Objective To assess the systematic reviews of magnesium sulfate used to treat severe asthma. Methods An electronic search was performed in The Cochrane Library (Issue 2, 2008), ACP Journal Club (1991 to June 2008), MEDLINE (1990 to June 2008), Chinese Journal Full-text Database (1979 to June 2008), Chinese Scientific and Technological Periodical Databases (VIP) (1980 to June 2008), and Chinese Bio-medicine Database (CBM) (1980 to June 2008) to collect systematic reviews of magnesium sulfate treatment for severe asthma. The retrieved systematic reviews were reassessed, and then we adopted the evidence for clinical practice. Results Nine systematic reviews were included, and all of them included 14.1 ± 2.9 items of QUOROM (the quality of reporting of Meta-analyses) on average. In general, the included systematic reviews had comparatively high quality. Evidence illustrated that intravenous infusion of magnesium sulfate could improve pulmonary function and reduce hospital admission without any serious side effects. However, no evidence could verify that patients with asthma can benefit from aerosolized and oral magnesium sulfate. In a specific case with severe asthma, we used magnesium sulfate via intravenous infusion which helped the control of symptoms with no adverse reactions. Conclusion Magnesium sulfate via intravenous infusion can improve pulmonary function and reduce hospital admission rates. Due to its effectiveness, safety, and low cost, it deserves widespread application in patients with severe asthma.
Objective To systematically evaluate the effects of magnesium sulfate on postoperative pain and complications after general anesthesia. Methods A literature search was conducted in following databases as The Cochrane Library, EMbase, PubMed, EBSCO, Springer, Ovid, CNKI and CBM from the date of establishment to September 2011 to identify randomized controlled trials (RCTs) about intravenous infusion of magnesium sulfate during general anesthesia. All included RCTs were assessed and the data were extracted according to the standard of Cochrane systematic review. The homogenous studies were pooled using RevMan 5.1 software. Results A total of 11 RCTs involving 905 patients were included. The results of meta-analyses showed that compared with the control group, intravenous infusion of magnesium sulfate during general anesthesia significantly reduced the visual analog scale (VAS) scores at the time-points of 2, 4, 6, 8, 16, and 24 hours, respectively, after surgery, the postoperative 24 hours morphine requirements, and the incidents of postoperative nausea and vomiting (RR=0.61, 95%CI 0.40 to 0.91, P=0.02) and chilling (RR=0.29, 95%CI 0.14 to 0.59, P=0.000 7). Although the incidents of bradycardia (RR=1.93, 95%CI 1.05 to 3.53, P=0.03) increased, there were no adverse events or significant differences in the incidents of hypotension and serum concentration changes of magnesium. Conclusion Intravenous infusion of magnesium sulfate during general anesthesia may obviously decrease the pain intensity, and the incidents of nausea and vomiting and chilling after surgery, without increasing cardiovascular adverse events and risk of hypermagnesemia. The results still need to be confirmed by more high-quality and large-sample RCTs.