DPTD 872 - pulmonary system, evaluation, & pharmacology

for air to enter the lungs during inspiration, the pressure inside the lungs must drop below…

760 mmHg

expiration at rest is a ____ process via __________

passive; elastic recoil of the lungs

breathing during exercise or forced breathing requires…

stronger & more active use of respiratory muscles

forced expiration is an ___ process

active

emphysema results in..

• air becoming trapped in the lungs

• increased residual volume

• barrel chest

restrictive lung disease

• lung tissue e becomes stiff or scarred

• reduced lung compliance (ability to stretch)

• inspiration becomes more difficult while expiration is normal

• rapid, slow breaths to reduce work of breathing

neuromuscular diseases that affect ____ can impair ventilation

diaphragm or intercostal muscles

ventilation-perfusion matching

relationship between the air that reaches the alveoli & the blood that reaches the alveoli via pulmonary capillaries

for optimal gas exchange to occur, the amount of air reaching the alveoli must…

be appropriately matched with the amount of blood flow in the pulmonary capillaries

average V/Q ratio at rest/adequate amount for gas exchange

0.8

low V/Q indicates…

poor ventilation relative to perfusion

ex: airway obstruction - blood is flowing to the alveoli but O2 cannot reach it efficiently

high V/Q suggests..

adequate ventilation but poor perfusion

ex: pulmonary embolism - blood flow is blocked to parts of lungs that are still being ventilated

hypoxic pulmonary vasoconstriction

• body’s automatic mechanism to minimize V/Q mismatch

• pulmonary arteriole vasoconstriction in poorly ventilated areas of the lung → divert blood to better-ventilated regions

pulmonary embolism V/Q

• high V/Q mismatch

• ventilation may be normal but perfusion is absent

COPD & pneumonia V/Q

• low V/Q mismatch

• perfusion is intact but ventilation is impaired

oxygen is transported in the blood in two forms:

• bound to hemoglobin

• dissolved in plasma

binding of oxygen to hemoglobin is influenced by….

pH, temp, CO2 levels, & 2,3-BPG

carbon dioxide is transported in the blood in three forms:

• bicarbonate

• Bound to hemoglobin

• dissolved in plasma

anemia pathology

reduced hemoglobin available to bind to oxygen, even if PaO2 is normal

oxygen-hemoglobin dissociation curve is the relationship of..

PaO2 & percent of hemoglobin saturated with oxygen (SaO2)

oxygen-hemoglobin dissociation curve rightward shift is due to…

• there is a reduced affinity for oxygen & more unloading at tissues

• caused by increased temp, increased CO2, acidosis, and increase 2,3-BPG

oxygen-hemoglobin dissociation curve shifts to right when an individual is…

exercising or has a fever

oxygen-hemoglobin dissociation curve rightward shift promotes..

oxygen unloading at tissues caused→ help meet metabolic demand

oxygen-hemoglobin dissociation curve leftward shift is due to…

• increase affinity to oxygen, less unloading the tissues

• decreased CO2, alkalosis, & decreased temperature

oxygen-hemoglobin dissociation curve shift to left when an individual is..

in cold environment (hypothermia) or alkaloid status (hyperventilation)

crackles/rales sound caused by…

fluid in the lungs or collapsed alveoli; sounds like rustling plastic wrapper

eupnea

normal breathing rate & depth

strider

higher pitched sound cased by an obstruction or inflammation in the larynx or trachea

wheezing

whistling sound that can be heard w/ or w/out stethoscope; represents obstruction or inflammation in the airways

hemoptysis

blood present during coughing

primary diagnosis

recurrent pulmonary-related infections

secondary diagnosis

neuro or MSK diagnosis that impact the function of the pulmonary system

what should be seen on a normal chest x-ray

• heart appears white

• lungs appear clear

• R side of diaphragm is 1-2 cm higher than L

normal inspiration/expiration ratio

1:2

paradoxical breathing

if abdominal wall moves inward during inspiration while the chest moves outward or vis versa - may be due to diaphragmatic flattening or paralysis

characteristics of excessive accessory muscle use

increased upper chest movement with SCM, scalene, & other upper chest/neck muscles

accessory muscle use during breathing is a ___ effort

abnormal

flail chest

increased rib mobility due to fractures with outward movement during exhalation

pets excavatum

sternum is sunken in, worsens with age

pectus carinatum

sternum is more prominent & sticks out

tracheal/bronchial sounds

• 1:2 ratio, I:E

• loud/harsh

• heard over trachea

bronchovesicular sounds

• 1:1 ratio

• heard over 1st and 2nd intercostal space & between the scapulae

• expiration & inspiration are equal in length & volume

vesicular sounds

• 3:1 ratio, I:E

• heard over lungs & are a softer/ lower pitched sound

• no pause between inspiration & expiration

what disease process are associated with sounds early in inspiration

bronchitis, emphysema, asthma

what disease process are associated with sounds Later in inspiration

interstitial lung disease, pulmonary edema

trachea will shift towards the pathology side if…

there is a loss of lung volume

trachea will shift away from the pathology side if…

there is an increase in lung volume (atelectasis or fibrosis) or intrathoracic pressure (pneumothorax or pleural effusion)

tactile fremitus

vibrations caused by air moving through the airways in the lungs that an examiner can feel when patient phonates

increased fremitus =

consolidation of the underlying tissue

decreased fremitus =

decreased density of presence of fluid/air

consolidation

smaller airways are filled with fluid or solid material instead of air

mediate percussion assesses…

density of lungs

increased lung density persuasion sound

dull

decreased density percussion sound

hyper-resonant

stages of a cough

• voluntary closure of glottis

• buildup of intrathoracic & intraabdominal pressure

• sudden quick release of pressure w opening of glottis

• forceful air helps clear airways

long term use of supplemental oxygen may cause…

cytotoxic damage (structural damage to lungs) & depression of ventilation

short acting beta-2 agonist inhaler mechanism of action

• stimulate the beta-2 receptors in the smooth muscle cells that line the bronchi → relaxation & dilation of airways

• act quickly and used for relief from sudden attacks/onset of symptoms

long-acting beta-2 agonist inhaler mechanism of action

• stimulate beta-2 receptors in smooth muscle cells surrounding bronchi → relaxation & dilation of airways

• longer acting (up to 12 hours) for chronic asthma & COPD

effects of SABAs & LABAs inhalers

increased sympathetic activation & HR

inhaled corticosteroids mechanism of action

• suppress airway inflammation

• enhance beta-2 adrenergic receptor expression & function

• often used with LABAs in treatment of airway obstruction

at high doses, inhaled corticosteroids may increase risk of…

hypertension, hyperlipidemia, & glucose intolerance

muscarinic antagonists mechanism of action

• muscarinic receptors activate bronchoconstriction

• inhibition of this mechanism causes bronchodilation

dead space

space that is well ventilated but lacks perfusion, so no respiration (gas exchange) occurs

shunt

a space that has adequate perfusion but lacks ventilation