What is a contraindication for the use of a bag-valve-mask?

Severe facial trauma is a contraindication for the use of a bag-valve-mask because such trauma can severely compromise the airway and hinder the ability to obtain an adequate seal around the mask. In cases of significant facial injuries, anatomical structures may be disrupted, making effective ventilation difficult or even impossible. Additionally, blood or tissue swelling may obstruct the airway or prevent the mask from functioning optimally, leading to ineffective ventilation and a higher risk of complications.

While obesity can complicate bag-valve-mask ventilation due to the potential for difficult mask fits and reduced lung capacity, it is not an absolute contraindication. Aging can affect airway mechanics but does not necessarily negate the use of this ventilation method. A history of asthma is relevant in terms of respiratory issues but does not directly contraindicate the use of a bag-valve-mask in emergencies.