Day 5: Inflammation / immune response — fever, swelling, WBCs, steroids/NSAIDs

Inflammation

The body’s protective response to injury, infection, or irritation that helps contain damage and begin healing.

Why does inflammation cause redness and heat?

Inflammatory chemicals cause vasodilation, increasing blood flow to the affected tissue.

Why does inflammation cause swelling?

Capillaries become more permeable, allowing fluid and immune proteins to leak into surrounding tissue.

Why does inflammation cause pain?

Inflammatory chemicals stimulate pain receptors, while swelling puts pressure on nearby nerves.

Why can inflammation cause loss of function?

Pain, swelling, and tissue damage can limit movement or normal organ function.

Fever

Fever occurs when pyrogens signal the hypothalamus to raise the body’s temperature set point.

Why does a patient shiver as a fever begins?

The hypothalamus has raised the temperature set point, so the body produces heat to reach the new set point.

Why can fever cause tachycardia?

Higher temperature raises metabolic demand, so the heart beats faster to deliver oxygen and nutrients.

Why can fever cause dehydration?

Fever increases fluid loss through sweating and faster breathing.

White blood cells

WBCs defend the body against infection, damaged cells, and abnormal cells.

Neutrophils

White blood cells that respond quickly and commonly increase with bacterial infection.

Lymphocytes

White blood cells important for viral defense and adaptive immunity.

Eosinophils

White blood cells associated with allergies, asthma, and parasites.

Why can WBCs rise during infection?

Immune signals stimulate the bone marrow to release more white blood cells.

Why does a normal WBC count not rule out infection?

Older, immunocompromised, or severely ill patients may not produce a strong WBC response.

Local inflammation

Inflammation limited to one area, causing redness, warmth, swelling, and pain.

Systemic inflammation

Inflammation affecting the whole body, causing findings such as fever, tachycardia, fatigue, and elevated WBCs.

How are infection and inflammation different?

Infection is invasion by a pathogen, while inflammation is the body’s response and can occur without infection.

Why can fever with confusion be dangerous?

It may indicate systemic illness, hypoxia, poor perfusion, or sepsis rather than a minor local problem.

NSAIDs

NSAIDs reduce prostaglandin production, decreasing pain, fever, and inflammation.

Why can NSAIDs cause stomach irritation or bleeding?

Prostaglandins help protect the stomach lining, so reducing them weakens that protection.

Why can NSAIDs affect kidney function?

Prostaglandins help maintain kidney blood flow, especially when circulating volume is low.

Why can NSAIDs worsen fluid overload?

They can cause sodium and water retention, worsening edema, hypertension, or heart failure.

Corticosteroids

Steroids broadly suppress immune and inflammatory responses.

Why do steroids reduce swelling?

They decrease inflammatory chemicals, immune-cell activity, and capillary leakage.

Why do steroids increase infection risk?

They suppress immune defenses, making it harder to fight pathogens.

Why do steroids increase blood glucose?

They increase glucose production and reduce insulin sensitivity.

Why can steroids delay wound healing?

They suppress inflammatory and immune processes needed for tissue repair.

Why should long-term steroids not be stopped suddenly?

They can suppress natural cortisol production, so abrupt withdrawal may cause adrenal insufficiency.

Do NSAIDs or steroids kill bacteria?

No. They reduce inflammation or symptoms but do not directly treat bacterial infection.

What is the nursing priority with systemic inflammation?

Assess ABCs, vital signs, mental status, perfusion, urine output, and possible infection source.