Introduction:
This project was designed to evaluate the influence of antibiotics on the survival of patients in the intensive care unit (ICU) undergoing cardiopulmonary bypass (CPB) treatment.

Material and methods:
This retrospective cohort study included data of 7,296 patients who underwent CPB surgery and were admitted to the ICU from MIMIC-IV database. Patients with CPB were grouped according to their survival time of more than 30 days or less after admission and whether antibiotics were used, with baseline characteristics analyzed. Survival differences were demonstrated by utilizing Kaplan-Meier (K-M) curves.

Results:
In CPB patients grouped according to survival time, great differences were detected in laboratory indexes, comorbidities, and treatment information. In terms of disease severity scores, vital signs, and comorbidity, there were notable differences in the data in CPB patients grouped by whether antibiotics were administrated. K-M curves manifested that the use of antibiotics substantially increased the 30-day survival rate of all CPB patients as well as CPB patients without sepsis complications. Landmark analysis indicated that the use of antibiotics greatly heightened the survival rates of all CPB patients and CPB patients without sepsis complications at 7 and 14 days after ICU admission.

Conclusions:
In CPB patients admitted to the ICU, the rational use of antibiotics for treatment and prophylaxis can remarkably minimize the risk of patient mortality. These findings proffer essential references for clinical practice, assisting healthcare professionals to better assess and manage CPB patients in the ICU and formulate appropriate treatment plans to improve patient survival rates.