

Look carefully for hidden trauma.

Central nervous system injury is really common.

You might see temporary paralysis, especially in the legs, called carinoparalysis.

It usually resolves within hours, but it's scary.

And they need continuous ECG monitoring because the electricity can definitely affect the heart muscle, causing arrhythmias or damage.

All right, let's head up high.

Altitude -related illnesses or high -altitude disease, HAB, these happen because of the lower partial pressure of oxygen at higher elevations generally kicks in above 1 ,500 feet or so, but more common, much higher.

Right, and the body tries to compensate.

It does.

The primary response to hypoxia, the low oxygen, is the hypoxic ventilatory response.

You start breathing faster and deeper, trying to pull in more oxygen.

Which blows off CO2.

Exactly, which leads to hypokapnia and initially respiratory alkalosis.

Over days or weeks, the body adjusts through acclimatization, making more red blood cells, changing kidney function, et cetera.

But if you ascend too quickly, problems arise.

And there are three main syndromes described.

Yep, the most common and mildest is acute mountain sickness, AMS.

Feels like a bad hangover headache, fatigue, nausea.

Usually gets better with rest and acclimatization, maybe some Tylenol.

Okay, then it can get more serious.

That's more serious.

Next up is high -altitude pulmonary edema, HEE.

Fluid starts leaking into the lungs.

Key signs are a persistent dry cough that just won't quit.

Maybe sinusis, blue lips or nails, and being really short of breath and tachycardic, even when resting.

And the really bad sign for HEP.

Pink frothy sputum.

That's a late and very dangerous sign indicating significant pulmonary edema.

That's a medical emergency.

And the third one affects the brain.

Right, high -altitude cerebral edema, HACE.

This is fluid leaking into the brain due to the hypoxia and pressure changes.

People become confused, extremely lethargic, just total apathy.

But the key diagnostic sign, the thing that really points to HACE, is ataxia.

Ataxia, like problems with coordination.

Exactly, specifically trouble with balance and coordination.

The classic test is asking them to walk heel to toe in a straight line.

If they can't do it, if they're stumbling and weaving, that's ataxia and strongly suggests HACE.

Untreated, it rapidly leads to coma and death from brain swelling.

So for HAPE and HACE, these are true emergencies.

What's the absolute number one intervention?

It seems almost too simple.

It does, but it's absolutely critical.

The single most important treatment for serious altitude illness is descent.

Get them down to a lower altitude as quickly and safely as possible.

Nothing else works as well or as definitively.

So the drugs we hear about, like acetazolamide or dexamethasone.

They're important adjuncts.

Acetazolamide, Dianbox, helps speed up acclimatization, often used preventatively too.

Dexamethasone is a powerful steroid that reduces cerebral edema in HACE can be lifesaving.

Oxygen therapy is vital too, but none of them are a substitute for descent.

Descent is king.

Get down, get down, get down.

Okay, last topic, drowning.

Still a major cause of accidental death.

Tragically common, yeah.

The path of physiology involves aspiration of water and it doesn't really matter if it's fresh water or salt water.

Both wash out surfactant in the lungs.

Surfactant, that's the stuff that keeps the little air sacs, the alveoli open.

Exactly.

Without surfactant, the alveoli collapse, making gas exchange impossible, leading to hypoxia and pulmonary edema.

Interestingly though, a couple of things can sometimes offer a bit of protection, especially in cold water incidents with kids.

Hypothemia itself can slow metabolism and the diving reflex.

Diving reflex.

Yeah, it's triggered by cold water hitting the face.

It slows the heart rate and shunts blood away from the periphery towards the brain and heart, conserving oxygen for the vital organs.

It can sometimes extend survival time underwater.

Okay, first aid for drowning.

What's the critical rescue point here?

Safe removal from the water is priority one.

Then start rescue breaths as soon as possible.

Even if you're still in shallow water, if you can do it safely, start breaths.

The critical safety point is, do not waste time trying to get water out of the lungs.

Forget the old movies with people turning victims upside down or doing abdominal thrusts to remove water.

So no Heimlich unless you think they choked on something else.

Precisely.

Abdominal or test thrusts are only for suspected foreign body airway obstruction.

Trying to force water out is ineffective and just delays ventilation and oxygenation, which is what they actually need.

Right, get air in.

And in the hospital setting, anything specific?

Once they're in the hospital, besides oxygenation and ventilation support, gastric decompression is often necessary.

Placing an NG or OG tube to empty the stomach.

Why is that so important?

Because drowning victims often swallow large amounts of water and air.

A distended stomach pushes up on the diaphragm, making it much harder to ventilate the lungs effectively.

Emptying the stomach improves lung mechanics and also reduces the risk of them vomiting and aspirating these stomach contents later, which is a common and serious complication.

Hashtag, tag, tag, tag outro.

So we really covered a lot of ground today.

A huge amount of crucial clinical info.

If we boil it down, the absolute key takeaways have to include the urgent need for rapid cooling and heat stroke and remembering no antipyretics.

The careful, gentle handling needed for severe hypothermia and actively avoiding external warming due to that after -drop risk, using internal warming instead.

For snake bites, immediate rest and getting poison control involved for anti -venom guidance.

For serious altitude illness, HP or HACE, descent, descent, descent is the ultimate priority.

Nothing needs getting down.

Absolutely.

So when we step back and think, what does this all mean?

The chapter itself kind of frames these emergencies by connecting them to bigger environmental shifts.

Yeah, it does mention the context of climate change.

Right.

And the frequency, the severity of these kinds of incongruence, the heat waves, maybe even vector changes for bites and stings they're changing.

So thinking about these core principles of emergency care,

how will they need to adapt?

How will we need to adapt as we face more temperature extremes, more environmental challenges?

This knowledge isn't just about treating today's emergency, is it?

It's really about being prepared for what seems to be a shifting clinical landscape.

That's a really crucial point.

It's about resilience and adaptability in our practice going forward.

Definitely something for all of us in healthcare to consider.

Thanks so much for joining us on this deep dive into environmental emergencies.

Yeah, thanks for listening.

We'll catch you next time.