A hand-held, mask with an attached self-inflating bag, that permits air to be forced into the lungs each time it is squeezed. Manual resuscitators can be difficult to use properly; complications can arise if the mask does not seal the patient’s face properly; excessive pressure is used during ventilation; inadequate supplemental oxygen is provided; or the rate or volume of ventilations is excessive or insufficient to inflate the lungs and remove carbon dioxide.