Tracheostomy reduces dead space by

Impoant effects of tracheostomy on respiratory physiologyTracheostomy decreases dead space as upper airways and nasal cavity are bypassedTracheostomy decreases ventilation/perfusion (V/Q) ratio. Increased dead space increases ventilation/perfusion ratio as the dead space (containing air) is ventilated but not perfused for gaseous exchange. Tracheostomy decreased the dead space, therefore it will decrease the V/Q ratioTracheostomy reduces the airflow resistance(Refer: Morgan and Mikhail's Clinical Anaesthesiology, 5th edition, pg no. 1237)