CABS/ Clin Med: Regulation of respiration, respiratory drive/ PFT and ABG Flashcards
pH is determined by
H+ concentration
Increased H+ =
acidosis
Decreased H+ =
alkalosis
pH = _____ / _____
HCO3- / pCO2
What is the bloods pH
7.35 - 7.45
pH of blood is determined/ balanced by
CO2 and HCO3- concentrations
Henderson Hasleback equation
CO2 + H2O – H2CO3 – HCO3- + H+
Typical PaCO2 =
40 mmHg
Carbonic Acid is the combination of
CO2 and H2O
Carbonic acid is a weak acid that readily
dissociates
Bicarbonate is controlled by what organ
kidney
Normal bicarb level =
24-26 mEq/L
Low O2 =
hypoxia
Insufficient O2 dissolved into plasma =
hypoxemia
What two molecules are needed to survive
O2 and glucose
Voluntary breathing =
talking, singing, laughing, breath holding, etc
involuntary breathing =
CO2
H+
H2CO3 = carbonic acid
HCO3- = bicard
pO2 = partial pressure O2
Chemoreceptors are
sensory cells that will trigger response based on chemical activation
centrally located in the medulla
CO2 increases =
hypercapnia (pH becomes more acidic)
CO2 drops =
hypocapnia (pH more alkalotic)
Hypercapnia stimulates
respiration
Hypocapnia inhibits
respiration
As CO2 increased pH will
decrease
When pH is decreased due to increased CO2 this will stimulate respiratory centers to
stimulate and blow off CO2 to return pH to normal
When the pH is increased due to low CO2 the respiratory centers are
inhibited and will cause H+ to accumulate and pH to drop back to normal levels
Chemoreceptors can be disrupted in pts with
chronic hypoxia
Pneumotaxic center is found in the
pons
Pneumotaxic center modifies
breathing rhythm that is set forth by the dorsal and ventral respiratory groups
helps with inspiration/ expiration transition
Pneumotaxic center receives input from
peripheral receptors
Apneustic center modifies
breathing rhythm that is set forth by the dorsal and ventral respiratory groups
primarily involved in inspiration
Apneustic center receives input from
stretch receptors
Apneustic center is found within the
pons
Dorsal respiratory group primary control of
respiratory drive
Dorsal respiratory group signals
the calm breathing muscles (diaphragm and external intercostals) to begin inspiration
Typical driver; that influences respiratory rate =
CO2
Ventral respiratory group is activated
during times of increased effort
Ventral respiratory group controls
the rhythm of breathing
assists with both inspiration and expiration
DRG stimulates VRG to increase
frequency of ventilation
Phrenic nerve is at what level in the spine
C3-C5
intercostal nerves are at what level in the spine
T1-T11
Baroreceptor will note increased ___ and cause vagal stimulation to _____
BP
decrease
Chemoreceptors will detect change in
CO2 (and O2, if low) and pH
Carotid chemoreceptors will send respiratory stimuli to _____ via ______
medulla
glossopharyngeal
Aortic chemoreceptors will send respiratory stimuli to ____ via ____
medulla
vagus
Lung receptors will all send afferent stimuli to the ______ of the medulla
DRG
dorsal respiratory group
Irritant receptors react to
noxious stimuli and trigger cough reflex
Irritant receptors are located on
the conducting airway epithelium
Stretch receptors assist
with ventilatory rate/volume as the smooth muscles sense/ react to over inflation and deflation
(will stopped continued inhalation to prevent barotrauma)
Stretch receptors are located
within the pleura and bronchioles
Herring Breuer reflex is
stimulation of stretch receptors activate vagus –> inhibition of the DRG, VRG –> stop inspiration and trigger expiration
J-receptors sense
pulmonary capillary pressure
J-receptors react to
pulmonary edema, shallow/rapid breathing
Lung innervation: Parasympathetic causes
constriction of the airways
Lung innervation: Sympathetic causes
relaxation of the airways
FiO2 is
the setting on ventilators - how much O2 we are breathing in
PaO2 =
partial pressure of O2 (pressure exerted by a gas within the confined container)
Pressure in the pulmonary artery
40 mmHg
Pressure in the pulmonary vein
100 mmHg
Each hemoglobin can carry ___ O2 molecules
4
Oxyhemoglobin will change the form of ______ to open the overall configuration
hemoglobin
Left shift is called
Haldane effect
Right shift is called
Bohr effect
During a left shift the affinity for O2 will
increase
During a right shift the affinity for O2 will
decrease
ABG are
arterial blood gas
ABG is gold standard test for evaluating
Acid-base balance
oxygenation
ventilation
ABG indications
critically ill pts, respiratory conditions, metabolic disorders
ABGs need to be done _____
ASAP
sensitive to temp and time (must place on ice after draw)
ABG alternative
VBG (venous blood gas)
Thing you can’t get from a VBG that you can from a ABG
O2 level
pH abnormalities on cardio system:
Acidosis can lead to
hyperkalemia
decreased CO
vasodilation - hypotension
pH abnormalities on cardio system:
Alkalosis can lead to
ventricular tachyarrhythmias
SVT
hypokalemia
pH on pulm system:
acidosis can lead to
tachypnea
drop CO2
pH on pulm system:
alkalosis can lead to
low resp rate
Metabolic acidosis means we are losing too much
bicarb
Resp acidosis means we are retaining too much
CO2
Resp alkalosis means we are losing too much
CO2
Metabolic alkalosis means we are retaining too much
Bicarb
The ROME criteria means
respiratory are opposite
metabolic is equivalent