Background:
Several studies have investigated the role of the neutrophil-to-lymphocyte ratio (N/L ratio) in the early diagnosis of infection with controversial results. We assessed this ratio in the early diagnosis of gram-negative sepsis cases admitted to intensive care unit (ICU).

Methods:
Patients with gram-negative sepsis admitted to general intensive care unit were enrolled. The following data was recorded: demographic characteristics; APACHE II score; duration of mechanical ventilation and ICU length of stay; average neutrophil and lymphocyte count, along with their ratio, on the first, second and third day of hospitalisation; and the mortality rate.

Results:
One hundred and thirty nine patients were studied during a period of one year with a mean age 68.29 ± 17.4 years. One hundred and thirty six patients received mechanical ventilation, with a mean duration of 13.85 ± 2.07 days. The mean white blood cell (WBC) count on the first day of hospitalisation was 11776.04 ± 5789.60, while on the second and third days this was 12446 ± 2101.16 and 13241.01 ± 7077.17, respectively. The N/L ratio on the day of hospitalisation was 11.38 ± 1.02, and 11.98 ± 0.99 and 12.94 ± 1.3 on the second and third days, respectively. Moreover, 46.8 percent of patients died during the study. From applying Student’s t-test, significant differences were observed between two groups of patients (discharged and deceased) in terms of their APACHE II score, neutrophil count, WBC and N/L ratio on the second and third days of hospitalisation (P < 0.05).

Conclusion:
Blood cell analysis and N/L ratio can be used as a predictor for the severity of gram-negative sepsis along with other diagnostic procedures.