Clinical Laboratories, Stanford Hospital & Clinics
Jing Jin, CLS, MT (ASCP) (JJin@stanfordmed.org)
Story from the Clinical Laboratory
I am a clinical laboratory scientist working in the Coagulation department of the Stanford Clinical Laboratories. One morning, after taking over from the night shift, I found 4 specimens taken over a 3 hour period (3:15 am to 6:20am) from a 66-year-old ICU patient, all with the same critical results: PT>300.0sec, INR>60, and aPTT>300.0sec.
Questions which arose in my mind included:
“Can we trust the specimens?”
“Are the results reliable?”
“Are there any instrument or quality control (QC) problems?”
I jumped on these questions right away.
I found no instrument or QC problems. Specimens were rechecked for clot, hemolysis and tube type, pre-analytical variables could affect results. All 4 specimens were good. To rule out possible intravenous fluids or heparin contamination in the specimens, we contacted the patient’s nurse who confirmed that the last specimen was drawn from a peripheral stick. Therefore, at least results from the last specimen were reliable.
Then what was wrong with the patient? Although PT and aPTT were the only two tests ordered by the doctor, I added D-dimer, heparin activity level by anti-Xa method (HAL), fibrinogen (FIB) and thrombin time (TT) on these 4 specimens and re-tested PT and aPTT at the same time. The four specimens had identical results: D-dimer >20000 ng/ml FEU and “no clot” on PT, PTT, fibrinogen and thrombin time tests. HAL results were “zero” indicating no heparin contamination. It was most likely that the patient had severe Disseminated Intravascular Coagulation (DIC).
We informed the doctor right away. The patient was immediately transfused with blood products. DIC panel on coagulation tests were checked frequently. Five hours later, results showed: PT 20.3sec, INR 1.8, PTT 46.8 sec, FIB 145mg/dl TT 20.2 sec. (Patient had developed severe DIC right after liver transplant.)
Working in the clinical laboratory, we play an important role in patient care.
Extra steps could save a life!