This tutorial is about Automatic Tube Compensation (ATC). ATC is a setting that has been included in most modern ventilators. Its aim is to reduce the work of breathing associated with the drop in pressure across the endotracheal tube. The ventilator senses pressure, flow and resistance and changes the pressure during the breath to ensure that the patient has the sensation that they are breathing through their own airway. There are two configurations of ATC – one is as an alternative to pressure support in patients who are essentially weaned from mechanical ventilation: essentially a spontaneous breathing trial. The second configuration is as an accessory to all pressure limited modes – such that the pressure waveform is crafted in inspiration and expiration to reduce the workload of breathing during both phases of respiration. @ccmtutorials http://www.ccmtutorials.org