Respiratory Flashcards
what is the epithelial lining of the larynx, trachea, bronchi, and bronchioles
pseudostratified columnar epithelium (true vocal folds - stratified squamous epithelium)
what are the secretions from the bronchial mucosa
neuroendocrine cells that secrete serotonin (vasodilation), gastrin (HCL acid secretion), and calcitonin (reduces plasma Ca++)
what are the characteristics of type 1 and 2 pneumocytes
type 1 - flat, thin, large surface area, facilitates gas exchange, vulnerable to injury type 2 - cuboidal, produce surfactant
how are particles deposited in the respiratory tract based on their size
large - trapped in nose medium - deposit on bronchi and bronchioles, moved by mucociliary action small - deposit on alveoli, removed by macrophages very small - behave as a gas and are breathed out
what are the characteristics of bronchial atresia
- involves apico-posterior BPS of L upper lobe - results in a compensatory expansion of the other lobes, eventually leading to emphysema - bronchial mucus accumulation appears as a mass on x-rays
what are the characteristics of hypoplasia on the lung (agenesis)
- lung is smaller than normal due to fever or small acini - 90% cases present with other congenital anomalies - seen in trisomies 13,18,21 - another cause is oligohydroamnios (inadequate amniotic fluid)
what are the characteristics of bronchogenic cysts
- fluid filled mass lined by respiratory epithelium - usually common, asymptomatic, and only affect one lobe - mostly seen in ages 0-2, and may compress a major airway, causing respiratory distress - secondary infection may cause hemorrhage and perforation
what are the classifications of bronchogenic cysts
type 1 - large cysts, ciliated epithelium, 50% of cases type 2 - multiple small and relatively uniform cysts, ciliated epithelium, 40% of cases type 3 - solid and bulky lesions causing mediastinal shift, cuboidal epithelium, 10% of cases
what is bronchopulmonary sequestration
- pulmonary tissue is situated outside the lung parenchyma - blood supply is directly from aorta or via its branches - often associated with diaphragmatic hernias/defects, cardiopulmonary anomalies, or abnormal communication with foregut
what are the characteristics of an intralobar sequestration
- within lung substance (base)
- usually in older children
- associated with recurrent infection
- 90% cases on L side
- more common in males (4:1)
what are the characteristics of extralobar sequestration
- external to lung, anyhwere in the thorax/mediastinum
- pyramidal/round masses covered by pleura
- more common in males
what are the macro- and microscopic presentation of a bronchopulmonary sequestration
- macroscopic: fibrosis and honeycomb cystic changes resulting from recurrent infection
- microscopic: cystic spaces lined by columnar or cuboidal epithelium, lumen contains foamy macrophages and esoinophilic material
what are the clinical presentations of a patient with a bronchopulmonary sequestration
- cough, sputum, recurrent infection
- dyspnea and cyanosis in 90% of extralobar cases, esp: children
- increased vascular markings on x-ray
what is neonatal respiratory distress syndrome
- aka hyaline membrane disease
- most common cause of respiratory failure in newborns
- due to surfactant deficiency or immature lung development
- indicator of fetal pulmonary maturity is a lecithin:sphingomyelin ratio of 2:1 in amniotic fluid
what are some indicators of disease you might find on inspection of a patient’s breathing
- pursed lips breathing: slow air expiration associated with chronic obstructive pulmonary disease
- kussmal breathing: deep gasping breath associated with severe diabetic acidosis
- barrel chested: increased A-P chest diameter due to increased functional residual capacity associated with chronic bronchitis and emphysema
- pink puffers: noncyanotic, severe emphysema
- blue bloaters: cyanotic, chronic bronchitis
what are pleural rubs
- scratching sounds due to roughened pleura
- can be amplified by compressing the stethoscope further against the lung field and asking the patient to take deeper breaths
what are rhonchi
- long continuous sounds due to obstructed airways
- diffuse sounds are associated with generalized airway obstruction (ex: COPD, asthma)
- localized sounds are associated with specific airway obstruction (ex: tumor, mucus)
what are the classifications of rhonchi
- stridor: loud, audible inspiratory
- sibilant: high-pitched
- sonorous: low-pitched
- crackle: adventitious when heard at end of inspiration or start of expiration
what is acute respiratory distress syndrome (ARDS)
- a group of disorders with endo- or epithelial injuries characterized by rapid onset of severe respiratory insufficiency
- idiopathic form: diffuse alveolar damage (DAD)
- neonatal form: newborn respiratory distress syndrome (NRDS)
what are the causes of ARDS
- infection
- physical injury
- inhale irritants
- drugs
- hematological conditions
what is the pathophysiology of ARDS
- injury results in pro-inflammatory cytokine release (IL-1, IL-8, TNF)
- neutrophils adhere to pulmonary capillaries and release factors that contribute to the local damage
- result: fluid accumulation in airspaces, surfactant inactivation, hyaline membrane formation
what is hyaline membrane formation
eosinophilic glassy membranes consisting of precipitated plasma proteins as well as cytoplasmic and nuclear debris from sloughed epithelial cells
what are the clinical presentations of a patient with ARDS
- tachypnea, dyspnea, cyanosis, hypoexemia
- respiratory acidiosis (blood gas)
- diffuse bilateral infiltrate on x-rays
what are the pathological mechanisms of pulmonary edema
- increased hydrostatic pressure: caused by L-sided heart failure, mitral stenosis, volume overload
- decreased oncotic pressure: caused by hypoalbuminuria due to nephrotic syndrome, liver disease, protein-losing enteropathies
- microvascular injury: caused by infection, inhaled gases, aspiration, drugs, radation
what are the symptoms of pulmonary edema
- history of coughing up blood (hemoptysis)
- difficulty breathing when lying down (orthopnea)
- wheezing with breathing
- inability to speak in full sentences due to shortness of breath
- crackles in the lungs
- abnormal heart sounds
- increased HR and RR
- pallor or cyanosis
what is localized emphysema
- involves destruction of alveoli
- occurs in only one or just a few locations
what is compensatory emphysema (hyperinflation)
emphysema that follows surgical removal of a diseased lung or lobe
what are the different types of emphysema based on anatomical distribution
- centriacinar: upper lobes (smokers)
- panacinar: loss of acinus (a-1-antitrypsin deficiency)
- paraseptal: involves ducts (underlies spontaneous pneumothorax in young adults)
- irregular: involves bullae/blebs (most common form)
what is interstitial emphysema
entrance of air into the connective tissue stroma of the lung, mediastinum, or subcutaneous tissue
what are the signs of a patient with emphysema
- destruction of septal walls
- bronchiole deformations
- compression of vasculature
what are the characteristics of chronic bronchitis
- definition: excessive cough and sputum production on most days for at least 3 months per year for at least 2 years
- primary factors: chronic irritants, smoking
- more common in urban areas with substantial air pollution
- interferes with ciliary action and inhibits ability of leukocytes to clear bacteria
what are the clinical presentations of a patient with chronic bronchitis
- mucopurulent secretion and cast
- clustering of macrophages
- infiltration of leukocytes
- increase in goblet cells
- bronchiolar wall fibrosis
- bronchiolitis: small airway disease
what is the difference between obstruction and restriction regarding lung pathology
obstruction: airway obstruction results in decreased forced expiratory volume and presents with wheezing
restriction: reduced compliance due to infiltrative lesions results in decreased total lung capacity and presents with dyspnea and cyanosis
what are the common obstructive pulmonary diseases
- asthma
- COPD
- emphysema
- chronic bronchitis
- bronchiectasis
- bronchiolitis obliterans
what are the common restrictive pulmonary diseases
- intrinsic: sarcoidosis, pneumocomiosis, tuberculosis
- extrinsic: kyphoscoliosis, obesity
- neuromuscular: diaphragmatic paralysis, myasthenia gravis, muscular dystrophy
CASE: 69-yr-old male smoker presents with shortness of breath following several bouts of lower respiratory tract infection over the last two years. Dx?
chronic bronchitis (large airway obstruction) and emphysema (small airway obstruction)
CASE: 69-yr-old male smoker…
- pO2 = 73 mmHg (normal = 80-100)
- pCO2 = 50 (normal = 35-45)
- pH = 7.32 (normal = 7.3-7.5)
Why are value increased?
increased pCO2 and pH due to difficulty of exhalation of CO2 at a sufficient rate
CASE: 69-yr-old male smoker… Why would giving this patient O2 be dangerous for him?
- probably has had chronically elevated CO2 levels, which is the primary stimulus for breathing rate in the brainstem
- patients CO2 receptors have been elevated for so long that they are probably desensitized, thus his primary stimulus is probably his low O2 levels
- if given 100% O2, levels would rise too much and remove stimulus, thus he could go into respiratory failure
CASE: 69-yr-old male smoker…. Why is he susceptible to lower respiratory tract infection?
- chronic irritation of bronchial epithelium by cigarette smoke causes inflammation that results in excessive mucus production
- mucus pools in the bronchial tree causing the “smokers cough” and providing medium for bacteria
what are the clinical presentations of a patient with bronchial asthma
- macroscopic: lungs distended with air, airways filled with mucus plugs
- microscopic: Charcot-Leyden crystals, Curschmann spirals (cast of mucoid exudate)
what are the 4 classic histological findings in bronchial asthma? what is the 5th finding is etiology is allergy
- inflammation
- bronchial narrowing
- increased mucus
- smooth mm. hyperplasia
* - eosinophils
what are the characteristics of atelectasis
- aka collapsed lung
- incomplete expansion of neonatal lung or collapse or previously inflated lung
- obstructive: airway obstruction, mediastinum shifts to affected lung
- compressive: pleural cavity filled by fluid exudate, blood, air, or tumor, mediastinum shifts away from affected lung
- contractive: fibrotic changes in lung or pleura
what are the characterisitics of bronchiectasis
- consequence of another disease process that destroys airways
- permanent dilation and destruction of bronchioles
what are the characteristics of Kartagener syndrome
- immotile cilia syndrome, aka ciliary dyskeneis
- triad: dextrocardia, bronchiectasis, sinusitis
- also sterile b/c of immobility of vas deferens/fallopian tube
what are the types of bronchiectasis
- saccular: involves proximal bronchial branches, bronchi, and sacs are dialted
- varicose: bronchi resemble varicose veins on imaging
what are th clincal presentations of patients with bronchiectasis
- severe presistent cough with sputum (bloody)
- dysnpnea, orthopnea, hemoptysis
- episodic fever
CASE: 28-yr-old female with cystic fibrosis presents with shortness of breath with abundant foul-smelling sputum. Dx?
bronchiectasis
the following characteristics of sputum present with which condition
- clear, white: viral respiratory tract infection
- white, yellow: acute bronchitis, acute pneumonia, asthma (thick)
- yellow, green: chronic bronchitis, chronic pneumonia
- frothy white, pink: pulmonary edema
- reddish brown: penumococcal pneumonia, tuberculosis, lung cancer
- brown, black: coal worker’s penumoconiosis
what are the stages of acute inflammation
- early: vasodilation, congestion
- exudation: polymorphs, proteins
- late: fibrin deposition, macrophage cleaning
- repair: replacement with normal tissue if minimal damage, fibrosis if extensive damage
what are the stages of chronic inflammation
- persistance of irritant
- activation of macrophages
- activation of fibroblasts and vascular endothelial cells
- repair via fibrosis
- loss of function with longer duration
what are the characteristics of bronchopneumonia
- scattered foci in same or several lobes
- typically of terminally ill patients
- due to strep. pneumonia, h. influenza, or staph. aureus
what are the characteristics of lobar pneumonia
- consolidation of entire lobe
- due mostly to strep. penumoniae or klebsiella
- associated with alcoholism, diabetes, chronic lung diseases
what are the characteristics of segmental pneumonia
- common feature is idiopathic fibrosis
- due mostly to strep. pneumoniae
what is the cause of interstitial pneumonia
due mostly to h. influenza or mycoplasma pneumoniae
compare community-acquired, nosocomial, and opportunistic pneumonia
community - acquired: arises outside hospital in patient with no primary disorder of the immune system
nosocomial: develops in hospital
opportunisitc: involves patients with deficient immunity, caused by p. carinii, aspergillus, or cytomegalovirus
what are the causes of bacterial pneumonia
- most common: strep. pneumonia
- also: h. influenza, s. aureus, k. pneumoniae, m. catarrhalis, p. aeruginosa, l. pneumophila (aquatic organism associated with contaminated water)
what are the causes of viral/mycoplasmal pneumonia
- influenza A and B
- adenovirus and rhinovirus
- measles and varicella
- severe acute respiratory syndrome (SARS)
what are the stages of acute lobar pneumonia
- congestion: vascular enlargement, lungs become heavy and boggy, fluid exudate with few neutrophils, numerous bacteria present
- red hepatization: massive exudation with red cells and neutrophils
- grey hepatization: appearance of macrophages, compression of alveolar capillaries
- resolution: exudate coughed up or pushed up by cilia, the rest is phagocytosed
CASE: 64-yr-old male presents with fever, chills, shortness of breath, pleuritic chest pain, crackles and decreased breath sounds, tachypnea, flaring nares, rusty-yellow sputum. Cause of infection?
strep. pneumoniae
CASE: 62-yr-old male with small cell carcinoma begins chemotherapy. During treatment, he presents with 103 fever, productive cough with foul-smelling sputum, increased respirations, leukocytosis, and x-ray shows air/fluid level distal to tumor. Dx?
pulmonary abscess
what are the causes of pulmonary hypertension
- primary: idiopathic
- secondary (more common): COPD, chronic interstitial pulmonary disorders, CHF, recurrent pulmonary emboli
what is the pathogenesis of pneumonconiosis
- dust/irritant inhalation
- impairment of mucociliary apparatus
- reactivity of the particles
- oxidant and protease release causes inflammation
- macrophage and neutrophil recruitment and activation
- fibroblast stimulation
- granuloma formation
what are the characteristics of silicosis
- inhalation of silicon dioxide (quartz, silica)
- early phase: black nodules
- late phase: hard collagenous scars
- egg-shell calcification
what are the types of asbestosis
- chrysotile: caused by a white curly asbestos fiber that contain magnesium
- amosite: brown/gray straight fibers that contain magnesium and iron
- crocidolite (riebeckite): blue straight fibers that contain magnesium, iron, and sodium
what is the pathophysiology of asbestosis
- can lead to diffuse pulmonary interstitial fibrosis
- presence of “asbestos bodies”
CASE: 60-yr-old male presents with dyspnea and nonproductive cough. Non-smoker but worked at ship-builder with known asbestos exposure. What is this patient predisposed to?
malignant mesothelioma of the pleura
what are the charactersistics of sarcoidosis
- systemic dz of unknown cause characterized by noncaseating granumolas
- more common in females and africans
- more commonly affecting lungs and lymph nodes
- presence of asteroid bodies (star shaped) or Schaumann bodies (lamellar structures composed of calcium and proteins)
CASE: 25-yr-old African-American non-smoking female presents with fatigue, dyspnea, nonproductive cough, and chest pain. Lab work shows bilateral hilar lymphadenopathy and hypercalcemia. Dx?
sarcoidosis
what are the characteristics of primary tuberculosis
- caused by m. tuberculosis via droplet inhalation
- starts as Gohn lesion which becomes fibrotic
- if spread to lymphatics, called Ghon complex
what are the characteristics of secondary tuberculosis
- reactivation of primary TB or new infection in previously sensitized host
- typical features: apical/upper parts of lung affected, caseous granuloma, local or systemic/miliary
what are the features of tuberculous/case ating granuloma
- round outlines
- central caseous necrosis that appears irregular, amorphous, pink
- macrophages -> epitheloid cells
- fibroblasts and Langhans giant cells
