Pulmonary - CLS and HB Flashcards
Spirometry is helpful in distinguishing between what three states?
normal, obstructive lung dz, restrictive lung dz
What are four variables in lung capacity?
Height (taller =more), race (caucasian > asian; least important), age, gender
The _____ is the amount of air which can be forcibly exhaled from the lungs after taking maximal inhalation
FVC
The _____ is the maximal amount of air you can forcefully exhale in 1 second and is used for marker for degree of obstruction
FEV1
What are four obstructive lung conditions?
asthma, COPD, bronchiestasis, cystic fibrosis
What are five restrictive lung conditions?
pulmonary fibrosis, scoliosis, diaphragmatic disorder (happens in pregnancy), neuromuscular disease, obesity
An FEV1/FVC value of <70% would indicate a?
obstruction
An FEV1/FVC value of 80% or above would indicate?
nothing, this is normal
An FVC value below 80% would indicate what?
restrictive
A patient presents with an FEV1/FVC value of 85% and a FVC value of 60%. Which of the following would NOT be a likely cause of breathing issues?
a) scoliosis
b) pulmonary fibrosis
c) neuromuscular disease
d) bronchiestasis
e) obesity
D - bronchiestasis is OBSTRUCTIVE. These values point to a restrictive disease.
An obstructive pattern would yield what changes in the following: a) FEV1/FVC? b) FEV1? c) FVC?
FEV1/FVC less than 70%, FEV1 <80%, FVC normal or reduced
Describe the FEV1 levels that would indicate a) mild, b) moderate, c) severe, and d) very severe obstruction
a) mild is >80%, b) 50-80%, c) 30-50%, d) <30%
A restrictive pattern would yield what changes in the following: a) FEV1/FVC, b) FEV1, c) FVC
a) FEV1/FVC normal or greater than 70%, b) FEV1 normal, c) FVC <80%
What parameters would indicate a bronchodilator response in a spirometry test?
After bronchodilator, 12% increase + 200 mL improvement in either FEV1 or FVC
True/False: Lung capacities can be directly measured
FALSE, lung volumes can be directly measured. lung capacities are inferred from lung volumes.
________ is the volume of air during normal, resting breathing
Tidal volume
______ is the maximal amount of additional air that can be expired from the lungs after normal expiration
ERV (expiratory reserve volume)
___ is the maximal amount of additional air that can be INSPIRED from the lungs after normal inspiration
IRV (inspiratory reserve volume)
___ is the amount of air left in the lungs after maximal exhalation
RV (residual volume)
_______ is the maximum amount of air that can fill the lungs
total lung capacity
________ is the maximum amount of air exhaled after a mass inhalation
vital capacity
________ is the amount of air in the lungs at the end of passive expiration
functional residual capacity
_______ is the amount of air that can be inhaled after end of normal expiration
inspiratory capacity
Residual volume cannot be measured by spirometry. What are the three available methods to measure residual volume?
body plethysmography, helium dilution, nitrogen washout
Describe body plethysmography testing.
Patient sits in chamber with nose clips shutting nostrils. Breathes/pants against a mouthpiece both open and closed. Mouth pressure is measured - mouth P = alveolar P
Describe the O2 movement from alveoli to capillaries
alveolus, epithelial cells, basement membrane, endothelial cells, capillary
How is diffusion capacity tested?
Pt takes in breath and holds breath in maximal inspiration for 10 seconds, then exhales. 1st liter of exhaled gas discarded as dead space. 2nd liter of exhaled gas is analyzed for CO concentration
________ is the volume that diffuses across the capillary membrane
diffusion capacity (DLCO)
What four diseases may be indicated by a decreased diffusion capacity (DLCO)?
COPD, interstitial lung dz, pulmonary embolism, anemia
Describe how to interpret PFTs (stepwise)
First, look at FEV1/FVC ratio to determine if obstructive. If obstructive, look at FEV1 to gauge severity. If normal, then look at TLC and DLCO to determine if restrictive.
______ is the number one avoidable cause of death
smoking
Up to _____ of long-term smokers will die of a smoking caused disease
50%
Out of the 7000+ chemicals in tobacco smoke, how many are known to be harmful and how many cause cancer?
250, 69
What percent of smokers want to quit and what percent try to quiet each year
70, 44
____ of US adults use tobacco
20.8%
In which groups is prevalence of smoking high?
low SES, low education, some minority popns, those with psych disorders
A typical puff of cigarette smoke has ___ CO by volume
5%
Why can smoking lead to headache, fatigue, dizziness, and breathlessness, in addition to increased risk of blood clots?
Hemoglobin preferentially binds CO over O2 so less Hgb is available to transport O2.
What is the half-life of carboxyhemoglobin (%COHb) and how long should one wait after last cigarette to use CO monitor?
4-6 hours, 10 minutes
What are the stages of change?
Precontemplation, contemplation, preparation, action, maintenance, lapse/relapse
Treatment options for smoking include medication, aversion therapy, and supportive behavioral therapy. What are four medications used and how do they work?
Nicotine replacement [reduce cravings and withdrawal], Wellbutrin [same], Chantix [blocks nicotine receptors so smoking less rewarding]
What is the most effective option for quitting smoking?
Medication and intense counseling (8+ sessions)
What is the most common cause of hypoxemia?
V/Q mismatch
If a patient is acidotic, has a low PO2 and a high PCO2, but has a normal A-a gradient, what is the cause of their hypoxemia?
not ventilating enough
Why does pulmonary fibrosis lead to diffusion impairment?
Collagen and fibrous tissue in alveolar walls build up so the thickness between capillaries and alveoli is increased impairing diffusion
How does emphysema cause V/Q mismatch?
capillaries and alveoli are destroyed so lungs are being ventilated but not perfused
Only _____ results in high A-a gradient on 100% oxygen
shunting
