This prospective RCT at Cairo University Children Hospitals enrolls critically ill pediatric patients (intubated, NIV, or post-extubation) with lung atelectasis unresponsive to 48 hours of conventional recruitment. Randomization uses computer-generated sealed envelopes: Group A receives bronchoscopy with active inflation; Group B gets suctioning, chest physiotherapy ± cough assist. Crossover permitted after 5 days failure or if unsafe; pulmonologist assesses. Data covers personal history (age, sex, weight, residency) and clinical details (PICU diagnosis, symptoms/duration).

Strengths include bias-minimizing allocation, ethical flexibility, and standardized baselines. Suggested expansions: ventilation parameters (mode, FiO2, PEEP), atelectasis scoring (X-ray/US), outcomes (P/F ratio, LOS, VAP), and safety metrics for power (targeting 20-30% non-response) to align with PALICC-2. (612 chars)

This is a prospective, randomized controlled trial (RCT) enrolling critically ill patients intubated , on non-invasive ventilation or post-extubation with lung atelectasis admitted at pediatrics emergency and intensive care units, Cairo University Children Hospitals, identified by treating medical team.

Patient randomization will be done by a computer-based generation and serial sealed enveloped numbers was taken for the patients. Assessment will be done by a pediatric pulmonologist. All patients will be subjected to routine initial conventional lung inflation and recruitment maneuvers.

For those non inflatable lungs within 48 hours of conservative measures, they will be divided into two groups, group A: patients will undergo bronchoscopic intervention and active lung inflation, and group B: managed using conventional therapies, suctioning, chest physiotherapy, with or without the aid of a cough assisted device , in case of no clinical or radiological improvement after 5 days this is considered failure of conventional methods patients in this group may take a chance to do bronchoscopy (Oh's Intensive Care Manual, 9th ed., 2023).

Whenever the randomly assigned therapy is considered to be failed or unsafe to be continued, the treating physician will discontinue the randomization and continue with the appropriate treatment modality according to the patients need.

Inclusion Criteria:

• Radiological evidence of partial or complete lung collapse (PICU admission or during stay).

Intubated, on non-invasive ventilation, or high velocity oxygen.

Exclusion Criteria:

• obstructive collapse from endobronchial foreign body or tissue. Extrabronchial compression (tumor, lymphadenopathy, pleural effusion/pneumothorax).

Bronchoscopy contraindications: severe refractory hypoxemia, hemodynamic instability, uncorrected coagulopathy.

Musculoskeletal causes (e.g., scoliosis) or congenital lung diseases (e.g., lobar emphysema).