Patients are more likely to develop VAP from secretions aspirated past the cuff of the endotracheal tube than by what is breathed through the endotracheal tube. It may be more accurate to use the term "airway-associated pneumonia" rather than "ventilator-associated pneumonia" Several studies have now reported no change in VAP rates when circuits are only changed on an at-needed basis. There is also accumulating evidence that passive humidifiers and closed suction catheters do not need to be changed on a daily basis.