Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomised Controlled Trial of Oxygen Therapy in Acute Myocardial Infarction (AVOID - Air Verses Oxygen In myocarDial Infarction Study)
Brief Summary: - Aim

The AVOID (Air Verses Oxygen In myocardial infarction) trial is designed to determine if the withholding of routine oxygen therapy in patients with acute heart attack leads to reduced heart damage compared to the current practice of routine inhaled oxygen for all patients.

- Background

There is evidence supporting and refuting the current practice of providing oxygen to all patients with acute heart attack. A recent summary of clinical trials suggested that oxygen may increase the degree of heart damage during heart attack. It also highlighted that the few trials into oxygen therapy were performed before the use of modern medications and procedures to treat heart attack and that further studies were urgently needed, using contemporary practices.

- Design

A total of 334 patients will participate in this randomized controlled trial. Patients in this study will receive the best current management and care for their condition. Patients will be randomized to routine pre-hospital care with oxygen therapy vs pre-hospital care without oxygen therapy. Patients will then receive standard hospital care, aside from allocated oxygen or no oxygen therapy. The primary outcome measure of heart damage will be investigated using routine blood tests. With additional information gathered from other aspects of routine heart care including coronary angiogram, electrocardiograms and complications of hospital stay. Patients will be followed up at 6 months to determine any longer term effects of treatment.


Options:
A: Inclusion Criteria:

* Adults (age ≥18 years)
* Out-of-hospital cardiac arrest of presumed cardiac cause
* Initial cardiac rhythm ventricular fibrillation/ ventricular tachycardia ("shockable")
* Unconscious (Glasgow Coma Scale \<9)
* In cardiac arrest on ambulance arrival
* Sustained return of spontaneous circulation (\>2 minutes)
* Pulse oximeter trace with oxygen saturation measured at ≥95% on bag/ reservoir with oxygen set at ≥10L/min
* Patient is spontaneous breathing or ventilated using bag/valve/oxygen reservoir via endotracheal tube or SGA (i.e. laryngeal mask airway)

Exclusion Criteria:

* Female who is known or suspected to be pregnant
* Dependant on others for activities of daily living (i.e. facilitated care or nursing home residents)
* "Not for Resuscitation" order
* EMS witnessed arrests
B: Inclusion Criteria:

* Age 18 years or older.
* Laparotomy, acute or elective. In case of gynaecological surgery only if malignancy is suspected (defined as risk of ovarian malignancy index \>200 or a specimen with atypical or neoplastic cells).

Exclusion Criteria:

* Other surgery within 30 days (except surgery in local anaesthesia).
* Chemotherapy within 3 months.
* Inability to give informed consent.
* Inability to keep oxygen saturation above 90% without supplemental oxygen (measured preoperatively by pulse oximetry).
C: Inclusion Criteria:

* Witnessed out-of-hospital cardiac arrest with ventricular fibrillation (VF) or ventricular tachycardia (VT) as the initial rhythm
* Delay of return of spontaneous circulation (ROSC) 10-45 min from the start of the arrest
* Confirmed or suspected cardiac origin
* Mechanical ventilation
* Markedly impaired level of consciousness (no response to verbal commands and Glasgow coma scale \[GCS\] motor score \< 5)
* Deferred consent possible or likely
* Active intensive care initiated, including targeted temperature management (33-36 C)

Exclusion Criteria:

* Probable withdrawal of active ICU care due to terminal illness or poor prognosis because of severely reduced functional status before cardiac arrest
* Confirmed or suspected intracranial pathology and/or suspicion of raised intracranial pressure
* Pregnancy
* Severe oxygenation problem (PaO2 / FiO2 \< 100 mmHg)
* Severe COPD
D: Inclusion Criteria:

* Adults ≥ 18 years of age.
* Chest pain for \< 12 hours
* ST-elevation Myocardial Infarction including either: 1) Persistent ST-segment elevation of ≥1mm in two contiguous limb leads; 2) ST-segment elevation of ≥ 2mm in two contiguous chest leads, or; 3) New left bundle branch block (LBBB) pattern.
* Able to be transported to a participating hospital

Exclusion Criteria:

* Hypoxia with oxygen saturation measured on pulse oximeter \< 94% with the patient breathing air
* Bronchospasm requiring nebulised salbutamol therapy using oxygen
* Altered conscious state

Answer: D