Preoxygenation and FRC

[dipriMAN]

For some that has obstructive lung disease, their FRC will be increased. Does this mean that for someone with COPD, all else being equal, they will maintain their sats longer with apnea after preoxygenation than a lung with comparatively normal FRC.

 

[deleted162650]

No

 

[FFP]

Not all alveoli participate in oxygen exchange in severe COPD-ers.

 

[drmwvr]

Not as bad as obesity but not as good as a college kid. Assuming no exacerbation. I understand this is more academic than clinical reality, but good preoxygenation (black rubber face strap, not distracted OR nurse) for several minutes will give at least 3-4 minutes of safe apnea in the non obese COPD'er. Add reverse trendellenburg and it may be more. You shouldn't notice a difference, all else being equal.

 

[timgasman]

For some that has obstructive lung disease, their FRC will be increased. Does this mean that for someone with COPD, all else being equal, they will maintain their sats longer with apnea after preoxygenation than a lung with comparatively normal FRC.

The lung is diseased so the problem isn't just that you have a large FRC, but you cannot get the oxygen out due to loss of passive recoil.