A Patient Was Drawn for PT and PTT Testing

Multiple Choice

A patient was drawn for PT and PTT testing. The laboratory professional noticed that the packed cell volume appeared abnormally elevated. A CBC was also drawn with the coag and the hematocrit was 63%. A new Na Citrate tube was prepared to correct for the elevated hematocrit and a repeat coag sample was drawn. How much anticoagulant is needed for a 4.5ml draw?

A) 1.9 ml
B) 3.1 ml
C) 3.4 ml
D) 1.6 ml