The prognostic value of lymphopenia in adult intensive care patients in critical condition

Introduction: A lower than normal lymphocyte count is indicative of a weak immune system, which can lead to a predisposition to infection. Infection is among the most significant causes of morbidity and mortality in intensive care units. This study aimed to do determine the correlation between lymphopenia and mortality in adult intensive care patients in critical condition. Materials and methods: All patients admitted to the intensive care unit (ICU) in 2016 were included in this retrospective study. Patient age, gender, diagnosis, surgical history, APACHE II score within the first 24 h of ICU admittance, and duration of ICU stay and hospitalization were obtained from the hospital’s archives. The lymphocyte count at the time of ICU admittance was also obtained from patient records. Results: Among the 447 patients included in the study, 300 remained alive and 147 died during the follow-up period. The mean lymphocyte count was significantly lower in the deaths group than in the survival group (P = 0.004). The sensitivity of an APACHE II score for predicting mortality ≥21.5 was 88.4% and the sensitivity of a lymphocyte count for predicting mortality ≤0.85×10³ µL^–1 was 46.9%. The specificity of an APACHE II score for predicting mortality ≥21.5 was 94.3%, whereas the sensitivity for a lymphocyte count for predicting mortality ≤0.85 ×x10³/µL^–1 was 44.5%. Conclusion: Lymphopenia in adult ICU patients in critical condition might be considered a simple biomarker for predicting prognosis, although it may not be as accurate as the APACHE II score.