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?

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The PaO₂ and SaO₂ are normal, indicating normal oxygen trAnswerfer across the lung. However, the hemoglobin of 7 g/dL indicates severe anemia. The CaO₂ is calculated as follows: CaO₂ = (7 x 1.34 x 0.975) + (100 x 0.003) CaO₂ = 9.45 mL/dL Thus, CaO₂ is less than half of normal, although PaO? and SaO? are normal. Is oxygen delivery (O₂ DEL) adequate? O₂ DEL = (9.45 mL oxygen/dL x 10 dL/L) x 8 L/min O₂ DEL = 756 mL/min Thus the O? DEL is less than normal (normal = 1000 mL/min) as a result of the low CaO₂. The high $\dot Q $ of 8 L/min is a compensatory response to anemia that offsets the effects of reduced CaO₂. Although O₂ DEL is still below normal, it is well above the normal resting oxygen consumption of 250 mL/min. If this anemic person has coronary artery disease, a special danger exists because blood flow to heart muscle is hampered even at rest. The high workload placed on the heart by anemia greatly increases the heart muscle's need for more blood flow and oxygen; diseased coronary arteries may not be able to deliver enough blood flow to meet this need.

A Patient Has the Following Arterial Blood-Gas Values While Breathing Q˙\dot Q Q˙​

A Patient Has the Following Arterial Blood-Gas Values While Breathing $\dot Q$