Let’s Go Down the Correct Path(way)

To the Editor:

“Acquired Liver Injury in the Intensive Care Unit” by Lescot et al.¹  is an excellent discussion of the multifaceted causes of liver injury. One correction is in order, however. The review incorrectly states that the international normalized ratio reflects intrinsic pathway activity. It is the activity of the extrinsic coagulation pathway, often now referred to as the tissue factor pathway, that is measured by the international normalized ratio and initiates the coagulation cascade.²  An understanding of the specific pathway measured by a coagulation test is paramount to the treatment of defects secondary to liver disease. It should also be pointed out that the international normalized ratio, one component of the model for end-stage liver disease scoring used to prioritize liver transplantation waiting lists, can be highly variable depending on the laboratory analyzing the sample.³