Nur219respch25 andwewerwer 26
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Transcript of Nur219respch25 andwewerwer 26
Pulmonary System
Pulmonary system:
Two lungs 3 lobes on right 2 lobes on left
Their airways Blood vessels that serve them Chest wall (thoracic cage)
Conducting airways
allows air into and out of the gas exchange structures of the lung
upper airway nasorpharynx oropharynx
lined with ciliated mucosa that warms and humidifies inspired air and removes foreign particles
nose breathing more effective in warming and humidifying
Pulmonary Defense Mechanisms
Upper respiratory tract mucosa Nasal hairs Mucus Cilia Alveolar macrophages Irritant receptors in the nose Irritant receptors in the trachea and
large airways
Impaired Defense Mechanisms Any nursing or medical intervention
that interferes with the airways will impair the defense mechanisms Risk for infection Ineffective breathing patterns Ineffective airway clearance
larynx connects upper and lower airways Vocal cords, supporting cartilage, muscles
that help with swallowing Trachea- connects larynx to bronchus bronchi- carina where bronchi branch
Gas Exchange airways
respiratory bronchioles- 3 layers: epithelial lining, smooth muscle lining and the connective tissue layer
Epithelial lining consists of the mucus secreting goblet cells and the ciliated cells
alveolar ducts alveoli- primary gas-exchange units of
the lung where oxygen enters the blood and carbon dioxide is removed.
Alveoli Type 1 provide structure Type 2 secretes surfactant
Surfactant- a lipoprotein that coats the inner surface of the alveolus and lowers alveolar surface tension at the end-expiration preventing lung collapse.
Blood Flow Through the Heart
Pulmonary and bronchial circulation The pulmonary circulation
1. facilitate gas exchange 2. delivers nutrients to lung tissue 3. acts as a reservoir for the left ventricle 4. serves as a filtering system that removes clots, air, and other
debris from the circulation
Pulmonary Circulation
Entire cardiac output from the right ventricle goes into the lung
Pulmonary circulation has a lower pressure and resistance
Each pulmonary vein drains several pulmonary capillaries
Pulmonary veins have no valves in them
There is also deep and superficial lymphatic's in this system
pulmonary circulation has a lower pressure and resistance than the systemic circulation
about 1/3 of the pulmonary vessels are filled with blood at any given time-
gas exchange occurs at the alveolocapillary membrane
lymphatic system keeps the lung free of fluid
Chest wall and Pleura
protects muscles, along with the diaphragm
perform the muscular work of breathing the pleura is a serous membrane that
adheres firmly to the lungs and then folds over itself and attaches firmly to the chest wall. Visceral pleura- membrane covering the lung Parietal pleura- lining of the thoracic cavity Pleural space
Function of pulmonary system Ventilation Breathing Diffusion Perfusion compliance
Ventilation- is the mechanical movement of gas or air into and out of the lungs
Adequate ventilation is necessary to maintain normal PaCO2 levels, diseases that limit ventilation result in CO2 retention
Oxygen Transport
Consist of Lungs and CV system
Ventilation
Perfusion
Carrying Capacity
Pulmonary Function Tests
Measure lung volumes and flow rates
Used to diagnose lung disease, effective treatment, not done that often in each client, maybe one time a year
Ventilation Continued
CO2 is the gaseous form of carbonic acid H2CO3 that is produced by cellular metabolism
This is eliminated to maintain a normal arterial CO2 of about 40 mmHg and normal acid base balance
You need adequate ventilation to maintain this
Chemo receptors
Help to monitor pH, PaCO2, PaO2 of arterial blood Central chemo receptors monitor pH by sensing
changes of pH in CSF If alveolar ventilation is inadequate, PaCO2
increases and diffuses across the BBB until PCO2 in the blood and CSF reach equilibrium
Central receptors stimulate the respiratory center to increase the depth and rate of ventilation, this causes the CO2 to return to normal, if possible
Over time and in the presence of long term disease processes, the receptors become insensitive to changes
Neurochemical control of Ventilation
breathing is usually involuntary
voluntary breathing is necessary for certain things
respiratory center in the brain stem controls respiration
pattern of breathing can be influenced by what?
Peripheral Chemo receptors Not as sensitive to changes in CO2
and pH
Primarily sensitive to oxygen levels in the blood
PO2 must drop well below normal before the peripheral sensors act
Ventilation
Centrally controlled by the medulla
The phrenic nerve, innervates the diaphragm and intercostal muscles
Chemo receptors are in the carotid and aortic bodies, the brainstem.
If additional O2 is needed, what happens?
Successful ventilation involves the mechanics of breathing The interaction of forces and
counterforces involving the muscles of inspiration and expiration
Alveolar surface tension Elastic properties of the lungs and chest
wall resistance to air flow through the
conducting airways
major muscle of inspiration is the diaphragm
when the diaphragm contracts, it moves downward in the thoracic cavity, creating a vacuum that causes air to flow into the lungs
- no major muscle of expiration
The Alveoli
Represent Type 1 and Type II epithelial cells Type I form the alveolar walls, where gas
exchange occurs
Type II are the cells that produce surfactant which allows alveoli to expand uniformly and prevents collapse during expiration
Alveolar Surface Tension
In a sphere such as the alveoli, surface tension makes expansion difficult
Alveolar ventilation is made possible by surfactant
Surfactant has a detergent like effect
Surfactant is missing in premature infants and becomes deleted in severe lung damage in adults
Gas Transport
There are four steps Ventilation of the lungs Diffusion of O2 from the alveoli Perfusion of the systemic capillary with
oxygenated blood Diffusion of the CO2 from the cells into
the systemic capillaries
Transport of carbon dioxide
diffusion of carbon dioxide from the cells into the systemic capillaries
perfusion of the pulmonary capillary bed by venous blood
diffusion of carbon dioxide into the alveoli
removal of the carbon dioxide from the lung by ventilation
Carbon dioxide
is more soluble in plasma than oxygen
diffuses readily from tissue cells into plasma
Compliance is the ease with which the lungs and chest wall expand during inspiration lung compliance is based on adequate surfactant
- chest wall expansion depends on flexibility
Elastic recoil is the lungs returning to the resting state after inspiration Accessory muscles The elastic recoil forces of the lungs and chest
wall are in opposition and pull on each other creating the negative pressure of the pleural space
Ventilation and Perfusion The amount of gas exchange depends on the
amount of air in the alveoli and the amount of blood in the capillaries
The amount of air refers to ventilation
The amount of blood refers to perfusion
The ratio of ventilation to perfusion is called the V/Q ratio, the effectiveness of gas exchange
In the normal lung, the alveoli receive air at about 4L/minute
The capillaries supply blood to the alveoli at a rate of 5L / minute
This creates a V/Q ratio of 4:5
V/Q mismatch
This occurs from V/Q dysfunction or altered lung mechanics
It accounts for most of the impaired gas exchange in respiratory disorders
Ineffective gas exchange can affect multiple body systems as a result of impaired tissue perfusion
Outcomes of ineffective gas exchange Shunting
Reduced ventilation to a lung unit Unoxygenated blood reaches the left side of
the heart Dead-space ventilation
Reduced perfusion to a lung unit Pulmonary embolism, pulmonary infarct,
cardiogenic shock
Conditions Affecting Chest Wall Movement Pregnancy Obesity Musculoskeletal Abnormalities Trauma Muscle Disease Nervous System Disease Burns
Developmental Factors
Prematurity – insufficient Surfactant Infants and Toddlers – Increase in
URI, 2nd hand smoke, aspiration School Age / Adolescents – Smoking Young Middle Adult – Unhealthy diet,
poor lifestyle, stress, drugs, smoking Older Adults – normal aging process
Behavioral Factors
Nutrition Exercise Smoking Environmental Anxiety
Atelectasis
The collapse of the alveoli that prevents normal respiratory exchange of CO2. As alveoli collapse, less of the lung can be ventilated
Alt. Respiratory Patterns Tachypnea Bradypnea Apnea Kussmal Cheyne-Stokes Biot’s
Signs and Symptoms
Hyperventilation
Hypoventilation
Hypoxia
Tachycardia Headache *Restless
SOB Lethargy Cyanosis
Chest Pain Disorientation Dyspnea
Dizziness Cardiac Dysrhythmias
* ↑ HR
Blurred Vision Coma *Anxiety
Lab Tests
CBC Chemistry Arterial Blood Gas
Provides information about diffusion of gas across the alveolar-capillary membrane and adequacy of tissue oxygenation.
Looks at hydrogen ion concentration, PCO2, PO2, SAO2
Classifications of pulmonary disease
acute chronic obstructive restrictive infectious noninfectious
Terms
dyspnea- subjective sensation of uncomfortable breathing
feel like not able to get enough air breathlessness short of breath labored breathing
Orthopnea Dyspnea when lying down
S/S of Pulmonary Disease
Dyspnea- At rest On exertion Orthopnea Paraxsysmal nocturnal (PND)
paroxysmal nocturnal dyspnea (PND)- results from fluid in the lungs caused by the redistribution of body water when person is lying down. Can by seen in some individuals with left ventricular failure who wake up gasping for air.
Objective signs of dyspnea
Use of accessory muscles Retraction of the intercostal spaces Flaring of nostrils
Normal breathing
eupnea is rhythmic and effortless ventilatory rate is 12- 20 breaths
per minute
Abnormal breathing patterns kussmaul respiration (hyperpnea)
slightly increased ventilatory rate large tidal volumes no expiratory pause
Cheyne-stokes respirations Alternating periods of deep and shallow breathing Apnea (no breathing) lasts from 15 – 60 seconds This is followed by ventilations that increase in volume
until a peak is reached Then ventilation decreases again to apnea
Hypoventilation
is inadequate alveolar ventilation in relation to metabolic demands Build up of CO2 called hypercapnia
(PaCO2) Results in respiratory acidosis that can
affect the function of tissues in the body
hyperventilation
is alveolar ventilation exceeding metabolic demands lungs remove CO2 faster than it is
produced results in decreased PaCO2 or
hypocapnia. Occurs in anxiety and acute head
injuries
cough is a protective reflex that cleans the lower airways by an explosive expiration Need to consider cancer when patients
have chronic cough Hemoptysis is the coughing up of
blood or bloody secretions Infection or inflammation Tuberculosis Lung abscess Cancer
cyanosis
is a bluish discoloration of the skin and mucous membranes caused by increasing amounts of desaturated or reduced hemoglobin in the blood lack of cyanosis does not necessarily mean the
there is normal oxygenation in adults cyanosis is not evident until severe
hypoxemia is present and is not a good indication of respiratory failure (late sign)
clubbing is the selective bulbous enlargement of the distal segment of a digit
Hypercapnia-
increased carbon dioxide in the arterial blood ( increased PaCo2) caused by hypoventilation of the alveoli- drugs that depress the respiratory center- diseases of the medulla- abnormalities of the spinal conducting pathways- diseases of the neuromuscular junction or of the respiratory muscles themselves
- large airway obstructions, sleep apnea- increased work of breathing or physiologic
dead space ( emphysema)- acidosis can result
Hypoxemia
Decreased oxygen content (PO2) of inspired gas
Hypoventilation Diffusion abnormalities Abnormal ventilation-perfusion ratios Pulmonary right-to-left shunt (blood passes
through portions of the pulmonary capillary bed that receive no ventilation because of an obstruction)
an area where alveoli are ventilated but not perfused is termed alveolar dead space
Acute respiratory failure defined as inadequate gas exchange or
hypoxemia PaO2 <50 mm Hg and PaCO2>50 mm
Hg pH < 7.25 can result from direct injury to the
lungs, airways or chest wall indirectly from injury to another body
system such as the brain or spinal cord can result due to patient having
chronic pulmonary disease
if the respiratory failure is primarily hypercapnic, there is inadequate alveolar ventilation and the individual must receive ventilatory support – mechanical ventilator or bag-valve mask
if the respiratory failure is primarily hypoxemic, it is the result of inadequate exchange of oxygen between the alveoli and the capillaries and the individual will need supplemental oxygen therapy.
Many have combination
Pulmonary edema
excess water in the lung predisposing factors
heart disease (most common) acute respiratory distress syndrome inhalation of toxic gases (cellular injury) blockage in the lymphatic system --hydrostatic pressure push exceeds
oncotic pressure (which holds fluid in the capillary) fluid moves out into the interstitium or interstitial space
Clinical manifestations - dyspnea- hypoxemia- increased work of breathing- inspiratory crackles (rales) - pink frothy sputum
treatment is to find underlying cause and treat it
Pulmonary Edema
Pulmonary Edema
Treatment
Aspiration
is passage of fluid and solid particles into the lung
tends to occur in those whose normal swallowing mechanism and cough reflex are impaired
predisposing factorsaltered level of consciousness due to
substance abusesedationseizure disorderscerbrovascular accidentmyasthenia gravis (neuromuscular disease)Guillain -Barre syndrome (inflammation of
nerves)the rate of deaths resulting from aspiration-caused
pneumonitis (localized lung inflammation) is greater than 50%
Atelectasis
is the collapse of lung tissue Two types:
- compression atelectasis - Absorption atelectasis
Signs and symptoms- dyspnea- cough- fever- leukocytosis
tends to occur after surgery- don’t breath deep due to pain or change positions so viscous secretions pool in dependent portions of the lung
1. walk2. cough and deep breath3. Incentive spirometer
Pneumothorax
is the presence of air or gas in the pleural space
caused by rupture in the visceral pleuraor the parietal pleura and chest wall
destroys the negative pressure of the pleural space
lung collapses open pneumothorax (communicating
pneumothorax)
tension pneumothorax site acts a one-way valve permits air in on inspiration prevents its escape by closing up
during expiration more air moves in the pleural space,
air pressure in the pneumothorax begins to exceed barometric pressure
life threatening deterioration occurs quickly
Signs and symptoms - hypoxemia - dyspnea - hypotension Spontaneous pneumothroax - Sudden pleural pain - Tachypnea - Mild dyspnea
Pleural effusion
is the presence of fluid in the pleural space source of the fluid is usually blood or lymphatic
vessels can be an abscess or lesion draining into the space pleura is relatively permeable membrane and fluids
can cross into the pleural space does not cause the lung to collapse can be transudative (watery) or exudative (high
white cell count) small amounts can be drained by lymphatic system Thoracentesis (needle aspiration) may need to be
done for larger effusions
Empyema infected pleural effusion, usually pneumonia
first signs and symptoms
cyanosis, fever cough tachycardia pleural pain breath sounds decreased over the site of the
empyema Antibiotics Thoracentesis Chest tube Pleurisy (pleuritis) is inflammation of the pleura
Pulmonary fibrosis
is excessive amount of fibrous or connective tissue in the lung can be caused by healing after active
disease inhalation of harmful substance
causes marked loss of lung compliance lungs become stiff very poor prognosis
Acute Respiratory Distress Syndrome (ARDS)
characterized by acute lung inflammation diffuse alveolocapillary injury with
noncardiogenic pulmonary edema affects about 200,000 to 250,000 people per
year in the US most survivors have almost normal lung
function 1 year after the acute illness caused by lung injury
most common causes sepsis multiple trauma pneumonia burns aspiration pancreatitis drug overdose smoke inhalation
injure the alveolcapillary membrane and produce severe pulmonary edema, shunting and hypoxemia
Signs and symptoms
rapid shallow breathing respiratory alkalosis dyspnea decreased lung compliance hypoxemia unresponsive to oxygen therapy diffuse alveolar infiltrates seen on chest
radiographs
progressive symptoms: 1. hyperventilation 2. respiratory alkalosis 3. dyspnea and hypoxemia 4. metabolic acidosis 5. Respiratory acidosis 6. further hypoxemia 7. hypotension, decreased cardiac output,
death goal is to maintain adequate oxygenation
and ventilation while preventing infection smokers are at risk for postoperative
respiratory failure
Most common postoperative pulmonary problems are
- atelectasis- pneumonia- pulmonary emboli- pulmonary edema
Obstructive Pulmonary Disease
airway obstruction that is worse with expiration
more force needed for expiration most common are
asthma bronchitis emphysema
Asthma
is a chronic inflammatory disorder of the airways
- occurs at all ages- familial disorder- genetics may play a role
- environmental factors interact with inherited factors to increase the risk
Three phases 1. remission 2. partial remission 3. attacks
treatment- education- avoid triggers- oral steroids - inhalers (bronchodilators)
COPD (chronic obstructive pulmonary disease)
Defined as pathologic lung changes with airflow limitation that is not fully reversible
chronic bronchitis- hypersecretion of mucus and chronic productive cough for at least 3 months of the year for 2 consecutive years
incident increases with smokers those exposed to air pollution repeated infections are common major health problem for the elderly
Treatment- stop smoking- bronchodilators- expectorants- chest physical therapy
Acute bronchitis
acute infection or inflammation of the airways or bronchi
commonly follows a viral illness and is usually self-limiting
Emphysema
abnormal permanent enlargement of the gas exchange airways with destruction of alveolar walls
obstruction is the result of changes in lung tissue
loss of elastic recoil smoking major cause primary emphysema linked to deficiency of
enzyme alpha 1-antitrypsin destruction of alveolar septa which
eliminates portions of the pulmonary capillary bed
because expiration becomes difficult of loss of elastic recoil reduces the volume of air that can be expired passively
hyperinflation of alveoli produce large air spaces (bullae) and air spaces adjacent to pleurae (blebs)
bullae and blebs are not effective in gas exchange and there is a ventilation/perfusion mismatch and hypoxemia
late disease develop hypercapnia
signs and symptoms- dyspnea- productive cough- smoking history- barrel chest
Treatment and evaluation- pulmonary function tests- chest x ray- CT scan- ABG (arterial blood gases)- may need home O2- respiratory inhalers- lung reduction or lung transplant
may be needed
Respiratory tract Infection
most common cause of short-term disability in the US
a. colds
b. pharyngitis
c. Laryngitis
- most infections are in the upper respiratory tract
- infections of the lower tract most often in individuals whose normal defense mechanisms are impaired
Pneumonia is an acute infection of the lower respiratory tract
caused by bacteria, viruses, fungi, protozoa or parasites
6th leading cause of death in the US elderly are more at risk risk factors
age immunocompromised lung disease alcoholism smoking endotracheal intubation malnutrition immobilization altered consciousness
Community acquired Nosocomial
High mortality rate More opportunistic infections
streptococcus pneumoniae most common community acquired pneumonia and has a low overall mortality
legionella- contaminates cooling systems and water supplies
pseudomonas aeruginosa and staphylococcus aureus most common nosocomial pneumonias
HIV and transplant patients susceptible to pneumocystis carinii, and fungal infections Hard to treat High mortality rate
Signs and symptoms - fever - chills - productive or dry cough- pleural pain- sometimes dyspnea- hemoptysis (sometimes)
Evaluation
elevated WBC Chest x-ray shows infiltrates Need sputum culture to identify the
organism May need bronchoscopy or lung biopsy Blood cultures
Treatment
Antibiotics for bacterial Viral is treated with supportive therapy Adequate hydration Supplemental oxygen Respiratory treatments Incentive spirameter
Tuberculosis (TB)
is an infection caused by Mycobacterium tuberculosis, an acid-fast bacillus that usually affects the lungs but can be in other body systems
risk factors emigration of infected individuals from
certain countries crowded institutional settings homelessness substance abuse lack of access to medical care all have
contributed to spread of TB
Transmitted via airborne droplets The body walls off the infection It can lay dormant in the body for
life If immune system is impaired,
however, or if live bacilli escape into the bronchi, active disease occurs and may spread in the body
Signs and Symptoms
may be asymptomatic if symptoms do appear, it can be
gradually fatigue weight loss lethargy hemoptysis dyspnea night sweats fever in afternoon chest pain
Evaluation and treatment
diagnosed with a positive tuberculin skin test
****sputum culture chest x ray
Treatment
Antibiotic therapy isoniazid rifampin pyrazinamide ethambutol streptomycin
recommended treatment is 9- 12 months
patient is considered safe when three sputum test come back negative for the bacilli
Pulmonary Hypertension
is high blood pressure in the pulmonary arteries
normal pressure is 15- 18 mm/Hg it is rare has no known cause usually occurs in women between the ages of 20
and 40 years of age may be hereditary primary pulmonary hypertension has a poor
prognosis most die within 5 years of diagnosis
secondary pulmonary hypertension- usually associated with cardiovascular disorder elevated left ventricular filling pressures
(CHF and Mitral valve disease) increased blood flow through the pulmonary
circulation ( obliteration or obstruction of the pulmonary
vascular bed by a pulmonary embolus or by chronic destruction of alveolar wall (emphysema)
vasoconstriction of the vascular bed (hypoxemia, acidosis or both)
other causes include obstructive sleep apnea, cystic fibrosis, cirrhosis with portal hypertension, use of appetite suppressants
Secondary pulmonary hypertension can be reversed if the primary disorder is resolved Oxygen Digoxin Diuretics Vasodilators Anticoagulants Lung transplant
damage can become irreversible if pulmonary hypertension continues long enough
Cor pulmonale- also called pulmonary heart disease right ventricular enlargement a. Hypertrophy
b. dilation develops as pulmonary hypertension produces chronic
pressure overload in the right ventricle
the right ventricle usually fails when pulmonary artery pressure equals systemic blood pressure
goal of treatment is to decrease the workload of the right ventricle and is same as primary pulmonary hypertension
Lung cancer- Tobacco smoke is responsible for
80 – 90 % of lung cancers- Believe there is an inherited
genetic predisposition to cancers