pulmonary pathophysiology Flashcards
week 4 (55 cards)
pathophysiological differences
obstructive
restrictive
obstructive = impaired FLOW of air
Restrictive = impaired VOLUME of air
TLC
total lung capacity
FVC
force vital capacity
FEV1
force expiratory volume in 1 second
pulmonary function tests (PFTs)
airway integrity is assessed by analyzing
lung volume, diffusion capacity
pulmonary function tests (PFTs)
body plethysomography
airtight chamber; pressure at the airway (mouth piece) + chamber is measured
- used commonlly in research
barriers–> claustrophobia
pulmonary function tests (PFTs)
incentive spirometer
very common and easy to perform bedside
- used after surgery to encourage deep breathing
nursing or respirtatory therapists work with these
Diffusion capacity of lungs for carbon monoxide (DLCO)
ease of transfer for CO moleucles from alveolar gas to Hgb of RBCs in the pulonary circuit
volume, amount of time and how much pressure it is having to overcome
normal DLCO
abdnormal DLCO
normal: >75% of predicted (25-30 mL/min/mmHg)
abnormal: decreased Hgb; increased thickness of alevolear capillary membrane; decreased surface area available for diffusion
mild = <75%-60%
moderate= 60-40%
severe <40%
restrictive lung disease (RLD)
lung expansion is restricted, adn therefore the volume of air or gas moving in and out of the lungs is decreased
- chest wall or lung compliance, or both is decreased
- takes a greater transpulmonary pressure to expand the lung to a given volume in a person with decreased lung compliance
this means the patient has to work harder just to move air into the lungs
restrictive lung dysfunction: impaired ventilation –> decreases volume and capacities resulting in
- decreased inspiratory reserve volume
- decreased expiratory reserve volume
- decreased total lung capacity
- decreased diffusion capcity of lungs for carbon monoxide (DLCO)
what are the 3 charcteristsics of RLD you would assess
- lung volume
- lung compliance
- work of breathing
RLD - lung volume
- decreased TLC
- FEV1/FVC ratio is preserved
capacity is lower but still able to breath out 1/2 of inspired air at 1 second
RLD- lung compliance
RLD - work of breathing
3 symptoms of RLD
dyspnea
- typically manifests with exercise, but as RLD progresses dyspnea at rest may also be experienced
irritating,dry, and non productive cough
wasted, emaciated appearance these patients present ast he disease progresses
- work of breathing increased as muc has 12fold over normal, these individuals are using caloric requirements similar to those necessary for running a marathon 24 hrs a day
- breating is hrad work and eating makes breathing mroe difficult
- cachectic- continual weight loss cycle
supportive measures for treatment of restrictive lung dysfunction
- supplemental O2
- antibiotic therapy for secondary infection
- interventions to promote adequate ventilation
- interventions to prevent accumulation of secretions
- good nutritional support
hypoxemic state
seen in RLD
PaO2 < 80 mmHg
- lung scarring
- capillary fibrosis –> pHTN –> R CHF
- widened interstitial spaces –> inability to support alveoli
- collapsed alveoli (end-inspiration)
what is normal intrapulmonary shunting
shunting = cutting off blood flow from one area and moving it to another. think of frost bite
normal = anatomic shunting
- blood flows from R to L side of heart, bypassing capillary exchange
what is abnormal intrapulmonary shunting
abnormal= capillary shunting
- blood flows from R to L side of heart by way of pulmonary capillaries
intrapulmonary shunting overloads the pulmonary system and what occurs
side18
pulmonary hypertension (pHTN)
resting PAP >25 mmHg; exertional PAP >30 mmHg
what are the groups of pHTN per WHO
Group 1: pulm. arteries are narrow/thick/stiff –> R CHF
Group 2: pulm. arteries are not as narrowed; back up of blood –> L CHF
Group 3: due to an onstructive or restrictive pattern; arteries constrict –> shunting to more ventilated alveoli –>pHTN
Group 4 chronic thromboembolic pHTN; undissolved clot –> scar tissue w/in pulmonary blood vessels –> decerase bld flow –> increase work on R heart
who severity classification
class I
Class II
Class III
Class IV