Dead space is increased by all except:

Ans: D (Endotracheal intubation) Ref: Miller Textbook of Anaesthesia. 6th editionExplanation:Dead SpaceEndotracheal intubation bypasses the gases from upper respiratory tract thereby decreasing the anatomical dead space.Dead space increases with standing and hyperextension of the neck as the volume of the upper respiratory tract increases.Anticholinergics increase the diameter of the upper airway by hronchodilatation and antisialagogue action thereby increasing the dead space.Normal dead space-150 ml (l/3rd of the normal tidal volume).