Vitamin K deficiency in critical ill patients; a prospective observational study

Abstract

Background: Vitamin K is a cofactor for proteins involved in cardiovascular health, bone metabolism and cancer. Measuring uncarboxylated prothrombin, also termed as "protein induced by vitamin K absence or antagonism for factor II (PIVKA-II)", has been used to assess vitamin K status. High levels may indicate vitamin K deficiency. The aim of this study was to measure PIVKA-II and prothrombin time (PT-INR) in intensive care (ICU) patients and correlate vitamin K status with mortality.

Methods: Ninety-five patients admitted to the ICU had blood samples taken near admission and every third day. In addition to PIVKA-II and PT-INR, critical-care severity scores were computed.

Results: The median baseline PIVKA-II was 4.97 μg/L compared to the upper reference of 2.0 μg/L. PIVKA-II further increased at days 3 and 6, (median 7.88 μg/L, p = .047 and median 8.14 μg/L, p = .011) predominantly in cardiac arrest patients (median 21.4 μg/L, day 3).

Conclusion: Intensive care patients have increased PIVKA-II levels at admission, which increases during the ICU stay, especially in cardiac arrest patients. There were no correlations between PIVKA-II and PT-INR, SOFA score or mortality. Further studies are needed to determine why PIVKA-II increases and whether high PIVKA-II levels in ICU patients affect long-term mortality or morbidity.

Keywords: Cardiac arrest; Intensive care; Matrix Gla protein; PIVKA-II; Vitamin K deficiency.