Patients residing in the intensive care unit typically receive mechanical ventilatory support. Selecting the appropriate level of mechanical ventilation is not trivial, and it has been shown that lung protective settings can reduce mortality in patients with lung injury. Despite being a life- saving therapy, duration of mechanical ventilation should be kept at a minimum to reduce effects of immobilization, long-term sedation, patient discomfort, risk of ventilator associated pneumonia, leading to decreasing mortality and economic costs etc. The duration of mechanical ventilation is also an important factor in weaning from ventilatory support, with prolonged ventilator support making the weaning process more difficult.

The purpose of this study is to compare mechanical ventilation following advice from the Beacon Caresystem to that of standard care in general medical intensive care unit (ICU) patients, from the start of requiring invasive mechanical ventilation until successful extubation. The Beacon Caresystem will be compared to standard care to investigate whether use of the system results in similar care or reduced time for weaning from mechanical ventilation.

All patients admitted to the ICU with mechanical ventilation are screened for inclusion. Patients receiving invasive mechanical ventilation (≥ 24 h) will be considered for inclusion in the study on a daily basis. Patient screening will be performed by clinical researchers or a delegated clinician and consent/assent will be sought. Then patients will be randomised to the Beacon group or Standard Care group. Randomisation will be performed using sealed envelopes, and in blocks of patients, allowing interim analysis of results in appropriate steps during the study. To avoid that results are affected by patient disease type, randomisation will be stratified for equal distribution between randomisation groups.

Patients will be randomly assigned to either standard care of mechanical ventilation, or to follow the advice of the Beacon Caresystem. The results of these two strategies will then be compared based upon the following outcome measurements.

Inclusion Criteria:

• Patient is expected to be on invasive mechanical ventilation more 24 hours.
• Age > 18 years
• Haemodynamically stable (with instability defined by the presence of two or more of the following criteria: acidosis pH < 7.2, poor urine output < 0.5ml/kg, use of vasopressors, e.g. noradrenline > 25 μg/min).
• Patient consent or, in the case that the patient is unable, assent from the next of kin or treating physician following understanding and accept of oral and written information describing the study

Exclusion Criteria:

• The absence of an arterial catheter for blood sampling at study start.
• Medical history of home mechanical ventilation which may lead to prolonged stay in the ICU, including long term oxygen therapy and non-invasive ventilation not associated with sleep apnoa.
• Clinical conditions requiring treatment with extracorporeal membrane oxygenation, i.e. an inspired oxygen of 100% for more than 24 hours.
• Head trauma or other conditions where intra-cranial pressure may be elevated and tight regulation of arterial CO2 level is paramount.
• Primary neurological patients (Glasgow coma score <10, neurologic damage with limited prognosis, stroke hemiplegia).
• Severe heart failure, classified as grade 4 of the Association of Cardiology guidelines [2].
• End stage liver disease.
• Multiple medical ICU admissions, i.e. more than one admission.
• Corrective orthognathic surgery.
• Esophageal surgery.
• Morbidly obese patients defined as either BMI>45, or 35\