To assess the efficacy of thoracic epidural anesthesia (TEA) with or without general anesthesia (GA) versus GA in patients who underwent cardiac surgery, PubMed, Embase, the Cochrane online database, and Web of Science were searched with the limit of randomized controlled trials (RCTs) relevant to ‘thoracic epidural anesthesia’ and ‘cardiac surgery’. Studies were identified and data were extracted by two reviewers independently. The quality of included studies was also assessed according to the Cochrane handbook. Outcomes of mortality, cardiac and respiratory functions, and treatment-associated complications were pooled and analyzed. The comprehensive search yielded 2,230 citations, and 25 of them enrolling 3,062 participants were included according to the inclusion criteria. Compared with GA alone, patients received TEA and GA showed reduced risks of death, myocardial infarction, and stroke, though there were no significant differences (P > 0.05). With regard to treatment-related complications, the pooled results for respiratory complications (risk ratio (RR), 0.69; 95% CI: 0.51, 0.91, P < 0.05), supraventricular arrhythmias (RR, 0.61; 95% CI: 0.42, 0.87, P < 0.05), and pain (mean difference (MD), −1.27; 95% CI: −2.20, −0.35, P < 0.05) were 0.69, 0.61, and −1.27, respectively. TEA was also associated with significant reduction of stays in intensive care unit (MD, −2.36; 95% CI: −4.20, −0.52, P < 0.05) and hospital (MD, −1.51; 95% CI: −3.03, 0.02, P > 0.05) and time to tracheal extubation (MD, −2.06; 95% CI:−2.68, −1.45, P < 0.05). TEA could reduce the risk of complications such as supraventricular arrhythmias, stays in hospital or intensive care unit, and time to tracheal extubation in patients who experienced cardiac surgery.Electronic supplementary materialThe online version of this article (doi:10.1186/s40001-015-0091-y) contains supplementary material, which is available to authorized users.

Postoperative cognitive dysfunction (POCD) is very common complication of surgery in aged individuals. Accumulated evidence suggests that neuroinflammation may be the underlying cause of POCD. The aim of the present study was to investigate the effects of ulinastatin (UTI) on neuroinflammation and on learning and memory of aged rats after anesthesia and surgery. Our results showed that anesthetic isoflurane increased the hippocampal mRNA level of IL-1β, while surgery of partial hepatectomy increased the hippocampal mRNA levels of IL-1β, TNF-α, and IL-6 as well as impaired rats' spatial memory at day 7 post-surgery. UTI (10,000 U/kg, i.v.) decreased the anesthesia- and surgery-induced increases in mRNA levels of all three cytokines, but did not improve the rats' impaired working memory. In conclusion, moderate and temporary suppression of UTI-induced inflammatory cytokines in hippocampus is not sufficient to alleviate the impairment of working memory.

Tissue-type plasminogen activator (t-PA) and matrix metalloproteinase-9 (MMP-9) have been reported to play important roles in increased permeability of blood-brain barrier (BBB) under many pathological circumstances. We have showed that Ulinastatin, a broad-spectrum serine protease inhibitor, could alleviate inflammation in the hippocampus of aged rats following partial hepatectomy. In this study, we investigate the expression and potential roles of t-PA and MMP-9 in the protective effect of Ulinastatin. We found that partial hepatectomy increased Evans blue leakage in hippocampus at day 1 and 3 postoperatively. Furthermore, surgery decreased the protein levels of claudin-5, ZO-1, and NF-kB p65 while upregulating the mRNA and protein levels of t-PA and MMP-9 in brain capillaries. All these effects caused by surgery were partially reversed by administering Ulinastatin. Our study sheds light on the roles of t-PA and MMP-9 of BBB in post-surgical neuroinflammation and postoperative cognitive dysfunction. Besides, it could also help to understand the mechanism of Ulinastatin alleviating neuroinflammation.