A method of intubating a subject is disclosed. The method comprises inserting an endotracheal tube into the tracheal airway of the subject; inflating a cuff associated with the endotracheal tube within the airway below the vocal cords; measuring a level of at least one measure being indicative of leakage of secretion past the cuff to the lungs; comparing the level of the measure with an optimal level of the measure; and adjusting inflation of the cuff based on the comparison so as to generally minimize leakage of secretion from above the cuff to the lungs, while minimizing pressure associated damages to the airway. The measure(s) can be carbon dioxide concentration, a proxy measure from which such concentration can be inferred, or the level of one or more additives delivered to a subject during intubation.