As all techniques,<unk>  has indications, contraindications and side effects. It is associated with nausea/vomiting and it may cause esophageal rupture and also may make tracheal intubation and make ventilation difficult or impossible.<unk>  force greater than 40 N can compromise airway patency and make tracheal intubation difficult.<unk>  may displace the esophagus, make ventilation with a facemask or with a laryngeal mask airway (LMA) more difficult, interfere with LMA placement and advancement of a tracheal tube and alter laryngeal visualization by a flexible bronchoscope. However, other investigators have found that<unk>  does not increase the rate of failed intubation.
Cricoid pressure
Tragal pressure
Alveolar pressure
Diaphragmatic excursion
Esophageal speech
Chest wall oscillation
Intrapleural pressure
Breathing circuit