Abstract: A method of monitoring tracheal pressure of a subject is disclosed. The subject is ventilated with breathing gas flowing via an endotracheal tube having an inflatable cuff. The method comprises monitoring sealing of the trachea by the cuff using a close loop control, varying a ventilation pressure thereby varying flow level of the breathing gas, monitoring a response pressure within the cuff in response to the variation, and calculating the tracheal pressure using the ventilation pressure variations, the cuff response pressure and the flow level. In some embodiments, an under-pressure is applied for suctioning fluid carrying secretions, synchronously with variations in the tracheal pressure.