Exam 8: Oxygen Equilibrium and Transport

Which of the following are normal values for hemoglobin saturations and oxygen partial pressures? I.Arterial oxygen saturation (SaO₂) is approximately 97.5%. II.PO₂ is 100 mm Hg at SaO₂ of 97.5%. III.Mixed venous oxygen saturation (S $\bar{V}$ O₂) is normally 75%. IV. P $\bar{V}$ O₂ is 60 mm Hg at S $\bar{V}$ O₂ of 75%.

Under resting conditions, what percentage of the arterial oxygen content is extracted by the tissues?

What is the normal amount of oxygen delivered to the tissues?

A patient has the following arterial blood-gas values while breathing room air: PaO₂ = 100 mm Hg; SaO₂ = 0.975.The hemoglobin concentration is 7 g/dL, and the $\dot Q$ is 8 L/min.Will the resting oxygen consumption be affected?

What is the best explanation for the presence of peripheral cyanosis?

Which of the following conditions is an example of hypoxemia with cyanosis?

What is the normal amount of oxygen consumed by the tissues?

Which of the following statements are true of fetal hemoglobin? I.Hemoglobin present in the fetus has a high affinity for oxygen. II.HbF of normal-term infants has a P₅₀ of approximately 22 mm Hg. III.A cyanotic newborn infant has a much lower arterial PO₂ than an equally cyanotic adult. IV.By 6 months after birth, most HbF has been replaced with HbA.

What is the clinical consequence of the point below DO₂crit?

Which of the following are pathological features associated with HbS? I.Thromboemboli II.Ischemia III.Polycythemia IV.Tissue hypoxia

Assuming a concentration of 15 g/dL, what will be the hemoglobin's oxygen-carrying capacity?

Which of the following levels of PO₂ is associated with a significant oxygen content gain?

Which of the following conditions decrease hemoglobin's affinity for oxygen? I.Increased blood PCO₂ II.Decreased blood pH III.Increased blood temperature IV.Decreased blood levels of the organic phosphate 2,3-DPG

What is the effect of a high P₅₀?

What is the effect of transfusing banked blood stored with an acid-citrate dextrose anticoagulant?

Which of the following statements are true of oxygen transport? I.Hemoglobin allows whole blood to carry approximately 20 mL of oxygen per 100 mL of blood at the normal arterial PaO₂ of 100 mm Hg. II.Hemoglobin's capacity to carry oxygen is approximately 67 times more than the capacity of plasma alone when PaO? is 100 mm Hg. III.A normal cardiac output of 5 L/min delivers approximately 1000 mL of oxygen to the body's tissues each minute. IV.The amount of oxygen delivered is not enough to meet the tissues' resting requirement.

What is the name of the phenomenon associated with the decreased affinity of Hb for oxygen when PCO₂ is high?

Where is the majority of oxygen in blood?

Which of the following statements relate to the HbO₂ equilibrium curve? I.Large PO₂ changes cause small to minimal changes in oxygen content, especially at the extreme flat right end (60 to 100 mm Hg). II.Small PO₂ changes cause large blood oxygen content changes in the middle, steep portion of the curve (20 to 60 mm Hg). III.Large PO₂ changes cause large changes in oxygen content at the extreme flatter ends of the curve, especially the flat right end (60 to 100 mm Hg). IV.Small PO₂ changes cause small blood oxygen content changes in the middle, steep portion of the curve (20 to 60 mm Hg).

Which of the following statements are true of blood transfusion to improve oxygen delivery? I.It is recommended when DO₂crit is reached. II.It is associated with increased mortality. III.It is indicated when hypoxia is due to anemia (Hb of 8 g/dL). IV.It is associated with increased mortality.