Objective: To determine whether nasal submucosal injection of low-concentration epinephrine improved the surgical field visualization and physician satisfaction compared to placebo or without intervention. Methods: A literature search of PubMed, Scopus, Web of Science, Cochrane library, China National Knowledge Infrastructure, and Wanfang Database was conducted from inception to January 10, 2023. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analyses were performed using Review Manager (RevMan version 5.3; the Cochrane Collaboration). Quality was assessed by 2 reviewers using the Cochrane Risk of Bias Tool. And we used funnel plots to visually assess the risk of publication bias. Results: We included a total of 11 studies with 492 patients, all of which were randomized controlled trials. Among the studies, 4 had a low risk of bias, 4 had a moderate risk of bias, and 3 had a high risk of bias. Five studies reported visual bleeding grade in the surgical field ( P = 0.07) and total blood loss ( P = 0.16), 8 studies reported preoperative baseline heart rate ( P = 0.58) and baseline mean arterial pressure (MAP) ( P = 0.78), and 9 studies reported intraoperative heart rate ( P = 0.27) and MAP ( P = 0.56), which showed no significant differences in these parameters between the 2 groups. None of these outcomes were statistically significant between the epinephrine group and the control group. Conclusion: There is insufficient evidence to support the nasal submucosal application of low-concentration epinephrine to improve surgical field dryness and reduce total surgical bleeding.

Background: Many studies have investigated the relationship between spinal epidural lipomatosis and obesity, no meta-analysis of studies have provided definitive evidence. To summarize the evidence of associations between obesity factors and spinal epidural lipomatosis (SEL) and to evaluate the strength and validity of these associations. Methods: Electronic databases such as Wiley Online Library, PubMed, Embase, Cochrane Library were searched and manual retrieval of references, the time limit was from the establishment of the database to May 2020. The included literature was case-control studies that reported body mass index (BMI) and SEL correlation, and excluded any primary and secondary tumors or other compression diseases in the spinal canal. Methodological quality evaluations of the included studies were assessed using the bias risk assessment tool recommended by the Cochrane Guidelines. The RevMan 5.3 software was used for meta-analysis. Results: Finally, ten studies were included for systematic review, all of which were observational studies with mixed bias risk. These studies involved 1,541 patients, with an average age of 54.9 to 73.6 years, and 60.2 percent of the participants were male. The sample sizes for the included studies ranged from 28 to 398. The results of meta-analysis showed that high BMI was one of the factors affecting SEL. All reviews had a high risk of bias, and the most common source of bias was that there was no strict unified case diagnosis standard between researches, and some studies (four items) did not clearly describe the confounders that they controlled. Conclusions: We suggest that physicians should consider obesity as a factor leading to SEL, and to control body mass index actively should be considered as the preferred treatment strategy before surgical intervention is conducted.