Intro to Gas Exchange Flashcards
What is gas exchange ?
the process by which O2 is transported to the cells and carbon dioxide is transported from the cell
What is ventilation ?
the process of breathing O2 into the lungs
- inhalation and exhalation
What is perfusion ?
ability to pump the hemoglobin to the cells to exchange
What is ischemia ?
insufficient flow of oxygenated blood to tissues, may result in cell injury or death
What is anoxia ?
total lack of oxygen in body tissues
What is hypoxia ?
insufficient oxygen reaching cells
What is hypoxemia ?
reduced oxygenation in arterial blood
What is compliance ?
measure of the ease of lung expansion
Where is the respiratory system controlled ?
in the medulla
- located in the brainstem
What is PaO2 ?
partial pressure of O2 dissolved in the arterial blood
- shows how well the oxygen can move from the lungs to the blood
- normal: 80-100 mmHg
Who is at the greatest risk for impaired gas exchange ?
- older adults
- smokers
- presence of chronic medical conditions
- immunosuppression
- reduced state of cognition
- brain injury
- prolonged immobility
What is the difference between SaO2 and PaCO2 ?
- SaO2: O2 in the hemoglobin
- PaCO2: CO2 in the hemoglobin
How does the medulla respond to respiratory changes ?
it uses chemo receptors that respond to the changes in PaO2, PaCO2 and pH to affect the breathing patterns
What is oxygen saturation ?
the amount of O2 bound to the hemoglobin
What is SaO2 ?
percent of arterial hemoglobin that is saturated with O2
- normal in adults: 95-100%
What is hemoglobin concentration ?
a direct reflection of the number of RBCs in the blood
- determines the O2 and CO2 transport capacity
- 1 g of Hgb can carry 1.34 mL of O2
How is impaired gas exchange occur in older adults ?
- chest wall becomes stiffer so loss of elastic recoil
- respiratory muscles become weaker and reduce effectiveness of coughing
- decreased ability to initiate immune response
- reduction of erythrocytes which increases anemia risk
What does a end tidal CO2 monitoring do ?
tests for amount of CO2 in exhaled air
What are some diagnostics for gas exchange ?
- O2 sat monitoring
- end tidal CO2 monitoring
- sputum cultures
- arterial blood gases (ABGs)
- Hgb and Hct
- abnormal cell cytology
What are some considerations for a bronchoscopy ?
- pt is sedated
- NPO beforehand
- need consent
- assess for gag reflex before they can eat/drink/meds post op
What are some signs of pneumothorax ?
- sharp, stabbing chest pain that worsens when inhaling
- SOB
- low sats
- cyanosis
- fatigue
- rapid breathing and HR
- dry, hacking cough
What is a thoracentesis and some considerations ?
needles inserted into pleural space to drain any excess fluid
- position upright
- do not talk or breath during insertion
- monitor for pneumothorax
- encourage deep breathing afterwards
What are lung volume and capacity tests ?
measures the volume and airflow
- many respiratory illnesses impact these volumes
- avoid admin of bronchodilators 6 hrs before exam to get accurate lung function
What are some RN interventions for decreases gas exchange ?
- positioning (high fowlers or tripod)
- O2 therapy
- airway management and support (trach or airway)
- chest physiotherapy and postural drainage
- Nutrition: high protein and high calorie diet
- med admin
What is FiO2 ?
the fraction of inspired O2 being delivered to the pt at any time
- important for analyzing blood gases and gas exchange
When increased L of O2 how is FiO2 affected ?
FiO2 is increased by 3%
- which increases the amount of O2 to be delivered to the arterial blood (O2 ready to be used)
What are some characteristics of a nasal cannula ?
delivers low flow of O2
- in Liter flow
- 1 NC is about 24% O2 (RA is 21%)
- should not be delivered at more than 6L
What are some characteristics of high flow nasal cannula ?
blends O2 with compressed air
- generates a high FiO2 up to 100% to 60L
What are characteristics of a simple face mask ?
covers the mouth and nose
- O2 can be at 6-12 L flow of 40-50% FiO2`
What are characteristics of a non-rebreather O2 mask ?
used for high flow (concentration) O2 (10-15L)
- can give O2 up to 90% FiO2
- the bag contains O2
What are characteristics of a bag valve mask ?
the ambu bag controls the patients respirations
- they aren’t breathing on their own
- can hook up to O2 and deliver at 15L FiO2 100%
What is transportation in gas exchange mean ?
ability of hemoglobin and availability of hemoglobin to carry oxygen
What levels of CO2 are dangerous ?
> 40 is a concern for hyperventilation
What are characteristics of a venturi face mask ?
delivers low and/or high flow O2 at a constant concentration
- no matter the pt’s respiratory pattern
What is the first intervention for pt’s with impaired gas exchange ?
positioning
What is a CT scan used for ?
can visualize lesions in lungs and mediastinum
- can use contrast dye so assess allergies
