Harry Ch. 08 Mid term

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

60-80 mm Hg

Which of the following levels of PO2 is associated with sharp decreases in oxygen saturation and content?

<60 mm Hg

Which of the following terms describes the unoxygenated hemoglobin?

Deoxyhemoglobin

What is the effect of a high P50?

Hemoglobin's affinity for oxygen is decreased.

Which of the following are pathological features associated with HbS?

I. . Thromboemboli 2. Ischemia 3. Tissue hypoxia

Which of the following are normal values for hemoglobin saturations and oxygen partial pressures?

I. Arterial oxygen saturation (SaO2) is approximately 97.5%. 2. PO2 is 100 mm Hg at SaO2 of 97.5%. 3. Mixed venous oxygen saturation (Smc005-1.jpgO2) is normally 75%

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. 2 Hemoglobin's capacity to carry oxygen is approximately 67 times more than the capacity of plasma alone when PaO2 is 100 mm Hg. 3. A normal cardiac output of 5 L/min delivers approximately 1000 mL of oxygen to the body's tissues each minute.

Which of the following factors affect oxygen delivery to the tissues?

I. Hemoglobin concentration 2.Arterial hemoglobin saturation with oxygen 3. Cardiac output

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). 2. Small PO2 changes cause large blood oxygen content changes in the middle, steep portion of the curve (20 to 60 mm Hg).

Which of the following are statements related to P50?

I. Normally, a PO2 of 27 mm Hg produces an SO2 of 50%. 2.The P50 is a measure of hemoglobin's affinity for oxygen. 3.A normal P50 is accurate when the blood temperature is 37° C, pH is 7.40, and PCO2 is 40 mm Hg.

Which of the following statements are true of fetal hemoglobin?

I.Hemoglobin present in the fetus has a high affinity for oxygen. 2.HbF of normal-term infants has a P50 of approximately 22 mm Hg. 3.A cyanotic newborn infant has a much lower arterial PO2 than an equally cyanotic adult. 4.By 6 months after birth, most HbF has been replaced with HbA.

Which of the following conditions decrease hemoglobin's affinity for oxygen?

I.Increased blood PCO2 2.Decreased blood pH 3. Increased blood temperature

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

25%

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

250 mL/min

What is the minimum desaturated hemoglobin concentration in the capillaries when most observers perceive cyanosis?

5 g/dL

What is the normal amount of oxygen extracted by the tissues for each 100 mL of blood?

5 mL/dL

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

20.1 mL/dL

Which of the following is the conventionally accepted value for hemoglobin's oxygen-carrying capacity?

1.34 mL of oxygen per gram of hemoglobin

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

1000 mL/min

What is the rationale behind using an FIO2 of 1.0 to manage patients with acute CO poisoning?

An FIO2 of 1.0 greatly decreases the half-life of HbCO.

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

Bohr effect

Where is the majority of oxygen in blood?

Erythrocyte

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

It decreases oxygen availability to the tissues.

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

Low venous oxygen saturation

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 mc022-1.jpg is 8 L/min. Will the resting oxygen consumption be affected?

No, because the PaO2 is normal.

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

Polycythemia