After routine induction of general anaesthesia peak airway pressure (= P max) and other respiratory parameters(i.e. expiratory tidal volume, expiratory CO2) are measured with and without head support in three different head positions: neutral position, reclination of the head, a position deemed ideal by the anaesthesist; primary study goal is pmax depending on different head positions;

Inclusion Criteria:

• male and female patients ≥ 18 years
• elective operations in general anaesthesia
• patient´s written informed consent
• American Society of Anesthesiology scale I-III

Exclusion Criteria:

• non fasting patient
• body mass index > 35 kg/m2
• anamnestic cervical spine pathologies or other peripheral neurological deficiences due to pathologies of the cervical spine
• malformations of the head or upper airway
• history of perforation of stomach or esophagus
• anamnestic hiatus hernia or reflux
• acute respiratory infection or obstructive airway disease