Effects of supplemental oxygen and dexamethasone on surgical site infection: a factorial randomized trial

Abstract

ClinicalTrials.gov number: NCT00273377.

WHO Needs High FIO2?

“…In fact a recent analysis has demonstrated that subsequent randomized trials could not confirm the conclusions of a majority of earlier meta-analysis studies (71). Ironically the WHO and CDC guidelines rely on a meta-analysis after large clinical trials have failed to demonstrate an advantageous effect of perioperative 80% oxygen (10,17). One may also ask whether studies published in 2000 or earlier reflect present clinical practice, particularly in colorectal or thoracic surgery.…”

“…The guidelines are based on a meta-analysis and could be a final and conclusive document if there are no more studies coming out after the publication of the guidelines. However, studies on perioperative hyperoxia continue to be published that are at variance with the guidelines (17), and more are to come. We shall not accept guidelines that have weak scientific or statistical support, if any, and that are of very temporary validity, if any.…”

“…When subcutaneous tissue oxygen tensions stay above 60-80mmHg -which happens when PaO 2 >300 mmHg (2) SSI happens less frequently than expected. So, it's very likely that in most of the recent high FIO 2 and SSI outcomes studies, provided supplemental oxygen was not delivered sufficiently to the tissues, because their reported PaO 2 levels were not that high (10,(15)(16)(17). In fact, until now, there has been only one study where we know that optimum level of oxygen delivered to tissue (i.e.…”

The WHO recommendation for 80% perioperative oxygen is poorly justified

“…On the other hand 7 trials including 2992 patients reported no benefit of 80% inspired oxygen (. Table 1) [2,12,13,15,20,26,28]. The WHO panel members based their recommendations on a meta-analysis of 11 randomized trials of supplemental oxygen during and after general anaesthesia.…”

“…The WHO panel members based their recommendations on a meta-analysis of 11 randomized trials of supplemental oxygen during and after general anaesthesia. Using a random effects model, they estimated the odds ratio (OR) for SSI as 0.72 (95% confidence interval CI; 0.55-0.94) in favour of 80% inspired oxygen; however, it is quite unclear why the WHO panel excluded studies by Kurz et al [12] and Anthony et al [2]. The question is critical because including the results of Kurz et al [12] and Anthony et al [2] in the metaanalysis (using the same methodology) yields an OR of 0.84 (CI: 0.62-1.12, p = 0.242), a value that no longer supports this panel's recommendation.…”