Vital Capacity Recruitment Maneuver

 A sigh maneuver, or a large tidal volume (Vt), has been suggested for reversing atelectasis; however, atelectasis is not uniformly reduced by a Vt increase or sigh up to airway pressure (Paw) of 20 cm H2O. 

 Instead, a PAW of 30 cm H2O is required for initial opening, and 40 cm H2O for more complete reversal. In the presence of normal lungs, such inflation is equivalent to a Vital Capacity (VC) and can therefore be called a VC maneuver (albeit achieved with positive PAW). 

In addition, a significant hemodynamic effect is likely if the VC maneuver is sustained; in fact, inflation with a PAW of 40 cm H2O for 7 to 8 seconds appears to successfully open almost all anesthesia-induced atelectasis.