Diaphragm Response in Elderly for Acute Monitoring

Inclusion Criteria: * Patients aged ≥ 75 years * Emergency admission for acute dyspnea * Requiring an emergency ultrsoung. Exclusion Criteria: * Acute respiratory distress requiring immediate invasive or non-invasive ventilation * Respiratory rate ≥ 25 breaths/min, and/or SpO2 ≤ 90% on room air, and/or PaO2 ≤ 60 mmHg * Known diaphragmatic paralysis * Patients with degenerative neuromuscular disease * State of shock: systolic blood pressure \< 90 mmHg and/or mean arterial pressure \< 65 mmHg and/or presence of skin mottling and/or CTR \> 3s * Lactate levels \> 2 mmol/L * Hypercapnic respiratory acidosis (pH \< 7.38 and PaCO2 \> 45 mmHg) * Dyspnea due to metabolic acidosis (e.g., diabetic ketoacidosis, renal failure) * Dyspnea of traumatic origin * Refusal to participate or inability to provide informed consent * Patients deprived of liberty * Patients under guardianship or curatorship