Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Multicentre, Prospective, Observational, 4-week Inception Cohort Study Being Carried Out by the Acute Respiratory Failure Section of ESICM
Brief Summary: We wish to prospectively assess the burden of, management and therapeutic approaches to, and outcomes from acute hypoxaemic respiratory failure requiring ventilatory support, during the winter months in both the northern and southern hemispheres. We wish to specifically examine the contribution of ARDS as defined by the Berlin Definition to the burden of hypoxaemic respiratory failure.

Why?

The purpose of this study is to provide new and current data on the disease burden of acute hypoxemic respiratory failure and ARDS. It will answer the following questions:

* What is the frequency and disease burden of acute hypoxaemic respiratory failure in winter?
* What are the aetiologies of acute hypoxaemic respiratory failure requiring ventilatory support?
* What is the incidence of ARDS based on the Berlin definition within this patient cohort?
* What is the mortality from ARDS within this cohort, and how does this vary based on ARDS severity?
* What is the natural history of ARDS?
* What are the key patterns of therapeutic resource utilization, particularly approaches to sustain gas exchange, in these patients?

When?

The study is performed over a 4 week period between February 1st and March 31st 2014 in the Northern Hemisphere and June 1st to August 31st in the Southern Hemisphere.

What data is required?

A basic dataset is collected on all patients admitted with acute acute hypoxaemic respiratory failure requiring ventilatory support, with a more detailed dataset collected on patients diagnosed with ARDS.


Options:
A: Inclusion Criteria:

* All patients admitted to the participating ICUs receiving invasive or non-invasive ventilation will be screened and included in the database.

Exclusion Criteria:

* Age \< 16
B: Inclusion Criteria:

* adults who met acute respiratory failure requiring intubation
* adults who met hypoxemia, defined by a PaO2 less than 100 mm Hg under a high FiO2 mask driven by at least 10 L/min oxygen.

Exclusion Criteria:

* encephalopathy
* coma
* cardiac resuscitation
* hyperkaliemia (\>5.5 mEq/L)
* acute brain injury and recent thoracic surgery
C: Inclusion Criteria:

* Invasive mechanical ventilation
* Acute respiratory insufficiency (within past 28 days)
* Bilateral infiltrates on frontal chest radiograph
* Hypoxemia, defined as PaO2/FiO2\<=250

Exclusion Criteria:

* Primary cause of respiratory failure is cardiac
* Anticipated duration of mechanical ventilation \< 48 hours
* Inability to wean other experimental ventilation strategies
* Severe chronic respiratory disease
* Neuromuscular disease that will prolong mechanical ventilation
* Conditions where hypercapnia-induced intracranial hypertension should be avoided
* Morbid obesity (\> 1Kg per cm body weight)
* Pregnancy
* Very unlikely to survive and lack of commitment to life support Underlying irreversible condition with 6 month mortality \>= 50%
* Greater than 48 hours elapsed since first eligible
* Current participation in competing trial
* Lack of physician, patient or proxy consent
D: Inclusion Criteria:

* Intubated and mechanically ventilated
* Diagnosis of ARDS using American-European consensus criteria
* Enrollment in study \< 48 hours since diagnosis of ARDS
* For 12-36 hrs. (ideally 12-24 hrs) after diagnosis of ARDS, patient must be ventilated as follows: Volume A/C, Tidal volume of 4-8 ml/kg PBW, Plateau pressure ≤ 30 cmH2O, PEEP/FIO2 adjustments using ARDSnet table, Ventilator rate to keep PaCO2 = 35-60 mmHg
* During the 12-36 hour(ideally 12-24 hr) period, PaO2/FIO2 must remain \< 200 mm Hg for an ABG obtained 30 minutes after placement on the following specific ventilator settings: Volume A/C, Tidal volume = 6 ml/kg PBW, Plateau pressure ≤ 30 cmH2O, Inspiratory time ≤ 1 second, PEEP ≥ 10 cmH2O, FIO2 ≥ 0.5, Ventilator rate to keep PaCO2 = 35-60 mmHg
* No lung recruitment maneuvers or adjunct therapy.
* Total time on mechanical ventilation \< 96 hrs. at time of randomization.

Exclusion Criteria:

* Age \< 18 years or \> 80 years
* Weight \< 35 kg PBW
* Body mass index \> 60
* Intubated 2° to acute exacerbation of a chronic pulmonary disease
* Acute brain injury (ICP \> 18 mmHg)
* Immunosuppression 2° to chemo- or radiation therapy
* Severe cardiac disease(one of the following): New York Heart Association Class 3 or 4, acute coronary syndrome or persistent ventricular tachyarrhythmias
* Positive laboratory pregnancy test
* Sickle cell disease
* Neuromuscular disease
* High risk of mortality within 3 months from cause other than ARDS, e.g. cancer
* More than 2 organ failures (not including pulmonary system)
* Documented lung barotrauma, i.e. chest tube placement other than for fluid drainage
* Persistent hemodynamic instability or intractable shock
* Penetrating chest trauma
* Enrollment in another interventional study

Answer: A