•A normal PT is 11-12.5 seconds. For patient's on warfarin, the therapeutic level is 1.5 to 2 times the normal level. •A PT of 20 seconds falls within the therapeutic range, so the dose should not be held or altered.
The nurse is reviewing a patient's lab results and notes an elevated BNP (brain natriuretic peptide). The nurse understands that an elevated BNP is caused by: