Mod 3 - pulm pathos

obstructive lung disease

↑ resistance to expiration

• difficulty getting air out

• air trapping → hyperinflated alveoli = hypoventilation

obstructive PFTs

TLC → ↑

RV → ↑

FEV1 → ↓

FEV1/FVC → ↓

restrictive lung disease

↓ compliance for inspiration

• difficulty getting air in

• results in alveolar hypoventilation

restrictive PFTs

TLC → ↓

RV → ↓

FEV1 → ↓

FEV1/FVC → ↑

“COPD”

• chronic bronchitis

• emphysema

• asthma

restrictive lung dysfunction

caused by pathos that limit expansion of…

• lungs or

• chest wall/ ribcage

common INTRApulmonary causes of restrictive lung dysfunction

• pneumonia

• pulmonary fibrosis

• pneumothorax

• pulmonary edema

• atelectasis

common EXTRApulmonary causes of restrictive lung dysfunction

• CVA

• burn

• rib fx

• neuromuscular disease 

COPD etiology

long-term exposure to inhaled irritants → repeated inflammation

COPD dx

spirometry is gold standard

• FEV1/FVC < 0.7 → obstructive

GOLD stages

all have FEV1/FVC <0.7

FEV1

• I → > 80%

• II → 50-80%

• III → 30-50%

• IV → < 30%

COPD muscle changes

respiratory & skeletal

• diaphragm doming ↓

• diaphragm atrophies

• ↓ mitochondrial density

• ↓ capillary density

• ↑ dependence on anaerobic Type II fibers

skeletal muscle

• fat infiltration

chronic bronchitis pathophys

• inflamed bronchioles → narrow airways

• excess mucus secretion from goblet cells

chronic bronchitis presentation

air trapping & secretions

• course crackles

• low-pitched wheezes

• productive cough

  • eventually gets weak as muscles of forced expiration fatigue

• barrel-chested

  • + all the other things that some along with that

• SOB w/ exertion (& eventually @ rest)

emphysema pathophys

chronic inflammation of alveoli → alveolar destruction → poor gas exchange

they become stretched w/ decreased compliance 

asthma pathophys

bronchospasms in highly reactive airways

excess histamine response → lots of swelling & secretions

asthma at baseline, during, after an attack

baseline

• pretty normal

• might have ↓ aerobic capacity

during attack

• lots of air trapping

• accessory muscle use

• high-pitched wheezing

after attack

• hugeeee dump of secretions from excess histamine response

• coarse crackles 

• productive cough

CF pathophys

• genetic autosomal recessive mutation of CFTR

  • impacts epithelial lining (GI, liver, lungs)

• impaired lubrication & absorption → dehydrated airway w/ very thick secretions

CF presentation

• silver metal in productive coughing

• course crackles

• low-pitched wheezes

• ↓ breath sounds over air trapping

bronchiectasis pathophys

chronic inflammation → permanent enlargement of bronchioles → eventual alveolar destruction

bronchiectasis presentation

• most productive of all the coughs

  • secretions might be colorful

• very SOB

pneumonia pathophys

infected parenchyma (bacterial, viral, fungal)

pneumonia presentation

• coarse crackles

• low pitched wheezing

• bronchial sounds where the vesicular should be

bacterial

• higher fever

• isolated area of infection

viral

• lower fever

• diffuse infection

possible causes of atelectasis

from low tidal volume:

• post-op sedation

• pain

• CNS depression

• bed rest

could also be compression from…

• pneumothorax

• lesion

• pulmonary effusion

atelectasis pathophys

a separate patho ↓ ventilation → alveolar collapse 

• a sequelae, not a disease itself 

• large area of collapse presents like a consolidation

possible causes of pulmonary edema

• decompensated HF

  • LV struggles to push blood out → fluid backs up into alveoli → “congested” HF

• lots of noncardiogenic causes too

pulmonary edema presentation

• fluid pools where gravity pulls it

• fine crackles

  • alveoli popping open against fluid-filled neighbors

• irritated cough

pleural effusion pathophys

fluid in pleural space/cavity from…

• HF

• cancer

• autoimmune diseases

• post-surgical

pleural effusion presentation

• heart sounds are diminished or absent

• irritated cough

• TF & MP are different

  • over fluid buffer

    • TF → ↓

    • MP → dull

pneumothorax pathophys

air in pleural space from…

• open

  • foreign object penetration

• closed

  • internal rib fx

  • Marfans

  • fragile lung tissue w/ CF

** tension pneumothorax is a 911 medical emergency

pneumothorax presentation

• excursion ↓

  • may be absent if lung collapses

• absent lung sounds

  • bc air buffer around them

• no cough…they gasp

• TF & MP are different

  • over air buffer

    • TF → ↓

    • MP → hyper

pulmonary fibrosis, ARDS, sarcoidosis, asbestosis, etc. pathophys

causes of intrapulmonary restrictions to stretch

• poor compliance

• poor elasticity