Turning Ratios Into Prognosis: Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios as Powerful Predictors of ARDS in Pediatric Burn Patients: A Prospective Evaluation

The aim of this study is to evaluate the role of Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios as predictors for development of ARDS in pediatric burn patients.

• A prospective observational cohort study will be performed in our burn ICU at Ain Shams University Hospitals. Ethical clearance will be taken from the institutional ethics committee. Written informed consent will be obtained from the patients/authorized representatives of the patients.
• All eligible pediatric patients with severe burns will be enrolled within 24 hours of admission after obtaining informed consent.
• Minimum sample needed for statistical significance was calculated a priori and found to be (60).
• After consent, Patients' characteristics (age, sex, etc….), clinical parameters (TBSA, Abbreviated Burn Severity Index [ABSI], presence of inhalational injury), and comorbidities will be recorded.
• Complete blood count (CBC) will be done upon admission and will be repeated on days 1, 3, 5 and 7.
• Total leucocyte count (TLC), differential leucocyte count (DLC) and platelet count (PC) will be reported as part of the CBC results. NLR and PLR will be calculated as per the following: NLR: ratio of absolute neutrophil count to absolute lymphocyte count. PLR: ratio of platelet counts to absolute lymphocyte count.
• Data about respiratory status at ICU admission (invasive or non-invasive mechanical ventilation, high-flow oxygen therapy) and progression to endotracheal intubation and invasive mechanical ventilation (IMV), the day of endotracheal intubation and IMV initiation, and duration of ventilation will be recorded.
• Patients will be evaluated on days 0,1, 3, 5, 7 of admission for diagnosis of ARDS.
• ARDS will be determined using the pediatric ARDS criteria from the Pediatric Acute Lung Injury Consensus Conference.

Primary outcome:

o To evaluate the predictive value of admission NLR and PLR for development of ARDS within 30 days in pediatric burn patients.

Secondary outcomes:

• Determine optimal cut-off values (ROC) of NLR and PLR for ARDS prediction.
• Compare predictive performance of NLR and PLR with established clinical predictors (TBSA%, inhalation injury, age).
• Study the predictive value of the dynamic changes of NLR/PLR for mechanical ventilation need, ventilator days, ICU length of stay, and mortality.

Inclusion criteria

• Age 1-12 years.
• Patients presenting within 24 hours of burn injury.
• Patients presenting with severe burns 20-40% of total body surface area (TBSA).
• Thermal burns or scalds.
• Both sexes.

Exclusion criteria

• Patient refusal to participate in the trial.
• Age <1 & >12 years.
• Delayed admission >24h post-injury.
• Patients presenting with burns <20% or >40% of TBSA.
• Non-thermal burns.
• Associated medical comorbidities: Chronic liver or kidney diseases, anemia.
• Preexisting chronic lung disease (e.g., cystic fibrosis, severe bronchopulmonary dysplasia).
• Inflammatory conditions (e.g., inflammatory bowel disease).
• Immunocompromised individuals, autoimmune diseases, those undergoing treatment with immunosuppressants, corticosteroids, cytotoxic chemotherapy.
• Known malignancies, hematologic malignancy or conditions altering WBC/platelets significantly.
• Previous malnutrition.
• Immunosuppressive therapy prior to admission (e.g., chronic steroids).