Respiratory Physiotherapy and Inflammatory Biomarkers in Critically Ill Patients With Pneumonia

The goal of this observational study is to evaluate the safety and impact of a protocolized respiratory physiotherapy program on the dynamics of systemic inflammatory biomarkers (procalcitonin \[PCT\] and C-reactive protein \[CRP\]) in critically ill adult patients with pneumonia in the intensive care unit (ICU), compared with standard medical care. The main questions it aims to answer are: Does a protocolized respiratory physiotherapy program accelerate the decline of PCT and CRP levels in critically ill patients with pneumonia compared to standard care? What is the incidence and safety profile of adverse events (e.g., transient desaturation, hemodynamic instability, or mechanical displacement) associated with respiratory physiotherapy sessions? Researchers will compare a prospective cohort receiving structured respiratory physiotherapy against a historical control group receiving standard care to determine changes in inflammatory trajectories and ICU length of stay. Participants in the prospective intervention group will: * Receive an individualized, protocolized respiratory physiotherapy regimen (including high-frequency chest wall oscillation \[HFCWO\], intrapulmonary acoustic percussion, positive expiratory pressure \[PEP\], and/or inspiratory muscle training \[IMT\]) tailored to their clinical deficits. * Undergo continuous safety monitoring during and up to 30 minutes following each physiotherapy session. * Have serum PCT and CRP levels measured at baseline (T0), Day 3 (T1), Day 7 (T2), and at ICU discharge (T3).

Inclusion Criteria: * Consecutive adult patients (age \>= 18 years at the time of admission). * Confirmed diagnosis of pneumonia (community-acquired, hospital-acquired, or ventilator-associated pneumonia) as the primary cause of ICU admission or critical complication. * Anticipated or actual ICU length of stay \>= 48 hours. Exclusion Criteria: * Presence of limitation of medical treatment orders or exclusively palliative management upon admission. * Concomitant severe non-infectious systemic inflammatory diseases that massively alter or mask procalcitonin response (e.g., severe acute pancreatitis, extensive burns). * Refractory hemodynamic instability or uncontrolled septic shock with escalating vasopressor requirements that contraindicate physical manipulation.