Gas exchange during apnea creates subatmopsheric pressure in the alveoli
In healthy lungs, 200-250mL O2 per minute can be drawn into blood stream
In the absence of ventilation (i.e. during apnea), only 10-20mL CO2 enters alveoli from bloodstream per minute, due to increased CO2 tension
This causes a net decrease in gas in the alveoli
This gradient can draw air into the lungs, even absent diaphragmatic movement
Increases safe apnea time in healthy volunteers from 1 minute (room air) to 8-9 minutes
In healthy lungs, 200-250mL O2 per minute can be drawn into blood stream
In the absence of ventilation (i.e. during apnea), only 10-20mL CO2 enters alveoli from bloodstream per minute, due to increased CO2 tension
This causes a net decrease in gas in the alveoli
Apneic oxygenation
ECG axis
Mask squeeze
Lung recruitment maneuver
Breath-holding spell
Hypopyon
Ventilation modes
CO2 narcosis