Applicability of a compact PT-INR measuring device CoaguChek XS to perioperative management

In perioperative management, prothrombin time (PT) expressed as the international normalized ratio (INR) is an important preoperative test to assess bleeding risk. It is also used to assess the effect of discontinuing anticoagulant therapy, to determine whether to treat patients with vitamin K or fresh frozen plasma, and to decide whether a deep nerve block (e.g., epidural anesthesia) is needed. Compared with other devices used to measure prothrombin time, the CoaguChek XS is a smaller, lighter and more convenient-to-use PT-INR monitoring system that requires a smaller venous, skin puncture or arterial blood sample than other systems. In a surgical setting, it is often more convenient to collect arterial blood. However, the applicability of arterial blood PT-INR values has not been verified.

We evaluated the usefulness of the CoaguChek XS in anesthetic management by comparing PT-INR values for arterial blood with those of venous blood in 50 patients who were scheduled for elective surgery under general anesthesia.

Arterial PT-INR values were well correlated with venous PT-INR values (r2 = 0.9239; regression line y = 0.9537x + 0.0505).

These results indicate that the CoaguChek XS system can provide arterial PT-INR values and should be available in operating and emergency rooms.