Bag-mask ventilation is the cornerstone of basic airway management and is not a skill easily mastered . This procedure is most often needed because of inadequate ventilation, which can result from impaired respiratory effort or airway obstruction. Basic airway interventions may also be needed to manage the patient with inadequate oxygenation and during cardiopulmonary resuscitation.
This topic will review the essential techniques involved in basic airway management in adults. Airway management of children is discussed separately. (See "Emergent endotracheal intubation in children".) Issues related to endotracheal intubation in adults and other advanced airway management techniques are discussed elsewhere.
CAUSES OF INADEQUATE VENTILATION
Respiratory effort — Inadequate respiratory effort can result from intrinsic (eg, intracranial hemorrhage) or extrinsic (eg, opioid overdose) factors. Poor respiratory effort causing inadequate ventilation can be difficult to discern: it is often silent, and detection depends on close observation of chest wall movement. Thorough evaluation requires that the patient be undressed and the clinician observe the rate, pattern, and depth of breathing, use of accessory muscles, abnormal sounds, and signs of injury. Both laymen and health care professionals often fail to accurately determine the adequacy of respiratory effort [2,3].
Airway obstruction — Soft tissue airway obstruction in the unconscious patient can occur by several mechanisms. These include prolapse of the tongue into the posterior pharynx and loss of muscular tone in the soft palate [4,5]. Simple airway maneuvers, such as the head-tilt chin-lift or jaw-thrust with or without a head tilt, often ameliorate this problem quickly. (See 'Airway maneuvers' below.) Obstruction by foreign bodies, injured tissue, blood, and secretions can also occur.
Noises produced by the obstructed upper airway often make such obstruction easier to detect than poor respiratory effort. As an example, snoring or gurgling noises may be heard when the upper airway becomes partially obstructed by soft tissue or liquid (eg, blood, emesis). Complete airway obstruction is silent but may manifest transiently as retractions of the accessory muscles of respiration (suprasternal, supraclavicular, intercostal, subcostal) or as cyanosis, until frank respiratory arrest supervenes.