NUR 445 Exam 2 COMPLETE
QUESTIONS WITH DETAILED
VERIFIED ANSWERS
What is the definition of affinity? - correct Answer-the attraction between Hgb and O2
What does Hgb have an affinity to? - correct Answer-Hgb has an attraction for O2
molecules
What does the oxyhemoglobin dissociation curve represent? - correct Answer-
relationship between PaO2 and SaO2
What is PaO2? - correct Answer-partial pressure of arterial O2 (arterial O2 tension)
What is SaO2? - correct Answer-Hgb saturation
What does P50 represent? - correct Answer-measures when Hgb is 50% saturated with
O2
When does the P50 change? - correct Answer-when physiologic factors are altered
What does a left shift on the dissociation curve do to the affinity of O2 to hemoglobin? -
correct Answer-increases affinity = prevents release to tissues
What does a right shift on the dissociation curve do to the affinity of O2 to hemoglobin?
- correct Answer-decreases affinity = readily release to tissues
What causes a left shift on the dissociation curve? - correct Answer-alkalosis,
hypothermia, hypocapnia, decreased 2,3 DPG
What causes a right shift on the dissociation curve? - correct Answer-acidosis,
hyperthermia, hypercapnia, increased 2,3-DPG
What are three components of oxygenation? - correct Answer-pulmonary gas
exchange, O2 delivery, O2 consumption
What 2 problems in oxygenation does the nurse assess for and intervene? - correct
Answer-decreased O2 supply, increased O2 demand
,What is the definition of oxygenation? - correct Answer-the use of O2 for energy through
aerobic metabolism
What are the two goals in the assessment of oxygenation? - correct Answer-to
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? - correct Answer-
ventilation, diffusion, perfusion
What is the definition of ventilation? - correct Answer-movement of air between the
atmosphere and the lungs
What is the actual work of breathing called (using the muscles, lungs, airway, nervous
system)? - correct Answer-ventilation
What is the definition of diffusion? - correct Answer-movement 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? - correct
Answer-diffusion
What is the definition of perfusion? - correct Answer-pulmonary perfusion of pulmonary
capillaries; flow of blood to tissues/organs
What is perfusion affected by? - correct Answer-Hgb, O2 affinity, and blood flow
Why is the matching of ventilation to perfusion essential for gas exchange? - correct
Answer-when they are not matched, oxygen becomes impaired
When might ventilation to perfusion mismatching occur? - correct Answer-PE,
pneumothorax, hypoxemia
What are the components of oxygen delivery? - correct Answer-CO, CaO2, ANS
innervation, auto-regulation
What is afterload? - correct Answer-resistance ventricle pumps blood
What is the normal value for afterload? - correct Answer-800-1200
What is cardiac output? - correct Answer-amount of blood pumped each minute
What is the normal value for cardiac output? - correct Answer-4-8
What is CaO2? - correct Answer-Total O2 carried in arterial blood
,What is combined SaO2 and PaO2? - correct Answer-CaO2
What is contractility? - correct Answer-the force of contractions
What is DO2? - correct Answer-process of O2 transport to cells, utilizing CO, CaO2,
autoregulation, and ANS innervation
What is the product of CO and CaO2? - correct Answer-DO2
What is HgbO2? - correct Answer-hemoglobin fully saturated with O2
What is SaO2/SpO2? - correct Answer-ratio of HgbO2 to total Hgb
What is the difference between SaO2 and SpO2? - correct Answer-SpO2 means
obtained through pulse oximetry, where SaO2 is via arterial blood
What is stroke volume? - correct Answer-volume pumped with each beat
What is the normal value of stroke volume? - correct Answer-50-100
What is the normal value of Hgb? - correct Answer-12-17
What does PaO2 represent? - correct Answer-amount of oxygen dissolved in plasma
What does SaO2 represent? - correct Answer-Saturation of Hgb with O2
(oxyhemoglobin)
What is the percentage of the body's oxygen on HgbO2 (SaO2)? - correct Answer-97%
What percentage of the body's oxygen is dissolved in plasma (PaO2)? - correct Answer-
3%
What can impair O2 delivery? - correct Answer-dysrhythmias, heart failure,
uncompensated decrease in CO, Hgb, or SaO2
How is O2 delivery assessed? - correct Answer-CO, Hgb, SaO2, PaO2 (ABGs)
How can CO be assessed at the bedside? - correct Answer-pulses, 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? - correct Answer-the rate at which O2 is
used by cells to generate energy
, What is the definition of aerobic metabolism? - correct Answer-carbs/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? - correct Answer-backup 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? - correct Answer-pyruvate and lactate
What can a patient develop if anaerobic metabolism persists? - correct Answer-
ischemic stroke, cardiac arrest, lactic acidosis
What is oxygen extraction? - correct Answer-when cells take O2 from the blood
What % of O2 is taken up by the cells? - correct Answer-25%
What % of O2 is returned to the right heart? - correct Answer-75%
What is SvO2? - correct Answer-blood returned to the heart through venous circulation
Are tissue demands higher or lower with a left shift on the oxyhemoglobin curve? -
correct Answer-lower
Are tissue demands higher or lower with a right shift on the oxyhemoglobin dissociation
curve? - correct Answer-higher
How does a left shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - correct Answer-increases 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? - correct Answer-High SaO2, SpO2, SvO2
What are some precipitating conditions for a left shift on the oxyhemoglobin dissociation
curve? - correct Answer-environmental 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? - correct Answer-decreases 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
QUESTIONS WITH DETAILED
VERIFIED ANSWERS
What is the definition of affinity? - correct Answer-the attraction between Hgb and O2
What does Hgb have an affinity to? - correct Answer-Hgb has an attraction for O2
molecules
What does the oxyhemoglobin dissociation curve represent? - correct Answer-
relationship between PaO2 and SaO2
What is PaO2? - correct Answer-partial pressure of arterial O2 (arterial O2 tension)
What is SaO2? - correct Answer-Hgb saturation
What does P50 represent? - correct Answer-measures when Hgb is 50% saturated with
O2
When does the P50 change? - correct Answer-when physiologic factors are altered
What does a left shift on the dissociation curve do to the affinity of O2 to hemoglobin? -
correct Answer-increases affinity = prevents release to tissues
What does a right shift on the dissociation curve do to the affinity of O2 to hemoglobin?
- correct Answer-decreases affinity = readily release to tissues
What causes a left shift on the dissociation curve? - correct Answer-alkalosis,
hypothermia, hypocapnia, decreased 2,3 DPG
What causes a right shift on the dissociation curve? - correct Answer-acidosis,
hyperthermia, hypercapnia, increased 2,3-DPG
What are three components of oxygenation? - correct Answer-pulmonary gas
exchange, O2 delivery, O2 consumption
What 2 problems in oxygenation does the nurse assess for and intervene? - correct
Answer-decreased O2 supply, increased O2 demand
,What is the definition of oxygenation? - correct Answer-the use of O2 for energy through
aerobic metabolism
What are the two goals in the assessment of oxygenation? - correct Answer-to
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? - correct Answer-
ventilation, diffusion, perfusion
What is the definition of ventilation? - correct Answer-movement of air between the
atmosphere and the lungs
What is the actual work of breathing called (using the muscles, lungs, airway, nervous
system)? - correct Answer-ventilation
What is the definition of diffusion? - correct Answer-movement 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? - correct
Answer-diffusion
What is the definition of perfusion? - correct Answer-pulmonary perfusion of pulmonary
capillaries; flow of blood to tissues/organs
What is perfusion affected by? - correct Answer-Hgb, O2 affinity, and blood flow
Why is the matching of ventilation to perfusion essential for gas exchange? - correct
Answer-when they are not matched, oxygen becomes impaired
When might ventilation to perfusion mismatching occur? - correct Answer-PE,
pneumothorax, hypoxemia
What are the components of oxygen delivery? - correct Answer-CO, CaO2, ANS
innervation, auto-regulation
What is afterload? - correct Answer-resistance ventricle pumps blood
What is the normal value for afterload? - correct Answer-800-1200
What is cardiac output? - correct Answer-amount of blood pumped each minute
What is the normal value for cardiac output? - correct Answer-4-8
What is CaO2? - correct Answer-Total O2 carried in arterial blood
,What is combined SaO2 and PaO2? - correct Answer-CaO2
What is contractility? - correct Answer-the force of contractions
What is DO2? - correct Answer-process of O2 transport to cells, utilizing CO, CaO2,
autoregulation, and ANS innervation
What is the product of CO and CaO2? - correct Answer-DO2
What is HgbO2? - correct Answer-hemoglobin fully saturated with O2
What is SaO2/SpO2? - correct Answer-ratio of HgbO2 to total Hgb
What is the difference between SaO2 and SpO2? - correct Answer-SpO2 means
obtained through pulse oximetry, where SaO2 is via arterial blood
What is stroke volume? - correct Answer-volume pumped with each beat
What is the normal value of stroke volume? - correct Answer-50-100
What is the normal value of Hgb? - correct Answer-12-17
What does PaO2 represent? - correct Answer-amount of oxygen dissolved in plasma
What does SaO2 represent? - correct Answer-Saturation of Hgb with O2
(oxyhemoglobin)
What is the percentage of the body's oxygen on HgbO2 (SaO2)? - correct Answer-97%
What percentage of the body's oxygen is dissolved in plasma (PaO2)? - correct Answer-
3%
What can impair O2 delivery? - correct Answer-dysrhythmias, heart failure,
uncompensated decrease in CO, Hgb, or SaO2
How is O2 delivery assessed? - correct Answer-CO, Hgb, SaO2, PaO2 (ABGs)
How can CO be assessed at the bedside? - correct Answer-pulses, 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? - correct Answer-the rate at which O2 is
used by cells to generate energy
, What is the definition of aerobic metabolism? - correct Answer-carbs/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? - correct Answer-backup 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? - correct Answer-pyruvate and lactate
What can a patient develop if anaerobic metabolism persists? - correct Answer-
ischemic stroke, cardiac arrest, lactic acidosis
What is oxygen extraction? - correct Answer-when cells take O2 from the blood
What % of O2 is taken up by the cells? - correct Answer-25%
What % of O2 is returned to the right heart? - correct Answer-75%
What is SvO2? - correct Answer-blood returned to the heart through venous circulation
Are tissue demands higher or lower with a left shift on the oxyhemoglobin curve? -
correct Answer-lower
Are tissue demands higher or lower with a right shift on the oxyhemoglobin dissociation
curve? - correct Answer-higher
How does a left shift on the oxyhemoglobin dissociation curve affect tissue
oxygenation? - correct Answer-increases 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? - correct Answer-High SaO2, SpO2, SvO2
What are some precipitating conditions for a left shift on the oxyhemoglobin dissociation
curve? - correct Answer-environmental 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? - correct Answer-decreases 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
