Abstract: Objective To investigate the onset and progression, and the impact of anemia on the prognosis of the patients with severe pneumonia admitted to intensive care unit(ICU). Methods A retrospective case-control study was conducted involving the patients with severe pneumonia who were admitted to ICU of Nanjng First Hospital from March 1,2020 to March 31, 2022. The patients were divided into survival group and death group according to their clinical outcome. The clinical data were collected from electronic medical record system. The baseline data and the level of hemoglobin (Hb) during ICU hospitalization were compared between the two groups. Logistic regression analysis was used to analyze the risk factors affecting the prognosis of the patients. Results A total of 43 patients were enrolled in the study,of which 22 died and 21 survived. Compared with survival group, death group had older age, higher score of Sequential Organ Failure Assessment(SOFA)and Acute Physiology and Chronic Health Evaluation scoring system (APACHE Ⅱ), lower average level of Hb over ICU days. During the ICU stay, the level of Hb kept dropping. The average total decrease of Hb reached (24.70±23.39)g/L.Logistic regression analysis showed that age, comorbidity and the average level of Hb were associated with the risk of worse outcome of the patients with severe pneumonia. Conclusions Anemia has negative effect on the prognosis of the patients with severe pneumonia in ICU, and it is important to prevent and treat hospital-acquired anemia.

Key words: anemia, critical illness, severe pneumonia, prognosis