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 ≥ 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
B: Inclusion Criteria:

1. Males and females, age 18 years and over
2. Planned general anaesthesia for surgery that includes a skin incision and expected to exceed two hours, and the patient is expected to be in hospital for at least three days

Exclusion Criteria:

1. Endoscopic or radiological procedures
2. Cardiac surgery
3. Marked impairment of gas-exchange (requiring Fi02\> 0.3)
4. Thoracic surgery requiring one-lung ventilation (requiring Fi02\> 0.3)
5. Specific circumstances where N2O is contraindicated (eg. volvulus, pulmonary hypertension, raised intracranial pressure)
6. Lack of provision of N2O.
C: Inclusion Criteria:

* Scheduled VA adult elective colorectal surgery patient

Exclusion Criteria:

* Non VA adults, emergent colorectal surgery, scheduled multiple surgery procedures,pts with other infections being treated
D: 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).

Answer: A