Novel Mortality Markers for Critically Ill Patients

Inflammatory markers, such as the neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), derived from a complete blood count have recently attracted attention as potential markers of morbidity and mortality in various diseases. The aim of the present study was to assess the usefulness of the NLR and PLR as markers of hospital stay and mortality of patients in intensive care units (ICUs).

Patients treated in the ICU of our institution between October 2016 and August 2017 were enrolled in the study. After obtaining approval from the institutional committee, patient data were sourced from the institution's computerized database and retrospectively analyzed. The patients were assigned to 2 groups according to the outcomes: survivors and deceased.

The NLR of survivors and deceased patients was 2.06 (1.18-21.68) and 10.42 (2.85-48.2), respectively. The NLR was significantly elevated in deceased patients as compared with that of survivors (P < .001). Similarly, the median PLR of patients in the deceased group (268.9 [150-3000]) was significantly higher than that of patients in the survivor group (55.7 [11.8-152.5]). The difference in the PLR between groups was significant (P < .001).

Both the NLR and PLR, as well as C-reactive protein, predicted mortality in this critically ill population. The PLR and NLR are easy-to-measure, inexpensive markers. Physicians should be aware of elevations in PLR and NLR in patient care in ICUs.