pt and ptt are measures of coagulation. very important to measure for hemophilia, DIC, etc. i cant tell you the exact numbers but i believe a normal PT is less than 12-15sec, PTT less than 25 sec... i may be wrong (diff labs have diff norms). before i stick a pt for an ABG i check their PT and PTT for any extended bleeding times so that i can hold pressure longer b/c of course i dont want the pt to lose excessive amounts of blood just for a couple of cc's of blood. pts on coumadin also have their PT and PTT checked regularly. i would assume pts on lovenox would also have routine PT/PTT in their am labs.