Almost 10-28% of ICU patients suffer from Ventilatory Associated Pnuemonia (VAP) which increases mortality two times and increases length of stay in hospital and cost. As macro or microaspiration of gastric or oropharynx secretions to lower airway due to bacterial colonization of aerodigestive tract is one of the risk factors for VAP, a device that aspirates these secretions can help us. EVAC is a newly designed endotracheal tube which has a dorsal lumen above the cuff for suction of subglottic secretions. As there is not enough evidence about the effect of EVAC tube on reducing VAP, we decided to evaluate the effect of EVAC tube on reducing VAP compared to routine tubes in critically ill patients. After approval of the study in ethics commitee of Tabriz Medical University, 90 patients aging more than 18 year-old which will be intubated more than 72 hours will be entered in this study. Patients will randomly allocated to two 45-patient groups: EVAC group and Standard group. All standard and routine care will be done in patients and all patients will be monitored for VAP and will receive the therapeutic options. Age, sex, APACHE score, Pao2/Fio2, Duration of mechanical ventilation, tracheostomy, reintubation, cuff pressure, number of tube cuff suctioning per day and mortality will be recorded.