Oxygen Therapy Flashcards
Nasal Cannula: 1L/min
24% FIO2
Nasal Cannula: 2L/min
28% FIO2
Nasal Cannula: 3L/min
32% FIO2
Nasal Cannula: 4L/min
36% FIO2
Nasal Cannula: 5L/min
40% FIO2
Nasal Cannula: 6L/min
44% FIO2
Simple Face Mask: 5 - 8 L/min
40 - 60% FIO2
Partial Rebreather Face Mask: 5 - 11 L/min
60 - 75% FIO2
Non-rebreather Face Mask: 6 - 15 L/min
80 - 95% FIO2
3 essential factors for breathing
- Patent respiratory tree
- Functioning alveoli
- Intact cardiovascular system
Mechanism of the upper airway
warm, filter, and humidify air
Mechanism of cilia
propel secretions
Mechanism of coughing
remove secretions
What helps keep secretions thin enough to move?
hydration
Mechanism of mucus
trap irritants, bacteria, and pollutants
Mechanism of surfactant
decrease surface tension in alveoli to prevent collapse so it doesn’t take extra effort to reinflate lungs
ventilation
movement of air in and out of lungs
respiration
gas exchange that happens at the alveoli level
What mechanism causes a decrease in intrathoracic pressure?
inhalation - diaphragm contracting and expansion of ribs via the intercostals
What causes an increase in pressure in the intrathoracic cavity?
exhalation - diaphragm and intercostals relax to force air out
Boyle’s law
gas volume is inverse to pressure
7 issues with the lungs that can affect the compliance/elasticity
atelectasis
pneumonia
pleural effusion
pulmonary edema
pulmonary fibrosis
pneumothorax
hemothorax
pneumothorax
air in the pleural space
hemothorax
blood in pleural cavity
3 issues with the chest wall that can affect lung compliance/elasticity
obesity
kyphosis
injury
movement of a solute from an area of higher concentration to an area of lower concentration across a semipermeable membrane
diffusion
movement of solvent from an area of higher concentration to one a lower concentration
osmosis
passage of blood/fluid through a vessel or channel
perfusion
issues of diffusion
- decreased surface area
- atelactasis
- diseases that affect alveolar capillary membrane
- percentage of oxygen at different altitudes
conditions that may cause decrease in surface area
tumor
partial/total lung removal
conditions that may cause atelectasis
tumor
mucus plug
positioning
diseases that affect alveolar capillary membrane
pneumonia
pulmonary edema
How is the most O2 transported?
97% RBCs
3% plasma
How many binding cites does hemoglobin have for oxygen?
4
What influences the percentage of O2 attached to each hemoglobin molecule?
PaO2 (partial pressure of arterial oxygen)
What level of PaO2 provides an adequate amount of oxygen?
60 mmHg
(little change in SaO2 above that)
symptoms of hypoxemia
tachycardia
tachypnea
cyanosis/pallor
agitation + lethargy
anxious, inattentive, and change in level of conciousness
hypoxia
low oxygen in tissues
What occurs in a person without chronic respiratory problems when CO2 crosses BBB
CO2 combines with water (H20) and forms carbonic acid (H2CO3)
What happens to carbonic acid in a person without chronic respiratory problems?
H2CO3 is broken down to H+ and bicarbonate (HCO3)
What happens when there is an increase in H+ in the blood?
Blood becomes more acidic (higher pH) and causes faster and deeper breaths
hypoxic drive
people with chronic respiratory problems have become accustomed to increased CO2 levels in blood and breathing becomes controlled by decrease in O2
(accountable for only 10% of breathing)
parynchyma
alveoli and bronchi
How do chronic respiratory issues affect ventilation?
Exhalation becomes active > causes CO2 retention > barrel chest
hypoxic vasoconstriction
occurs at alveoli that aren’t functioning to shunt blood to the ones that are
minute respiration
tidal volume x respiration rate
5 effects of chronic hypoxemia
- cor pulmonale
- pulmonary hypertension
- nutritional problems
- CV problems
- slow recovery
Goal for O2 administration for a patient with chronic respiratory problems
Maintain SaO2: 90-93%
Pao2: 60-70mmHg
PaO2
Partial pressure of oxygen in arteries
(amount of O2 dissolved in blood)
Normal PaO2
80 - 100 mmHg
PaCO2
partial pressure of carbon dioxide
Normal PaCO2
35-45 mmHg
Arterial blood sample
information on lung functioning
represents gas exchange
venous blood sample
describes amount of oxygen tissues are removing from blood (PvO2)
Allen test
determines level of collateral circulation
done to determine need for ABG
Considerations for pulse oximetry
do not use on edemic skin
if using forehead/nose clean with alcohol wipes first and let dry
What does pulse oximetry measure?
percentage of Hg that is carrying full amount of oxygen (SpO2)
Normal SpO2
95-100%
What is PaO2 if SpO2 is 95-100%?
80 mmHg
What level of SpO2 is considered hypoxemic?
< 90%
(89% = 60mmHg PO2)
6 potential causes of inaccurate SpO2 reading
- motion artifact
- Hg is bound to CO
- reduced perfusion
- skin pigmentations
- nail polish/fake nails
- response delay of the site
2 conditions that require oxygen therapy
acute/chronic respiratory conditions with hypoxia/hypoxemia
conditions that increase O2 demand
5 conditions that increase O2 demand
- sepsis
- fever
- hyperactive thyroid
- reduced Hg+O2 carrying ability
- reduced cardiac output
FIO2
fraction of inspired oxygen
FIO2 of room air at sea level
21%
rule for determining FIO2
use lowest FIO2 possible to maintain the best blood oxygenation
what qualifies a low-flow device
8L/min or less
hi-flow device
exceeds patient demands
ex: venturi mask or aerosol mask
2 features of simple face mask
- need minimum of 5L/min to flush CO2 out of ports
- pulls RA in through ports
2 features of partial rebreather mask
- reservoir bag must be full - should be slightly full after inhalation
- brings in RA via ports
3 features of non-rebreather mask
- one way valve between reservoir and mask (only opens with inhalation)
- pt. breathes out of ports on side and CO2 does not go into reservoir
- RA does not enter mask
Important way to teach deep breathing
exhale through pursed lips - pressure keeps alveoli open
3 features of pulmonary toilet
- chest percussion
- chest vibration
- postural drainage
