Tubuslage

Tubuslage refers to the depth or position of an endotracheal tube (ETT) inside the trachea. The term describes how far the tube tip has been advanced beyond the lips or teeth and, conversely, how close it is to the carina. Correct tubuslage is essential for effective ventilation and protection of the airway.

In clinical practice, the target position is the ETT tip approximately 2 to 3 cm above the carina. This corresponds to a typical external depth at the teeth of around 21–23 cm in many adults, with some variation according to sex, height, and individual anatomy. The key principle is that the tube should be deep enough to avoid accidental extubation but shallow enough to prevent endobronchial intubation, most commonly into the right mainstem bronchus.

Verification and maintenance of tubuslage involve several methods. Immediately after placement, continuous capnography confirms tracheal placement and reliable ventilation. Bilateral breath sounds and symmetrical chest rise support correct positioning. A chest radiograph is commonly obtained to confirm the tube’s depth relative to the carina and to exclude mainstem intubation; ultrasound can also assist in bedside assessment when available.

Malposition risks include the tube being too shallow, which risks dislodgement and inadequate ventilation, or too deep, which can result in right mainstem intubation, leading to ventilation of only one lung and potential lung injury. If the tube is in the esophagus, there will be absent or minimal capnographic waveform and no lung ventilation.

Pediatric tubuslage requires careful consideration of age- and size-related anatomical differences; radiographic confirmation is routinely used to verify appropriate depth in children.