<prompt> Which one of the following is not a feature of type 2 respiratory failure?p CO2 38 mm Hg and pO2 50 mm HGp CO2 68 mm Hg and pO2 5O mm HgPapilloedemaAsterixis  <response>: Type 2 respiratory failure is characterised by aerial hypoxia with hypercapnia.Here,PaO2 is less than 60 mmHg8.0 kPa and PaCO2 is greater than 50 mmHg6.6 kPa.It can present with the signs of CO2 retention like confusion,flapping tremorsasterixis,bounding pulse Papilloedema. In Type 1 respiratory failure there is pao260 and paco2 normal or decreased. Reference:Davidsons Medicine-22nd edition,page no:664. 