Alterations in respiratory status

what is an obstructive lung disease ?

a condition that makes it hard to exhale all the air in the lungs

"Obstructive = hard to get Out"

what is a restrictive lung disease ?

having trouble fully expanding their lungs with air

"RestrIctIve = hard to get In"

what are some examples of obstructive pulmonary disorders ?

asthma, COPD (bronchitis & emphysema)

what triggers Type 1 hypersensitivity Asthma?

innocuous foreign substance (like dust, pollen or animal dander)

antigens will bind to more than one IgE that is bound to the membrane of a mast cell (basophil)

this attachment of two IgEs (cross linking) will trigger the release of mast cell granules full of histamine

what causes wheezing in a asthma attack ?

step 1. mast cells degranulate and release histamine.

step 2. histamine will influence smooth muscle on bronchioles and will cause bronchoconstriction while also increasing vasculature permeability - allowing fluid to go in.

step 3. fluid influx will cause edema - further narrowing the airway - and cause wheezing

what stimulates bronchoconstriction ?

histamine release from the wall of the conducting airways in response to the antigens

vasodilation and increased capillary permeability cause ______ to accumulate in the tunica submucosa of the bronchi

fluid (edema)

what causes edema ?

vasodilation and increase permeability leads to fluid build up in the tunica submucosa of the bronchi

irritation to the inner lining of the airway and the inflammatory response stimulate secretion of a thick ______

mucus

what are the two consequences to airway obstruction ?

1. ) decreased expiratory flow rates

2. ) air trapping

T/F: with airway obstructions, air is trapped in the alveoli

true, this is air trapping due to bronchiole constriction

what are some asthma triggers ?

environment allergens

environment air pollutants

cigarette smoke

what are two potent enviromental allergens that trigger asthma ?

dust mites, pet dander, and indoor molds

what are some air pollutants that trigger asthma ?

Ozone

- worse in hot summer days

particulate pollution

- tends to be worse on cold winter days - especially with inversions

Is cigarette smoke a asthma trigger ?

Yes. Primary and secondary smoke inhalation is a potent trigger

how can exercise in the cold air trigger asthma ?

air movement in and out of the airway changes airway humidity and temperature during aerobic activities. Drying and cooling of the airway stimulates a response, resulting in bronchospasm. inhalation of cold air stimulates a similar response

how can an upper airway infection trigger asthma ?

acute episodes of asthma can be trigger by acute viral infections of the upper respiratory tract. infection can also make exacerbate a chronic condition

T/F: children who have asthmatic symptoms with viral infections have a greater risk of developing asthma as they grow older

true

T/F: viral infections are some of the earliest triggers and these children have an underlying predisposition to developing more severe forms of the disease

true

can asthma be a genetic predisposition ?

the development of asthma can be a genetic predisposition with the development of Type 1 hypersensitivity

T/F: genetic predisposition is the main reason of most asthma cases

true. family hx if a risk factor

how do gene mutations linked to the development of asthma influence WBCs?

these mutations lead to production of many interleukins, eosinophils and mast cells that respond rapidly to allergen exposure, and alteration in the beta-2 receptors on the bronchial smooth muscle that cause the airways to be hyperresponsive

what are some manifestations of asthma ?

- cough

is often non-productive

- wheezing

occurs when air is being forced out through constricted bronchi and bronchioles

- Tachypnea (fast breathing) & Dyspnea (difficulty breathing) with the use of accessory breathing muscles (retractions)

- chest tightness and discomfort

(most likely related to the stimulus of visceral sensory neurons in the bronchi by bronchoconstriction and the release of inflammatory mediators that induce pain)

inspiratory and expiratory wheezing may be heard in what stages of an asthma attack?

late stages

what is type 1 hypersensitivity ?

trouble exhaling

what is COPD characterized by ?

abnormal lung function the doesn't improve over a period of several months. the main issue is reduced expiratory outflow manifested by prolonged forced expiratory volume in one second

the main issue of COPD is reduced ________ flow that is manifested by prolonged forced ______ volume in one second

expiratory; expiratory

what is the fourth leading cause of death in the U.S while over 16 million people live with this disease ?

COPD

smoking is responsible for approximately 90% of _________ cases

COPD

T/F: COPD is an umbrella term

true

what are the lung disease that fall under the COPD umbrella

- chronic bronchitis

- emphysena

- refractory (irreversible asthma)

- severe bronchiectasis

what is chronic bronchitis ?

disease caused by chronic inflammation of the bronchi leading to airway obstruction from hyper secretion of mucus and other changes

what are s/sx of chronic bronchitis

- frequent cough w mucus

(3 months of the year for at least 2 yrs)

- SOB (dyspnea)

- fast HR (tachycardia)

- whistling sound when breathing (wheezing)

- tiredness (fatigue)

- chest discomfort

what may cause chronic bronchitis

- chronic exposure to irritants

- cigarette smoking

- living in polluted areas

- occupation irritates like coal and mineral dust

what is the pathophysiology of chronic bronchitis ?

recurrent irritation leads to chronic inflammation. this inflammation leads to the release of mediators such as histamine, leukotrienes, and platelet activating factor, etc.

this chronic inflammation leads to scarring of the bronchi causing a build up of collagen. unlike elastic that stretches, collagen doesn't. so this collagen build up will limit expansion of bronchi

what is bronchial edema ?

caused by increased capillary permeability in the tunica submucosa of the bronchi. this results in a narrowed airway lumen and contributes to airway obstruction (narrowing of the bronchi lumen)

what leads to airway obstruction in chronic bronchitis ?

Airway obstruction due to :

- bronchial edema

- bronchoconstriction

- mucus secretion

what lung infection are individuals with chronic bronchitis at risk for?

pneumonia due to the liquid build up from the edema/mucus (pneumonia can be fatal for some)

what leads to impaired ciliary function in chronic bronchitis ?

- chronic exposure to irritants destroys cilia (which help move things around

- mucus secretion impairs ciliary function

what leads to air trapping ?

During expiration (which is passive), the bronchioles collapse and the mucus plugs prevent air from leaving the alveoli

residual volume may increase with air trapping so its harder to get additional air in and this can interfere with gas exchange bc CO2 is being trapped in the alveoli. Additionally this increase in residual volume will make it hard for new air from being inhaled

what leads to increased risk of respiratory infection in chronic bronchitis ?

chronic mucus production provides a warm, wet environment for bacterial colonization

individuals with chronic bronchitis often develop recurrent bacterial infections in the bronchi and even in the alveoli (pneumonia). -> this leads to further inflammation and more inflammatory injury

what leads to tachypnea (fast HR), dyspnea (SOB) on exertion & at rest ?

due to decreased ventilation that results in hypoxemia

what causes hypoxemia in chronic bronchitis patients ?

- manifested by low SaO2/PaO2

- caused by airway obstruction and air trapping

what causes hypercapnia and respiratory acidosis ?

- manifested by high PaCO2

- caused by obstruction to expiratory air flow

what is clubbing ?

where the fingernail becomes convex and the finger thickened

is it a clinical manifestation that occurs with chronic hypoxemia which is often an issue with chronic bronchitis due to the airway obstruction and air trapping

it typically occurs with disorders affecting gas exchange at the alveolar-capillary membrane such as COPD

what is the physiologic cause of clubbing ?

not well understood. one explanation is that long term tissue hypoxia stimulates vasodilation in the peripheral tissues which results in hypertrophy and tissue growth. extra growth factors may also be released

how can chronic respiratory disease cause polycythemia ?

hypoxemia (caused by chronic respiratory disease) causes the release of erythropoietin from the kidneys . this stimulates the proliferation and release of red blood cells from the bone marrow resulting in high hematocrit (polycythemia) as an attempt by the bone marrow to increase oxygen delivery to the tissues

the polycythemia that may result from COPD puts an individual at risk of what ?

a clot

what is emphysema ?

(a type of COPD that increases the size of the alveoli and septa)

is characterized by the loss of alveolar recoil and destruction of the septa between adjacent alveoli

what does decrease in alveolar surface area do (in emphysema)?

impairs gas exchange

T/F: emphysema is considered normal in older adults

true, this contributes to the general decline in lung function associated with aging

how can Alpha-1 antitrypsin deficiency lead to emphysema ?

alpha-1 antitrypsin is a protein (enzyme) produced by the liver and released into the bloodstream. It plays a crucial role in protecting tissues, particularly the lungs, from damage caused by enzymes (like elastase which breaks down elastin that provides alveoli recoil) released during inflammation and immune responses

T/F: problems with the alpha-1 antitrypsin enzymes are also the root of acquired emphysema

true

what leads to enzymatic digestion of elastin?

if alpha-1 antitrypsin is deficient (not active) in the lung tissue, it wont be able to protect the lung from elastases (which breaks down elastin) that is produced by alveolar macrophages ( and other proteolytic enzymes). as a result elastase will dominate

T/F: alpha-1 antitrypsin is not active in the lung tissue w Alpha-1 antitrypsin deficiency

true

elastase breaks down _____ which is what helps alveoli recoil

elastin

elastin fibers on the outside of the alveoli help ______ air during _______

rid/expel; exhalation

breakdown of elastin reduces _______ air flow and increased _______ volumes

expiratory; residual

T/F: elastin assists with alveoli compliance

true

where is alpha-1 antitrypsin protein made ?

liver

where does antitrypsin travel to through the blood stream ? and what does it do once it gets to that destination ?

is travels to the lungs and coats and protects the alveoli (air sacs)

T/F: altered alpha-1 antitrypsin get stuck int eh liver and will damage the liver while leaving the lungs unprotected

true

T/F: smoking increases elastase activity

true

most cases of emphysema are caused by an acquired inhibition of _______

alpha-1 antitrypsin (inhibition of an enzyme causes the same effects as deficiency

what is the most common secondary cause of emphysema ?

cigarette smoking, although ther inhaled air pollutants have been linked to the disease

what is the septa ?

the wall that sedates alveoli

what are the implications of septa destruction in emphysema ?

over time the damage to the septa between individual alveoli are destroyed with emphysema leading to permanent enlargement of the alveoli ( the alveoli mesh together w/o the septa wall)

T/F: the alveoli will mesh together with septa destruction caused by emphysema

true

with septal destruction, the "air bubbles" that are visible by eye on autopsy or on a high resolution CT are called _______ that are within the lung and _______ that are outside of the lungs

bullae; blebs

with emphysema, what happens to the capillaries that lie between the alveolar septa and what are the implications of that ?

with emphysema, the septal wall becomes destroyed, this will also destroy the capillaries that lie between the alveolar septa as the alveolar walls disappear

implication: interference with gas exchange and perfusion

what can be used to visibly see a bullae or bleb?

an autopsy or a high resolution CT

where are blebs located

outside the lung

where are bullae located ?

within the lung

under normal conditions, with a full tidal volume the alveoli expand and stretch the elastin. when the diaphragm is released, the elastin fibers recoil and help squeeze the air out of the individual alveoli.

how would this differ in the case of emphysema ?

in emphysema, loss of elastin causes the alveoli to overinflated during inhalation. the loss of elastin will also reduce alveolar recoil which will result in air trapping. air trapping causes obstruction to airflow into the lungs

loss of elastin due to emphysema reduces ________ recoil resulting in air trapping. This air trapping causes an _________ to airflow into the _______

alveolar; obstruction; lungs

what are the implications of alveolar septa and septal capillaries destruction ?

significant surface area for gas exchange is lost so V/Q mismatching and hypoxemia result

septa destruction (caused by increase of residual value of alveoli) leads to septal capillaries destruction which will lead to V/Q mismatching, this leads to hypoxemia. how does that hypoxemia occur?

because ventilation decreases due to the air trapping that takes place as a result of decreased elastin. loss of elastin results in decrease in inspired O2 and also makes it hard to rid CO2 from the alveoli

loss of alveoli and pulmonary capillaries decreases the available surface area for gas exchange (When you lose alveoli and tiny blood vessels in the lungs, there's less space for oxygen and carbon dioxide exchange.)

what is hypercapnia ?

increased CO2 in the arterial blood caused by hypoventilation of the alveoli

why is hypoventilation often overlooked and how can this be an issue?

it is often overlooked bc breathing patterns and ventilatory rate may appear rate, but this can be an issue bc it can lead to hypercapnia

what are some causes of hypyercapnia (5)?

- depression of the respiratory center by drugs

- diseases of the medulla including infections of the CNS or trauma

- disease affecting the respiratory musculature or thoracic cage abnormalities

- obstruction of the large airways

- COPD

a clinical manifestation of emphysema is dyspnea on exception which progresses to dyspnea at rest. this is due to ________ ventilation and resulting in ________

decreased; hypoxemia

a clinical manifestation of emphysema is tachypnea and use of accessory muscles. Accessory muscles are at a mechanical ______ due to a hyperinflated chest wall caused by air trapping. This _______ the work of breathing

disadvantage; increases

a clinical manifestation of emphysema is prolonged expiration that is manifested by _______ forced expiratory volume in one second (FEV1)

decreased

how does an increased A-P diameter of chest occur with emphysema ?

due to increased residual volumes from air trapping. air pressures within the lungs deform the rib cage over time causing a Barrel Chest.

T/F: always give 100% to COPD patients

false bc this may throw off their respiratory drive

T/F: Barrel chest can happen in any cardiac or lung disorder

true

what are some complications of emphysema in regards to the bones ?

- risk of osteoporosis

(due to use of oral corticosteroids)

what are some complications of emphysema in regards to lung infection?

- frequent lung infections

(like pneumonia)

what are some complications of emphysema in regards to weight ?

weight problems

(chronic bronchitis -> need to lose weight

emphysema-> may need to gain weight and muscle mass due to the wt loss from the increased respiratory effort )

T/F: COPD can cause pneumothorax

true. COPD can damage the lung's structure and allow air to leak into the chest cavity

T/F: COPD can cause sleep problems

true. this is due to decreased oxygen