I am the supervisor of a moderately complex lab in a busy physicians’ office. We work closely with patients and get to know them on a personal level. One of our avenues of patient care is providing POC- INR testing to monitor our patients who need anticoagulation therapy. It is extremely important that the patient stay within a specific INR range for their continued health.
One day, an elderly lady patient our staff knew quite well came in for her regular monitoring visit. We did her POC-INR test and our instrument was not able to give us a result. The first protocol is to recheck the test. This happened again and the instrument gave us the same default reading of “unable to determine”. The next step was to perform a venipuncture and draw a sample to send to our reference lab. The patient seemed fine, finished her visit and went home.
Later that day, we received a concerned call from the patient’s family member indicating that “the lab tech must have done a horrible job drawing her blood”, because her arm was completely black and blue and swollen. We advised them to return to the clinic so she could be evaluated. Our examination of the patient showed that she did have swelling and bruising to her entire arm and her fingers were still bleeding from the capillary sticks of her POC testing that we had done hours earlier.
It was clear that the tech had done nothing wrong when the patient’s INR result from the reference lab came back as > 20. This very critical result was the reason her blood was not clotting and she was continuing to bleed. The abnormally high value was over our instrument’s linearity, causing the “unable to determine” error. The lab’s ability to quickly get the results allowed the patient’s provider to immediately send her to the hospital to begin Vitamin K therapy.
Upon further investigation, it was discovered that she had received the incorrect dosage of her anticoagulation medicine from her pharmacy and had been taking that dose, which was much too high for her, for several days.
In this patient’s case, the lab had successfully determined her abnormal clotting issue in a timely manner and quite possibly saved her life.