Body Lateralization and Its Effects on Respiratory Drive, Ventilation, and Pulmonary Aeration in Critically Ill Patients

Inclusion Criteria: * Patients of both sexes will be included; * Aged ≥ 18 years; * BMI 18-35 kg/m²; * Under invasive mechanical ventilation via orotracheal tube for ≥ 24 hours and expected to remain on mechanical ventilatory support for at least 48 hours; * Sedated (Richmond Agitation-Sedation Scale \[RASS\] -1 to -4); * Well adapted to protective ventilation strategies in VCV or PSV modes; * Presenting neural respiratory drive evidenced by a drop in Delta Pocc and/or the presence of assisted cycles; * Hemodynamically stable (mean arterial pressure between 60-120 mmHg, systolic arterial pressure between 90-180 mmHg, diastolic arterial pressure between 60-100 mmHg, and heart rate between 50-150 bpm) with or without vasoactive drugs at the time of data collection (\> 0.1 to 0.3 mcg/kg/min); * Respiratory stability, no use of accessory muscles and target SpO₂ achieved; * No indication for nebulization or heated humidification at the time of collection; * Positive tolerance test for lateral decubitus positioning; * Chest circumference of 78-87.9 cm (XS), 88-99.9 cm (S), or 100-111.9 cm (M). Exclusion Criteria: * Patients presenting medical restrictions to body repositioning, or to the use of EIT or sEMG; * Those in therapeutic failure; * Individuals with spinal cord injury, brain injury, or stroke with a history of functional loss and respiratory impairment prior to hospitalization; * Neurological diseases affecting respiratory myoelectric conduction; * History of postural deformities, diaphragmatic abnormalities, or colostomy bag; * Unstable fracture (lower or upper limbs in proximal regions or thorax); * Pleural effusion requiring drainage; * Presence of drains in the thoracic and/or abdominal regions; * Unstable intracranial pressure; * Pregnant patients; * Immediate postoperative period of orthopedic surgeries; * Use of mucolytics; * Open ventriculostomy for drainage; * Uncontrolled agitation; * Pacemaker or implantable cardioverter-defibrillator; * Pneumothorax; * Use of neuromuscular blockers; * Active tuberculosis; * Traction devices; * Active bleeding; * Suspected or confirmed pulmonary embolism without prior treatment within 24 hours; * Presence of a large mass in the right and/or left hemithorax; * History of cardiopulmonary arrest within the past 24 hours under neuroprotection; * In the total weaning phase from IMV and/or tracheostomy and/or enteral feeding tube and/or scheduled CT scan within the next 6 hours; * Intolerance to the TLA test (SpO₂ drop \<92% or ≥20% from baseline, need for FiO₂ increase \>50% or ≥20% from baseline, need for PEEP increase, or hemodynamic instability within the first 5 minutes of lateralization testing); * Those who refuse to provide consent, as determined by the legal representative.