The endotracheal tube secures free airway in patients undergoing surgical procedures or mechanical ventilation. The extraluminal airway needs to be sealed by a cuff. The cuff needs to be adequately inflated with air. The cuff pressure should be between 20 and 30 cm H2O. A cuff pressure in excess of the target range is associated with a risk of tracheal injury, whereas a cuff pressure below the lower limit includes a risk of micro-aspiration of subglottic secretions, with risk of subsequent ventilator-associated pneumonia. It is unknown whether the cuff pressure changes following changes in body position of the patient. The objective of this study is to investigate to which extent - if any - cuff pressures change after body position changes of the patient.

Inclusion criteria are age 18 - 70 years, oral intubation with a taperguard EVAC endotracheal tube (Covidien®), conventional mechanical ventilation, adequate sedation (Richmond Agitation-Sedation Scale -5) and analgesia (Behavior Pain Scale 3 to 4).

Exclusion criteria are factors with potential influence on the cuff pressure or factors that disturbed the safety or well-being of the patient: pregnancy, palliative care, difficult intubation, decreased mobility of the neck, history of neck surgery, temperature of <35°C or >37.5°C, morbid obesity (body mass index >35) and every potential contra-indication for position changes such as unstable spinal cord injury or hemodynamic and/or respiratory instability.