Once upon a time, there was a little doctor named Dr. Goldilocks. One beautiful summer day, she went for a walk in the hospital. Pretty soon, she came upon the rehabilitation unit. Her pager went off and she ventured inside.
At the entrance to the unit, there were three rooms, each with a patient inside. Dr. Goldilocks found her sign-out and discovered that each of these patients had atrial fibrillation and was being anti-coagulated with coumadin.
She checked the INR on the first patient. It was 1.6.
"This INR is too low!" she exclaimed.
So, she checked the INR on the second patient. It was 3.9.
"This INR is too high!" she cried.
She skipped off to the final room and checked the INR on her last patient. It was 2.1.
"Ahhh, this INR is just right," Dr. Goldilocks said happily and she curled up in a corner and fell fast asleep.