Unit 3 Most Important Things Flashcards
Causes of Dyspnea
- Ventilatory pump failure- hypoxia- not enough O2 is in the blood and likely CO2 build up
- Cardiac Pump/supply failure- ischemic hypoxia- typical of someone having an MI b/c the vessels are occluded also happens in strokes + PVD
- Blood’s O2 carrying capacity- anemic hypoxia - if the blood isn’t able to carry enough O2 even though the heart + lungs are functioning properly
What are the 3 main causes of breathing disorders?
- Damage to the breathing control mechanism within the brainstem - restrictive disease can’t inhale well
- Difficulty in generating the differential pressure required to create airflow - obstructive disease can’t exhale well
- Difficulty in generating airflow for a given differential pressure between the atmosphere and alveoli
Restrictive Disease
- Cannot fully fill their lungs with air b/c their lungs feel like they are restricted from fully expanding/breathing is restricted as if the movement of the chest is restricted
- Greater effort to move chest to breathe regardless of strength of muscle
2 types
1. Normal strength but to stiff
2. Normal stiffness but to weak
- Restrictive disease includes diseases of muscle, lung tissue, soft tissue, nervous system, edema,
T/F All spirometry volumes are reduced in restrictive disease
True
Obstructive Disease
- Shortness of breath due to difficult exhaling air from their lungs
- Exhaled air comes out more slowly due to damage or narrowing of the airways
- Characterized as: Increased FRC (functional residual capacity), marked increase in A-P diameter of chest (barrel-chest), and slow expiration
- Can be acute and Chronic
What is the most efficient way to breathe with Obstructive Disease
Long slow breathing
What are the 2 causes of Obstructive Disease
- increased airway resistance
- Decreased elastic recoil; diminished ability to expire has same consequences as physical obstruction
- Elasticity of the alveoli helps push the air out if they lose their elasticity they become like a deflated balloon that is limp and has no air in it and end up collapsing on themselves
-Emphysema primarily loss of elastic recoil; can have some airway obstruction
- Cystic fibrosis results in obstructive disease ; either bronchiectasis or chronic bronchitis
Equal Pressure point
Why do airways collapse in obstructive disease?
- Point in airway anatomy where the outside compressive pressure equal the inside elastic pressure
- In obstructive disease loss of pressure moving air through obstruction moves the equal pressure point distally because the decrease in elasticity
–> Forced expiration, couching, ect becomes less effective as small airways collapse, trapping air and mucus behind - If this happens in smaller airways they will collapse during forced expiration
T/F COPD is a category of diseases
True
COPD
Chronic Obstructive Pulmonary Disease
- Category of diseases
- Usually a combination of emphysema and chronic bronchitis
- Also denoted as COLD Chronic obstructive lung disease
Emphysema
- Abnormal, permanent enlargement of air spaces distal to bronchioles with destruction of their walls
- Elastic fibers in alveolar walls destroyed
- Lack of alveolar recoil necessary for expiration
- Lungs increase in size until recoil sufficient to drive air out *****
- FRC increases, resulting in barrel chest
What are the 4 diseases that make up COPD
- Asthma
- Bronchiectasis
- Chronic bronchitis
- Emphysema
Pathophysiology of COPD
- Mostly caused by smoking
- Which tissue is damaged determines whether emphysema, chronic bronchitis or both occur
- usually insidious because but perceived as acute because they will not notice without exertion and blame it on things like being out of shape
- Small airways are involved first in COPD
- Respiratory reserve dwindles progressively
- Loss of reserve becomes evident during illness or extraordinary exertion
Pathophysiology of Emphysema
-Smoking irritates the lining of the lungs and causes the white blood cells and neutrophils to accumulate in the walls of the alveoli
- Smoking increases the level of lung proteases and impairs the action of antiproteases
–> Protease are found through out the body especially in neutrophils and macrophages and they serve to digest the conductive tissue elements when needed to destroy foreign bodies
–> Normally antiproteases protect living tissue but b/c the smoking inhibits that we actually get damage to the connective tissue
- Smoking –> neutrophils accumulate in alveolar walls–> release of proteolytic enzymes–> Alpha 1 Antitrypsin activity critical (type of antiprotease)–>normally inhibits proteolysis
Signs and Symptoms of Emphysema
- Barrel Chest
- Emaciated
-FEV1/FVC ration <0.6 - Pink Puffer
- Tripod position
- hypertrophied SCM and scalenes
- Prolonged Expiration
Can progress to: LHF, Corpulmonale- right sided HF, cyanosis
Pulmonary Hypertension
-Pulmonary hypertension is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart.
-In one form of pulmonary hypertension, called pulmonary arterial hypertension (PAH), blood vessels in the lungs are narrowed, blocked or destroyed. The damage slows blood flow through the lungs. Blood pressure in the lung arteries goes up. The heart must work harder to pump blood through the lungs. The extra effort eventually causes the heart muscle to become weak and fail.
- Untreated Pulmonary hypertension is the most common cause of RHF b/c the gas exchange abnormality, destruction of the pulmonary vascular bed –> when the alveoli are destroyed the vascular bed is also destroyed as well which causes a decrease in surface area in which the blood flow therefore increases the pressure in the pulmonary system
Barrel Chest
- Less surface area for gas exchange
- Less vascular bed for gas exchange
- COMPENSATE BY HYPERVENTILATION
- Low cardiac output and develop muscle wasting and weight loss b/c they are working so hard to breathe
Hypoxemia
Hypoxemia is a low level of oxygen in the blood. It starts in blood vessels called arteries. Hypoxemia isn’t an illness or a condition. It’s a sign of a problem tied to breathing or blood flow. It may lead to symptoms such as:
Shortness of breath.
Rapid breathing.
Fast or pounding heartbeat.
Confusion.
Medical & Surgical Management of Emphysema
- Bronchodilators = increase airway size and improves air movement and decrease resistance to expiration
- Supplemental O2= improves the perfusion of the available exchange of O2 ; it gives the air higher percentage of O2 and makes it less difficult for a person to breathe
- Lung reduction surgery
- Airway clearance not specifically needed for pure emphysema
Lung Volume Reduction Surgery
LVRS
- procedure that removes approximately 20%-35% of the poorly functioning space occupying lung tissue from each lung
- By reducing the lung size the remaining lung and surrounding tissue like the intercostals and diaphragm are able to work more efficiently; should make breathing easier
- Lungs regain dome shape
- Significant improvements in exercise capacity
Chronic Bronchitis
- Excessive sputum production on most days for at least 3 months of the year for at least 2 consecutive years
- Airway is swollen so its size is diminished
Presents with:
–>Impaired mucus clearance
–> Chronic rattling cough
–> inflamed bronchial tube
Progression of Chronic Bronchitis
- Smoking predisposes to infection
-Primary and secondary Bronchi are continuously inflamed and irritation of the airways cause hyperplasia of the mucus glands b/c they are constantly scus in response to irritation - Decreased ciliary clearance
- Damaged epithelium
- Interference with WBC function
- Irritation of airways
- Hyperplasia of mucus glands in large airways
Blue Bloater
- Chronic bronchitis
- Greater obstruction than one with empysema
- Overwight and cyanotic
- Hypercapnic
- -> lose responsiveness to CO2 becomes less senstitive causing control of ventilation to be controled more by[ PaCO2
- Cor Pulmonale
–> RHF caused by respiratory disease –> cor pulmonale can cause LHF
Hypercapnic
Hypercapnia is the increase in partial pressure of carbon dioxide (PaCO2) above 45 mm Hg
Cor Pulmonale
Cor pulmonale is an enlarged right ventricle in your heart that happens because of a lung condition. Pushing against high pressure in your pulmonary artery can cause your right ventricle to fail.
Medical Management of Chronic Bronchitis
- frequently co-morbid with emphysma
- Bronchodilators
- Supplmental O2
- Antibiotics
- Airway clearance
Bronchiectasis
- Chronic and permanent dilation of bronchi due to inflammation of infection
- Copious amounts of foul smelling sputum
- Dilated, obliterated, damaged bronchi in dependent airways
- mucus plugging of bronchi
- Common problem in CF
Bronchiectasis Signs and Symptoms
- Chronic coughing
- Coughing blood
- coughing up large amounts of mucus
- abnormal sounds or wheezing in the chest on breathing
- Shortness of breath
- chest pain
- daily bad breath
- skin has a blue apperance
- weight loss
- fatigue
- thickening of the skin under your nails and toes
Causes of Bronchiectasis
- Idopathic
- Obstruction by tumor or foriegn object
- Immotile cilia
- Congenital
- Post-infective/cystic fibrosis
Medical/Surgical Management of Bronchietasis
- Antibiotics
- airwayclearance
- Surgical removal of affected area
Ventilation is driven by>
Driven by levels of CO2 in the body not O2 ***
- ventilation regulated to rid the body of CO2
- CO2 is a volatile acid
What is the mechanism of ventialtion?
- Primary mechanism is negative feed back loop between pH of CSF and ventilation
- pH of CSF is primarily determined by paCO2
Secondary mechanism includes: arterial PO2 and pH, negative feedback loop
Feedforward mechanism: limb movements
When there is a decrease in pH what happens to ventilation?
- Ventilation increases in order to blow off the excess CO2 and to normalize the pH
-Chronically, kindey and buffering systems respond to eliminate fixed acid= they do this by increasing the rate hydrogen ion secreations and increacease reabsorption of bicarbonate ions to increase plasma and HCO3
What is the response to increased pH?
- Ventilation is slowed
- CO2 accumulates
- pH is normalized
- CHronically, kidneys and buffering systems respond
T/F ventilations affects are on CO2 and not on how fast/slow you breathe
true
Euventilation
produces normal PaCO2
Hyperventilation
Decreased PaCO2
Hypoventilation
Increased PaCO2
Effects of CO2 on the Brain
- Hgih CO2 depresses cerebral function
* Giddy–> somnolent–>unconscious–> dead* - Cerebral blood flow rids the brain of CO2 by negative feedback loop –> if there is high CO2 in the brain the body will react by increasing blood flow ot the brain to normalize the CO2 by taking it away faster
- Headache from increased blood volume in the skull
Hyperventilation
–> decreased cerebral blood flow
–> Compromise Cerberal function - ->Lightheaded, dizzy, ataxic, other
- ->Mechanical ventilation used to decrease cerebral edema post- CVA, head injury
Hypercapnia
Hypercapnia (hypercarbia) is when you have high levels of carbon dioxide in your blood. Carbon dioxide is a waste product that your body gets rid of when you exhale. If you can’t get rid of it, it can build up in your blood. COPD and conditions that affect your lungs, brain, nerves and muscles are the most common causes.
T/F breathing to maintain blood in PO2 at high altitudes results in hyperventilation
True
Supplemental O2
- Normal air has 21% O2 (FIO@ = 0.21)
- Spplemental oxygen is measured as FIO2 (fraction of inspired air)
FIO2 Increases by:
- increasing flow rat
- increasing % of O2
- Usually by incresing flow rat of 100% O2
Changing the dose of O2 must be ordered by a physician