The Study Seeks to Determine Potential Correlations Between Ventilation and Hematological Alterations, Contributing to a Better Understanding of Its Physiological Effects and Optimizing Patient Management in Critical Care Settings.

Inclusion Criteria: * 1- Pediatric patients aged 1 month to 18 years 2- Diagnosis of sepsis based on (Specify Criteria, e.g., Sepsis-3 criteria) 3- Requirement for invasive mechanical ventilation for at least 24 hours. 4- Patients admitted to the PICU during the study period. 5- Availability of complete hematological data before and during mechanical ventilation Exclusion Criteria: * 1- Patients with pre-existing hematological disorders (e.g., leukemia, aplastic anemia, congenital coagulopathies). 2- Patients who received a blood product transfusion within the 7 days before MV initiation or during it. 3- Patients with incomplete medical records or missing hematological data. 4- Patients discharged or deceased within 24 hours of mechanical ventilation initiation. 5- Patients who received Hematopoietic drugs during MV.