Respiratory Flashcards
3 Step Process of Oxygenation
- Ventilation (moving gases in and out of lungs)
- Perfusion (oxygenated blood to tissue and deoxygenated blood to lungs)
- Diffusion (movement of molecules from high to low concentration)
Factors that compromise oxygenation
- Physiological (cardiac disorders, anemia, pregnancy, fever, infection, CNS, chest wall conditions)
- Developmental (aging, decreased ability for the lungs to expand)
- Lifestyle (smoking, obesity, malnourishment)
- Environmental (smog, asbestos, high altitudes)
Partial pressure of oxygen or carbon dioxide
Amount of oxygen or carbon dioxide dissolved in plasma
Normal arterial oxygen tension (PaO2)
80-100 mmHg
Normal arterial carbon dioxide tension (PaCO2)
35-45 mmHg
Hyperventilation
Ventilation greater than required (exhaling more than you inhale)
- decreased level of CO2 in blood
- at the alveoli level
- clinical presentation: increased depth and rate
Causes of hyperventilation
- anxiety
- infections
- fever
- shock
- acid-base imbalance
- meds (i.e. ASA, amphetamines)
Hypoventilation
Ventilation less than required
- elevation of carbon dioxide
- alveolar ventilation is inadequate in meeting body’s oxygen demand
Atelectasis
collapse of the alveoli that prevents normal respiratory exchange of O2 and CO2 (lead to hypoventilation)
Causes of hypoventilation
- atelectasis
- inappropriate administration of excess O2 in patients with COPD
COPD
adapted to high CO2 level, their stimulus to breathe is low O2 concentrations
if O2 concentration increase, respiratory rate decreases
pulse oximetry levels: high 80s to low 90s
Hypoxia
inadequate tissue oxygenation at the cellular level
- life threatening condition
- can result in dysrhythmia and possibly death
Causes of hypoxia
- decreased hemoglobin level and lowered O2 carrying capacity
- decreased concentration of O2 (high altitude)
- inability of tissue to extract O2 from blood
- decreased diffusion of O2 from alveoli to blood (pneumonia)
- poor tissue perfusion (shock)
- impaired ventilation
signs and symptoms of hypoxia
- restlessness
- apprehension/agitation
- declining LOC
- dizziness
- fatigue
- increased pulse, resps and bp (unless caused by shock) (decreased vitals when things get worse)
- cyanosis (around lip)
Pulmonary Function Test (PFT)
- measures lung volume and capacity
- done by RT
- take deep breath and forcefully exhale
Arterial Blood Gases (ABG)
- measures the adequacy of tissue oxygenation
- radial artery most commonly used
- pH: 7.35 - 7.45
Pulse Oximetry (SpO2)
indirect measure of oxygen saturation
99% = 99% of hemoglobin have O2 attached
Normal = 95 - 100%
70% or lower is considered life threatening
Imaging
xray and CT scans provide visualization of lung fields
Common Respiratory Tests
- Pulmonary Function Test (PFT)
- Arterial Blood Gases (ABG)
- Pulse Oximetry (SPO2)
- Imaging
Factors that affect pulse oximetry
- poor peripheral circulation
- nail polish
- artificial nails
- tremors