A seven-item simplified score (the MACOCHA score) has been validated to predict difficult tracheal intubation in intensive care unit patients. In the prehospital or in the emergency department settings, no such validated predictive score is available yet. The aim of the present study is to assess the feasibility the quick calculation of the MACOCHA score before emergent intubation, in the prehospital and emergency department contexts.

All patients who will have to undergo emergent tracheal intubation for any reason in the prehospital context or at the emergency department at a single 1100-bed regional and teaching hospital in France, will be included in this observational, prospective study, provided that neither the patient him/herself, if capable, or next-of-kin if present have declined participation.

Items of the MACOCHA score will be recorded before intubation by investigators, who are all certified emergency physicians skilled with urgent tracheal intubation.

For any intubation procedure, either in the out-of-hospital context or in the Emergency Department, one of these emergency physicians is always present.

The feasibility the quick MACOCHA score calculation before urgent intubation will be assessed by the number and percentages of patients for whom all the seven items of the score have been collected.

Inclusion Criteria:

• Patient ≥ 18 yrs
• Patient who have to undergo rapid sequence tracheal intubation as judged by the Emergency Physician

Exclusion Criteria:

• Pregnancy
• Cardiac arrest of any cause as the indication for intubation
• Patient or next-of-kin declining participation

Patients will be adult patients requiring emergent tracheal intubation for acute respiratory failure, coma, or shock, while cared for by an Emergency Physician either in the prehospital setting or in the hospital Emergency Department.