Summary of findings 3. Bad lung down compared with good lung down for critically ill patients with unilateral lung disease.

Bad lung down compared with good lung down for critically ill adult patients with unilateral lung disease
Patient or population: critically ill adult patients with unilateral lung disease Settings: critical care areas Intervention: bad lung down Comparison: good lung down
Outcomes	Illustrative comparative risks* (95% CI)		Number of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Good lung down	Bad lung down
Hypoxaemia PaO2 < 60 mmHg Follow‐up: 10 to 15 minutes after turninga	Mean PaO2 for good lung down was 122.185 mmHgb	Mean PaO2 for bad lung down was 49.26 lower (67.33 to 31.18 lower)	19 (2 studiesc)	⊕⊕⊝⊝ Lowd	Hypoxaemia detected in 1 study
Global indicators of tissue oxygenation impairment Arterial‐venous oxygen content difference (C(a‐v)O2) ‐ not reported	See comment	See comment	30 (1 study)	See comment	Sample data not available from single cross‐over study
*The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: confidence interval; RR: risk ratio (other abbreviations, e.g..OR)
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: We are very uncertain about the estimate

^aComposite time interval includes early turning (10 minutes) and short‐term turning (15 minutes) responses

^bAverage of study means (good lung down 122.185 mmHg; bad lung down 73.12 mmHg; rounding to two decimal places)

^cCross‐over trials with participants as their own control

^dGRADE downgraded four levels because of methodological variability, including risk of bias (unclear risk of selection, performance, selective reporting biases, and unclear risk of other bias related to cross‐over designs including washout inadequate to rule out carryover effects), inconsistency (inconsistent finding of hypoxaemia for bad lung down between studies, small samples not representative of critically ill adults with unilateral lung disease (some participants were breathing room air, and one study included a child)), indirectness (no dichotomous data, cross‐over studies with continuous data had mean values extracted to detect critical thresholds for each outcome) and insufficient number of studies to test for publication bias.