• Inadequate oxygenation or ventilation, as bridge to intubation

■ Open airway via jaw thrust and naso- or oropharyngeal airway.
■ Position mask to cover mouth and nose.
        - Single-handed mask hold: Thumb and index fingers on mask with remaining fingers wrapped around mandible. This is a difficult technique but may be necessary for a single rescuer.
        - Two-handed technique: Thumb and index fingers on either side of mask with remaining fingers wrapped around mandible.
■ Lift mandible into mask to form seal.
       - Two-handed mask hold obtains better seal!
■ Squeeze bag and administer volume necessary to achieve chest rise.
      - Verify oxygen flow rate of 15 L/min.
      - Avoid pop-off valves (if present).

■ Inadequate mask seal
■ Inadequate ventilation
■ Gastric distention → emesis and aspiration.
■ Insufflation of vomitus/blood/debris into trachea
■ Air trapping or pneumothorax
        - From overaggressive ventilation or too large a bag (pediatrics)
        - If you suspect air trapping (eg, history of asthma or COPD), stop bagging and squeeze the chest to help the patient exhale, then bag at a slower rate.