Inflammation & Phagocytosis: Body's Defense

Inflammation Concepts

• Inflammation is a protective response to injury, infection, or harmful stimuli, aimed at removing the cause and initiating healing
• Classic signs of inflammation are Pain, Redness, Immobility, Swelling, and Heat ("PRISH")
• Pain results from chemicals like prostaglandins irritating nerves
• Redness is due to vasodilation, increasing blood flow
• Immobility results from loss of function due to swelling or pain
• Swelling is caused by fluid leaking from blood vessels into tissues (edema)
• Heat occurs because increased blood flow brings warmth to the area
• The body responds in steps: injury/infection, release of chemical signals (e.g., histamine), blood vessel dilation, white blood cell movement, and healing

Phagocytosis and Defence

• Phagocytosis involves white blood cells engulfing and destroying bacteria or harmful particles
• Neutrophils are first responders that act quickly but are short-lived
• Macrophages are slower but more powerful, cleaning up dead cells and invaders
• Monocytes become macrophages after leaving the bloodstream
• First-line defenses are barriers that prevent pathogens from entering the body
• Skin acts as a physical barrier
• Mucous membranes trap microbes in the nose, mouth, etc.
• Tears, saliva, and mucus contain enzymes that kill bacteria
• Stomach acid destroys swallowed pathogens
• Cilia are tiny hairs in airways that move germs out

Skin Infections and Hypersensitivity

• Focus on defining the listed skin infections
• Hypersensitivity reaction is an overreaction of the immune system to a harmless substance
• Type I hypersensitivity includes anaphylaxis and is immediate
• Types II, III, and IV hypersensitivity reactions are delayed
• Anaphylaxis is a severe, life-threatening allergic reaction with rapid onset
• Clinical manifestations include swelling, breathing difficulty, hives, drop in blood pressure, rapid heartbeat, and dizziness
• Treatment for anaphylaxis: epinephrine injection, emergency call, antihistamines, and steroids

Ventilation, Oxygenation, and Circulation

• The primary function of the respiratory and cardiovascular systems is to bring oxygen in and expel carbon dioxide
• Key respiratory parts: Nose & mouth (air entry), Trachea (windpipe), Bronchi & bronchioles (lung branches), Alveoli (gas exchange), Diaphragm (breathing muscle)
• Gas exchange involves oxygen moving from alveoli to blood and CO₂ moving from blood to alveoli
• The cardiovascular system's main function is to pump blood and deliver oxygen and nutrients
• Key cardiovascular parts: Heart (4 chambers), Arteries (carry oxygenated blood away), Veins (carry deoxygenated blood back), Capillaries (exchange in tissues)
• Blood flow path: Body → right heart → lungs → left heart → body

Hypertension Causes and Mechanisms

• Hypertension is when the force of blood against artery walls is too high
• Thrombosis (blood clot in a vessel) blocks blood flow, increasing pressure
• Thrombus (actual clot) can cause stroke or heart attack
• Embolus (clot or air that moves) blocks smaller vessels, increasing pressure
• Aneurysm (bulge in vessel wall) can rupture due to pressure
• Hypoxemia/Hypoxia (low oxygen) prompts the body to compensate with increased heart rate and pressure
• Hyperlipidemia (high cholesterol) narrows arteries, raising pressure
• Arteriosclerosis (stiff arteries) requires more pressure to push blood
• Atherosclerosis (plaque build-up) narrows vessels, increasing pressure
• Smoking damages vessel walls, causes vasoconstriction, and raises heart rate/pressure
• Hyperlipidemia leads to plaque formation, narrowed vessels, and increased blood pressure

Rheumatic Fever and Heart Disease

• Rheumatic fever occurs after untreated strep throat
• It is when the body's immune system attacks its own tissues, mainly affecting children
• Rheumatic heart disease is permanent damage to heart valves from rheumatic fever
• It can lead to valve problems, heart failure, or stroke
• Key rheumatic fever symptoms: Fever, joint pain/swelling, chest pain, fatigue, rash, and jerky movements
• Prevention involves early treatment of strep throat with antibiotics

Pulmonary Edema and Angina

• Pulmonary edema is fluid buildup in the lungs, making breathing difficult
• It inhibits oxygen exchange within the alveoli
• Common causes include heart failure, kidney failure, high altitude, and severe infections
• Symptoms: shortness of breath, wet sounds in lungs, coughing up sputum, feeling like drowning, and fast heart rate
• Angina is chest pain from reduced blood flow to the heart, often caused by narrowed arteries from atherosclerosis. It is triggered by blocked/narrowed coronary arteries and physical activity or stress
• Symptoms: chest pain, shortness of breath, sweating, and nausea, triggered by exertion and relieved by rest
• Management: rest, GTN spray/tablets, beta-blockers/aspirin/statins, lifestyle changes, and surgery

Unstable Angina and Valve Stenosis

• Unstable angina presents with pain even at rest and is a warning sign of a heart attack (MI)
• A sudden blockage in a coronary artery causes it
• Partial blockage leads to unstable angina; full blockage leads to myocardial infarction, resulting in heart muscle death
• Valve stenosis is when a heart valve becomes narrowed or stiff, making it harder for blood to flow through
• Types: Aortic and Mitral stenosis
• This causes the heart to work harder and can lead to heart failure, arrhythmias, or sudden death if untreated
• Symptoms: chest pain, shortness of breath, fatigue, and dizziness

Cardiac Arrhythmias and ECG

• Cardiac arrhythmias are irregular heartbeats (too fast, too slow, or uneven)
• Types: Tachycardia, Bradycardia, Atrial fibrillation (AF), and Ventricular fibrillation (VF)
• Causes: Heart damage, electrolyte imbalance, stress, medications, and heart surgery
• Symptoms: Palpitations, dizziness, fainting, shortness of breath, and chest pain
• Treatments: Medications, pacemaker, defibrillator, and cardioversion
• ECG (Electrocardiogram) checks the heart's electrical activity using electrodes on the chest, arms, and legs
• It detects heart rhythm, rate, and problems, like arrythmias
• Normal ECG waves represent: P wave (atria contraction), QRS complex (ventricle contraction), and T wave (ventricles relax)

Abnormal Breathing Patterns

• Tachypnea is fast breathing
• Bradypnea is slow breathing
• Apnea is a temporary stop in breathing
• Dyspnea is difficulty breathing
• Kussmaul breathing is deep, labored breathing, often seen in diabetes
• Cheyne-Stokes respiration involves periods of deep breathing followed by no breathing, typically seen in brain injury or end-of-life

Pulmonary Tuberculosis and Asthma

• Pulmonary Tuberculosis is a serious lung infection caused by Mycobacterium tuberculosis, spread through airborne droplets
• Symptoms: persistent cough, coughing up blood, night sweats, weight loss, fever, and fatigue
• Treatment involves a long course of antibiotics
• Asthma is a chronic condition with narrowed and inflamed airways, triggered by dust, pollen, cold air, exercise, stress, or smoke
• Symptoms: wheezing, shortness of breath, chest tightness, and coughing
• Management: reliever inhalers, preventer inhalers, and trigger avoidance

Hyperventilation and Hypoventilation

• Hyperventilation is breathing too fast or deep, leading to excessive CO₂ removal, causing dizziness, tingling, and light-headedness
• It is often linked to anxiety or panic attacks
• Hypoventilation is breathing too slow or shallow
• Not enough CO₂ is released, causing drowsiness or confusion, and it is seen in drug overdose or neuromuscular disorders

Bronchitis and Bronchiolitis

• Bronchitis is inflammation of the bronchi, marked by cough, mucus, wheezing, and chest tightness, often from infection or smoking
• Bronchiolitis is inflammation of the bronchioles, common in babies and young kids, often caused by RSV, marked by cough, wheezing, difficulty breathing, and poor feeding

Pulmonary Function and Respiratory Assessments

• Pulmonary function assesses lung efficiency in air intake/outtake and oxygen movement into the blood
• Pulmonary function tests include spirometry and peak flow
• Respiratory assessments involve observing breathing, auscultating lung sounds, measuring oxygen saturation, performing percussion, and assessing capillary refill/colour

Emphysema

• Emphysema is chronic lung disease under COPD, where alveoli are damaged/stretched, impairing exhalation
• Commonly caused by smoking
• Symptoms: shortness of breath, barrel-shaped chest, wheezing, and fatigue

Pleural and Plural Effusion

• Pleural Effusion is fluid accumulation between the lungs and chest wall
• It is caused by infections, heart failure, cancer, or pneumonia
• Symptoms: shortness of breath, chest pain, and diminished breath sounds
• Treatment consists of fluid drainage and addressing its cause

Pneumonia and Croup

• Pneumonia is an infection of the lungs where alveoli fill with pus/fluid
• It is caused by bacteria, viruses, or fungi
• Symptoms: Cough, fever, chest pain, shortness of breath and crackles
• Treatments: antibiotics, rest, fluids, and oxygen
• Croup is a viral infection marked by swelling in larynx/trachea, mainly in children
• Symptoms: Barking cough, hoarseness, and stridor
• Treatments: Humidified air and steroids

Bronchiectasis, Haemoptysis, Rhinitis, and Atelectasis

• Bronchiectasis involves permanently widened/damaged bronchi, leading to mucus build-up and infections, often resulting from repeated lung infections or cystic fibrosis
• Symptoms: Long-term cough, phlegm, repeated infections, wheezing, and fatigue
• Treatment: Airway clearance, antibiotics and physiotherapy
• Haemoptysis is coughing up blood
• Rhinitis is inflammation of the nose
• Atelectasis is lung collapse which reduces gas exchange, often caused by post-surgery shallow breathing
• Symptoms: Shortness of breath and low SpO2

Stroke and Transient Ischemic Attack

• Stroke results from blocked or burst blood vessels in the brain, causing brain cell death
• Types: Ischemic (clot) and Hemorrhagic (burst)
• TIA is a mini-stroke involving temporary blockage, with symptoms resolving in <24 hours
• Symptoms: Face droop, arm weakness, and slurred speech
• Calling emergency services is critical

Encephalitis, Parkinson's Disease, and Alzheimer's Disease

• Encephalitis is brain inflammation, often caused by viral infections
• Symptoms: Fever and headache
• Parkinson's disease is a chronic condition caused by the loss of dopamine in the brain, affecting movement
• Symptoms: Tremor, muscle stiffness, slowed movement, balance problems, and expressionless face
• Alzheimer's disease is the most common type of dementia, where brain cells gradually die, leading to memory and thinking problems
• Symptoms: Memory loss, confusion, poor judgement, and mood changes

Brain Abscess

• Brain abscess is a pus-filled swelling in the brain due to infection
• It is caused by bacteria and fungi that spread
• Symptoms include headache, fever, nausea, seizures, and drowsiness

Brain Tumors and Meningitis

• Brain tumors are abnormal growths in the brain that may be benign or cancerous; Symptoms vary based on location
• Symptoms can be headaches, vision problems, nausea, seizures, and personality changes
• Treatment for brain tumors includes surgery, radiotherapy, and chemo
• Meningitis is infection/inflammation of the meninges (brain/spinal cord covering)
• It is caused by viruses and bacteria
• Symptoms include stiff neck, fever, vomiting, and sensitivity to light
• Bacterial meningitis is an emergency and requires antibiotics

Vertigo and Multiple Sclerosis

• Multiple Sclerosis is an autoimmune disease, where the immune system attacks the myelin sheath around nerves
• Symptoms include fatigue, muscle weakness, vision problems, difficulty walking, and bladder issues
• There is no cure, medications can only slow down the disease
• Vertigo is a spinning sensation often caused by inner ear problems
• Common causes are stroke, inner ear infection, and Meniere disease
• Symptoms include dizziness and nausea

Seizures and De-escalation

• Seizures are sudden abnormal electrical activity in the brain
• Types: Tonic-clonic, absence, and focal
• Causes: Epilepsy and fever
• What is needed during first aid: Stay with the individual and call for proper medical assistance if a seizure lasts longer than 5 minutes
• Key techniques to de-escalate: Keeping calm, giving space and empathy, speaking softly, and possible suggestions

Mental Health Medications

• Antipsychotics are used for schizophrenia: bipolar and psychosis
• Antidepressants include a variety of side effects
• Mood stabilizers need constant monitoring

Would Assessment

• HEIDI would assessment (history, examination, investigation, and diagnosis)