Chapter 12: Inflammation & Healing Processes

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Welcome to the Deep Dive.

We're here to pull out the absolute must -know info from your key sources.

And today, we're getting into something fundamental, how the body reacts to starts to heal.

Yeah, exactly.

We're talking inflammation, wound healing,

and something nurses deal with constantly.

Pressure injuries.

Think about a patient like GN62, multiple sclerosis in a wheelchair.

Comes in with a UTI.

And then you find he's also got a new stage two pressure injury on his sacrum.

Bit of fever, high weight count.

It just shows how interconnected everything is, doesn't it?

It really does.

And understanding the basics, the inflammation, how wounds actually is key to managing all of that effectively.

So that's our mission today.

We're digging into Lewis's Medical Surgical Nursing, the 12th edition, pulling out the core concepts, making sense of the jargon, and really focusing on your role as the nurse.

Right.

It's about giving you the knowledge for practice and honestly for nailing those NCLEX questions.

Okay, let's unpack this.

We're talking fundamental concepts that underpin so much of patient care.

What's fascinating here is how precisely the body orchestrates its response to injury.

I mean, from that very first signal to the mental star tissue, it's quite a system.

It really is.

And our goal is to map out that system, right, and show how your observations, your actions can really change things for a patient.

Exactly.

So let's jump right in.

The body's first line of defense,

inflammation.

Here's where it gets really interesting.

Because you hear inflammation and infection thrown around together all the time.

But they're not the same thing, are they?

Getting that straight is critical.

Oh, absolutely vital.

It's a key diagnostic point.

So inflammation is the body's reaction.

It's a sequence of events really responding to any cell injury.

Its job is to neutralize whatever caused the harm, clean up the dead cells, the debris, and then get the area ready for healing.

Okay, neutralize, remove, prepare.

Right.

Now, infection always involves microorganisms like bacteria or viruses actually invading the So here's the crucial bit.

Infection always causes inflammation.

Always.

Got it.

Infection leads to inflammation.

But you can definitely have inflammation without an infection.

Think about

a simple ankle sprain, or a burn, or even an allergic reaction.

That's inflammation, but no microbes involved.

Right, right.

Makes sense.

And this matters clinically.

Take a neutropenic patient, someone with a really low white blood cell count.

They might have a raging infection, but they can't mount that classic inflammatory response.

You won't see the usual redness, the swelling, maybe not even much pus.

Wow, so you'd have to look for other signs.

Exactly.

More subtle things.

Maybe just a change in mental status or feeling generally unwell.

It really highlights why knowing the difference is so important for your assessment.

That's a really powerful point.

Okay, so inflammation is this emergency response.

What happens first?

What are the immediate steps in this cascade?

It starts almost instantly.

First, a really brief vasoconstriction, like the vessels clamp down for a second.

Okay.

But then almost immediately, they dilate.

Chemical mediators, especially histamine, cause this vasodilation.

So more blood rushes to the area.

That's your redness and heat.

Okay.

Direct link.

Yep.

And then the capillaries become more permeable, leakier.

Fluids start seeping out into the tissues.

First, it's watery, sears fluid,

but then plasma proteins like albumin follow.

And that's the swelling.

That's the swelling, the edema.

And fibrinogen, another protein, gets converted to fibrin, forming this sort of mesh, like a clot.

Okay.

This clot traps bacteria, keeps the problem contained, but it also provides a scaffold, like a framework, for the healing cells to build on later.

And platelets are there too, releasing growth factors that signal, okay, time to start repairing.

So much happening right away that visible redness, heat, swelling, it's all this vascular action.

Precisely.

It's the body mobilizing its resources.

Then the cells themselves start arriving, the movers and shakers.

Exactly.

This process is called chemotaxis.

It's like a chemical signal drawing the white blood cells to the injury site.

Like a bat signal for immune cells.

Huh, kind of.

Right.

And the first ones on the scene are the neutrophils.

They arrive fast, usually within six to 12 hours.

Their main job is phagocytosis, basically eating up bacteria, foreign material, and dead cells.

The first wave of defense.

Right.

But they don't live long, maybe 24 to 48 hours.

When they die, they pile up with the debris they've ingested, and that mix is what we see as pus.

Ah, okay.

So pus is basically dead neutrophils and junk.

Pretty much.

And here's a key thing for you to watch for in lab results, the shift to the left.

I've heard that term.

What does it mean?

It means the bone marrow is working over time, pumping out neutrophils so fast that it starts releasing immature ones called bands into the bloodstream.

Immature ones?

Yeah.

Seeing a high number of these bands that shift to the left is a really common sign of an acute bacterial infection.

Like with our patient, Jian, his elevated white count with bands is a big clue.

Okay, red flag.

Got it.

So neutrophils are the quick responders.

Who comes next?

After the neutrophils, the monocytes arrive.

They take a bit longer, maybe three to seven days.

Slower backup.

Sort of.

But they're crucial.

Once they get into the tissue, they transform into macrophages.

Think of them as the heavy duty cleanup crew.

Okay.

Macrophages are also phagocytic, but they live much longer than neutrophils.

They gobble up all the remaining inflammatory debris,

dead neutrophils, damaged cells, basically preparing the site for actual healing.

So they're essential for the later stage.

Absolutely.

And because they live longer in chronic situations like tuberculosis, they can fuse together to form giant cells to wall off particles the body can't get rid of, or even form granulomas.

Lymphocytes also show up later, playing more of a role in the specific immune response.

Wow.

It's like a whole coordinated cellular army.

It really is.

And what's fascinating here is how precisely the body orchestrates this response through its own internal signaling.

The chemical messengers you mentioned.

Exactly.

Chemical mediators.

They're tiny molecules, but they have powerful effects.

There are several key systems.

The complement system, for example, is a cascade of proteins in the blood that gets activated.

What does it do?

It does a few things.

It makes pathogens easier for phagocytes to grab, enhances inflammation, and can even directly poke holes in bacterial cell walls, killing them.

Powerful stuff.

Definitely.

Then you have prostaglandins, or PGs.

These are really important.

They're potent vasodilators, contributing to that redness and heat.

But they also sensitize pain receptors.

That's a big reason why inflammation hurts so much.

And they can trigger fever.

Okay, so that explains the pain aspect.

Yep.

And there's thromboxane, which does the opposite.

It's a vasoconstrictor and helps platelets clump together to form quats.

Okay.

And another group, leukotrienes.

These are particularly important, things like asthma, because they constrict bronchioles in the lungs.

They also increase capillary permeability, adding to swelling and edema, especially airway edema.

So understanding these helps explain why certain drugs work.

Precisely.

Drugs like NSAIDs, ibuprofen, naproxen, and aspirin work largely by blocking the enzymes needed to make prostaglandins and thromboxane.

Corticosteroids work further up the chain, blocking multiple pathways.

Knowing the mediators helps you understand the why behind the treatment.

That makes so much sense.

Okay, so all this cellular action and fluid shifting leads to the exudate, right?

The drainage we see.

Right.

Exudate is just the accumulation of fluid and white blood cells at the site.

And the type of exudate tells you a lot about what's going on.

Okay.

What are the main types we should recognize?

Well, you've got serous exudate that's thin, clear, watery fluid.

Think of the fluid in a simple blister.

Usually means mild injury.

Okay.

Then serousanguinous, this is pale pink, watery.

It's a mix of serous fluid and some red blood cells.

You often see this in surgical drains right after an operation.

Right.

Fabrenous exudate happens with more inflammation, leads to thick, sticky strands of fibrin.

This can cause tissues to adhere together inappropriately forming adhesions.

Ah, like internal scar tissue.

Kind of, yeah.

Then hemorrhagic exudate is mostly blood indicating bleeding.

A hematoma is basically a collection of this.

Okay.

Pyrrolein exudate, that's pus.

Thick, yellowish, greenish, maybe tan, often has an odor.

This is a hallmark sign of infection, full of live and dead bacteria, neutrophils, and debris, like in an abscess.

Definitely need to recognize that one.

For sure.

And lastly, cataral exudate.

That's mucus production, like you get with a runny nose during a cold.

So looking at the drainage gives you real clues.

Big time.

It's part of your assessment.

Okay.

So inflammation itself isn't just one thing.

It could be acute or chronic.

Exactly.

Acute inflammation is usually short, maybe lasts up to two or three weeks.

Typically, the injurious agent is removed and healing occurs with little or no residual damage.

Neutrophils are the main cells involved here.

Like that sprained ankle example.

Perfect example.

Subacute just means it has features of acute, but lasts a bit longer.

Chronic inflammation, though, that can last for weeks, months, even years.

Why would it last so long?

Usually because the injurious agent persists, like in chronic infections, say osteomyelitis, or it could be due to an autoimmune reaction where the body attacks itself, like in rheumatoid arthritis.

Here, the main cells are lymphocytes and macrophages, not neutrophils, and it often leads to tissue damage.

Okay.

So different timeframes, different cells, different outcomes.

We talked about local signs, redness, heat, swelling, pain,

anything else.

Loss of function is the fifth classic local sign.

If your ankle is swollen and painful, you can't walk on it Gene's fever and white count seem to fit here.

Absolutely.

Systemic signs include an increased white blood cell count, often with that shift to the left we discussed.

Patients might feel malaise, just generally unwell, fatigue,

maybe nausea or anorexia.

Their pulse and respiratory rate might increase.

And yes, fever.

Fever is a big one.

How does that actually happen?

It's triggered by cytokines, those chemical messengers released by immune cells, things like IL -1 and tumor necrosis factor, TNF.

They travel to the hypothalamus in the brain.

The body's thermostat.

Exactly.

They basically tell the hypothalamus to reset the thermostat to a higher temperature.

Prostaglandins are involved in this signaling within the brain too.

The body then initiates mechanisms like shivering and vasoconstriction in the skin to generate and conserve heat, raising the body temperature to that new set point.

So it's a regulated process.

Is fever always bad?

Should we always try to bring it down?

That's a great question.

Fever is often seen negatively, but it actually has benefits.

Increased temperature can increase the killing of microorganisms, boost phagocytosis by neutrophils, and increase the proliferation of T cells, which are important immune cells.

Huh.

So it helps fight the infection.

It can, yes.

Up to a point.

Very high fevers, say over 104 degrees Faffer or 40 degrees C, can start to damage body cells, especially brain cells.

And even moderate fevers can be dangerous for the very young, the very old, or people with significant heart or lung problems because fever increases metabolic rate and oxygen demand.

So it's a balancing act.

It is.

And older adults sometimes have a blunted fever response.

They might have a serious infection, but only a mild temperature elevation or none at all.

Another reason to be vigilant with older patients.

Definitely.

So bringing this all together for the nurse,

what's our role in managing inflammation?

How do we walk that tightrope?

Your role starts with assessment, assessment, assessment.

Early recognition is key.

Look for potential causes.

Is it trauma, infection, allergy?

Assess for risk factors.

And remember, like we said, immunosuppressed patients might not show classic signs.

For them, just feeling off might be your biggest clue.

And vital signs.

Always vital signs.

Temperature, pulse, respiration, blood pressure.

Then think about diagnoses, things like, well, inflammation itself,

altered temperature, maybe impaired tissue integrity if there's a wound.

Okay.

And interventions?

General care aims to manage the inflammation and support healing.

Nutrition is huge.

Patients need adequate fluid intake.

And they often need increased calories, especially with fever.

For every one degree aerofoil arise above 100 degrees aerofoil, the metabolic rate goes up about 7%.

Wow, that's significant.

It is.

They might need protein supplements too.

Now for fever management, it's nuanced.

We don't necessarily treat every mild fever.

But for vulnerable patients, or if the fever is very high or causing significant discomfort, then antipyretics like acetaminophen or NSAids are usually given.

It's generally best to give them regularly, around the clock, rather than waiting for the temperature to spite high again.

This prevents those big swings that cause chills and discomfort.

Good tip.

What about cooling blankets or sponge baths?

Those are most effective after an antipyretic has been given to lower the hypothalamic set point.

If you try to cool someone down externally while their internal thermostat is still set high, they'll just shiver intensely trying to generate heat, which is uncomfortable, and increases metabolic demand.

Ah, okay.

Lower the set point first, then cool.

Exactly.

And for drug therapy, besides antipyretics, you might be giving anti -inflammatory drugs, NSAids, aspirin, or corticosteroids, depending on the cause and severity.

Right.

And for injuries like sprains, strains, the classic rice approach.

Yes.

Rice is still fundamental for soft tissue injuries and inflammation.

Rest.

Protect the injured part.

Allow healing to start.

Ice.

Apply cold packs, especially in the first 24 -48 hours.

Cold causes vasoconstriction, which helps reduce swelling, pain, and congestion.

Contrast it with heat later on.

Right.

Heat is usually used later, maybe after 48 hours, to increase circulation and help remove debris.

Compression.

Using an elastic bandage helps counter vasodilation and reduce edema.

But you must assess circulation distal to the bandage check pulses, capillary refill, sensation – don't wrap it too tight.

Critical safety point.

Very.

And elevation.

Raising the injured part above the level of the heart helps drain excess fluid via gravity, reducing edema and pain.

Just be cautious if the patient has reduced arterial blood flow to that limb.

Okay.

ICE.

Rest.

Ice.

Compression.

Elevation.

Got it.

Right.

That's a really solid overview of inflammation.

Now after that initial response, the body has to actually repair the damage, right?

This leads us to wound healing.

Exactly.

The art of repair, as you called it.

And the body has two main ways to do this.

Okay.

The ideal way is regeneration.

This means the damaged cells are replaced with new cells of the same type.

So the tissue structure and function are basically restored.

Like skin healing after a minor scrape.

Perfect example.

Skin cells are labile.

They divide constantly, so they regenerate well.

Liver cells and bone cells are stable.

They don't normally divide, but they can if they're injured.

But some cells, like neurons in the brain and spinal cord or cardiac muscle cells, are permanent.

They generally don't divide after birth.

So if they're destroyed?

They can be replaced by the same type of cell.

Damage there usually heals by the second method.

Repair.

Okay.

What's repair?

Repair is more common, especially for deeper or larger injuries.

It involves replacing the lost cells with connective tissue.

This leads to scar formation.

So regeneration is replacement.

Repair is patching with scar tissue.

That's a good way to put it.

And repair happens through different intentions of healing.

Intentions.

Like the wound has a plan.

Sort of.

It describes how the wound closes.

Primary intention healing is what you see with a wound that has nice, clean, well -approximated edges.

Like a surgical incision that's been sutured or stapled or even a paper cut.

Okay.

Neat and tidy.

Exactly.

It heals in phases.

First, an initial phase.

Basically the inflammation we just talked about.

Plus clot formation.

Then the granulation phase, which is really interesting.

What happens then?

Fibroblasts, which are connective tissue cells, migrate in and start secreting collagen, the main protein in scars.

Lots of new capillaries also grow into the area.

This network of new tissue is called granulation tissue.

It looks pink or red and bleeds easily.

The wound is quite fragile at this stage.

Finally, there's the maturation phase and scar contraction.

The collagen gets reorganized and strengthens.

And special cells called myofibroblasts actually contract, pulling the wound edges together, making the scar smaller over time.

Eventually the scar becomes paler as the capillaries regress.

Wow.

That's quite a process for just a simple cut.

It is.

Now, secondary intention is different.

This happens when wounds have significant tissue loss, irregular edges, or maybe infection.

Think of large trauma wounds, burns, or pressure injuries like GN stage two.

Okay.

So not neat and tidy.

Right.

The inflammatory reaction is usually greater because there's more debris to clean up.

And the wound heals from the edges inward and the bottom upward.

It fills in with granulation tissue, but it takes longer.

And the scar is much larger and more noticeable.

So GN's pressure injury would probably heal this way?

Most likely, yes.

Then there's tertiary intention, sometimes called delayed primary closure.

What's that?

This is when a contaminated wound is intentionally left open for a few days to allow for drainage, cleaning, and maybe antibiotic treatment to control infection.

Then once it looks clean, the edges are surgically closed.

Or sometimes a wound healing by primary intention gets infected, has to be opened up, allowed to granulate, and then closed again.

So it's a combination almost.

Kind of.

It results in a larger, deeper scar than primary intention, but potentially better infection control than just letting a heavily contaminated wound close right away.

Okay.

That makes sense.

Now, healing doesn't always go perfectly.

There can be complications, right?

Unfortunately, yes.

And if we connect this to the bigger picture, preventing these complications is crucial for patient recovery and quality of life.

They can range from annoying to life -threatening.

What are some key ones nurses need to watch for?

Well, you can get adhesions, which are bands of scar tissue that form between organs, sometimes causing pain or obstruction later.

Contractions can occur, especially over joints, where the scar tissue tightens excessively and limits movement.

A big one after surgery is dehiscence, where the wound edges suddenly separate.

And even worse is evisceration, where the edge is separate and internal organs actually protrude through the opening.

That is a surgical emergency.

Cover with sterile, saline -soaked gauze and call the surgeon immediately.

Definitely an emergency.

What else?

You can have excess granulation tissue, sometimes called proud flesh, that bulges above the surface and hinders healing.

Fistula formation, an abnormal passage between two organs or an organ and the skin.

Of course, infection is always a risk.

Hemorrhage or bleeding, especially early after injury or surgery.

And then problems with the scar itself.

Hypertrophic scars are inappropriately large, red, raised scars that stay within the bounds of the original wound.

But keloid formation is where the scar tissue grows beyond the original wound boundaries, creating a large protruding mass.

This is more common in people with darker skin and can have a genetic component.

Lots of potential pitfalls,

which highlights the importance of good nursing care.

Absolutely.

Your assessment and interventions are key to preventing or catching these early.

So let's talk about that nursing role.

We're often the ones doing the wound care, assessing progress.

Sometimes we collaborate with specialized nurses, right?

W -O -C -Ns.

Yes.

Wound Osteomy and Continence Nurses, W -O -C -Ns, are fantastic resources.

But every nurse needs solid wound assessment skills.

Your assessment is paramount.

What exactly should we be documenting?

You need to be precise.

Note the location of the wound.

The type is it.

Surgical, trauma, pressure injury,

then measurements, length, width, and depth.

Use consistent methods.

For any tunnels or undermined areas where the tissue destruction goes under the skin edge, describe their location using the clock face analogy with 12 o 'clock towards the patient's head and measure the depth.

Okay.

The clock method.

Describe the wound bed.

What does it look like?

Is it nice red granulation tissue, yellow slough, which is dead tissue, black escher, which is thick, hard necrotic tissue?

What percentage of each?

Note the wound margins or edges.

Drainage, too.

Critically important.

The drainage or exudate.

What type is it?

Serous, purulent, etc.

How much is there?

Scant, moderate, copious.

Does it have an odor?

Assess the perfusion around the wound.

Is the surrounding skin warm, good capillary refill?

Look at the surrounding tissue itself.

Is it red, macerated from moisture, intact?

Always assess for clinical signs of infection, increased redness, warmth, swelling, pain, purulent drainage, fever,

and assess the patient's pain level related to the wound or dressing changes.

That's a lot to look at.

It is, but it's essential for tracking progress and guiding care.

Knowing common wound pathogens like Staphylococcus and Pseudomonas also helps anticipate potential problems.

And we know certain things can slow down healing.

What are the big factors that delay wound repair?

There are quite a few critical ones.

Advanced age is a factor.

Anemia, because oxygen delivery is crucial.

Corticosteroid use suppresses inflammation and immunity.

Diabetes is huge.

It impairs circulation and immune function.

Inadequate blood supply for any reason.

Active infection in the wound, obviously.

Mechanical friction or shear forces.

Nutrition seems like it would be key, too.

Absolutely critical.

Deficiencies in vitamin C needed for collagen synthesis.

Protein and zinc are major culprits.

Obesity can sometimes impair healing due to poor blood supply and fatty tissue.

Poor general health overall.

And smoking nicotine is a potent vasoconstrictor, reducing blood flow to the tissues.

So many factors we need to consider in our overall patient assessment.

Okay, we've assessed the wound, considered the risk factors.

Now, how do we actually manage the wound?

What are the core principles?

I remember you saying airing out is bad.

That's the biggest myth to bust.

Wounds heal best in a moist environment.

Dryness kills the cells needed for healing and creates a hard scab that can block epithelial cells from migrating across the surface.

But keep it moist.

Got it.

Yes.

The basic principles are protect clean wounds from trauma and infection.

Clean, dirty or contaminated wounds to remove debris and bacteria.

And treat infection if it occurs.

And dressings play a big role here.

There are so many types.

There are.

And choosing the right one depends entirely on the wound characteristics.

Your goal is usually to maintain that moist environment, absorb excess exudate without drying the wound out, protect it, and sometimes deliver medication or de -bride.

Can you give a few examples?

Sure.

Gauze is traditional.

Used for cleansing, packing, covering.

Transparent films are like clear plastic wrap.

Good for superficial wounds with minimal drainage.

Let's you see the wound.

Hydrocolloids form a gel over the wound.

Good for light to moderate drainage and using the body's own enzymes.

Hydrogels actually donate moisture so they're great for dry wounds.

Foams are very absorbent.

Good for moderate to heavy exudate.

Also used for pressure injury prevention under devices.

Alginates, derived from seaweed, are also super absorbent.

Good for heavy drainage.

They form a gel in the wound.

And antimicrobials, often containing silver or honey, are used for infected wounds or those at high risk.

So it's really about matching the dressing's function to the wound's needs.

Exactly.

Maintain moisture, manage exudate, protect the wound.

Sometimes drains, like a Jackson -Pratt drain, are used initially to remove larger amounts of fluid.

Right.

What about de -bridement, removing the dead stuff?

Often essential, especially if there's slough or eschar blocking healing.

There are different ways.

Autolytic de -bridement uses moisture -attentive dressings to let the body's own enzymes break down dead tissue.

Enzymatic de -bridement uses special ointments.

Mechanical de -bridement includes things like wet -to -dry dressings, though these are less common now as they can damage healthy tissue,

or wound irrigation using saline under gentle pressure to flesh out debris.

You need enough pressure to clean, but not so much you drive bacteria deeper.

Tricky balance.

It can be.

Conservative sharp de -bridement involves using sterile scissors or scalpels at the bedside to remove loose dead tissue, usually done by trained nurses or physicians.

Surgical de -bridement is done in the OR for extensive dead tissue.

And there's even biologic de -bridement using sterile maggots.

Maggots.

Seriously.

Seriously.

They selectively eat only dead tissue and disinfect the wound.

Very effective in some cases.

Wow.

Okay.

Are there more advanced therapies, too?

Yes.

Negative pressure wound therapy, MPWT, often called a wound vac, is very common now.

A special foam dressing is placed in the wound, sealed with film, and connected to a vacuum pump.

What does the vacuum do?

It creates gentle, continuous, or intermittent negative pressure.

This pulls out excess fluid, reduces edema, decreases bacterial load, and actually stimulates blood flow and granulation tissue formation.

It's great for complex wounds like diabetic foot ulcers or large surgical wounds.

Okay, and PWT.

Hyperbaric oxygen therapy, HBOT.

The patient breathes 100 % oxygen inside a pressurized chamber.

This forces much more oxygen to dissolve in the blood plasma, getting it to tissues that might have poor circulation.

It promotes new blood vessel growth, angiogenesis, helps kill anaerobic bacteria, and generally accelerates healing for certain chronic wounds.

Fascinating.

And nutrition keeps coming up.

Can't emphasize it enough.

High fluid intake, high protein for building blocks, enough carbohydrates for energy so protein isn't used for fuel, and key vitamins.

C for collagen, B, complex vitamins as coenzymes, vitamin A for epithelialization.

If they can't eat enough, you need to advocate for supplements, enteral feeding, tube feeding, or parenteral nutrition, IV nutrition.

Okay, and infection control is woven through all of this.

Absolutely.

Strict aseptic technique for dressing changes.

Hand washing, hand washing, hand washing.

If you suspect infection, a wound culture is needed before starting antibiotics, if possible.

This can be done by swabbing the clean wound bed, needle aspiration, or tissue biopsy.

Got it.

Culture first.

Finally, the patient themselves.

Wounds can be really distressing.

Hugely.

Think about body image issues, especially with large or visible wounds.

Odor from drainage can be embarrassing and isolating.

Pain is often significant.

As nurses, it's so important to be sensitive, non -judgmental, and provide emotional support.

Your facial expression matters when you take off that dressing.

Good point.

And patient teaching is key.

Essential.

Patients and caregivers need to know how to do dressing changes, recognize signs of infection or complications,

understand the importance of nutrition and rest, and when to call for help.

Empowering them is crucial for successful healing, especially after discharge.

That's a fantastic overview of the healing process.

Now let's pivot to a specific and often preventable type of wound.

Pressure injuries.

Here, that phrase, prevention is key, is everything, isn't it?

It absolutely is, because once they develop, they can be incredibly difficult, costly, and painful to heal, and they significantly impact quality of life.

So what exactly causes them?

It's not just pressure, is it?

Pressure is the main factor, but it's usually intense or prolonged pressure.

Typically over a bony prominence like the sacrum, heels, hips, elbows.

But it's often pressure combined with shear.

Shear.

What's that again?

Shear happens when layers of tissue slide over one another.

Imagine the patient sliding down in bed, the skin sticks to the sheet, but the underlying bone and muscle move downwards.

This stretches and angulates blood vessels, cutting off flow.

It's very damaging.

Ah, okay.

Pressure plus shear.

Right.

And it's not just the pressure intensity and duration, but also the tissue's ability to tolerate that pressure.

This tolerance is affected by many things.

Moisture, like from incontinence, which makes skin fragile.

Nutrition, perfusion, blood flow, overall health, and the microclimate of the skin, temperature and humidity.

So it's a combination of external forces and the patient's internal resilience.

Exactly.

The sacrum and heels are the most common site, because they bear a lot of weight and have little padding.

And remember, GN wheelchair -bound issues with mobility and nutrition, he's ticking a lot of risk factor boxes.

Right.

So what does this all mean when you're looking at a patient?

It means we need to be vigilant.

Let's list those critical risk factors again.

Okay.

Key ones include advanced age, because skin gets thinner and less elastic.

Immobility is huge, inability to change position independently.

Incontinence, both urinary and fecal, leads to moisture damage.

Diabetes affects circulation and sensation.

Poor nutrition and hydration compromise tissue integrity.

Low diastolic blood pressure can mean poor perfusion.

Cognitive impairment patients may not recognize or communicate discomfort.

And things like long surgical procedures where someone is immobile for hours.

That list really highlights who needs extra attention.

Yeah.

Now, when an injury does occur, we stage it to classify the severity, right?

Can you walk us through the stages?

Sure.

It's important to know these.

Stage one.

This is intact skin, but it has persistent non -blanchable redness over a bony area.

Blanching means it turns white when you press it and then pinks up again when you release.

Non -blanchable means it stays red even when pressed.

In darker skin tones, this redness might look different, maybe darker purple or maroon, and you might rely more on changes in skin temperature or texture compared to the surrounding area.

Okay.

Stage one.

Intact skin, non -blanchable redness.

Stage two.

Now we have partial thickness skin loss.

The epidermis and maybe part of the dermis are gone.

It looks like a shallow open ulcer with a reddish pink wound bed, or it could present as an intact or ruptured serum -filled blister.

There's no slub or escher yet.

This is what Jian had.

Stage two.

Partial thickness loss, shallow ulcer or blister.

Stage three.

This is full thickness skin loss.

Subcutaneous fat might be visible, but bone, tendon, or muscle are not exposed.

Slaw might be present, but it doesn't obscure the depth.

You might see undermining or tunneling.

The edges might be rolled.

Stage three.

Full thickness skin loss, fat visible.

Stage four.

Full thickness skin and tissue loss.

Now you have exposed bone, tendon, or muscle.

Slaw or escher might be present.

Undermining and tunneling are often extensive.

These are deep damaging injuries.

Stage four.

Full thickness tissue loss, down to muscle or bone.

Then there's unstageable.

This is a full thickness injury, but the base of the wound is completely covered by slow, yellow, tan, gray, green, or brown.

Or escher, tan, brown, or black.

You can't see how deep it is, so you can't stage it accurately until enough slouch is removed.

Can't stage what you can't see.

Exception.

The exception is stable escher dry adherent intact on the heels.

It often serves as a natural protective cover and usually shouldn't be removed.

Okay.

Stable heel escher stays put.

And finally, deep tissue pressure injury, DTPI.

This is tricky.

It presents as persistent non -blanchable deep red maroon or purple discoloration of intact or non -intact skin.

Or it might look like a blood -filled blister.

It signals damage to the underlying soft tissue from intense or prolonged pressure shear.

These can deteriorate rapidly, revealing the full extent of tissue loss later.

So that purple area needs very close watching.

Very close.

We also classify injuries related to medical devices like oxygen tubing on ears, or cast and mucosal membrane pressure injuries inside the mouth or nose.

Okay.

That staging system is clear.

And like other wounds, infection is a risk.

A major risk, especially in stages three and four.

Signs of infection in a pressure injury include increased drainage, change in odor, redness or warmth in the surrounding skin, cellulitis, possibly fever, or an elevated white count.

But remember, chronic wounds are often colonized with bacteria, so clinical signs are key.

And complications can be severe cellulitis spreading, bone infection, osteomyelitis, sepsis, and critically recurrence.

These injuries have a high tendency to come back.

Which brings us back to the nurse's essential role.

Assessment and prevention seem even more critical here.

Absolutely crucial.

Prevention starts with identifying who's at risk, use a validated tool like the Braden Scale on admission, and regularly thereafter.

The Braden Scale looks at sensory perception, moisture, activity, mobility, nutrition, and friction shear.

Okay, Braden Scale for risk assessment.

Then, perform a thorough head -to -toe skin assessment as soon as possible after admission to catch any existing injuries.

And you need to reassess skin regularly.

Maybe daily in acute care, weekly in long -term care, every visit in home care, depending on the setting and risk level.

Remember those challenges in assessing dark skin, look for changes in color compared to surrounding skin, temperature differences, edema, induration, hardness.

Got it.

Regular, thorough assessment.

What about planning?

Patient goals usually focus on no deterioration of the existing wound, if any, preventing infection, achieving healing, and preventing recurrence.

And implementation.

How do we actually prevent these?

Prevention is paramount.

Once you identify someone at risk, you implement a bundle of strategies.

Skincare.

Keep skin clean and dry.

Use moisture barriers if needed for incontinence.

Inspect skin frequently.

Nutrition.

Ensure adequate intake.

Consult dietary if needed.

Mobility.

Encourage movement.

Reposition frequently.

For bedbound patients, turning schedules need to be individualized based on risk, support surface, and skin condition.

The old every two hours rule isn't always enough or appropriate.

For chairbound patients, shifting weight every hour is often recommended.

Use positioning techniques to minimize friction and sheer lift.

Don't drag.

Use pressure -reducing support surfaces, special mattresses, or overlays for beds, cushions for chairs.

So it's a multi -pronged attack on risk factors.

Exactly.

It requires consistent effort from the whole team.

And if an injury, like Jan's stage two, does develop,

what's the focus in acute care?

You combine meticulous wound care with ongoing holistic support, manage pain, optimize nutrition, continue pressure redistribution.

You need to document the wound characteristics carefully, maybe using a tool like the NPWAP POSH tool to track healing over time.

POSH tool?

Pressure Ulcer Scale for Healing.

It scores based on surface area, exudate amount, and wound bed tissue type to give an objective measure of progress.

Okay.

What about cleaning and dressing?

Debridement might be needed if there's necrotic tissue, except for that stable heel usher.

Clean the wound with each dressing change using a non -cyto -toxic solution, usually normal saline.

Use gentle irrigation pressure.

Dressings should maintain that moist environment.

The choice depends on the stage, depth, amount of drainage, presence of infection, etc.

Refer back to those dressing types we discussed.

Keep the wound bed moist, but the surrounding skin dry.

Aim infection.

Be vigilant.

Remember, stages two, three, and four are considered contaminated or colonized.

Look for clinical signs of infection.

Immunocompromised patients might not show classic signs, again, culture before antibiotics if systemic treatment is needed, and push that nutrition patients with pressure injuries often need increased calories, maybe 30, 35 kilocalorie, and protein, 1 .25, 1 .50 kilocalorie to heal.

Nutrition, nutrition, nutrition.

Okay.

What about when the patient goes home?

Teaching is critical because recurrence is so high.

Patients and caregivers need to understand their specific risk factors.

Teach them proper incontinence care, how to position correctly, never directly on the injury, how often to reposition, how to inspect the skin daily using mirrors if needed, the no -touch technique for dressing changes if they're doing them, and reinforce, reinforce, reinforce good nutrition.

It really takes a partnership.

It absolutely does.

Okay, let's quickly circle back to GN62, MS, wheelchair, UTI.

Now the stage two sacral PI fever elevated WBC with bands.

If you're the nurse listening, what question should be popping into your head right now?

Good prompt.

You should be thinking.

What specific risk factors led to his pressure injury?

How would I thoroughly assess that stage two wound?

What characteristics would I document?

What's the significance of his fever and that shift to the left on his WBC count, especially since he also has a UTI?

What are my absolute priority nursing interventions right now for both the pressure injury and his overall condition?

Great critical thinking questions.

If we connect this to the bigger picture, what we've really explored today is the body's incredible symphony of defense and repair and your vital role in conducting that symphony.

Yeah, from that initial inflammatory flare -up.

To the different ways wounds knit themselves back together.

And the absolute critical need for vigilance in preventing and managing pressure injuries.

Every step matters.

It truly does.

Understanding the why behind the redness, the swelling, the drainage, the healing process, it empowers you to act effectively.

So consider this as we wrap up.

How might a subtle failure in one aspect of this intricate system say

That's a sobering thought.

It really highlights how every detail in nursing care matters.

You are that frontline detective, that advocate, that crucial part of the healing process.

Keep digging into these essential concepts.

Thanks for joining us for this deep dive.