Preoxygenation before induction is done:
|A||To improve oxygen saturation|
|B||To increase dissolved fradion|
|C||To eliminate carbon dioxide|
|E||All of the above|
a. Denitrogenation means removal of nitrogen from lungs is the aim of preoxygenation.
b. The oxygen reserve which can be utilized by body is in the form of functional residual capacity (FRC) in lung which contains only 500 ml of oxygen (21% of normal FRC which is 2.5 liters) which will last for 2 minutes only (oxygen consumption is 250 m/min).
c. With preoxygenation 95% of the nitrogen can e removed in 3 minutes making the almost whole FRC to be filled with oxygen which can last for 8-10 minutes.