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NR 283 Pathophysiology Exam 2 Concept Review
Immunology : The Immune system seeks out invaders that attack our bodies constantly The Immune system must be able to Recognize Respond and Remember the invader. Immunity means you have protection, but before that you must have been attack by the virus to be immune to it. E.g chicken pox, when someone is exposed to chicken pox virus for the first time, after a couple of days the signs will appear (rash on skin) while the immune system is busy fighting it off. After the person gets better the virus the immune system has the ability to create the memory cells which carries the memory of the chicken pox virus forever. That’s why people that previously had chicken pox rarely get it for the second time. Another example is through vaccination, when we get vaccinated our immune system thinks we already have the virus and builds a line of defense through the memory cells. Memory cells allow Instant recognition to invaders and immediate response to those threats. Transfer factors are memory molecule which educates our immune system the ability to respond immediately because it recognize threats through those memory cells which act like “wanted posters” 3 specific lines of defense Innate immunity (also known as natural or native immunity) is the first line of defense in the body. It is in place at birth to prevent damages from things in the environment. Innate immunity is comprised of physical and chemical barriers Physical barriers include your skin and the cells that you have lining your GI tract and esophagus Chemical barriers include things like mucus, tears, saliva, and the normal flora that lives in our gut and colon If the natural barriers are breached, the second line of defense is the
Inflammatory response which will cause a rapid activation of many chemical
and cellular mechanisms. Inflammation is usually the first response to any type
of injury. The inflammatory response will protect the body from further injury,
prevent infection of the injured tissue, and promote healing.
Microscopic changes occur within seconds of the injury and include:
Vasodilation
Increased vascular permeability
Adherence of WBC’s to the site of injury
Manifestations of the inflammatory response include:
Redness
Heat
Swelling
Pain
Loss of function
The third line of defense is adaptive immunity (acquired or specific immunity). This defense is typically slower and targets specific microorganisms for destruction. Adaptive immunity also has a memory , so that the next time the body is attacked by the same microorganism, the response will be more rapid. This is where antigens and antibodies come into play Antigens are either foreign substances or they can be normally found on the surface of human cells. Their main job is to activate the immune system to produce matching antibodies Antibodies are specific proteins that are produced in response to bind with an antigen Antibodies are also known as Immunoglobulins , of which there are 5 different types The most common antibody that forms in the blood is IgG Antibodies bind to the antigen and destroy it B Cells and T Cells An important difference between T-cells and B-cells is that B-cells can connect to antigens right on the surface of the invading virus or bacteria. This is different from T-cells , which can only connect to virus antigens on the outside of infected cells. Titer - checking for immunity Lab Values for Immune System Hypersentivities -is an altered or inappropriate immunologic response to an antigen that results in disease or damage to the individual (this is the actual response to the immune deficiency) 3 types of Hypersentivity An allergy – which is a hypersensitivity to an environmental antigen, such as medicines, natural products (pollen, bee stings, mold), or infectious agents An Autoimmunity – which is a problem with the body’s ability to tolerate or recognize its own antigens (or self-antigens). Autoimmune diseases occur when the body reacts to the self-antigens causing the autoantibodies to damage tissue Alloimmunity – occurs when the immune system of one person produces an immunologic reaction against tissues of another person. This can be seen in reactions from transplanted tissue or in the fetus during pregnancy
Microscopic changes occur within seconds of the injury and include: o Vasodilation o Increased vascular permeability o Adherence of WBC’s to the site of injury o Manifestations of the inflammatory response include: o Redness o Heat o Swelling o Pain o Loss of function
Response/ process of Inflammation - e.g- Nail that is covered in cow manure (bacteria) pierces the
skin.
- epithelial cells release chemokines
- activation of mast cells to release histamine
- histamine causes vasodilation of capillaries - increased blood flow (swelling)
- histamine also causes increased vascular permeability
- neutrophils escape the capillaries and go to site of injury. they phagocytose the bacteria.
-other WBC's also go to the site of injury.
"the initial field of battle"
Anaphylactic shock - Anaphylaxis is a severe, life-threatening, systemic allergic reaction that is almost always unanticipated and may lead to death by airway obstruction or vascular collapse. Anaphylaxis occurs as the result of an allergen response , usually immunoglobulin E–mediated , which leads to mast cell and basophil activation and a combination of dermatologic, respiratory, cardiovascular, gastrointestinal, and neurologic symptoms. Dermatologic and respiratory symptoms are most common, occurring in 90 and 70 percent of episodes, respectively. The three most common triggers are food, insect stings, and medications. The diagnosis of anaphylaxis is typically made when symptoms occur within one hour of exposure to a specific antigen. (type I hypersensitivity) Causes - foods, latex, drugs, and hymenoptera venom. Epinephrine given early is the most important intervention.
S/S of Anaphylactic Shock- Lower airway: bronchospasm with wheezing or cough, chest tightness,
tachypnea, decreased peak expiratory flow, cyanosis, respiratory collapse/arrest Eyes: periorbital swelling/erythema, injected conjunctiva, tears Oral mucosa: angioedema of the tongue and lips Skin: urticarial rash, pruritus or flushing, morbilliform rash, piloerection, angioedema Gastrointestinal - Nausea, vomiting, diarrhea, abdominal cramps
Blood transfusion reaction- A hemolytic transfusion reaction is a serious complication that can
occur after a blood transfusion. The reaction occurs when the red blood cells that were given during the transfusion are destroyed by the person's immune system.
SLE: LUPUS Key Feature : butterfly rash
Etiology: autoimmune
RA- Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis.caused by chronic inflammation and can cause permanent joint destruction and deformity. It is triggered by a faulty immune system (the body’s defense system) and affects the wrist and small joints of the hand , including the knuckles and the middle joints of the fingers , early treatment can control joint pain and swelling, and lessen joint damage. Perform low-impact aerobic exercises , such as walking , and exercises to boost muscle strength. This will improve your overall health and reduce pressure on your joints HIV/ AIDS- HIV stands for human immunodeficiency virus. If left untreated, HIV can lead to the disease AIDS (acquired immunodeficiency syndrome). HIV attacks the body’s immune system , specifically the CD4 cells (T cells), which help the immune system fight off infections. If left untreated, HIV reduces the number of CD4 cells (T cells) in the body, making the person more likely to get infections or infection-related cancers. Over time, HIV can destroy so many of these cells that the body can’t fight off infections and disease. These opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS, the last state of HIV infection. By using HIV medicines (called antiretroviral therapy or ART ) consistently, you can prevent HIV from progressing to AIDS. ART helps control the virus so that you can live a longer, healthier life and reduce the risk of transmitting HIV to others.
These are the three stages of HIV infection:
1. ACUTE HIV - large amounts of virus are being produced in your body. The virus uses CD
count to replicate and destroys them in the process. Because of this, your CD4 cells can fall rapidly. Eventually your immune response will begin to bring the level of virus in your body back down to a level called a viral set point people develop flu-like symptoms, often described as “the worst flu ever.” Symptoms can include fever, swollen glands, sore throat, rash, muscle and joint aches and pains, and headache. This is called “acute retroviral syndrome” (ARS) or “primary HIV infection,” and it’s the body’s natural response to the HIV infection.
2. CLINICAL LATENCY STAGE- Latency” means a period where a virus is living or developing in a person without producing symptoms. (This stage is sometimes called “asymptomatic HIV infection” or “chronic HIV infection.”) During the clinical latency stage, the HIV virus continues to reproduce at very low levels, although it is still active. If you take ART, you may live with clinical latency for several decades because treatment helps keep the virus in check. If you have HIV and you are not on ART, then eventually your viral load will begin to rise and your CD4 count will begin to decline. As this happens, you may begin to have constitutional symptoms of HIV as the virus levels increase in your body.
Wound healing by primary intention is a surgical incision. Secondary Intention Healing – A wound that is extensive and involves considerable tissue loss, and in which the edges cannot be brought together heals in this manner. This is how pressure ulcers heal
ESR and Inflammation: Sed rate, or erythrocyte sedimentation rate (ESR), is a blood test that can
reveal inflammatory activity in your body. A sed rate test isn't a stand-alone diagnostic tool, but it can help your doctor diagnose or monitor the progress of an inflammatory disease. When your blood is placed in a tall, thin tube, red blood cells (erythrocytes) gradually settle to the bottom. Inflammation can cause the cells to clump. Because these clumps are denser than individual cells, they settle to the bottom more quickly. The sed rate test measures the distance red blood cells fall in a test tube in one hour. The farther the red blood cells have descended, the greater the inflammatory response of your immune system. Infection Control Measures: Recommended infection control practices include the following: 1) Hand hygiene; 2) Standard precautions/transmission-based precautions (Contact, Droplet, Airborne); and 3) Respiratory hygiene. When followed properly, each practice decreases the risk of spreading common respiratory pathogens. Immune deficiency When the immune system fails to respond and function normally, it is called an immune deficiency This will result in an increase susceptibility of the person to infections from mild to life threatening severity Immune deficiencies can be: (causes) Primary (or congenital) is caused by some type of genetic defect or mutation Secondary (or acquired) is caused by another condition, like cancer, infection, or normal processes like aging o These are most common and typically the alteration is minor and occurs for a short period of time o However, there are some cases of extreme secondary immune deficiencies that result in life threatening infections such as with AIDS. The clinical hallmark of an immune deficiency is a tendency to develop unusual or recurrent severe infections Respiratory
The pulmonary system is made up of 2 lungs (broken down into lobes) and their airways,
the vessels that serve these structures, and the chest wall or thoracic cage
The space in-between the lungs is called the mediastinum
That is where the heart and the esophagus lie
The pulmonary system is then broken down into the different airways
The upper airway includes the mouth and nose, pharynx, and larynx
The main function of the upper airway is to warm and humidify air, and remove
any foreign materials
The lower airway includes the trachea, the bronchi, the bronchioles, and the alveoli
The main function of the lower airway is gas exchange
The alveoli are the primary gas exchange units of the lung
Without them there would be no gas exchange
We have over 300
Each alveoli is composed of 2 types of cells:
Type 1 – provide structure to the alveoli
Type 2 – secrete the surfactant necessary to keep the alveoli patent
The major function and purpose of the Pulmonary system is gas exchange And this is done by what structure? (the alveoli ) There are 3 main functions of the pulmonary system Ventilation The mechanical movement of air into and out of the lungs When we are assessing our patient’s respiratory rate, we are actually assessing their ventilation rate, or the number of times gas is inspired and expired in 1 minute We breathe in Oxygen and breathe out CO2. (Remember, CO2 is a gas form of acid) There are many things that have a role in ventilation: Breathing is mainly involuntary, but at times we can voluntarily control it The respiratory center in our brain Receptors throughout our body that sense chemical levels and pressures Muscles and tissue – the elasticity of the lung tissue and the muscles of the chest wall and diaphragm Diffusion
PH: 7.35-7.
Paco2: 35-45 (opposite 45-35) (respiratory) Haco3: 22-26 (metabolism) Respiratory Labs Acute Respiratory Failure - is defined as inadequate gas exchange in the lungs
- It can be the result of damage to any of the structures of the pulmonary system, or it can be caused indirectly by damage to the brain or spinal cord affecting the ability to breathe
- Hypercapnia and Hypoxemia are typically seen Signs and Symptoms of Pulmonary Disease Dyspnea - Pulmonary disease is associated with many sign s and symptoms, the most common of which are dyspnea Dyspnea is a subjective experience of breathing discomfort It can also be described as breathlessness, SOB, or labored breathing It can be related to or be a result of many things, including diseases, pain, or anxiety The severity of the dyspnea may not correlate with how severe the pulmonary disease is Signs of dyspnea include nostril flaring , use of accessory muscles , and retraction (pulling back) of the intercostal muscles Dyspnea can occur transiently or it can become chronic Types of dyspnea - The first step of dyspnea is often Dyspnea on exertion (DOE) or SOB with exercise Orthopnea is dyspnea that occurs when the individual lays flat Paroxysmal nocturnal dyspnea (PND) is when an individual with pulmonary or heart disease wakes up at night gasping for air and they have to sit up or stand to relieve the dyspnea
Cough - A cough is a protective reflex that clears the airways by explosive expiration
The irritant receptors in the airway can stimulate the cough reflect when certain particles have been inhales, there is a buildup of mucus, or a foreign body is present An acute cough is one that resolves within 2-3 weeks of the onset of an illness or resolves with treatment of the specific condition (URI’s, pneumonia, CHF, bronchitis) A chronic cough is one that last for at least 3 weeks, sometimes beyond 7-8 weeks
Abnormal Sputum Changes in the amount, color, and consistency of sputum can give us information about a disease and its treatment Hemoptysis is the expectoration of blood or bloody secretions The blood is usually bright red and mixed with frothy sputum Hemoptysis usually indicated infection, inflammation or cancer of the lungs or airways Normal breathing pattern is rhythmic and effortless Some abnormal breathing patterns include:
Kussmaul respirations : caused by strenuous exercise or metabolic acidosis particularly
diabetic ketoacidosis (DKA) but also kidney failure.This is breathing with an increased
ventilatory rate, large tidal volumes, and no expiratory pause.
Labored breathing occurs with an increased work of breathing especially with
obstructed airways. This is breathing with a slow ventilatory rate, large tidal volumes,
increased effort, prolonged inspiration and expiration, and strid or audible wheezing
Cheyne-Stokes respirations are characterized by alternating periods of deep and shallow
breathing. Apnea lasting 15-60 seconds is followed by ventilations that increase in
volume until a peak is reached and then ventilation decreases again to apnea. This occurs
with reduced blood flow to the brain stem
Hypoventilation is inadequate ventilation in relation to metabolic demands This is caused by alterations in pulmonary mechanics or in the neurological control of breathing (this is why some people are on ventilators forever) Carbon dioxide removal is slower than the production, causing CO2 levels in arterial blood to increase causing hypercapnia (increased CO2) which results in respiratory acidosis Hyperventilation is ventilation exceeding metabolic demands. The lungs remove the CO2 faster than it can be produced resulting in hypocapnia (decreased CO2) which results in respiratory alkalosis Cyanosis is a bluish discoloration of the skin and mucous membranes caused by increased amounts of desaturated or reduced hemoglobin in the blood Clubbing is a bulbous enlargement of the end of a finger This is associated with disease that cause chronic hypoxemia such as pulmonary fibrosis and lung abscesses Pain caused by pulmonary disorders originates in the pleura, airways, or chest wall Can be caused by inflammation, infection, or muscle/bone trauma
-types Primary pneumothoraxes occur spontaneously in healthy people This is due to the formation of blebs or blister like formation in the visceral pleura. Once enough of them pop, the pneumothorax will occur Secondary pneumothoraxes are caused by trauma to the chest Both primary and secondary can be classified as open or tension pneumothoraxes In an open pneumo, the air pressure in the space is equal to barometric pressure Air that is drawn into the pleural space during inspiration is forced out during expiration A tension pneumo is more life threatening The rupture acts like a one way valve, so air enters the pleural space during inspiration but is not allowed to leave during expiration As more air build up it compresses all the organs in chest, especially the heart and great vessels, which can kill you CM typically begin with sudden pain, tachypnea, and dyspnea. Physical assessment will show absent breath sounds on the affected side Tension pneumo’s are complicated by severe hypoxemia and tracheal deviation Pleural effusion-types, causes, s/s - A pleural effusion is the presence of fluid in the pleural space Often this fluid comes from the migration of other fluids through the walls of pleural capillaries -types -Effusions can be transudative (or watery) or exudative (high in WBC count and plasma) Other types are characterized by the presence of microorganisms ( empyema), presence of blood (hemothorax ), or lymphatic fluid (chylothorax) Typically small collections of fluid are not noticed and the lymph system is able to carry it away Common clinical manifestations include: Dyspnea, cough, tachycardia , and pain An empyema is an infected pleural effusion with microorganisms and cellular debris or pus in the pleural space The typical infectious organisms that cause this are S. Aureus and E. Coli Pulmonary edema-cause, s/s - Pulmonary edema is excess water in the lungs Typically the lung is kept dry There are many causes of pulmonary edema:
The most common cause of pulmonary edema is left side heart disease When the left ventricle fails, volume backs-up into the pulmonary capillary Pulmonary edema can also be caused by capillary injury which causes water to leak out of the capillary into the interstitial space Pulmonary edema can also be caused by a blockage of the lymph system The lymph system is supposed to remove excess fluid and return it back to the bloodstream CM includes dyspnea, and increased work of breathing. Physical assessment will show crackles in the lung fields Severe pulmonary edema can cause pink frothy sputum Atelectasis - is the collapse of lung tissue It starts out with the collapse of alveoli and then leads to the collapse of lung tissue Causes include : compression of alveoli from a tumor or fluid Decreased production or destruction of surfactant CM include dyspnea, cough , and fever Aspiration - which is the passage of fluid or solid particles into the lungs Typically found in someone whose swallowing and cough reflexes are impaired (after stroke) Predisposing factors include altered LOC, stroke, and neuromuscular disease The right lung is more susceptible because the branching angle of the right bronchus is straighter than the left because of the heart Aspiration of large food particles can obstruct a bronchus leading to bronchial inflammation and airway collapse CM include sudden onset of choking, coughing, dyspnea, and wheezing Prevention of aspiration, especially in the healthcare setting is key – So sitting our patient’s up, assessing for swallowing difficulty, etc
Asthma - which is a chronic inflammatory disorder of the bronchial lining that causes hyper-
responsiveness and constriction of the airways Causes of asthma
Some of them are productive cough , barrel chest, prolonged expiration , and dyspnea Chronic Bronchitis - is defined as a hypersecretion of mucus and chronic productive cough for at least 3 months of the year, for at least 2 years Causes of chronic bronchitis include: Tobacco smoke Inhaled irritants or occupational dust Air pollution Pathophysiology: Inhaled irritant causes airway inflammation Bronchial edema and mucus glands affected Production of large amounts of mucus Defense mechanisms of lungs compromised as well Emphysema - is an abnormal permanent enlargement of the airways combined with the destruction of the alveolar walls Obstruction results from changes in the lung tissue, rather than inflammation and mucus production Emphysema can have a primary or secondary cause: o Primary causes are related to an inherited deficiency of an alpha 1-anti-trypsin enzyme o Normally this enzyme prevents the action of certain enzymes whose job it is to breakdown tissue o If this enzyme is lacking, lung tissue will get destroyed and remodeled o Secondary causes are related to cigarette smoke inhalation, air pollution or occupational exposures Pathophysiology o Destruction of the alveolar wall and the loss of elastic recoil o Difficulty expiring air, leading to air trapping o Increased WOB, Hypoventilation
Pneumonia - is an infection of the lower respiratory tract Risk factors include advanced age, compromised immunity, malnutrition, immobilization and impaired swallowing (last 2 are common in hospitalized individuals) There are different types of pneumonia: Community acquired – most commonly caused by Streptococcus Pneumoniae Hospital acquired (nosocomial) – most commonly caused by Staph. Aureus Viral Pneumonia – like the H1N1 virus. The viral form is usually mild and self-limiting Pathophysiology: When a micro-organism gets inhaled, macrophages (one of the cells of the inflammatory response) will recognize that it is foreign and stimulate a massive inflammatory response in the lungs The inflammatory response will cause damage to the lining of the bronchi and alveoli and cause them to fill with infectious fluid and cells (aka exudate) Some micro-organisms can also produce their own damage to the bronchi and alveoli, causing further damage The accumulation of exudate in the lung causes the manifestations Manifestations include: Fever, chills, productive or dry cough, pain, dyspnea, and crackles TB Tuberculosis: is a respiratory infection caused by an acid fast bacillus called
mycobacterium tuberculosis
TB is highly contagious and is transmitted from person to person via airborne droplets
Risk factors and Cultural influences that increase the incidence of TB include:
Emigration, overcrowded institutions, homelessness, substance abuse, lack of
access to medical care
A latent TB infection is when someone has been exposed to the organism and have
gotten it into their system, but it is not producing any active S/S
Pathophysiology:
The bacilli enter the lung, multiply, and cause a local area of inflammation
Acute Respiratory Distress Syndrome (ARDS)- is characterized by acute lung inflammation and alveolocapillary membrane injury Causes of ARDS include trauma, shock, inhalation of toxins, but the most common is sepsis or an infection of the blood Pathophysiological Process Injury to lung, stimulating inflammatory response Injury to alveolocapillary membrane Increased capillary permeability Collapsed or fluid filled alveoli Overall affects ventilation, diffusion, work of breathing Manifestations: Dyspnea, Rapid-shallow breathing, crackles, hypoxemia Pulm. HTN- Pulmonary hypertension is an abnormally high pulmonary artery pressure Primary pulmonary hypertension is idiopathic However, other possible causes include pulmonary or cardiac disease, hypoxia, and sometimes recreational drugs The main problem is the vasoconstriction of the pulmonary arteries causing an increased pulmonary artery pressure Pulmonary hypertension can be classified in several ways, usually depending on the cause CM is not typically detected until the pulmonary HTN is severe. Fatigue, chest discomfort, tachypnea, and dyspnea Cor Pulmonale - is right sided ventricular hypertrophy caused by pulmonary hypertension, or some other chronic pulmonary disease In fact, 80-85% of patient’s who have COPD will develop cor pulmonale The increased pressure causes the right ventricle of the heart to work harder causing hypertrophy CM are often hidden under other respiratory or cardiac diseases and may only show up during strenuous activities or exercise Integumentary
Your skin is formed by 3 main layers : The epidermis which is the outer layer of the skin The dermis which is the deeper skin or true skin The hypodermis or subcutaneous tissue which is the lowest layer, and where most of the dermal appendages arise from The dermal appendages include the nails, hair, sebaceous glands, eccrine, and the glands Nails are the protective keratinized plates that appear at the ends of fingers and toes Hair color, density, and distribution vary among people and depend on age, gender and race Sebaceous glands are open on the surface of the skin They secrete sebum which is mainly composed of lipids which oil the skin and hair and protect it from drying The eccrine sweat glands are found in the palms of the hands and the soles of the feet Important in thermoregulation and body cooling There are less apocrine sweat glands They are found in the axillae, scalp, and face They produce more sweat The blood supply to the skin is limited to papillary capillaries or the plexus of the dermis Bacterial Infections The most common causative bacteria for these infections is Staph Aureus Folliculitis is a bacterial infection of a hair follicle Inflammation is caused by the release of enzymes from the bacteria Lesions appear as pustules on the scalp Furuncles or boils are an inflammation of a hair follicle May develop after folliculitis that spreads into the dermis Initial lesion is a deep, firm, red, painful nodule Carbuncles are a collection of infected hair follicles They are usually found on the back of the neck, upper back, or thighs The lesion begins in the subcutaneous tissue and lower dermis as a firm mass that evolves into an erythematous painful, swollen mass that drains through many openings Chills, fever, and malaise (feeling of general discomfort) can occur Cellulitis is an infection of the dermis and subcutaneous tissue usually caused by S.Aureus
