Background and Goal of Study
There have been questions about comparability of randomized, controlled trial (RCT) data from disparate geographies, where clinical practice and event rates may vary. This systematic review and meta-analysis was performed to assess the impact of capnography on patient safety outcomes during procedural sedation (PS) and considers whether there is consistency of data across geographies.
Materials and methods
Systematic, independent review of PubMed, the Cochrane Library and EMBASE was performed in March 2016 for RCTs published in or after 1995 and enrollingpatients undergoing PS. Title and abstract screening of 928 unique results was performed independently by 2 reviewers using Sourcerer. Full-text review of 22 studies resulted in 12 being included for analysis. Extracted data were assessed for clinical utility by 2 physicians. The primary endpoint was oxygen desaturation, and the protocol allowed for the analysis of other endpoints reported by ≥3 studies.
Meta-analysis with OpenMEE used a random effects model. Results are presented as the odds ratio (OR) of events with capnography versus control across all eligible studies, whereby values <1 indicate improved safety with capnography.
Results and discussion
All studies reported mild desaturation, which was significantly reduced with capnography: the mean (95% confidence interval) OR was 0.65 (0.52, 0.81). The reduction was significant in the USA (OR 0.53: 0.31, 0.89) and Europe (OR 0.69: 0.51, 0.92). Six studies defined mild desaturation as <90%, the OR with capnography was 0.60 (0.47, 0.78).
Severe desaturation occurred in 102 of 1,440 capnography patients and 186 of 1,460 control patients, giving an OR of 0.52 (0.40, 0.67). Removal of any one study did not influence the outcome (Figure 1A). Of the 6 studies reporting severe desaturation, 3 were German, 2 USA, and 1 Chinese. In all geographies, capnography significantly reduced severe desaturation (Figure 1B). Meta-regression confirmed no difference between geographies for both mild and severe desaturation.
There were no differences between capnography and control in other endpoints. All studies that reported bag-mask ventilation found it to belower with capnography, OR 0.60 (0.30, 1.22).
Conclusions
Capnography helps to reduce oxygen desaturation during PS. Our results are generalizable over different geographies, suggesting that early detection of respiratory compromise may universally improve patient safety.

Does geography matter: meta-analysis of patient safety during procedural sedation with and without capnography