Red blood cell (RBC) distribution width (RDW), calculated by dividing the standard deviation of RBC volume by the mean corpuscular volume and multiplied by 100, is routinely reported as part of the complete blood count (CBC) using automated flow cytometry. RDW has been traditionally used as additional information in the differential diagnosis of the cause of anemia.

RDW has been recently reported as a strong prognostic factor in several diseases of various organ systems, including the cardiovascular, respiratory, renal, neurologic, and gastrointestinal systems.It also showed significant associations with ventilator-free days, postoperative outcome, intensive care unit (ICU) discharge outcome, out-of-hospital outcome, and all-cause mortality in critically ill patients. However, most studies were conducted in adult patients. Only a few studies have investigated RDW in children, especially in the critically ill pediatric population.

The aim of this study is to know the prognostic significance of red blood cell distribution width ( RDW ) in critically ill pediatric patients as regard ; the duration of hospital & PICU admission ,the use of inotropic drugs and or mechanical ventilation (MV) and the outcome of the case .

Inclusion Criteria:

• All critically ill pediatric patients, 1 month to 12 years age, admitted to Pediatric intermediate & Intensive Care Unit ( PICU ) in Sohag University Hospital.

Exclusion Criteria:

• - patients who received blood transfusion prior to admission in PICU
• patients with incomplete data for pediatric risk of mortality (PRISM), pediatric sequential organ failure assessment (pSOFA), pediatric logistic organ dysfunction-2 (PELOD-2), and pediatric multiple organ dysfunction syndrome (pMODS) scores were excluded.

All patients included in this study will be subjected to the following (as detailed in the attached patient's data sheet).