Gas Exchange Flashcards
What is gas exchange?
Gas exchange is the process by which oxygen is transported to cells and carbon dioxide is transported out of cells
What is ischemia?
insufficient flow of oxygenated blood to tissues; can result in hypoxemia –> cell injury or death
What is hypoxia?
insufficient oxygen reaching cells
What is anoxia?
Total lack of oxygen in body tissues
What is hypoxemia?
reduced oxygenation of arterial blood
What is the scope of gas exchange?
spectrum of optimal perfusion to no perfusion
optimal gas exchange –> impaired gas exchange –> no gas exchange
What drives respiration?
carbon dioxide
Primary purpose of the respiratory system is…
gas exchange
Babies born after 30 weeks have sufficient ____ to prevent alveoli from collapsing after ____
Babies born after 30 weeks have sufficient surfactant to prevent alveoli from collapsing after exhalation
Infants are _______ until 3 months
obligate nose breather
Respiratory patterns for newborns may be…
irregular, with brief pauses between breaths of no more than 10-15 seconds
Older adults may have…
decreased strength of respiratory muscles that reduce maximal inspiratory & expiratory force (weaker cough)
(Pop.) Risk factors for infants
fetal hemoglobin in the first 5 months postnatal that reduces lifespan of erythrocytes –> causing physiological anemia at 2/3 y.o.
infants are also immunocompromised
Risk factors for impaired gas exchange of infants and children
less alveolar surface area for gas exchange and narrow peripheral airways that are easily obstructed
Risk factors for impaired gas exchange of older adults
anatomic & physiological changes caused by:
stiff chest wall due to loss of elastic recoil, respiratory muscles are weaker, reduced effectiveness of cough (which prevent aspiration)
dilation of alveoli, decreased surface area for gas diffusion, decreased ability to initiate an immune response, decreased pulmonary capillary network
Adequate ventilation is apparent when what occurs:
- quiet, effortless breathing
- oxygen stat 95-100%
- regular lips, skin, and nail bed color
- thorax is symmetrical
- equal thoracic expansion bilaterally
-spinous process in alignment - scapulae bilaterally symmetric
- midline trachea
- clear, bilateral breath sounds
non modifiable risk factors are
age, air pollution , allergies
What is the most preventable cause of death & most significant factor for impaired gas exchange?
smoking
What increases risk of aspirations?
altered state of consciousness, such as:
chemical alteration (alcoholism, drug overdose)
neurologic disorder (head injury, seizure, stroke)
What causes reduced thoracic expansion, increasing the likelihood of developing atelectasis & pneumonia?
bed rest & prolonged immobility
Baseline history
lifestyle behaviors, diet, exercise, smoking habits, pt’s work/home/social environments, chronic diseases, allergies, and medications
Problem based history should include
chest pain, shortness of breath, coughing
Clinical findings of impaired gas exchange
sputum, abnormal breathing patterns, adventitious breath sounds, decreased level of consciousness
Vital signs indicative of impaired gas exchange
increase in respiratory rate, decrease in pulse ox, increase in HR, & increase in temp
Auscultation assessment indicative of impaired gas exchange
narrowed bronchi may produce expiratory and/or inspiratory wheezing or stridor, mucus or secretions in the bronchi may create rhonchi & fluid in alveoli may generate crackles
Primary prevention methods
infection control, smoking cessation, immunizations, and preventing postoperative pulmonary complications
Secondary prevention methods
nutrition therapy, positioning, invasive procedures, chest physiotherapy & postural drainage, airway management & breathing support, oxygen therapy, pharmacotherapy
Auscultation of the lungs must be done…
bilaterally
