Exam 3 patho - Respiratory system

What are the two types of lower airway diseases?

non-infectious

infectious

What are the two categories of non-infectious lower airway diseases?

Obstructive and restrictive

What is the main problem in obstructive diseases?

air can’t get out

What is the main problem in restrictive diseases? 

air can’t get in 

What causes obstructive diseases?

narrowed/blocked airways → bronchoconstriction, inflammation, mucus

What causes restrictive diseases?

pulmonary stiffness, respiratory muscles weak → lungs don’t expand

What is the result of obstructive diseases?

air trapping → hyperinflation → decreased O2, increased CO2

What is the result of restrictive diseases? 

decreased lung volumes/capacity - decreased O2 

Signs and symptoms of obstructive diseases

wheezing, prolonged exhalation, barrel chest, air hunger, decreased FEV

Signs and symptoms of restrictive diseases

rapid, shallow breathing, low TV, decreased total lung capacity

Examples of obstructive diseases

Asthma, COPD

Examples of restrictive diseases

Pulmonary fibrosis, sarcoidosis, neuromuscular disorders

What is asthma?

chronic disorder characterized by acute exacerbations

What are the main features of asthma? 

• Acute inflammation of the lung
• Bronchoconstriction
• Increased mucus production
• Hyperresponsiveness to triggers
• Status asthmaticus

What do triggers cause in asthma? 

Triggers cause release of inflammatory mediators

What does the release of inflammatory mediators lead to in asthma?

• Recurrent episodes of wheezing
• Breathlessness
• Chest tightness
• Coughing

What are common asthma triggers?

• Allergens
• Pharmacological
• Environmental
• Infectious
• Exercise related

What happens first in the pathophysiology of asthma?

Mediators are released - starts inflammatory response

What mediators are involved in the inflammatory response in asthma?

Histamines, leukotrienes, bradykinin, serotonin

What does the release of mediators lead to in asthma?

Cough, bronchial edema, and airway constriction

When does the early stage of asthma occur?

within 90 minutes of exposure

What happens during the late stage of asthma?

• Cellular components are activated – increases/prolongs inflammatory response
• Includes eosinophils, neutrophils, macrophages

What does the late stage of asthma lead to?

airway obstruction and hyperresponsive airways

When does the late stage of asthma occur?

3 to 10 hours after exposure

What are the four big changes in the late stage of asthma?

1. inflammation

2. edema

3. increased mucus production

4. smooth muscle contraction 

Manifestations of asthma

wheezing, louder on exhalation

coughing 

accessory muscle use

anxiety

cyanosis - circumoral and fingertips

longer breathing cycle 

hypoxia - decreased LOC, tachycardia 

what lab test is commonly used to assess respiratory function in asthma?

ABGs (arterial blood gas)

In asthma what happens to pO2?

pO2 may be decreased

In asthma what happens to pCO2 initially and why?

initially decreased due to increased respiratory effort

in asthma what happens to pCO2 later on and why? 

later may be increased related to air trapping

What does a low PaO2 on a ABG indicate? 

Hypoxemia 

What does a high PaCO2 indicate?

Hypoventilation

What does an increase in HCO3- indicate in ABGs?

metabolic compensation

pCO2 / pO2 means

partial pressure which just means the amount of it

What is the purpose of Pulmonary Function Testing (PFT)?

Used to screen patients for lung disease before symptoms appear

Used to differentiate between obstructive and restrictive diseases

What are the key components tested in PFT?

• airway flow rate

• lung volumes and capacities

• gas exchange

What lung volume is abbreviated as TV ?

Tidal volume - the amount of air you breathe in or out during a normal, relaxed breath

What does VC stand for in pulmonary testing ?

Vital capacity - The maximum amount of air you can breathe out after taking the deepest breath in.

What does FVC stand for?

Forced vital capacity - The amount of air you can forcefully exhale after taking a deep breath

What does FEV stand for?

Forced expiratory volume - The amount of air you can forcefully blow out in 1 second during the FVC test

What does PEFR stand for ?

Peak expiratory flow rate - the fastest speed at which you can exhale

What tool can be used to detect early changes in airflow in asthma?

Peak flow meters

What is COPD? 

Progressive airflow limitation associated with abnormal inflammatory
response of lungs to noxious particles and gasses

Is COPD reversible?

no

What are the two main problems in COPD?

Emphysema and chronic bronchitis

What is emphysema characterized by?

• Hyperinflation
• Abnormal, permanent enlargement of alveoli
• Destruction of alveolar walls
• Loss of elasticity
• Decreased recoil
• Increased energy to breathe

what is chronic bronchitis characterized by? 

• Chronic inflammation
• Hypersecretion of mucus
• Bronchial wall thickening
• Decreased lumen diameter

What causes air trapping in COPD?

• Stagnant air trapped in enlarged alveoli
• No lung recoil to force it out
• Narrowed or collapsed small airways filled with mucus prevent egress

Why is air trapping bad?

• No gas exchange
• Breeding ground for bacteria and viruses

What is air trapping?

Air trapping happens when air gets stuck in the lungs and can’t be fully exhaled because small airways are narrow or blocked

what do normal alveoli look like?

small, numerous, lots of surface area 

what do emphysema alveoli look like?

enlarged, fewer walls, less surface area

Risk factors for COPD

Smoking

• Increases production of elastase which leads to breakdown of elastin in alveoli
• 8 pack year history results in some PFT changes
• 20 pack year history results in symptomatic problems
Occupational exposure
Recurrent lung infections
Airway hyperresponsiveness
Low birth weight

Genetic factors: 
• Atopy
• Alpha-1 antitrypsin deficiency

What causes remodeling in COPD lungs?

Remodeling due to recurrent inflammatory response

What does COPD do to the capillary beds?

damages capillary beds

How does damage to capillary beds affect blood flow?

Increases resistance to blood flow

What condition does increased resistance to blood flow lead to in COPD?

Pulmonary hypertension

What happens to the right side of the heart in COPD?

Right ventricular hypertrophy and right heart failure

What happens to the bronchioles in COPD? 

Narrows bronchioles and fixed airway obstruction 

What are the effects of bronchiole narrowing and fixed airway obstruction in COPD?

causes air trapping, hyperinflation

What happens to gas exchange in COPD?

Decreased gas exchange

What blood gas changes occur in COPD?

Hypercapnia and hypoxia

What does pulmonary mean?

means anything related to the lungs

Complications of COPD

Increased risk for
• Hypoxemia/acidosis
• Respiratory infections
• Cardiac failure related to cor pulmonale (right heart failure)
• Dysrhythmia

Clinical manifestations of COPD - general appearance

◦ Cachectic
◦ Muscle wasting
◦ Stooped over
◦ Barrel chest
◦ Tripod position
◦ Disheveled

Clinical manifestations COPD - CV

◦ Increased HR
◦ Cyanosis
◦ Clubbing
◦ Dependent edema

Clinical manifestations of COPD - neuro

decreased LOC

Clinical manifestations of COPD - respiratory

◦ Use of accessory muscles
◦ Wheezing
◦ Cough
◦ Decreased diaphragm movement
◦ Pursed lips breathing
◦ Increased rate
◦ Paradoxical breathing
◦ Orthopnea
◦ SOB
◦ Air hunger
◦ Fragmented speech

Clinical manifestations of COPD - mental

• anxiety 

• depression

Tests for COPD - PFTS (pulmonary function test)

Decreased FEV1/FVC indicates obstruction

Tests for COPD - ABGs (arterial blood gas)

Hypoxia, hypercapnia, respiratory acidosis with complete compensation

Tests for COPD - CBC (complete blood count)

Elevated RBCs, hemoglobin and hematocrit

Tests for COPD - CXR (chest x- ray)

Hyperinflation with rib separation and flattened diaphragm

What is forced expiratory volume (FEV) measured at?

At one (FEV1), two (FEV2), and three (FEV3) seconds

What ratio is used to diagnose COPD and what does a low value indicate?

FEV1:FVC ratio is used; a low ratio indicates a problem

What are PFTs used for in COPD management?

• To assess efficacy of medications
• To monitor progression of disease

*Can also be used to diagnose restrictive disease

What is atelectasis? 

Collapse of alveoli (few or many), part of lung reduces oxygen exchange 

What are common causes (etiology) of atelectasis?

• Airway obstruction
• Compression
• Postoperative

What is the pathophysiology of atelectasis?

Alveoli collapse → no ventilation → impaired gas exchange → hypoxia

What are the manifestations of atelectasis?

• Shortness of breath
• Tachypnea
• Diminished breath sounds
• Cough
• Cyanosis

What is aspiration?

Entry of foreign material into the airway

what are common causes (etiology) of aspiration?

• Swallowing difficulties
• Impaired gag or cough
• Gastroesophageal reflux
• Altered level of consciousness (LOC)

What is the pathophysiology of aspiration?

• Obstruction
• Inflammation or infection
• Impaired gas exchange

What are the manifestations of aspiration?

• Coughing, choking, clearing throat
• Wheezing, abnormal breath sounds
• Dyspnea, tachypnea

What are the two main infectious lower airway diseases ?

Pneumonia and tuberculosis

What is pneumonia?

Acute or chronic infection with an end result of impaired oxygen exchange

What causes pneumonia?

• Microorganisms: virus, bacteria, fungus, parasites

• Chemical irritants: smoke, petroleum, aspiration of stomach contents

How is pneumonia classified?

Based on:

• Causative agent

• Anatomic location of infection (throughout both lungs or consolidated in one lobe)

• Pathophysiologic changes (changes in interstitial tissue, alveolar septae, or alveoli)

• Epidemiologic data (nosocomial or community-acquired)

What is the pathophysiologic process in pneumonia?

• Bacteria gain access

• Inflammatory response

• Increased fluid in alveoli, bronchioles & interstitial tissue

• Lung congestion

• Hypoxia

What characterizes Community-Acquired Bacterial Pneumonia?

• Often preceded by viral infection that suppresses immune system

• Symptom onset may be insidious

• 25-35% caused by Strep pneumoniae

What characterizes Community-Acquired Viral Pneumonia?

• More commonly seen in younger patients

• Half of all pneumonia is caused by virus

• Symptoms worsen more rapidly

• Further complicated by bacterial infections, heart disease or pregnancy

What is Atypical Pneumonia?

• Affects older children and young adults

• Violent spasms of coughing with little mucus production

• Example: Mycoplasma

What characterizes Hospital-Acquired Pneumonia (Nosocomial infections)?

• Occur > 48 hours after admission

• Pneumonia bacteria found in oro and nasopharynx

• 70% of healthy people are colonized

• Usually related to:
  o Aspiration
  o Invasive procedure
  o Mechanical ventilation

Who is at greatest risk for severe pneumonia?

Very young children, older adults, and immunocompromised individuals

What other groups are at high risk for severe pneumonia?

• Enteral feedings

• Decreased level of consciousness (LOC)

• Ventilator support

• Underlying chronic lung disease

• History of multiple/inappropriate use of antibiotics

• Endotracheal intubation

• Invasive procedures

What factors increase the risk for mortality in pneumonia?

• Increased age

• Alcohol use (ETOH)

• Malignancies

• Immunosuppression

• Neurological disease

• Diabetes

• Congestive heart failure (CHF)

Clinical manifestations of pneumonia 

Cough, Rusty sputum, Fever, Chills,  Sweats, Pleuritic pain, Dyspnea, Tachypnea, Malaise, Fatigue, Abdominal pain, Headache, Anorexia, Tachycardia, Cyanosis,
Flushing, Anxiety, Confusion

What causes tuberculosis?

M. tuberculosis transmitted by oral droplets from persons with active infection

How resistant is M. tuberculosis?

Somewhat resistant to drying and many disinfectants; destroyed by ultraviolet light, heat, alcohol, glutaraldehyde, formaldehyde

What immune response does not occur normally in TB?

Normal neutrophil response