NUR 445 Exam 2 COMPLETE EXAM
QUESTIONS WITH DETAILED
VERIFIED ANSWERS (100% CORRECT
ANSWERS) ALREADY GRADED A+
What is the definition of affinity? - ANSWERSthe attraction between Hgb and O2
What does Hgb have an affinity to? - ANSWERSHgb has an attraction for O2 molecules
What does the oxyhemoglobin dissociation curve represent? - ANSWERSrelationship
between PaO2 and SaO2
What is PaO2? - ANSWERSpartial pressure of arterial O2 (arterial O2 tension)
What is SaO2? - ANSWERSHgb saturation
What does P50 represent? - ANSWERSmeasures when Hgb is 50% saturated with O2
When does the P50 change? - ANSWERSwhen physiologic factors are altered
What does a left shift on the dissociation curve do to the affinity of O2 to hemoglobin? -
ANSWERSincreases affinity = prevents release to tissues
What does a right shift on the dissociation curve do to the affinity of O2 to hemoglobin?
- ANSWERSdecreases affinity = readily release to tissues
What causes a left shift on the dissociation curve? - ANSWERSalkalosis, hypothermia,
hypocapnia, decreased 2,3 DPG
What causes a right shift on the dissociation curve? - ANSWERSacidosis,
hyperthermia, hypercapnia, increased 2,3-DPG
What are three components of oxygenation? - ANSWERSpulmonary gas exchange, O2
delivery, O2 consumption
What 2 problems in oxygenation does the nurse assess for and intervene? -
ANSWERSdecreased O2 supply, increased O2 demand
What is the definition of oxygenation? - ANSWERSthe use of O2 for energy through
aerobic metabolism
,What are the two goals in the assessment of oxygenation? - ANSWERSto determine
the overall adequacy of oxygenation and to determine which component of oxygenation
dysfunction should be manipulated
What are the three components of pulmonary gas exchange? - ANSWERSventilation,
diffusion, perfusion
What is the definition of ventilation? - ANSWERSmovement of air between the
atmosphere and the lungs
What is the actual work of breathing called (using the muscles, lungs, airway, nervous
system)? - ANSWERSventilation
What is the definition of diffusion? - ANSWERSmovement of gas across pressure
gradient from area of high concentration to low concentration
What is it called when O2 moves from alveoli to pulmonary capillaries? -
ANSWERSdiffusion
What is the definition of perfusion? - ANSWERSpulmonary perfusion of pulmonary
capillaries; flow of blood to tissues/organs
What is perfusion affected by? - ANSWERSHgb, O2 affinity, and blood flow
Why is the matching of ventilation to perfusion essential for gas exchange? -
ANSWERSwhen they are not matched, oxygen becomes impaired
When might ventilation to perfusion mismatching occur? - ANSWERSPE,
pneumothorax, hypoxemia
What are the components of oxygen delivery? - ANSWERSCO, CaO2, ANS
innervation, auto-regulation
What is afterload? - ANSWERSresistance ventricle pumps blood
What is the normal value for afterload? - ANSWERS800-1200
What is cardiac output? - ANSWERSamount of blood pumped each minute
What is the normal value for cardiac output? - ANSWERS4-8
What is CaO2? - ANSWERSTotal O2 carried in arterial blood
What is combined SaO2 and PaO2? - ANSWERSCaO2
What is contractility? - ANSWERSthe force of contractions
,What is DO2? - ANSWERSprocess of O2 transport to cells, utilizing CO, CaO2,
autoregulation, and ANS innervation
What is the product of CO and CaO2? - ANSWERSDO2
What is HgbO2? - ANSWERShemoglobin fully saturated with O2
What is SaO2/SpO2? - ANSWERSratio of HgbO2 to total Hgb
What is the difference between SaO2 and SpO2? - ANSWERSSpO2 means obtained
through pulse oximetry, where SaO2 is via arterial blood
What is stroke volume? - ANSWERSvolume pumped with each beat
What is the normal value of stroke volume? - ANSWERS50-100
What is the normal value of Hgb? - ANSWERS12-17
What does PaO2 represent? - ANSWERSamount of oxygen dissolved in plasma
What does SaO2 represent? - ANSWERSSaturation of Hgb with O2 (oxyhemoglobin)
What is the percentage of the body's oxygen on HgbO2 (SaO2)? - ANSWERS97%
What percentage of the body's oxygen is dissolved in plasma (PaO2)? - ANSWERS3%
What can impair O2 delivery? - ANSWERSdysrhythmias, heart failure, uncompensated
decrease in CO, Hgb, or SaO2
How is O2 delivery assessed? - ANSWERSCO, Hgb, SaO2, PaO2 (ABGs)
How can CO be assessed at the bedside? - ANSWERSpulses, heart sounds, monitor,
fluid balance, CVP, heart sounds, O2 status, BP, pulse pressure, Hx of previous MI,
acute MI or ischemia
What is the definition of oxygen consumption? - ANSWERSthe rate at which O2 is used
by cells to generate energy
What is the definition of aerobic metabolism? - ANSWERScarbs/fats/proteins broken
down into ATP (through Krebs cycle); creates intracellular energy stores to release
when energy is required
What is the definition of anaerobic metabolism? - ANSWERSbackup mechanism to
generate energy in the absence of O2; this occurs through the metabolism of carbs, the
only food that can generate ATP without oxygen
, What are byproducts of anaerobic metabolism? - ANSWERSpyruvate and lactate
What can a patient develop if anaerobic metabolism persists? - ANSWERSischemic
stroke, cardiac arrest, lactic acidosis
What is oxygen extraction? - ANSWERSwhen cells take O2 from the blood
What % of O2 is taken up by the cells? - ANSWERS25%
What % of O2 is returned to the right heart? - ANSWERS75%
What is SvO2? - ANSWERSblood returned to the heart through venous circulation
Are tissue demands higher or lower with a left shift on the oxyhemoglobin curve? -
ANSWERSlower
Are tissue demands higher or lower with a right shift on the oxyhemoglobin dissociation
curve? - ANSWERShigher
How does a left shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - ANSWERSincreases affinity of Hgb for O2, Hgb binds with O2 (high
HgbO2/SaO2), Hgb does not readily release oxygen, so less O2 is extracted and cells
become hypoxic, more O2 remains in blood as it flows back to heart through venous
system
What assessments are associated with a left shift on the oxyhemoglobin dissociation
curve? - ANSWERSHigh SaO2, SpO2, SvO2
What are some precipitating conditions for a left shift on the oxyhemoglobin dissociation
curve? - ANSWERSenvironmental exposure (cold-water near drowning, cold weather
exposure, induced hypothermia from surgery); hyperventilation; GI-associated loss of
acid or gain of alkaline through vomiting or NG drainage; sodium bicarbonate
How does a right shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - ANSWERSdecreases affinity of Hgb for O2, Hgb doesn't bind as readily
with O2 (HgbO2/SaO2), Hgb readily releases O2, O2 extracted rapidly, leaving
insufficient O2 for all tissue, less O2 remains in blood as it flows back to heart through
venous system
What assessments are associated with a right shift on the oxyhemoglobin dissociation
curve? - ANSWERSLow SaO2, SpO2, SvO2
What are some precipitating conditions for a right shift on the oxyhemoglobin
dissociation curve? - ANSWERSrespiratory failure, high fever, metabolic acidosis
QUESTIONS WITH DETAILED
VERIFIED ANSWERS (100% CORRECT
ANSWERS) ALREADY GRADED A+
What is the definition of affinity? - ANSWERSthe attraction between Hgb and O2
What does Hgb have an affinity to? - ANSWERSHgb has an attraction for O2 molecules
What does the oxyhemoglobin dissociation curve represent? - ANSWERSrelationship
between PaO2 and SaO2
What is PaO2? - ANSWERSpartial pressure of arterial O2 (arterial O2 tension)
What is SaO2? - ANSWERSHgb saturation
What does P50 represent? - ANSWERSmeasures when Hgb is 50% saturated with O2
When does the P50 change? - ANSWERSwhen physiologic factors are altered
What does a left shift on the dissociation curve do to the affinity of O2 to hemoglobin? -
ANSWERSincreases affinity = prevents release to tissues
What does a right shift on the dissociation curve do to the affinity of O2 to hemoglobin?
- ANSWERSdecreases affinity = readily release to tissues
What causes a left shift on the dissociation curve? - ANSWERSalkalosis, hypothermia,
hypocapnia, decreased 2,3 DPG
What causes a right shift on the dissociation curve? - ANSWERSacidosis,
hyperthermia, hypercapnia, increased 2,3-DPG
What are three components of oxygenation? - ANSWERSpulmonary gas exchange, O2
delivery, O2 consumption
What 2 problems in oxygenation does the nurse assess for and intervene? -
ANSWERSdecreased O2 supply, increased O2 demand
What is the definition of oxygenation? - ANSWERSthe use of O2 for energy through
aerobic metabolism
,What are the two goals in the assessment of oxygenation? - ANSWERSto determine
the overall adequacy of oxygenation and to determine which component of oxygenation
dysfunction should be manipulated
What are the three components of pulmonary gas exchange? - ANSWERSventilation,
diffusion, perfusion
What is the definition of ventilation? - ANSWERSmovement of air between the
atmosphere and the lungs
What is the actual work of breathing called (using the muscles, lungs, airway, nervous
system)? - ANSWERSventilation
What is the definition of diffusion? - ANSWERSmovement of gas across pressure
gradient from area of high concentration to low concentration
What is it called when O2 moves from alveoli to pulmonary capillaries? -
ANSWERSdiffusion
What is the definition of perfusion? - ANSWERSpulmonary perfusion of pulmonary
capillaries; flow of blood to tissues/organs
What is perfusion affected by? - ANSWERSHgb, O2 affinity, and blood flow
Why is the matching of ventilation to perfusion essential for gas exchange? -
ANSWERSwhen they are not matched, oxygen becomes impaired
When might ventilation to perfusion mismatching occur? - ANSWERSPE,
pneumothorax, hypoxemia
What are the components of oxygen delivery? - ANSWERSCO, CaO2, ANS
innervation, auto-regulation
What is afterload? - ANSWERSresistance ventricle pumps blood
What is the normal value for afterload? - ANSWERS800-1200
What is cardiac output? - ANSWERSamount of blood pumped each minute
What is the normal value for cardiac output? - ANSWERS4-8
What is CaO2? - ANSWERSTotal O2 carried in arterial blood
What is combined SaO2 and PaO2? - ANSWERSCaO2
What is contractility? - ANSWERSthe force of contractions
,What is DO2? - ANSWERSprocess of O2 transport to cells, utilizing CO, CaO2,
autoregulation, and ANS innervation
What is the product of CO and CaO2? - ANSWERSDO2
What is HgbO2? - ANSWERShemoglobin fully saturated with O2
What is SaO2/SpO2? - ANSWERSratio of HgbO2 to total Hgb
What is the difference between SaO2 and SpO2? - ANSWERSSpO2 means obtained
through pulse oximetry, where SaO2 is via arterial blood
What is stroke volume? - ANSWERSvolume pumped with each beat
What is the normal value of stroke volume? - ANSWERS50-100
What is the normal value of Hgb? - ANSWERS12-17
What does PaO2 represent? - ANSWERSamount of oxygen dissolved in plasma
What does SaO2 represent? - ANSWERSSaturation of Hgb with O2 (oxyhemoglobin)
What is the percentage of the body's oxygen on HgbO2 (SaO2)? - ANSWERS97%
What percentage of the body's oxygen is dissolved in plasma (PaO2)? - ANSWERS3%
What can impair O2 delivery? - ANSWERSdysrhythmias, heart failure, uncompensated
decrease in CO, Hgb, or SaO2
How is O2 delivery assessed? - ANSWERSCO, Hgb, SaO2, PaO2 (ABGs)
How can CO be assessed at the bedside? - ANSWERSpulses, heart sounds, monitor,
fluid balance, CVP, heart sounds, O2 status, BP, pulse pressure, Hx of previous MI,
acute MI or ischemia
What is the definition of oxygen consumption? - ANSWERSthe rate at which O2 is used
by cells to generate energy
What is the definition of aerobic metabolism? - ANSWERScarbs/fats/proteins broken
down into ATP (through Krebs cycle); creates intracellular energy stores to release
when energy is required
What is the definition of anaerobic metabolism? - ANSWERSbackup mechanism to
generate energy in the absence of O2; this occurs through the metabolism of carbs, the
only food that can generate ATP without oxygen
, What are byproducts of anaerobic metabolism? - ANSWERSpyruvate and lactate
What can a patient develop if anaerobic metabolism persists? - ANSWERSischemic
stroke, cardiac arrest, lactic acidosis
What is oxygen extraction? - ANSWERSwhen cells take O2 from the blood
What % of O2 is taken up by the cells? - ANSWERS25%
What % of O2 is returned to the right heart? - ANSWERS75%
What is SvO2? - ANSWERSblood returned to the heart through venous circulation
Are tissue demands higher or lower with a left shift on the oxyhemoglobin curve? -
ANSWERSlower
Are tissue demands higher or lower with a right shift on the oxyhemoglobin dissociation
curve? - ANSWERShigher
How does a left shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - ANSWERSincreases affinity of Hgb for O2, Hgb binds with O2 (high
HgbO2/SaO2), Hgb does not readily release oxygen, so less O2 is extracted and cells
become hypoxic, more O2 remains in blood as it flows back to heart through venous
system
What assessments are associated with a left shift on the oxyhemoglobin dissociation
curve? - ANSWERSHigh SaO2, SpO2, SvO2
What are some precipitating conditions for a left shift on the oxyhemoglobin dissociation
curve? - ANSWERSenvironmental exposure (cold-water near drowning, cold weather
exposure, induced hypothermia from surgery); hyperventilation; GI-associated loss of
acid or gain of alkaline through vomiting or NG drainage; sodium bicarbonate
How does a right shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - ANSWERSdecreases affinity of Hgb for O2, Hgb doesn't bind as readily
with O2 (HgbO2/SaO2), Hgb readily releases O2, O2 extracted rapidly, leaving
insufficient O2 for all tissue, less O2 remains in blood as it flows back to heart through
venous system
What assessments are associated with a right shift on the oxyhemoglobin dissociation
curve? - ANSWERSLow SaO2, SpO2, SvO2
What are some precipitating conditions for a right shift on the oxyhemoglobin
dissociation curve? - ANSWERSrespiratory failure, high fever, metabolic acidosis
