From Michael Huang, MicroPoint Bio:
An 80 yr old male on warfarin was admitted to A&E of a local hospital for the complaint of shortness of breath. Lab test results showed INR of 15 after his admission. Just 8 hours before, the POC instrument his doctor used to monitor his INR showed a reading of 2.6. The patient died of pneumonia and possibly CCF (no post-mortem autopsy was performed). Why did the INR of the patient increase from 2.6 to 15 in about 8 hours? What are the possible causes? POC not accurate? lab not accurate? patient medical conditions changed?
Hi, Michael, and thank you for your question. Given your description, my first speculation would be acute disseminated intravascular coagulation (DIC) that consumed coagulation factors rapidly within the 8 hours between collections. With a diagnosis of pneumonia, the patient could have gone rapidly septic. There is, of course, the possibility of a specimen collection error, perhaps occurring at the time of admission. A short draw or clotted (poorly mixed) specimen could result in a falsely prolonged prothrombin time. Because the poor gentleman expired, there is no way to confirm this. I’m eager to see if any of our participants may have another explanation.