The purpose of this observational study is to investigate the prognostic relevance of lung ultrasound (LUS) performed on older patients (aged 65 and above) admitted to the hospital with acute respiratory symptoms. The primary objective is to determine if LUS-detected pulmonary abnormalities upon hospital admission are associated with the development of delirium during hospitalization. Secondary objectives include assessing the association between LUS patterns and clinical outcomes such as oxygen supplementation duration, non-invasive ventilation use, mortality, and length of hospital stay. This study involves no interventions and will monitor patients using LUS as part of their regular clinical care in multiple centers.

This is a multicenter, prospective, observational study designed to explore the prognostic value of lung ultrasound (LUS) in older patients admitted with acute respiratory symptoms. The study, titled "Exploring the Correlations of Lung Ultrasound with Delirium and Outcomes in Acute Geriatrics world (ECO-AGE)," aims to evaluate whether the presence of LUS abnormalities, such as pleural or lung parenchymal changes, detected upon admission is associated with the onset of delirium during hospitalization.

The study will recruit participants aged 65 years or older who are admitted to the hospital through the emergency room due to acute respiratory complaints (e.g., dyspnea, cough, reduced oxygen saturation, clinical suspicion of pneumonia, acute heart failure, or chronic obstructive pulmonary disease). Patients will undergo LUS as part of their routine clinical management, and data collected from the LUS exams will be analyzed to assess correlations with clinical outcomes.

The primary endpoint of the study is the incidence of delirium, measured using the 4AT scale, during the hospital stay. Secondary endpoints include associations between LUS patterns and the following outcomes:

Duration of oxygen therapy Requirement for non-invasive mechanical ventilation Length of hospital stay In-hospital mortality Readmission rates and mortality at 3 months post-discharge The study hypothesizes that certain LUS abnormalities, such as diffuse or focal comet-tail artifacts (B-lines), pleural effusion, or parenchymal consolidations, will be predictive of adverse outcomes like delirium or prolonged respiratory support.

Data will be collected via electronic Case Report Forms (eCRFs) and analyzed using multivariate regression models, adjusting for potential confounders such as age, sex, frailty, and comorbidities. The estimated recruitment period is 12 months, and patient outcomes will be monitored throughout hospitalization and for 3 months following discharge. The findings of this study are expected to inform better risk stratification and clinical management of older patients with acute respiratory illnesses.

Inclusion Criteria:

• Patients aged 65 years or older, admitted directly from the Emergency Room or Emergency Medical Services with acute respiratory symptoms or signs.

Presence of acute respiratory symptoms, including:

• Dyspnea or cough.
• Oxygen saturation less than 94% or respiratory rate ≥ 22 breaths per minute, or PaO2/FiO2 < 300.
• Clinical suspicion of acute respiratory illness (e.g., pneumonia, acute congestive heart failure, pulmonary edema, COPD, pleural effusion, pneumothorax).
• Lung ultrasound (LUS) performed within 48 hours of admission for clinical reasons.
• Signed informed consent for participation in the study.

Exclusion Criteria:

• Presence of delirium upon admission.
• Refusal to sign the informed consent form or consent to data collection.
• Terminal illness with an estimated survival prognosis of no more than 3 months.
• Previous open thoracic or cardiothoracic surgery compromising the quality of LUS images.
• Lack of cooperation during the LUS examination.
• Any condition determined by the investigators that could introduce bias into the study or compromise the quality of the LUS examination.

The study population will consist of patients aged 65 years and older admitted to participating hospitals through the emergency room or emergency medical services with acute respiratory symptoms (e.g., dyspnea, cough, low oxygen saturation). These patients will undergo lung ultrasound (LUS) as part of their routine clinical management. The study will focus on older adults presenting with conditions such as pneumonia, acute congestive heart failure, chronic obstructive pulmonary disease (COPD), pleural effusion, or pneumothorax. The population will include both male and female patients from multiple centers across Italy, with a particular focus on those at higher risk of delirium and poor clinical outcomes due to underlying frailty or multimorbidity.