Chapter 26 Alterations of Pulmonary Function

total lung capacity

total amount of volume the lungs can hold

FEV1

how much air can be exhaled in 1 second

What are the clinical manifestations of pulmonary disease?

dyspnea, abnormal breathing patterns, cough, cyanosis, clubbing, abnormal sputum, pain, hemoptysis, hyperventilation, hypoventilation

What are the effects from pulmonary diseases?

hypercapnia, hypoxemia, acute respiratory failure, pulmonary edema, atelectasis, bronchiecstasis, pneumothorax, pleural effusion, empyema

Hypercapnia

increased carbon dioxide leads to respiratory acidosis

What are the manifestations of hypercapnia?

dysrhythmias, electrolyte imbalances, somnolence, coma, death

Hypoxemia

decreased oxygenation of arterial blood

What causes hypoxemia?

1. Decreased oxygen delivery to alveoli (due to FiO2 levels and ventilation)
2. Decreased diffusion of oxygen into blood (due to V/Q imbalances and thickness/decreased surface area of alveolar capillary vessels)
3. Decreased capillary perfusion (due to bl

What does a low V/Q mean?

inadequate ventilation of well-perfused areas

What does a high V/Q mean?

adequate ventilation of poorly perfused areas

Acute Respiratory Failure

decreased arterial oxygen and increased arterial carbon dioxide with low pH; results in hypercapnia and hypoxemia

Pulmonary Edema

excess water in the lung

What are the 3 causes of pulmonary edema?

1. Heart failure-left side failure, increase of capillary hydrostatic pressure in pulmonary vessels, forced into interstital space in lungs
2. Capillary injury-increased permeability and disruption of surfactant, fluid moves into interstitial space and al

What are the manifestations of pulmonary edema?

dyspnea, hypoxemia, increased work of breathing, crackles, dullness to percussion

Atelectasis

collapse of lung tissue

What are the manifestations of atelectasis?

dyspnea, cough, fever, leukocytosis

When does atelectasis tend to occur?

Postoperatively

Aspiration

the passage of fluid and solid particles into the lung; usually happens to an individual with dysphagia and inadequate cough reflex

Bronchiectasis

persistent dilation of bronchioles due to mucus plugs, atelectasis, etc.

What are the manifestations of bronchiectasis?

large amounts of sputum, hemoptysis, clubbing (decreased oxygenation of peripheral tissues)

Pneumothorax

presence of air or gas in the pleural space caused by a rupture in the visceral pleura or parietal pleura and chest wall; air separates the pleura, destroying the negative pressure and disrupts the equilibrium of elastic recoil and chest wall; the lung tr

What is spontaneous pneumothorax?

spontaneous rupture of bleb on visceral pleura; usually occurs in 20-40 year olds

What is secondary pneumothorax?

AKA traumatic pneumothorax; caused by chest trauma

What is an open pneumothorax?

air pressure in pleural space=barometric pressure; air inspired is also expired through the damaged chest wall

What is a tension pneumothorax?

the site of pleural rupture acts as a one way valve; air can enter upon inspiration but cannot be exhaled; air pressure increases and pushes against the already recoiled lungs; displaces heart and trachea; life-threatening

Pleural effusion

Collection of fluid in the pleural cavity

What are the manifestations of pleural effusion?

dyspnea, compression atelectasis with impaired ventilation, mediastinal shift, decreased breath sounds

Empyema

infection pleural effusion (pus)

What are the 4 categories of pulmonary disease?

Restrictive, Obstructive, Infection, Pulmonary vascular

Restrictive Lung Disease

decreased compliance of lung tissue resulting in an increased work of breathing; affects alveolocapillary membrane resulting in hypoxemia

What are the manifestations of a restrictive lung disease?

dyspnea, increased respirations, decreased tidal volume (breathing at rest), decreased forced vital capacity (ability to inhale/exhale using accessory muscles)

What are the 3 examples of a restrictive lung disease?

pulmonary fibrosis, pneumoconiosis, acute respiratory distress syndrome (ARDS)

Pulmonary Fibrosis

too much connective tissue is in the lung

What are the causes of pulmonary fibrosis?

idiopathic

What does pulmonary fibrosis lead to?

formation of scar tissue

Pneumoconiosis

changes in the lung caused by inhalation of dust particles

What does pneumoconiosis cause?

chronic inflammation and scarring; can result in pulmonary fibrosis

Acute Respiratory Distress Syndrome

acute lung inflammation and alveolocapillary injury

What happens in ARDS?

injury to the lung initiates platelet aggregation, thrombus formation, complement cascade, stimulates neutrophils and macrophage activity and the inflammatory response; neutrophils damage the membrane and cause an increase in capillary permeability, resul

What are the manifestations of ARDS?

dyspnea, rapid, shallow breathing, respiratory alkalosis, crackles, hypoxemia unresponsive to oxygen therapy, alveolar infiltrates

Obstructive Lung Disease

airway obstruction resulting in forced expiration

What are the manifestations of an obstructive lung disease?

dyspnea, wheezing, V/Q mismatch, increased work of breathing decreased FEV1

What are the 3 types of obstructive lung disease?

Asthma, Chronic Bronchitis, Emphysema

Asthma

a chronic inflammatory disorder usually associated with an airflow obstruction that is acute and reversible

What trigger asthma?

allergies, irritants, pollution, smoking

When is asthma most diagnosed?

childhood

Chronic Obstructive Pulmonary Disease

includes chronic bronchitis and emphysema

COPD

an abnormal inflammatory response that results in progressive, irreversible decrease in airflow

Chronic Bronchitis

hypersecretion of mucus; chronic, productive cough for at least 3 months of the year for at least 2 years; almost always caused by smoking and exposure to air pollution; common in winter

What are the manifestations of chronic bronchitis?

productive cough, intermittent wheezing, prolonged expiration, cyanosis, hypoventilation, polycythemia, cor polmonale

Polycythemia

a compensatory increase in red blood cells due to hypoxemic conditions

Emphysema

irreversible obstruction of airflow caused by destruction of alveoli, enlargement of acini and loss of elastic recoil; mainly caused by smoking

alpha1-antitrypsin defiency

results in emphysema; normally inhibits the proteolytic enzymes that destroy surfactant on the alveloli; when this enzyme isn't present, the alveoli are destroyed by proteolytic enzymes

What 2 things can emphysema affect?

1. bronchioles and alveolar ducts (centriacinar); tends to occurs in persons who smoke and have chronic bronchitis
2. entire acinus (panacinar); tends to occur in elderly and persons with alpha1-antitrypsin deficiency

What are the manifestations of emphysema?

dyspnea, wheezing, barrel chest (A:P=1:1), prolonged expiration

What are the late signs of emphysema?

cough, hypoventilation, polycythemia, cor pulmonale

How do we diagnose COPD?

ABGs, chest x-ray, CT, pulmonary function tests, physical exam (look for individual used pursed-lip breathing and sitting in the tripod position)

What are the 3 types of respiratory infections?

pneumonia, acute bronchitis, tuberculosis

Pneumonia

infection of lower respiratory tract that is community acquired or hospital acquired; more frequently caused by bacteria, inflammation causes exudate and debris in acini resulting in crackles

What are the bacteria involved in community acquired pneumonia?

streptococcus pneumoniae, mycoplasm pneumoniae, influenza virus

What are the bacteria involved in hospital acquired pneumonia?

pseudomonas aeruginosa, staphylococcus aureus, klebsiella pneumonia

How do individuals get pneumonia?

1. Aspiration of microorganisms
2. Activation of alveolar macrophages without inflammation
3. Virulent or large numbers of microorganisms trigger inflammatory and immuse response
4. Inflammatory mediators and immune complexes damage bronchial and alveoloc

What are the manifestations of pneumonia?

URI, fever, chills, cough, malaise, dyspnea, hemoptysis, pulmonary consolidation (fluid build up in lungs), increased WBCs; sputum culture and gram stain confirms pneumonia

What is bronchitis?

an infection of the upper airways and bronchi that is usually viral, inflammation causes increased mucous and constriction of later airways resulting in rhonchi and wheezing; bronchitis can turn into secondary bacterial pneumonia

Tuberculosis

caused from the bacteria mycobacterium tuberculosis

What are the risk factors for tuberculosis?

immunocompromised, foreign born, institutional settings, homeless, substance abuse, lack of medical care

How is TB spread?

airborne droplet transmission

What happens in TB?

the bacilli lodge in the upper periphery of lungs; inflammatory response activates alveolar macrophages and neutrophils which isolate the bacilli, forming a tubercle; caseation necrosis develops and isolates the bacilli; can spread to other organs

What are the manifestations of TB?

can be asymptomatic, fatigue, weight loss, low grade fever, night sweats, anorexia, gradual onset of productive cough, hemoptysis, dyspnea

How is TB diagnosed?

TB skin test, chest x-ray, sputum culture

What are the 3 types of pulmonary vascular disease?

pulmonary embolism, pulmonary hypertension, cor pulmonale

Pulmonary Embolism

blockage of pulmonary vessels by an embolus (clot)

What are the risks for pulmonary embolism?

hypercoagulability, venous stasis, injuries to vessels, genetic clotting disorders, longer airplane rides

How does pulmonary embolism occur?

1. Venous stasis, vessel injury, hypercoagulability
2. Thrombus formation
3. Dislogement
4. Occludes portion of pulmonary circulation
5. Hypoxic vasoconstriction, decreased surgactant, release of neurohumoral and inflammatory substances, pulmonary edema,

How is pulmonary embolism diagnosed?

spiral chest CT, chest x-ray, ABGs, V/Q scan, D-dimer

What is a D-dimer?

a test that measures a patient's risk of developing a clot

Pulmonary Hypertension

increased pressure in the pulmonary artery

What is the primary cause of pulmonary hypertension?

idiopathic

What is the secondary cause of pulmonary hypertension?

diseases of the respiratory system

How does pulmonary hypertension occur?

1. Chronic hypoxemia and acidosis (from COPD, fibrosis, obesity-hypoventilation syndrome)
2. Endothelial dysfunction
3. Overproduction of vasoconstrictors and underproduction of vasodilators
4. Vascular smooth muscle remodles, thickens, and becomes fibrou

What are the manifestations of pulmonary hypertension?

enlarged right side of heart, tachypnea, dyspnea, peripheral edema

Cor Pulmonale

heart failure