We confirm blood types on patients with no previous type and if patient's type is other than group O. If there is a specimen avaialble that was drawn at a different time such as Hgb/Hct or Protime etc. we use that to confirm. We only do it if patient is ordered red cells. Confirmations are not done for platelets, Type&Screens etc. Occasionally if we have problems obtaining a new sample we give group O Rh specific cells.