%0 Journal Article %T A fixed inhaled nitrous oxide/oxygen mixture as an analgesic for adult cancer patients with breakthrough pain: study protocol for a randomized controlled trial %A Guo-Xia Mu %A Jian-Qiang Yu %A Ning-Ju Wang %A Ping Chen %A Qiang Liu %A Xiang-Jiang Luo %A Xiao-Min Chai %A Xin Jin %A Yu Wang %A Yu-Xiang Li %A Yue-Juan Zhang %J Archive of "Trials". %D 2017 %R 10.1186/s13063-016-1739-9 %K Analgesia %K Breakthrough pain %K Cancer patients %K Nitrous oxide %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5225628/