Oxygen therapy for critically Ill and post-operative patients.

Nearly all patients receiving treatment in a peri-operative or intensive care setting receive supplemental oxygen therapy. It is biologically plausible that the dose of oxygen used might affect important patient outcomes. Most peri-operative research has focussed on oxygen regimens that target higher than normal blood oxygen levels. Whereas, intensive care research has mostly focussed on conservative oxygen regimens which assiduously avoid exposure to higher than normal blood oxygen levels. While such conservative oxygen therapy is preferred for spontaneously breathing patients with chronic obstructive pulmonary disease, the optimal oxygen regimen in other patient groups is not clear. Some data suggest that conservative oxygen therapy might be preferred for patients with hypoxic ischaemic encephalopathy. However, unless oxygen supplies are constrained, routinely aggressively down-titrating oxygen in either the peri-operative or intensive care setting is not necessary based on available data. Targeting higher than normal levels of oxygen might reduce surgical site infections in the perioperative setting and/or improve outcomes for intensive care patients with sepsis but further research is required and available data are not sufficiently strong to warrant routine implementation of such oxygen strategies.