Lung preoxygenation Some medical procedures require a patients airway to be temporarily

Chapter 7, Problem 17

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Lung preoxygenation Some medical procedures require a patients airway to be temporarily blocked, preventing the inspiration of oxygen. The duration of time over which such procedures can be performed safely may be increased by replacing a large fraction of the air in the patients lungs with oxygen prior to the procedure. Suppose the lung volume is 3 L and well-mixed air in the lungs is replaced with pure oxygen at a rate of 10 mLys. (a) What is the amount of oxygen in the lungs as a function of time if they initially contain 20% oxygen? (b) Use your answer from part (a) to determine how long the process of oxygenation should be run to result in an 80% oxygen content in the lungs