IRCT2015092821896N4 IRCT 2015-10-18 Vice Chancellor for research of Arak University Of Medical Sciences Comparison of weaning from mechanical ventilation as " Spontaneos breathing triales ," with " Sincronised Intermident Mandatory Ventilation " - Comparison of weaning from mechanical ventilation as " Spontaneos breathing triales," with "Sincronised Intermident Mandatory Ventilation " 2015-10-23 anticipated 44 Complete https://irct.ir/trial/19043 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Other design features: Data randomly divided into 2 groups and control. 3 Improve breathing. Intervention 1: " Intervention group" : At 8 o'clock first the parameters of Pao2, o2sat, respiratory rate, breathing patterns, heart rate, systolic blood pressure, diastolic blood pressure, and level of consciousness will measured and checklist will filled. If weaning from the ventilatortakes place, periodically every 1 hour until 12 mid daily those parameters will be measured.In method of SBT changes in respiratory parameters of mechanical ventilator for patient will start with change (A/C) mode to continuous positive airway pressure (CPAP) gradually, then by using (T piece) patients will extubate from ventilator. Intervention 2: " Control Group" : The routine method of Synchronized intermittent mandatory ventilation will be used on the patients. First at 8 o’clock via check list of physiological indices the patient will be checked and, if he/she has order of weaning, the process will start using SIMV. In this method, every half hour 2 breath rate will reduced. If respiratory muscles weakness will occurred immediately the breath of the patient will return to previous pattern. Then after 24 hours the procedure on the patient will repeated.