<prompt> Tracheostomy reduces dead space by -By-passing upper airwayIncreasing VQ ratioRaising airflow resistanceBy all of the above mechanisms  <response>: Ans. is a i.e., By-passing upper airway o Important effects of tracheostomy on respiratory physiologya Tracheostomy decreases dead space as upper air ways and nasal cavity are bypassed.b Tracheostomy decreases ventilationperfusion VQ ratio. Increased dead space increases ventilationperfusion ratio as the dead space containing air is ventilated but not perfused for gaseous exchange. Tracheostomy decreases the dead space, therefore it will decrease the VQ ratio.c Tracheostomy reduces the airflow resistance 