TOXYC study

A multi centre randomised controlled trial of targeted oxygen therapy in mechanically ventilated critically ill patients



There is a lack of available literature on the ideal level of oxygen that clinicians should target in patients who are critically ill. Whilst essential for life, oxygen is also a highly toxic molecule.  In our desire to provide critically ill patients with as much oxygen as they might need, we may expose them to harm from excessive exposure.  In this study, we are investigating the potential risks and benefits of allowing sick patients to have a relatively low level of blood oxygen (hypoxaemia), in order to reduce the impact of oxygen toxicity in our most vulnerable group of patients.

The intervention


The intervention is targeted oxygen therapy to achieve an arterial haemoglobin oxygen saturation (SpO₂) of 88-92%. The control group will also receive the current standard SpO₂ of 96% or above. The study will commence as soon as possible after admission to the critical care unit (following enrolment) and end following removal of the patient’s artificial breathing tube (endotracheal tube).

The team

Principal investigator: Dr Dan Martin

Sites: Royal Free Hospital and Southampton General Hospital