Predicting High-Flow Nasal Cannula Failure in Acute Hypoxemic Respiratory Failure Using Metabolomics and Clinical Data

The goal of this observational study is to determine whether metabolomic profiles combined with clinical data can predict high-flow nasal cannula (HFNC) failure and help optimize respiratory support in adult patients with acute hypoxemic respiratory failure (AHRF). The main questions it aims to answer are: Can metabolomic biomarkers identify patients at higher risk of HFNC failure? Does combining metabolomic and clinical data improve the prediction of respiratory support escalation and clinical outcomes? Participants will: Receive standard HFNC treatment according to clinical practice. Undergo collection of clinical, physiological, and laboratory data. Provide blood samples for metabolomic analysis during respiratory support.

Inclusion Criteria: * Adult patients (≥18 years old). * Admission to the intensive care unit (ICU) with acute hypoxemic respiratory failure (AHRF). * Treatment with high-flow nasal cannula (HFNC) as the initial respiratory support strategy. * Inclusion within the first 24 hours after HFNC initiation. * Provision of informed consent by the patient or legally authorized representative. Exclusion Criteria: * Age \