Synchronized intermittent mandatory ventilation (SIMV): Volume control method where preset breaths along with the predetermined volume is provided to help in natural breathing. The ventilator given breaths are matched with the patient's respiratory efforts. It prevents the patient from developing respiratory alkalosis but at the same time increases the work of breathing. With pressure control, the increase in work of breathing was eliminated. This method is considered as the least effective one. Following advantages are seen by using SIMV: •Increased synchronization between the patient and ventilator •Less chances of developing muscle atrophy •Better distribution of gases. However this method is considered as the least effective one as it increases the work of mechanical ventilation due to muscle fatigue and is associated with lower success rates.