patho: respiratory disorders

main functions of respiratory system

gas exchange (O2 in, CO2 out)

acid-base balance (pH regulation)

protection: cilia & mucus trap pathogens

upper respiratory tract

nose, pharynx, larynx

lower respiratory tract

trachea, bronchi, bronchioles, lungs

how many lobes does the right lung has?

3 lobes

how many lobes does the left lung have?

2 lobes (room for the heart)

what is the lung surrounded by

pleura (visceral & parietal layers)

what is the site of gas exchange

alveoli

• surfactant reduces surface tension

• surrounded by capillaries

infectious rhinitis (upper)

caused by rhinovirus & highly contagious; can lead to a secondary bacterial infection

incubation period is 2-3 days

aka common cold

manifestations of infectious rhinitis 

sneezing, nasal congestion/discharge, sore throat, nonproductive cough, malaise (feeling tired), myalgia (muscle aches), low-grade fever, hoarseness, headache & chills 

rhinosinusitis (upper) 

inflammation of the sinus cavities; preferred name for sinusitis

causes of rhinosinusitis

viruses, bacteria & fungi

what happens during rhinosinusitis?

the lining of the sinuses gets swollen & inflamed, mucus (exudate) builds up, which causes drainage to get blocked creating pressure & pain 

manifestations of rhinosinusitis 

facial pain, nasal congestion, fever, sore throat 

epiglottis (upper)

inflammation of the epiglottis, LIFE-THREATENING

causes of epiglottitis

haemophilus influenzae type B (Hib), common infection in children and throat trauma (ex. hot liquids, foreign objects) 

what happens during epiglottitis?

1. the epiglottis becomes inflamed & swollen

2. swelling pushes down and blocks the trachea (windpipe)

3. causes airway obstruction → trouble breathing, anxiety, & signs of respiratory distress

4. body struggles for oxygen → cyanosis, pallor “tripod position” 

manifestations of epiglottitis

fever, sore throat, difficulty swallowing, drooling with mouth open, tripod position, inspiratory stridor, respiratory distress, central cyanosis, anxiety, pallor

what is tripod position?

a sitting position where the person leans forward, supports themselves with their hands on their knees or on a surface like a chair or table

laryngitis (upper)

inflammation of the larynx, self-limiting (goes away on its own)

larynx (voice box) → affects the VOCAL CORDS

causes of laryngitis 

infection, increased upper respiratory exudate, & overuse of the voice (yelling, singing, talking loudly) 

manifestations of laryngitis

hoarseness, weak voice/voice loss, tickling sensation & raw feeling in the throat, sore throat, dry cough, difficulty breathing 

laryngotracheobronchitis (CROUP) 

common viral infection in children, usually parainfluenza & adenoviruses

what happens during laryngotracheobronchitis (CROUP); upper

larynx & surrounding area swell, leading to airway narrowing, obstruction, and respiratory failure 

manifestations of laryngotracheobronchitis (CROUP)

nasal congestion, seal-like barking cough, hoarseness, inspiratory stridor, dyspnea, anxiety, central cyanosis 

influenza (upper) 

viral infection that affects the upper & lower respiratory tract. it spreads fast and changes often (highly adaptive); incubation period of 1-4 days 

types of influenza 

type a: most severe & most common in the U.S.

type b: less severe

type c: usually causes small outbreaks 

influenza causes significant problems with what populations?

children, elderly, and immune compromised

manifestations of influenza

fever, headache, chills, dry cough, body aches, nasal congestion, sore throat, sweating, malaise 

prevention of transmission for influenza

hand washing, isolation, avoid big crowds, annual vaccination

acute bronchitis (lower)

inflammation of the tracheobronchial tree or large bronchi

causes of acute bronchitis

viruses, bacterial, irritant inhalation (smoke, fumes) and allergic reactions

manifestations of acute bronchitis

productive or non-productive cough, dyspnea, wheezing, low-grade fever, pharyngitis, malaise, chest discomfort 

how to diagnose acute bronchitis 

history, physical examination, & x ray 

bronchiolitis (lower)

common acute inflammation of the bronchioles, usually respiratory syncytial virus (RSV); more frequent in children, younger than 1 year old during winter months; can lead to atelectasis & respiratory failure

what happens during bronchiolitis

1. virus infects the bronchioles

2. causes swelling & mucus buildup 

3. narrow airways = harder to breathe

4. can lead to atelectasis (collapsed alveoli) 

5. if severe, can cause respiratory failure 

manifestations of bronchiolitis 

nasal drainage/congestion, cough, wheezing, rapid & shallow respirations, chest retractions, dyspnea, fever, tachycardia, malaise

difference between acute bronchitis & bronchiolitis

acute bronchitis: inflammation of the tracheobronchial tree or large bronchi

bronchiolitis: acute inflammation of the bronchioles 

• can lead to atelectasis & respiratory failure if not treated

• RSV is main cause 

pneumonia (lower)

inflammation damages bronchial & alveolar membranes

• some microbes release toxins that worsen tissue damage

• aspiration of oral secretions → most common cause

how is pneumonia spread

by inhaling droplets (cough, sneeze, talk), contaminated equipment (like respiratory devices) can spread germs, endotracheal tubes may carry bacteria into lungs 

most common cause of pneumonia

streptococcus pneumoniae, most deadly

what is the most common viral cause of community-acquired pneumonia?

influenza

what is the #1 cause of pneumonia

aspiration of oropharyngeal secretions (secretions are loaded with bacteria) 

manifestations of pneumonia

productive or nonproductive cough, fatigue, pleuritic pain, dyspnea, fever, chills, crackles or rales, pleural rub, tachypnea, mental status changes in elderly 

viral pneumonia 

usually mild, can lead to secondary bacterial pneumonia (nonproductive with low grade fever)

bacterial pneumonia

more common than viral, most often due to streptococcus pneumoniae (productive with higher fever) 

aspiration pneumonia

from aspirated fluid entering the lungs

causes: impaired gag reflex, improper lower esophageal sphincter closure, inappropriate gastric tube placement 

lobar pneumonia 

confined to a single lobe (described based on the affected lobe)

bronchopneumonia

most frequent type, a patchy pneumonia across several lobes

insteristial (atypical) pneumonia

occurs in the areas between the alveoli, routinely caused by viruses or by uncommon bacteria 

nosocomial pneumonia

develops more than 48 hours after a hospital admission

community-acquired pneumonia

acquired outside the hospital or healthcare setting

ventilator-associated pneumonia

occurs in patients that have been on mechanical ventilation for more than 48 hours

how to prevent pneumonia

hand washing, avoiding crowds, vaccinations, turning, coughing, deep breathing, smoking cessation

complications of pneumonia 

septicemia, pulmonary edema, lung abscess, acute respiratory distress syndrome 

tuberculosis (lower)

caused by mycobacterium tuberculosis, mostly affects the lungs but can spread to other organs, drug-resistant strains more common in the immunocompromised 

how is tuberculosis spread

by airborne droplets (coughing, sneezing, talking); airborne precautions

what happens in tuberculosis

• macrophages try to destroy the TB bacteria → causes inflammation

• some bacteria travel to lymph nodes → triggers type IV hypersensitivity (delayed immune response, shows symptoms after 2nd exposure) 

• granulomas (immune cells surround bacteria to “wall it off”) and tubercles form 

what is caseous necrosis 

cheese-like dead tissue inside granulomas 

ghon complex

calcified lesion seen on chest x-ray (tubercle & infected lymph node)

key note for tuberculosis

bacilli can remain dormant = inactive “asleep” in the body without causing symptoms

• person may feel fine but will test positive for TB
• secondary infection occurs during reactivation of dormant bacilli 

manifestations of tuberculosis 

productive cough, hemoptysis, night sweats, fever, chills, unexplained weight loss, anorexia 

how to prevent tuberculosis

vaccination, respiratory precautions, adequate ventilation, appropriate isolation

asthma

chronic condition with intermittent, reversible airway obstruction

• triggered by infections, smoke, allergens, cold air, stress, etc 

what are causes of asthma

airway inflammation, bronchoconstriction (tightened airway muscles), bronchospasm (sudden airway tightening), bronchial edema (swelling), mucus overproduction 

extrinsic asthma (allergic) 

starts in childhood/adolesence

• caused by igE response to allergens

• mast cells release chemicals → inflammation & mucus

triggers: pollen, dust, food, meds 

intrinsic asthma (non-allergic) 

starts after age 35

• not caused by allergens

triggers: infections, air pollution, stress, cold air, exercise, smoke 

nocturnal asthma

usually occurs between 3am-7am

• may be related to circadian rhythms- at night, cortisol & epinephrine levels decrease, while histamine levels increase, leading to bronchoconstriction

exercise-induced asthma

usually occurs 10-15 minutes after activity

• symptoms can linger for an hour

• may be a compensatory mechanism to warm & moisten the airways

• followed by a refractory period that begins within 30 mins and can last 90 mins 

occupational asthma

caused by a reaction to substances at work

• symptoms develop over time, worsening with each exposure & improving when away from work 

drug-induced asthma

potentially fatal attack up to 12 hours post ingestion

• frequently caused by aspirin- prevents the conversion of prostaglandins, which stimulate leukotriene release, a powerful bronchoconstrictor 

stage 1 of asthma 

peaks within 15-30 minutes, happens fast

• caused by bronchospasm

• often starts with coughing

• inflammatory mediators responsible: leukotrienes, histamine & some interleukins 

stage 2 of asthma

peaks within 6 hours of symptom onset, slower due to airway swelling & mucus buildup

• alveolar hyperinflation causes airway trapping

manifestations of asthma

wheezing, shortness of breath, dyspnea, chest tightness, cough, tachypnea, anxiety

status asthmaticus

a severe, life-threatening asthma attack

→ lasts a long time & doesn’t respond to usual meds (like inhalers)

status asthmaticus can lead to…

1. respiratory alkalosis (early stage-breathing too fast/hyperventilation, low CO2)

2. respiratory failure (late stage, can’t breathe enough) 

chronic obstructive pulmonary disease (COPD)

chronic, irreversible lung disease

• causes progressive airway obstruction & tissue damage

• includes chronic bronchitis, emphysema or both 

what are complications of chronic obstructive pulmonary disease (COPD)

• can lead to severe hypoxia (low O2) and hypercapnia (high CO2)

• may result in respiratory failure 

• can cause cor pulmonale (right-sided heart failure from lung disease) 

what are the causes of chronic obstructive pulmonary disease (COPD)

smoking (most common), pollution, chemical irritants, genetic mutations (ex. alpha-1 antitrypsin deficiency)

*often gets unnoticed early- symptoms can be masked by smoking 

emhysema

pathologic diagnosis: permanent enlargement & destruction of airspaces distal to the terminal bronchiole

what happens in emphysema

alveolar walls destroyed→ large, overinflated air sacs (hyperinflation)

elastic recoil lost → hard to push air out → air trapping

lungs become hyperinflated

what are the causes of emphysema

smoking, genetic predisposition (alpha-1 antitrypsin deficiency), enzyme deficiency prevents normal lung repair 

manifestations of emphysema 

dyspnea upon exertion, diminished breath sounds, wheezing, chest tightness, tachypnea, hypoxia, hypercapnia, increased anterior-posterior thoracic diameter (from 1:2 to 1:1); barrel chest, activity intolerance, anorexia, malaise, older & thin

chronic bronchitis

clinical diagnosis, daily productive cough for 3 months or more in at least 2 consecutive years; characterized by inflammation of the bronchi, a productive cough & excessive mucus production/secretions 

what can chronic bronchitis lead to 

frequent respiratory infections & respiratory failure 

manifestations of chronic bronchitis

hypoventilation, hypoxemia, cyanosis, hypercapnia, polycythemia, dyspnea at rest, wheezing, edema, weight gain, malaise, chest pain, fever, clubbing of the fingers, elevated hemoglobin, peripheral edema 

cystic fibrosis

life-threatening genetic disorder that affects lungs & digestive system

thick, sticky mucus blocks airways & ducts 

what are the causes of cystic fibrosis

autosomal recessive gene mutation (chromosome 7), defective chloride transport = sticky secretions (mucus, sweat, saliva, digestive fluids) 

what are the complications of cystic fibrosis

atelectasis, repeated lung infections, cor pulmonale, respiratory failure, malabsorption, malnutrition, electrolyte imbalances, infertility/sterility

manifestations of cystic fibrosis

meconium ileus (in newborns), salty skin, steatorrhea (fatty stools), fat soluable vitamin deficiency, chronic cough, hypoxia, fatigue, activity intolerance, audible rhonchi, delayed growth & development 

lung cancer

2nd most common cancer but #1 deadliest in men & women

• can be a primary tumor (starts in lungs) or secondary (spread from elsewhere)

• smoking = biggest risk factor (including second-hand smoke)

small cell carcinoma (oat cell)

type of lung cancer; almost only in heavy smokers, less common but very aggressive

non-small cell carcinoma

most common type of lung cancer; includes squamous cell carcinoma, adenocarcinoma, bronchoalveolar carcinoma; very aggressive 

complications of lung cancer 

airway obstruction, lung tissue inflammation, fluid accumulation, and paraneoplastic syndrome (immune system rxn)

manifestations of lung cancer

persistent cough or change in usual cough, dyspnea, hemoptysis frequent respiratory infections, chest pain, hoarseness, weight loss, anemia, fatigue

what is polycythemia

a blood disorder where the body makes too many red blood cells (RBCs) 

pleural effusion

excess fluid in the pleural cavity (space between lungs & chest wall)

pleural effusion: transudate

fluid from pressure imbalance (ex. heart failure)

pleural effusion: exudate

fluid due to inflammation or infection