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28 Cards in this Set
- Front
- Back
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CO poisoning is most often encountered in ____ (3).
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1. Building fires
2. Leaking heating systems 3. Suicide attempts |
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Symptoms of CO poisoning are initially _______ and include ______.
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vague; headache & nausea, fatigue, visual disturbances, paresthesia, chest/abdominal pains
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CO is very insidious because it is ______ and ______.
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colorless; odorless
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Inspired air has a partial pressure of _______.
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150 mm Hg; ([760-47]x0,21)
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The alveolar gas equation is used to calculate the _________.
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partial pressure of oxygen in the alveoli
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The alveolar gas equation is written as
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What does R in the alveolar gas equation represent?
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R is the ratio of CO2 produced to O2 consumed and is approximately 0.8.
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Henry’s law dictates that ____________.
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the concentration of dissolved gas (Cx) is proportional to its partial pressure (Px): C_x = K x P_x
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The hemoglobin-dissociation curve is essentially flat (O2 is avidly bound to Hb) between _____ and _______.
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60 mm Hg; 100 mm Hg.
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These factors move the Hb-O2 dissociation curve to the right.
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↑ temperature
↑ [H+] ↑ PCO2 ↑ 2,3-DPG |
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These conditions exist in peripheral muscle capillary beds during exertion.
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↑ temperature, ↑ [H+], ↑ PCO2, ↑ 2,3-DPG
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CO2 is transported in three forms, what are they?
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1. Dissolved
2. Carbamino compounds (CO2 reversibly binds amine groups on circulating proteins) 3. Bicarbonate |
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The solubility of CO2 is ________ than that of oxygen.
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20 times greater
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What is the haldane effect?
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That deoxygenated Hb has higher affinity for CO2 than oxygenated Hb.
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Bicarbonate is generated from CO2 in red
blood cells by the following reaction: |
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Because H+ cannot freely cross the red cell
membrane, ________ shifts into the cells to maintain electrical neutrality. This is known as ________. |
chloride; chloride shift
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60% of CO2 is transported as ______, 30% as ________ and 10% as _________.
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bicarbonate; carbamino; dissolved CO2
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True/False: It's not useful to measure oxygen saturation of hemoglobin during CO-poisoning.
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True. CO binds reversibly to Hb, forming carboxy-hemoglobin. O2 then binds, however, the molecular conformation is "locked" due to CO, and thus it does not release O2. O2-saturation remains essentially the same.
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How would CO affect the Hb-saturation curve?
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CO would make Hb release less O2 (increasing affinity), so it would left-shift it.
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CO has ______ the affinity for Hb than for oxygen.
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240 times
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How would you treat a person with CO-poisoning?
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Breathing 100% oxygen to reverse CO-Hb binding. Breathing 100% oxygen at several atmospheres greatly delivered concentration of O2.
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A person is CO-poisoned at 19 pm. When does the CO bound to Hb reach half of its original amount when the person breathes room air.
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at 23 pm, 4 hours later. Binding half life of CO to Hb is about 240 minutes. This is reduced to 80 minutes while breathing 100% oxygen and 20 minutes while breathing 100% O2 at 3 atm.
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Dissolved O2 accounts for ______ of arterial O2 content.
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only 1,5 %
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CO2 diffuses across the alveolar membrane ___________ than O2.
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more readily
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True/False: In anemia, the arterial oxygen tension is lowered.
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False. O2-tension is independent of hemoglobin
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What is the oxygen-carrying capacity in a person with a hemoglobin of 15 g/dL? Assume 100% O2-saturation.
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100% = 1.0
1.0 x 15 g/dL x 1.39 mL/g (Hb) = 20.8 mL/dL |
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Normal P50 is about ______.
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27 mm Hg
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How would the hemoglobin-oxygen dissociation curve look after CO poisoning?
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