Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effectiveness of Apneic Oxygenation Using High-flow Nasal Cannula in Morbidly Obese Patients Undergoing General Anesthesia
Brief Summary: Before going off to sleep patients are given oxygen to saturate blood with oxygen to extend time before a decrease in the level of oxygen in the blood occurs. During this period, obese patients have a faster decrease in the level of oxygen in their blood. This study uses a device called "high-flow nasal cannula" (HFNC), which delivers humidified high-flow oxygen through 2 small plastic tubes placed just inside nostrils. In the intensive care unit settings this device has been used extensively and has become a standard practice. Purpose of this study is to determine whether these high-flow nasal cannula increase the time safely when going to sleep during elective surgery.


Options:
A: Inclusion Criteria:

* Adults older than 18 years regardless of the gender
* Requiring orotracheal intubation in intensive care unit
* "No severely hypoxemic respiratory failure" defined as Oxygen Pression (Pa02)/FI02 \> 200 mmHg measured in the 4 hours before inclusion

Exclusion Criteria:

* Not the first Intubation during this stay in intensive care unit
* Contraindication to oro-tracheal intubation
* Intubation without anaesthesic rapid sequence induction
* Intubation during cardiac arrest
* Real emergency (as asphyxia) with immediate intubation needed (without time enough for randomization)
* Nasopharyngeal obstacle with contraindication to use Optiflow device
* Patients with a documented Cormack IV exposition before inclusion
* Protected adult
* Pregnancy or breastfeeding
* Lack of consent
* Patient already enrolled in another study that could interfere with the primary objective of this study
B: Inclusion Criteria:

1. Age ≥ 18 years
2. Mechanical ventilation \> 24 hours
3. Signed Informed Consent
4. Successful spontaneous breathing trial
5. PaO2/FiO2 ratio ≤ 300 (or SpO2/FiO2 ratio ≤ 300 if SpO2 is lower than 98%) within 30 min after extubation while breathing through a Venturi mask with a delivered FiO2 of 31%

Exclusion Criteria:

1. Pregnancy
2. Presence of tracheostomy
3. Need for immediate post-extubation Non-Invasive Ventilation (\>3 consecutive failures of the spontaneous breathing trial and/or a PaCO2 \> 45 mmHg before the spontaneous breathing trial, with a respiratory rate ≥ 25/min)
C: Inclusion Criteria:

1. Adult, \>18 years old
2. ENT-surgery where apnea is of benefit for the surgeon (eg. intraoral or laryngeal surgery) and the anesthesia time is \<40 mins.
3. Capable of understanding the study information and sign the written consent.

Exclusion Criteria:

1. ASA\>2
2. NYHA \>2
3. BMI \>30
4. Pregnancy
5. Manifest cardiac failure or coronary disease
6. Neuromuscular disease
D: Inclusion Criteria:

* Age more than18 years old
* ASA status I-III
* Elective surgery performed under general anesthesia requiring endotracheal intubation
* BMI more than 40 kg/m2

Exclusion Criteria:

* Chronic respiratory disease
* SpO2 \<98% after supplementing oxygen
* Previous or anticipated difficult intubation
* Uncontrolled hypertension
* Ischemic heart disease
* Congestive heart failure
* Increased intracranial pressure
* Uncontrolled GERD
* Known allergy or contraindication to anesthesia drugs
* Nasal blockade contraindicating the use of HFNC

Answer: D