Respiratory physiology 6 Flashcards
The Haldane effect states that in the presence of deoxygenated hemoglobin, the carbon dioxide dissociation curve shifts:
a. to the right
b. to the left
c. up
d. down
b. to the left
The Haldane effect describes
CO2 carriage
it says that oxygen causes the erythrocyte to release CO2
With the carbon dioxide dissociation curve right is ________ & left is ____________
release; love
The presence of oxygenated hemoglobin shifts, the CO2 dissociation curve to the
right
The presence of deoxygenated hemoglobin shifts the CO2 dissociation curve to the
left
What is the difference between the Haldane effect and the Bohr effect?
Bohr effect- describes oxygen carriage
Haldane effect- describes CO2 carriage
Where in the body is the CO2 dissociation curve right-shifted?
at the lungs (facilitates Co2 elimination)
Where in the body is the CO2 dissociation curve left-shifted?
at the systemic capillaries (facilitates CO2 loading and transport by Hgb)
Consequences of hypercapnia include: (select 2):
a. hypokalemia
b. increased myocardial oxygen demand
c. increased oxygen carrying capacity
d. hypoxemia
b. increased myocardial oxygen demand
d. hypoxemia
Hypercapnia is defined as
a PaCO2 greater than 45 mmHg
Etiologies of hypercapnia can be classified in 3 ways:
- increased CO2 production
- decreased CO2 elimination
- rebreathing
Causes of increased CO2 production include
sepsis, MH, thyroid storm, burns, overfeeding, prolonged seizure activity, & shivering
Causes of decreased CO2 elimination include
airway obstruction, ARDS, COPD, increased dead space, respiratory center depression, inadequate NMB reversal, increased Vd/Vt, and opioid overdose
Causes of rebreathing include
exhausted soda lime
faulty unidirectional valve in a circle system
inadequate FGF in a Mapleson circuit
Consequences of hypercarbia include
hypoxemia, acidosis, cardiac depression, hyperkalemia, increased pulmonary vascular resistance, increased Ca2+, SNS stimulation, & increased ICP
PaCO2 is equal to
CO2 production/ alveolar ventilation
During respiratory acidosis, the kidneys excrete
hydrogen and conserve bicarbonate to return to normal pH
may take several days for full compensation to occur
For every 10 mmHg increased above 40 mmHg in PaCO2 (acute), pH will
decrease by 0.08
For every 10 mmHg increase above 40 mmHg (chronic), pH will
decrease by 0.03 (due to bicarb retention by the kidneys)
Which conditions increase minute ventilation for a given PaCO2? (select 3)
a. surgical stimulation
b. salicylates
c. hypoxemia
d. sevoflurane
e. carotid endarterectomy
f. respiratory alkalosis
a. surgical stimulation
b. salicylates
c. hypoxemia
The carbon dioxide ventilatory response curve describes the relationship between
PaCO2 and minute ventilation
The __________________ is the primary monitor of PaCO2
central chemoreceptor in the medulla
The _____________________________________ play a secondary role in monitoring PaCO2
peripheral chemoreceptors in the carotid bodies and transverse aortic arch
Conditions that shift the CO2 response curve down and to the right include
volatile anesthetics
opioids
NMBs
metabolic alkalosis
carotid endarterectomy
