what is the normal tidal volume ranges in mL/kg of ideal body weight
7-9mL/kg ideal body weight
define the normal inspiratory to expiratory (I:E) ratio and explain why expiration takes longer than inspiration
(1:2) duration of inhalation to exhalation
takes longer because its a passive process
*in copd pt ratio 1:3 (longer to exhale due to obstruction)
what is subjective signs of dypnea
experiences felt/symptoms felt by pts
ex shortness of breath,labored breathing
objective signs of dypnea
observable signs
ex. hyperventilation, tachypnea, use of accessory muscles, distress facial expressions, flared nostrils
describe what happens when “demand to breath” exceeds “ capability to breath”?
respiratory system must work harder to supply O2 and remove CO2. cant meet metabolic needs
pt experiences dyspnea
explain the relationship between lung compliance and elasticity.
high compliance=low elasticity, lungs are easily stretched but hard to go back to normal, causes prolonged exhalation
low compliance=high elasticity lungs are thick/stiff more effort to expand, causes rapid/shallow breathing
what is lung compliance
lungs ability to stretch and expand
what is elastance
(recoil) lungs need to go back to original form after being stretched
which diseases are associated with increased lung compliance?
emphysema, COPD
what diseases are associated with decreased lung compliance
pulmonary fibrosis, ARDS
list 3 factors that can increase airway resistance
*changes in airway-secretions—>narrowing in airway
*changes in the wall of the airway-asthma, bronchoconstriction
*changes outside of the airway-tumors compressing the airways
what is airway resistance (Raw)
resistance created by airway to the flow of gas
high=more obstruction or narrowing of airways-harder for air to pass
low=clear airways, air flows freely
what are peripheral chemoreceptors
detect low O2(PaO2)levels and send signals to the medulla to increase RR and depth
how do peripheral chemoreceptors respond to hypoxemia: include the crainal nerves
hypoxemia is detected–>peripheral chemoreceptors to activate–>send signals(afferent) via (carotid)glossopharyngeal nerve(IX) and (aortic)vagus nerve(X) –>to the medulla–>send commands (efferent) to the respiratory muscle–> tells the body to increase depth of breathing (RR)
what is the difference in sensitivity between central and peripheral chemoreceptors?
peripheral= PaO2 (oxygen)
central=PaCO2 (carbon dioxide)*located in pons and medulla
explain why patients with chronic COPD may rely on peripheral chemoreceptors to drive ventilation?
“hypoxic drove”-peripheral primary receptors for ventilation control in COPD pts that have a high PaCO2 and low PaO2, helps maintain O2 levels by adjusting breathing rate in fluctuating gas levels
give two examples of acute onset respiratory conditions
(happens within mins/hr)
pneumonia, pulmonary edema & ARDS-rapid immediate medical attention
give examples of chronic conditions?
(happens over days/months/yrs)
COPD, TB, pulmonary fibrosis- requires ongoing management of longterm complications
which accessory muscles assist with inspiration
*pt has difficulty breathing and body trys to compensate to maintain ventilation
-scalene
-sternocleidomastoid
-pectoralis major
-trapezius muscle
which accessory muscles assist with expiration
*pt has difficulty w/passive exhalation
-rectus abdominis
-external oblique
-internal oblique
-transversus abdominis
what is the purpose of pursed lip breathing and how does it benefit pt with obstructive lung disease?
-offsets airway collapse and air trapping during exhalation
-(+) pressure creates airway stability
-slows ventilatory rate
-generates better gas mixing
why is nasal flaring a concerning sign particularly in neonates?
neonates naturally are nose breathers so cant breath out of mouth, needs immediate intervention to prevent respiratory distress
what is pleuritic chest pain and give one example
-sudden, sharp, or stabbing pain
-increases during deep inspiration and coughing
-ex:pneumonia, pneumothorax,tb, pleural effusion
what is non pleuritic chest pain
-constant pain located centrally
-doesn’t worsen with deep inspiration
-pain may radiate
-ex: myocardial ischemia, pericardial inflammation
