Pulm exam 1: study questions and impt topics

Mechanical barriers to pulmonary drug delivery

Oropharyngeal impaction; large airway impaction; mucociliary clearance

Chemical barrier to pulmonary drug delivery

Drug degradation by proteolytic enzymes

Immunologic barrier to pulmonary drug delivery

Engulfment by macrophages

How pulmonary disease affects drug delivery

Airway narrowing and mucus plugging divert medication away from diseased areas

Upper airway particle retention occurs due to

Impaction

Conducting airway particle retention occurs due to

Sedimentation

Deep lung (acinus) particle retention occurs due to

Diffusion

Ideal particle size (MMAD) for lung deposition

1–5 microns

Three main inhaler breathing rates

MDI/SMI: slow and deep

DMI: fast and deep

Why breathing rate matters

It determines where particles deposit in the lungs

Which device uses a propellant

MDI

HFA

Which device relies on patient inspiratory force

DPI

Classes for rescue inhalers

SAMA and SABA

Classes for maintenance

LABA

LAMA

ICS

“ol”

SABA or LABA

“ium”

SAMA or LAMA

“rolate”

LAMA

“one” or “ide”

ICS

**rinse and spit

Main benefits of using a spacer

Reduces oropharyngeal deposition

improves lung delivery

helps coordination

reduces thrush risk

MDI only

TOP acronym stands for

Twist

Open

Push

Which devices require priming

MDIs and SMIs

Which devices require shaking

MDIs (except breath-actuated)

Typical nebulizer treatment time

10-15 minutes

Conducting zone and its components

TRANSPORT! (also warming and cleaning of air)

Upper airways: Extrathoracic structures (outside of chest) —> nose, pharynx, larynx

Lower airways: Trachea, Bronchi, Bronchioles

Respiratory zone:

GAS EXCHANGE

Alveoli: sac of air surrounded by lots of circulation

What is the purpose of our Nasal Turbinates? Why is the air that we breathe through our nose “cleaner” than the air that we breathe through our mouth?

to warm and filter air before it goes to esophagus and trachea, making it cleaner than air from mouth

Describe the functional purpose of the alveoli

The powerhouse of the lungs bc it’s the site of gas exchange

4 types of cells

Type 1 pneumocyte

very thin that lines alveoli

Type 2 pneumocyte:

secrete surfactant to keep alveoli open

Capillary endothelium:

very thin that lines blood vessels and functions in transport of respiratory gases, water, solutes

Alveolar macrophages:

defend against pathogens

What is primarily different about gas concentrations in our Pulmonary Arteries versus our Pulmonary Veins? What process occurs that leads to this change?

Pulmonary arteries:

-       Carries DEOX blood away from heart to lungs

-       Drop off CO2 waste from the body tissues

(exchange of gas in capillaries)

Pulmonary veins:

-       Carried OX blood to the heart from the lungs for distribution to body tissues

Muscles of breathing:

intercostal muscles between ribs and diaphragm which is the main breathing driver

At rest, the diaphragm is a floppy dome shape at the base of the lungs

Muscles of diaphragm and thoracic cavity during INHALATION

-       Diaphragm contracts (tightens) and moves downwards (phrenic nerve causes contraction) and the rubs contract upward and out

-       These increase amount of space in thoracis cavity, which enables lungs to expand

-       Boyles law: volume and pressure are inversely proportional

-       When volume increases, the pressure is low so air will flow from high pressure (outside) to inside of lungs

Define hypOventilation and a few example causes

Breathing is too slow (low respiratory rate under 12) and/or too shallow (low TV), reducing the removal of CO2—> BUILDUP of CO2 in arterial blood

Causes: medications (benzos/opioids), COPD, spinal cord injuries (ALS), brain injuries (stroke)

Define hypERventilation and a few example causes

Breathing too fast (r.r > 20) and/or too deep (increased TV), increasing removal of CO2 (less CO2 in blood) which is needed for proper acid/base balance in the blood

Causes: Anxiety, panic attacks, stress, bleeding, interstitial lung disease (ILD), pregnancy, high altitude

What does Hypercapnia mean?

Buildup of CO2 in arterial blood (hypOventilation)

What does Hypoxemia mean?

Reduction in O2 in the arterial blood (hypOventilation)

Tidal volume:

Amount of air that moves into and out of the lungs during normal breathing (500mL)

Inspiratory Reserve Volume:

Additional amount of additional air that can be inhaled after a normal inhalation

Expiratory Reserve Volume:

Amount of additional air that can be exhaled after a normal inhalation

Residual Volume:

Volume of air that remains in the lungs after maximum exhalation

Vital Capacity:

total amount of air exhaled after taking the deepest breath possible (IRV + TV + ERV)

Total lung capacity:

maximum amount of air the lungs can hold after maximal breath in (VC + RV)

Define Perfusion

Flow of blood: maintain adequate blood supply to alveoli to be able to carry blood to and from tissues`

Define Diffusion. What attributes of Fick’s Law make diffusion possible at the alveoli?

Movement of blood gases across alveolar epithelium and alveolar capillaries

-       Requires adequate ventilation and perfusion

-       Goal: transport O2 from alveoli to blood and transport CO2 from blood to alveoli

Fick’s law: diffusing capacity of a membrane is dependent on tissue thickness, surface area, solubility, and driving pressure gradient – ALVEOLI are great at it

Describe DLCO. What is this test used for? If a DLCO result is below “normal”, what does this mean for patients?

Diffusing capacity of the Lungs for Carbon Monoxide: patient inhales very small amount of CO into airways→ hold breath for 10s →breath out air sample collected for analysis →amount of CO exhaled air measured to calc DLCO

-       CO used bc high affinity for Hb (similar to O2) but not in alveolus and bloodstream

-       Low DLCO = reduced ability to get O2 to bloodstream

-       ILD

Define Interstitial Lung Disease (ILD). How might ILD impact DLCO?

Damaged/thickened alveolar sacs increase barrier between epithelium and capillary causing reduced diffusion abilities

Can decrease DLCO bc harder for has exchange to occur quickly

Define “Hidden Hypoxemia” and what implications that hidden hypoxemia might have on a patient’s treatment

Pulse Oximetry measures o2 sat of bloodox Hb absorbs red and infrared light differently than deox Hb

Hidden Hypoxemia: skin pigmentation and melanin can affect a pulse ox ability to accurately measure O2 sat → may overestimate the true ox sat in ppl with dark skin tones which leads to high rates of hidden hypoxia

Compare and contrast use of a Peak Flow Meter with Spirometry testing

Peak flow: asthma and self-monitor to compare values so provider can identify an “action point”

-       Force exhales blow out super hard 3x and record highest number

Spirometry: most common pulmonary function tests (PFTs)

-       Relies on: lung volumes and flow of air over time to provide results

What are three key values are obtained from Spirometry Testing that we discussed in lecture?

-       Forced vital capacity (FVC): max volume of air that can be exhaled following maximal inspiration when patient is told to exhale with max speed and effort

-       Forced expiratory volume in 1 second (FEV1): volume of air forcibly exhaled from the lungs within 1 second following max inspiration

-       FEV1/FVC: ratio of volume of air in 1^st second vs total volume forcibly exhaled

• % was in 1^st second

Asthma prevalence trend (US):

Increased since 1990s (~50% increase per decade)

Major asthma risk factors:

Genetics, prematurity/low birth weight, obesity, environmental exposures, allergies

High-risk populations for asthma

African Americans, low-income individuals

Before puberty asthma predominance and after

Males before females after

Asthma Inequities: African Americans

• Asthma risk (African Americans): 40% more likely to have asthma

• Asthma mortality (African Americans): 3× more likely to die

• Asthma hospitalization (African Americans): 5× more likely to be admitted

• Asthma prevalence by income: Lower income = higher prevalence

Asthma Symptoms & Timing

• Common asthma symptoms: Wheezing, shortness of breath, chest tightness, cough

• Classic asthma symptom timing: Nighttime or early morning

• Asthma red flag: Nighttime awakenings around midnight

Asthma Triggers

• Tobacco smoke: Increases severity, especially in children

• Outdoor pollution: Up to 40% increase in symptoms

• Indoor allergens: Mold, dust mites, pet dander, cockroaches

• Respiratory viruses: Cause ~80% of exacerbations (rhinovirus common)

• Weather triggers: Cold/dry air and very humid air

• Exercise-induced asthma: Airway constriction during activity

• Medication triggers: Non-selective beta blockers, aspirin, NSAIDs

• Asthma heterogeneity: Triggers vary by patient

Primary driver of asthma:

Inflammation

• Bronchoconstriction: Smooth muscle contraction narrowing airways

• Airway hyperresponsiveness: Exaggerated bronchoconstriction response

• Airway edema: Swelling and mucus production

• Reversibility: Asthma changes are reversible with treatment

Airway Remodeling

• Airway remodeling: Permanent structural airway changes

• Why remodeling is dangerous: Causes irreversible airflow limitation

• Remodeling changes: Thickened walls, narrowed airways, mucus plugs, loss of cilia

Mucus Plug

• Mucus plug: Thick mucus blocking airflow

• Why mucus plugs are deadly: Prevent air exchange → respiratory failure

• Treatment for mucus plugs: Oral corticosteroids

Asthma Diagnosis

• Asthma diagnosis method: Combination of symptoms + tests

• Key diagnostic tools: Symptoms (SCHOLAR), spirometry, peak flow

• Spirometry purpose: Confirms airflow limitation and reversibility

Asthma Phenotype – Allergic Asthma

• Onset: Childhood

• Associated conditions: Eczema, allergic rhinitis, food allergies

• Inflammation type: Eosinophilic

• Response to ICS: Good response

Pediatric Asthma Risk Factors

• Childhood asthma predictors: Male sex, frequent wheezing, parental asthma

• Other risk factors: Atopic dermatitis, eosinophilia, allergen sensitivity

• Scoring tools: API, PARS

Reversibility Criteria

• Adult reversibility: FEV1 ↑ >12% AND ≥200 mL after SABA

• Child reversibility (>5 yrs): FEV1 ↑ >12% after SABA

FeNO Testing

• FeNO: Biomarker of airway inflammation

• High FeNO: Increased airway inflammation

• FeNO limitation: Cannot diagnose asthma alone

• Age for FeNO: ≥5 years

Predicted Spirometry Values

• Predicted values: Normal values based on age, sex, height

• Why useful in kids: Accounts for growth and development

• Reference population: Healthy, non-smokers

Asthma Control vs Severity

• Asthma control: How well symptoms are managed

• Asthma severity: Underlying disease intensity

• Key concept: Poor control ≠ severe asthma

Asthma Control Tests

• ACT: 5-question test for ages ≥12

• ACT timeframe: Past 4 weeks

• ACT score meaning: Lower score = worse control

• Poor control cutoff: ≤19

• C-ACT: Ages 4–11 (child + parent questions)

GINA Asthma Control Assessment

• Daytime symptoms: >2×/week?

• Nighttime awakenings: Yes/No

• SABA use: >2×/week?

• Activity limitation: Yes/No

• Well controlled: 0 criteria

• Partly controlled: 1–2 criteria

• Uncontrolled: 3–4 criteria

Asthma Follow-Up Steps

• Asthma visit steps: Assess, Adjust, Review

• Assess: Symptoms, inhaler use, adherence

• Adjust: Medications if needed

• Review: Response and education

Monitoring Asthma Over Time

• Spirometry monitoring: Every 1–2 years or with worsening control

• Peak flow monitoring: Daily tracking in severe asthma

• Peak flow benefit: Early detection of exacerbations