Patho Pulmonary System Flashcards
Alveoli and Lungs
Alveoli: Primary gas exchange units
Lungs contain approximately 25 million alveoli at birth and 300 million by adulthood
Pulmonary circulation has a lower pressure (18 mmHg) than systemic circulation (90 mmHg).
Only one third of vessels filled with blood at any given time.
Gases of Respiration
Primary function of respiratory system
- Remove CO2
- Addition of O2
Insufficient exchange of gasses
- Hypoxemia
- Hypercapnia
Hypoxemia
Hypoxemia results from
- An inadequate O2 in the air
- Disease of the respiratory system
- Dysfunction of the neurological system
- Alterations in circulatory function
Mechanisms of Hypoxia
Mechanisms
- Hypoventilation
- Impaired diffusion of gases
- Inadequate circulation of blood through the pulmonary capillaries
- Mismatching of ventilation and perfusion
Mild Hypoxemia
-Metabolic acidosis
-Increase in heart rate
Peripheral vasoconstriction
-Diaphoresis
-Increase in blood pressure
-Slight impairment of mental performance
Chronic Hypoxemia
- Manifestations of chronic hypoxia may be insidious in onset and attributed to other causes.
- –Compensation masks condition.
- Increased ventilation
- Pulmonary vasoconstriction
- Increased production of red blood cells
- Cyanosis
Signs and Symptoms of Dysfunction
Dyspnea Hyperventilation Abnormal breathing patterns Coughing Hypoxema Hypercapnia Cyanosis Changes in mentation
Areas Involved in Respiratory Tract Infections
Upper respiratory tract
–Nose, oropharynx, and larynx
Lower respiratory tract
–Lower airways and lungs
Upper and lower airways
Common Respiratory Infections
Common cold Influenza Pneumonia Tuberculosis Fungal infections of the lung
Transmission of Common Cold
Viral infection of the upper respiratory tract
—Rhinoviruses, parainfluenza viruses, respiratory syncytial virus, corona viruses, and adenoviruses
Fingers are the greatest source of spread.
Cough, sneeze
—The nasal mucosa and conjunctival surface of the eyes are the most common portals of entry of the virus.
Types of Influenza Viruses
Type A and Type B
Type A Influenza Virus
- Most common type
- Can infect multiple species
- Causes the most severe disease
- Further divided into subtypes based on two surface antigens: hemagglutinin (H) and neuraminidase (N)
Type B Influenza Virus
Has not been categorized into subtypes
Antiviral Drugs
Amantadine
Rimantadine
Zanamivir
Oseltamivir
Trivalent inactivated influenza vaccine (TIIV)
Developed in the 1940s
Administered by injection
Live, attenuated influenza vaccine (LAIV)
- Approved for use in 2003
- Administered intranasally
Pneumonia Definition
Respiratory disorders involving inflammation of the lung structures (alveoli and bronchioles)
Pneumonia Causes
Infectious agents: such as bacteria and viruses
Noninfectious agents: such as gastric secretions aspirated into the lungs
Factors Facilitating Development of Pneumonia
An exceedingly virulent organism
A large inoculum
Impaired host defenses
Classifications of Pneumonias
According to the source of infection
- –Community-acquired
- –Hospital-acquired
According to the immune status of the host
—Pneumonia in the immunocompromised person
Tuberculosis
World’s foremost cause of death from a single infectious agent
Causes 26% of avoidable deaths in developing countries
Lungs most commonly infected
1/3 of world’s population has TB
countries
Drug-resistant forms
Mycobacterium tuberculosis hominis
- –Aerobic
- –Protective waxy capsule
- –Can stay alive in “suspended animation” for years
Forms of Tuberculosis
M. tuberculosis hominis (human tuberculosis)
Bovine tuberculosis
M. tuberculosis hominis (human tuberculosis
Airborne infection spread by minute droplet nuclei harbored in the respiratory secretions of persons with active tuberculosis
Living under crowded and confined conditions increases the risk for spread of the disease
Bovine tuberculosis
Acquired by drinking milk from infected cows; initially affects the gastrointestinal tract
Has been virtually eradicated in North America and other developed countries
Diagnostic Studies
Tuberculin skin test (TST)
—AKA: Mantoux test
—Assess for induration in 48 – 72 hours
—Positive if ≥15 mm induration in low-risk individuals
—Response ↓ in immunocompromised patients
Reactions ≥5 mm considered positive
—Interferon-γ gamma release assays (IGRAs)
—Chest x-ray
—Bacteriologic studies
Tuberculosis: Clinical manifestations
Latent tuberculosis infection: Asymptomatic
Fatigue, weight loss, lethargy, anorexia etc Diagnosis
Positive tuberculin skin test (TST) a purified protein derivative (PPD): Does not differentiate past, latent, or active disease
Sputum culture, immunoassays, indirect drug susceptibility testing
Chest radiographs
Tuberculosis: Treatment
Isoniazid, rifampin, pyrazinamide, and ethambutol
Drug-resistant bacilli: Combination of at least four drugs to which the microorganism is susceptible, administering for 18 months
—-Review drug effectiveness at 6 months
Lung Cancer
Causative factors: Smoking
Asbestos
Familial predisposition
Primary lung tumors (95%) versus bronchial, glandular, lymphoma
Secondary via metastasis
Categories of Bronchogenic Carcinomas
Squamous cell lung carcinoma (25% to 40%)
Adenocarcinoma (20% to 40%)
Small cell carcinoma (20% to 25%)
Large cell carcinoma (10% to 15%)
Squamous cell lung carcinoma (25% to 40%)
Closely related to smoking
Adenocarcinoma (20% to 40%)
Most common in North America
Small cell carcinoma (20% to 25%)
Small round to oval cells, highly malignant
Large cell carcinoma (10% to 15%)
Large polygonal cells, spread early in development
Categories of the Manifestations of Lung Cancer
Those due to involvement of the lung and adjacent structures
The effects of local spread and metastasis
The nonmetastatic paraneoplastic manifestations involving endocrine, neurologic, and connective tissue function
Nonspecific symptoms such as anorexia and weight loss
Respiratory Disorders in Children
Upper airway infections
-Viral croup
-Spasmodic croup
Epiglottis
Lower airway infection
-Acute bronchiolitis
Impending Respiratory Failure in Infants and Children
Rapid breathing
Exaggerated use of the accessory muscles
Retractions
Nasal flaring
Grunting during expiration
Pleura
Parietal pleura lines the thoracic wall and superior aspect of the diaphragm.
Visceral pleura covers the lung.
Pleural cavity or the space between the two layers contains a thin layer of serous fluid.
Characteristics and Symptoms of Pleural Pain
Abrupt in onset
Unilateral; localized to lower and lateral part of the chest
May be referred to the shoulder
Usually made worse by chest movements
Tidal volumes are kept small.
Breathing becomes more rapid.
Reflex splinting of the chest may occur.
Disorders of the Pleura
Pleural effusion: abnormal collection of fluid in the pleural cavity
-Transudate or exudate, purulent (containing pus), chyle, or sanguineous (bloody)
Hemothorax
Pleuritis
Chylothorax
Atelectasis
Empyema
Types of Pneumothoraxes
Spontaneous Pneumothorax
Traumatic Pneumothorax
Tension Pneumothorax
Spontaneous Pneumothorax
Occurs when an air-filled blister on the lung surface ruptures
Traumatic Pneumothorax
Caused by penetrating or nonpenetrating injuries
Tension Pneumothorax
Occurs when the intrapleural pressure exceeds atmospheric pressure
Causes of Disorders of Lung Inflation
Conditions that produce lung compression or lung collapse
- -Compression of the lung by an accumulation of fluid in the intrapleural space
- -Complete collapse of an entire lung as in pneumothorax
- -Collapse of a segment of the lung as in atelectasis
Pleural Effusion definition
An abnormal collection of fluid in the pleural cavity
Pleural Effusion: Types of Fluid
Transudate Exudate Purulent drainage (empyema) Chyle Blood
Diagnosis of Pleural Effusion
Chest radiographs, chest ultrasound
Computed tomography (CT)
Treatment of Pleural Effusion
Treatment: directed at the cause of the disorder
Thoracentesis
Injection of a sclerosing agent into the pleural cavity
Open surgical drainage
Atelectasis Definition
The incomplete expansion of a lung or portion of a lung
Causes of Atelectasis
Airway obstruction
Lung compression such as that occurs in pneumothorax or pleural effusion
Increased recoil of the lung due to loss of pulmonary surfactant
Types of Atelectasis
Primary
Secondary
Chest Trauma
Traumatic injuries to chest contribute to majority of all traumatic deaths
Range of injuries --Simple rib fractures → life-threatening organ rupture --Blunt --Penetrating ------Open wound through pleural space
Chest Trauma
Hemothorax
- -Blood in pleural space
- -Treat with chest tube
Hemopneumothorax
Chylothorax
- -Lymphatic fluid in pleural space
- -Treat conservatively, with meds, surgery, or pleurodesis
Asthma
A chronic inflammatory disease of the airways that causes hyperresponsiveness, mucosal edema, and mucus production
Inflammation leads to cough, chest tightness, wheezing, and dyspnea.
The most common chronic disease of childhood
Can occur at any age
Allergy is the strongest predisposing factor.
Contributing Factors to an Asthmatic Attack
Allergens
Respiratory tract infections
Exercise
Drugs and chemicals
Hormonal changes and emotional upsets
Airborne pollutants
Gastroesophageal reflux
Factors Involved in the Pathophysiology of Asthma
Genetic
- Atopy
- Early versus late phase
Environmental
- Viruses
- Allergens
- Occupational exposure
Classifications of Asthma Severity
Mild intermittent
Mild persistent
Moderate persistent
Severe persistent
Asthma Clinical Manifestations
-Asymptomatic between attacks
- Chest constriction, expiratory wheezing, dyspnea, nonproductive coughing, prolonged expiration, tachycardia, tachypnea
- Pulsus paradoxus
- Status asthmaticus
- -Bronchospasm not reversed by usual measures
- -Life-threatening
-Ominous signs of impending death Silent chest (no audible air movement) and a Paco2greater than 70 mmHg
Chronic Obstructive Airway Disease
Inflammation and fibrosis of the bronchial wall
Hypertrophy of the submucosal glands
Hypersecretion of mucus
Loss of elastic lung fibers
–Impairs the expiratory flow rate, increases air trapping, and predisposes to airway collapse
Alveolar tissue
–Decreases the surface area for gas exchange
Causes of Chronic Obstructive Airway Disease
Chronic bronchitis
Emphysema
Bronchiectasis
Cystic fibrosis
Types of Chronic Obstructive Pulmonary Disease
Emphysema
Chronic Obstructive Bronchitis
Emphysema
Enlargement of air spaces and destruction of lung tissue
Types: centriacinar and panacinar
Chronic Obstructive Bronchitis
Obstruction of small airways
Characteristics of Pulmonary Emphysema
Smoking history
Age of onset: 40 to 50 years
Often dramatic barrel chest
Weight loss
Decreased breath sounds
Normal blood gases until late in disease process
Cor pulmonale only in advanced cases
Slowly debilitating disease
Characteristics of Chronic Bronchitis
Smoking history
Age of onset 30 to 40 years
Barrel chest may be present
Shortness of breath, a predominant early symptom
Rhonchi often present
Sputum frequent, an early manifestation
Often dramatic cyanosis
Hypercapnia and hypoxemia may be present.
Frequent cor pulmonale and polycythemia
Numerous life-threatening episodes due to acute exacerbations
Pathophysiology of Chronic Bronchitis
Mucous accumulation
Mucous plug
Hyperinflation of aveoli
Inflammation of epithelium
Enlarged submucosal gland
Bronchiectasis
Permanent dilation of the bronchi and bronchioles
Secondary to persisting infection or obstruction
Bronchiectasis demonstrates a damaged cell wall and increased mucuous
Manifestations of Bronchiectasis
Atelectasis
Obstruction of the smaller airways
Diffuse bronchitis
Recurrent bronchopulmonary infection
Coughing; production of copious amounts of foul-smelling, purulent sputum; and hemoptysis
Weight loss and anemia are common
Definition of Cystic Fibrosis
An autosomal recessive disorder involving fluid secretion in the exocrine glands and the epithelial lining of the respiratory, gastrointestinal, and reproductive tracts
Cause of Cystic Fibrosis
Mutations in a single gene on the long arm of chromosome 7 that encodes for the cystic fibrosis transmembrane regulator (CFTR), which functions as a chloride (Cl−) channel in epithelial cell
Manifestations of Cystic Fibrosis
Pancreatic exocrine deficiency
Pancreatitis
Elevation of sodium chloride in the sweat
Excessive loss of sodium in the sweat
Nasal polyps
Sinus infections
Cholelithiasis- the formation of gallstones
Definition of Diffuse Interstitial Lung Diseases
A diverse group of lung disorders that produce similar inflammatory and fibrotic changes in the interstitium or interalveolar septa of the lung
Types of Diffuse Interstitial Lung Diseases
Sarcoidosis
The occupational lung diseases
Hypersensitivity pneumonitis
Lung diseases caused by exposure to toxic drugs
Occupational Lung Diseases
Pneumoconioses
Hypersensitivity diseases
Byssinosis
Pneumoconioses
The inhalation of inorganic dusts and particulate matter
Hypersensitivity diseases
The inhalation of organic dusts and related occupational antigens
Byssinosis
cotton workers; has characteristics of the pneumoconioses and hypersensitivity lung disease
Development of Pulmonary Embolism
A blood-borne substance lodges in a branch of the pulmonary artery and obstructs the flow
Types of Development of Pulmonary Embolism
Thrombus: arising from DVT
Fat: mobilized from the bone marrow after a fracture or from a traumatized fat depot
Amniotic fluid: enters the maternal circulation after rupture of the membranes at the time of delivery
PE Risk Factors
Deep vein thrombosis Immobility or reduced mobility Surgery History of DVT Malignancy Obesity Oral contraceptives/ hormones Smoking Heart failure Pregnancy/delivery Clotting disorders Atrial fibrillation Central venous catheters Fractured long bones
Cor Pulmonale
Right heart failure resulting from primary lung disease and long-standing primary or secondary pulmonary hypertension
Involves hypertrophy and the eventual failure of the right ventricle
Manifestations include the signs and symptoms of the primary lung disease and the signs of right-sided heart failure.
Right Sided <3 Failure (Cor Pulmonale)
Manifestations: Fatigue Ascites Enlarged Liver and Spleen May be secondary to chronic pulmonary problems Distended Jugular Veins Anorexia and complaints of GI distress Weight gain Dependent Edema
Acute Respiratory Distress Syndrome
A number of conditions that produces pathologic lung changes that include diffuse epithelial cell injury with increased permeability of the alveolar–capillary membrane
Causes of Acute Respiratory Distress Syndrome
Aspiration of gastric contents
Major trauma (with or without fat emboli)
Sepsis secondary to pulmonary or nonpulmonary infections
Acute pancreatitis
Hematologic disorders
Metabolic events
Reactions to drugs and toxins
Causes of Respiratory Failure
Impaired ventilation
Impaired matching of ventilation and perfusion
Impaired diffusion
Impaired ventilation
Upper airway obstruction
Weakness of paralysis of respiratory muscles
Chest wall injury
Impaired diffusion
Pulmonary edema
Respiratory distress syndrome
Treatment of Respiratory Failure
Respiratory supportive care directed toward maintenance of adequate gas exchange
Establishment of an airway
Use of bronchodilating drugs
Antibiotics for respiratory infections
Ensure adequate oxygenation
Tracheostomy
Surgically created stoma (opening) used to
- Establish a patent airway
- Bypass an airway obstruction
- Facilitate secretion removal
- Permit long-term mechanical ventilation
- Facilitate weaning from mechanical ventilation
