Regulation of Respiration, Respiratory Drive, PFT's and ABG Flashcards
Acidosis occurs when there is an increase in what
Hydrogen ions
Alkolosis occurs when there is a decrease in what
Hydrogen ions
Carbon dioxide primarily triggers what
central chemoreceptors
Carbon dioxide is 20x more soluble than O2, and will diffuse very quickly which means what for oxygen
Oxygen is going to drop much more quickly and the change will be seen first
What is a normal bicarbonate level?
24-26 mEq/L
What is the difference in hypoxia compared to hypoxemia?
Hypoxia there is low O2 in the organ tissues where hypoxemia there is insufficient O2 dissolved into the plasma
What molecules control involuntary breathing?
CO2
H+
H2CO2 (carbonic acid)
HCO-3 (bicarbonate)
pO2
When CO2 increases (hypercapnia) pH becomes more acidic which stimulates
respiration
When CO2 drops (hypocapnia), more alkolotic pH is going to inhibit
respiration
Chemoreceptors are found near respiratory center and detect
pH of CSF
As CO2 increase, the pH will decrease (acidosis) this is going to cause
the respiratory centers to be stimulated to blow off CO2 to return pH to normal
The pneumotaxic center is found where
Pons
What is the role of the pneumotaxic center
Modify breathing rhythm that is set forth by the dorsal and ventral respiratory groups, helps with inspiration/expiration transition
The apneustic center is found where
Pons
What is the role of the apneustic center
Modify breathing rhythm that is set forth by the dorsal and ventral respiratory groups
What group is going to control the rhythm of breathing?
Ventral respiratory group
Irritant receptors react to what kind of stimulus
Noxious stimuli
Where are irritant receptors located
Conducting airway epithelium
J-receptors are responsible for what
Sense pulmonary capillary pressure, react to pulmonary edema
Parasympathetic activation will stimulate the vagus nerve and cause
constriction of the airways
Sympathetic activation will stimulate catecholamines which will cause
relaxation of the airways
Does CO2 or O2 diffuse more easily?
CO2
What are some of the implications of a right-shifted curve?
- Reduced oxygen affinity
- Increased oxygen delivery to tissues
What are the causes of right-shift?
Low pH
Increased CO2
High temperature
High 2, 3-BPG
Low O2 affinity Hb variants
What are the implications of a left-shift curve?
- Increased oxygen affinity
- Reduced oxygen delivery to tissues
What are the causes of left-shift?
High pH
Low temperature
Low 2,3-BPG
Fetal Hb
Methemoglobinemia
High O2 affinity Hb variants
Where is bicarbonate made?
Made in the kidneys to buffer acids
For every HCO3 made by the kidney’s how many H+ are eliminated?
one H+
Why does acidosis cause an increase in extracellular potassium (hyperkalemia)?
Shifts of potassium from the intracellular to the extracellular compartment
What are the effects of acidosis on the cardiovascular system?
- Decreased Cardiac Output
- Vasodilation
- Increased ectopic rhythms from unstable cellular function
- Hyperkalemia
What are the effects of alkalosis on the cardiovascular system?
- Leads to excitability
- Ventricular tachyarrhythmias
- SVT
- Hypokalemia
What are the effects of acidosis on the respiratory system?
- Tachypnea
- Can drop CO2 to about 10 at lowest point
- Right shift
What are the effects of alkalosis on the respiratory system?
- Low respiratory rate
- Left shift
What is the best time to calculate an anion gap?
Metabolic acidosis to determine what is driving the acidosis
What is Inspiratory reserve volume (IRV)?
Amount of air that can be forcibly inhaled after tidal volume (amount in a deep breath)
Normal = 1900-3300 mL
What is Tidal Volume (Vt)?
Amount of air that can be inhaled or exhaled in one respiratory cycle (normal breath). Will include volume to fill physiologic dead space.
What is total lung capacity (TLC)?
Total volume of air the lungs can accomodate with maximal inspiration (calculated)
What is a big driver of lung volume and is important to measure prior to initiating mechanical ventilation?
Height (length)
Body weight has nothing to do with ventilation
