The investigators seek to evaluate if the ultra-sound measure of the diaphragm expansion is predictive of admission into an ICU and/or intubation for patients with COPD.

Every patient coming to the ER with shortness of breath and a known or suspected COPD, will undergo standard of care associated with a diaphragm ultrasound.

The investigators will then gather, through the internal databases of the recruiting hospitals, information about admission into ICU and/or intubation.

The investigators think that this technique will help improve early detection of COPD patient requiring mechanical ventilation, using ultrasound, a non invasive technique.

Inclusion of every lawful age patient presenting to the ER with inclusion criterias

The patient must not have exclusion criteria and must have received the information and consent sheets to be signed jointly

Then, the investigators perform an online randomization for the first and second operator and the side (left/right) from which they start the ultrasound assessment.

The investigators then assess diaphragmatic excursion measurements in spontaneously ventilated patient at 45 ° proclive position for each hemi-diaphragm, with the 2 operators blinded to each other, for 3 consecutive respiratory cycles and save the images.

The date of inclusion is then reported in the register.

Inclusion Criteria:

• Spontaneous ventilation at arrival to the ER

• With Respiratory Failure defined by at least of the following criterias :

  • Respiratory frequency > 25 and/or clinical signs of respiratory failure
  • Hypoxia with a WpO2 < 90%
  • Hypercapnia > 45mmHg with a respiratory acidosis

Exclusion Criteria:

• Known diaphragmatic dysfunction
• Necessity of immediate intubation leaving no time for ultrasound measurements of diaphragmatic excursion
• Unable to provide informed consent
• Evolutive or degenerative neurological disease that could affect diaphragmatic function
• Intracranial Hypertension
• Haemodynamic instability
• Acute heart failure
• Pregnant or Breastfeeding

Every patient over 18, with known or suspected COPD, admitted to the ER for Respiratory Failure.