Please select the eligibility criteria that correspond to the clinical trial below.
Title: Prospective Randomised Study on Preoxygenation in the Intensive Care Unit Using a Nose-mouth Mask Versus High Flow Nasal Cannula Oxygen.
Brief Summary: Preoxygenation is routinely performed before endotracheal intubation. In the intensive care unit, preoxygenation is often accomplished using a nose-mouth mask. It seems probable that high flow nasal cannula oxygen, which is used in the treatment of patients with hypoxemic respiratory failure, is equally effective in preventing the development of hypoxemia during intubation. In this prospective randomized study preoxygenation using high flow nasal cannula oxygen is compared with preoxygenation via nose-mouth mask in patients with hypoxemic respiratory failure.


Options:
A: Inclusion Criteria:

* Able to provide informed consent.
* Undergoing general anaesthesia .
* Between the ages of 18 and 80 years.
* Body mass index (BMI) greater than 40 Kgm-2.

Exclusion Criteria:

* Unable to give informed consent.
* Significant cardiac history which is defined as current angina, myocardial infarction \<12 months before the date of the procedure.
* Significant peripheral vascular disease defined as claudication on minimal exertion or Ankle-Brachial index of \<0.7, a stroke or a transient ischaemic attack \<12 months before the procedure.
* Presence of significant heart-valve disease or congestive heart failure.
* Significant lower respiratory disease including brittle asthma; chronic obstructive pulmonary disease (GOLD stages 3 or 4).
* Strong predictors of both difficult intubation and difficult facemask ventilation on anaesthetic airway assessment.
* Patient with American Society of Anesthesiologists (ASA) grade of 4 for any reason.
B: Inclusion Criteria:

* patients treated in an intensive care unit
* indication for intubation
* presence of hypoxemic (SaO2/fraction of inspired oxygen(FiO2): 300 or less) respiratory failure
* informed consent

Exclusion Criteria:

* blocked nasopharynx
* contraindications for nose-mouth mask or high flow nasal cannula oxygen
* expected difficult airway
C: Inclusion Criteria:

* Obese patient with BMI \> 35kg/m2
* Age between 18 and 80 years
* Requiring a crash induction sequence for oro-tracheal intubation.

Exclusion Criteria:

* Pulse oxymetry \< 90% in ambient air
* Haemodynamic instability
* Burned patient
* Indication of intubation vigil in spontaneous ventilation
* Patients with a documented Cormack IV exposition before inclusion
* Protected adult
* Pregnancy
* Lack of consent
* Patient already enrolled in an other randomized study looking forward improving preoxygenation quality.
* Lack of French social protection
D: Inclusion Criteria:

1. Adult patients (18 years and above) requiring endotracheal intubation in the emergency department.
2. Intubation performed by the emergency medicine physician who are post graduate trainee year IV and above. The year IV and above cut off is taken because at this time the trainees have done more than 20 endotracheal intubations. The operators are assessed through direct supervision and confirmation through filing of their procedural log books

Exclusion Criteria:

1. Supervisor or operator feels specific intra-procedural oxygenation technique will be required.
2. Patients presenting with cardiac arrest
3. Pregnant patients (as the patients are at risk of aspiration and high oxygen delivery can have bad outcomes on the fetus)
4. Patients with 'Do not resuscitate' order.
5. Morbidly obese on assessment as such patient may need pre intubation preparation of the head side and more controlled settings.
6. Patient who are shifted from another hospital post intubation
7. Patients with interstitial lung disease or lung tumor
8. Neck trauma (expanding neck hematoma)
9. Neck and Oral cavity cancers, or patients with cancers of the neck and oral cavity who have undergone surgery, post radiation of the neck and oral cavity cancers.
10. Pulse oximetry \<90% in ambient air.
11. Body mass index \> 35kg/m2

Answer: B