Evaluation of Dynamic Variation in Red Cell Distribution Width as a Septic Marker in Comparison with Procalcitonin Levels and Clinical Scores in Patients with Sepsis or Septic Shock: A Prospective Observational Study

BACKGROUND: Sepsis is a dysregulated host response to infection resulting in potentially life-threatening organ dysfunction. Elevation in red cell distribution width (RDW), a simple routinely done investigation, could be a prognostic marker in these patients. AIM: We performed this prospective observational study to assess role of dynamic variation of RDW in predicting 30-day mortality in patients with sepsis or septic shock presenting and getting admitted in intensive care unit (ICU) in Fayoum, Egypt. METHODS: Between January 2019 and January 2021, 150 patients with sepsis or septic shock at admission were prospectively evaluated for association between RDW value on admission, on day 4, on day 7, and 30-day mortality. To find out factors associated independently with 30-day mortality, we applied multivariate logistic regression analysis and used the analysis to develop nanogram for prediction of mortality on admission. RESULTS: Among 150 patients, 89 (59.3%) were male. Mean age of the patients was 59.6 ± 12.28 years. Regarding RDW on admission (RDW-0), the mean was 14.1 ± 1.9 while on day 4 (RDW-4), the mean was 14.5 ± 1.97, and on day 7 (RDW-7), the mean was 14.4 ± 2.03. Seventy-four (49.3%) patients died during the period of 30 days follow-up. Multiple logistic regression models for the parameters associated with the mortality outcome at admission were done, for age, higher age was associated with higher probability of mortality, OR = 1.07 (95% CI: 1.02, 1.13). Male sex was associated with lower probability of mortality as compared to females, OR = 0.02 (95% CI: 0.06, 0.80). Higher acute physiologic assessment and chronic health evaluation (APACHE) II score, RDW value, and procalcitonin level, all were associated with higher mortality probability. For APACHE II score, higher level was associated with higher odds of mortality, OR = 1.16. For RDW value on admission, higher value was associated with higher odds of mortality, OR = 1.66. For procalcitonin level at admission, higher level was associated with higher odds of mortality, OR = 1.54. Odds for mortality for those who showed any increase in RDW in day 4 as compared to day 0 are higher as compared to those who showed a decrease or no change in RDW, OR = 2.8, p-value = 0.007. CONCLUSIONS: We found that an increase in RDW value on admission and on day 4 is significantly associated with mortality. And that, an increase in RDW value from day 0 to day 4 is also significantly associated with mortality Therefore, a combination of baseline RDW value and an increase in serial RDW values can be a promising independent prognostic marker in patients with sepsis or septic shock.