Prophylactic Topical Tranexamic Acid Versus Placebo in Surgical Patients: A Systematic Review and Meta-analysis∗.

OBJECTIVES: Perioperative bleeding remains a major concern to all clinicians caring for perioperative patients. Due to the theoretical risk of thromboembolic events associated with tranexamic acid (TXA) when administered intravenously, topical route of TXA has been extensively studied, but its safety and efficacy profile remain unclear in the literature. The primary aim of this review was to assess the effect of topical TXA on incidence of blood transfusion and mortality in adults undergoing surgery. DATA SOURCES: EMBASE, MEDLINE, CENTRAL, and ISI Web of Science were systematically searched from their inception until May 31, 2019. REVIEW METHODS: Parallel-arm randomized controlled trials were included. RESULTS: Seventy-one trials (7539 participants: orthopedics 5450 vs nonorthopedics 1909) were included for quantitative meta-analysis. In comparison to placebo, topical TXA significantly reduced intraoperative blood loss [mean difference (MD) -36.83 mL, 95% confidence interval (CI) -54.77 to -18.88, P < 0.001], total blood loss (MD -319.55 mL, 95% CI -387.42 to -251.69, P < 0.001), and incidence of blood transfusion [odds ratio (OR) 0.30, 95% CI 0.26-0.34, P < 0.001]. Patients who received topical TXA were associated with a shorter length of hospital stay (MD -0.28 days, 95% CI -0.47 to -0.08, P = 0.006). No adverse events associated with the use of topical TXA were observed, namely mortality (OR 0.78, 95% CI 0.45-1.36, P = 0.39), pulmonary embolism (OR 0.73, 95% CI 0.27-1.93, P = 0.52), deep vein thrombosis (OR 1.07, 95% CI 0.65-1.77, P = 0.79), myocardial infarction (OR 0.79, 95% CI 0.21-2.99, P = 0.73), and stroke (OR 0.85, 95% CI 0.28-2.57, P = 0.77). Of all included studies, the risk of bias assessment was "low" for 20 studies, "unclear" for 26 studies and "high" for 25 studies. CONCLUSIONS: In the meta-analysis of 71 trials (7539 patients), topical TXA reduced the incidence of blood transfusion without any notable adverse events associated with TXA in adults undergoing surgery. PROSPERO: CRD 42018111762.

Effectiveness of preoxygenation during endotracheal intubation in a head-elevated position: a systematic review and meta-analysis of randomized controlled trials.

Preoxygenation during endotracheal intubation is important to ensure the safety of the procedure. This systematic review and meta-analysis aimed to evaluate the efficacy of preoxygenation in the head-elevated position as compared to the supine position. The Medline, PubMed, Scopus, Embase, and CENTRAL databases were searched systematically from inception of the study until 29 June 2021. Only randomized controlled trials (RCTs) were included. The Cochrane Risk of Bias Assessment Tool and GRADE assessment of certainty of evidence were used. Seven RCTs (n = 508) were analysed, of which 6 were included in the meta-analysis (n = 227). Six studies were carried out in the operating theatre (OT), while one was performed in the critical care (ICU) setting. Compared to the supine position, the head-elevated position significantly increased the duration of the safe apnoea period (mean difference 61.99 s; 95% confidence interval 42.93-81.05 s; P < 0.00001; I2 = 30%; certainty of evidence = high). This improvement was seen in both the obese and non-obese population (I2 = 0%). No differences were seen between both groups with regard to recovery time after apnoea, arterial oxygen tension after preoxygenation, and the incidence of adverse events. In the ICU setting, no difference was found between groups for the incidence of hypoxaemia and the lowest oxygen saturation between induction and after intubation. This meta-analysis demonstrated that the head-elevated position significantly improved the efficacy of preoxygenation during elective intubation in the OT. Clinicians should consider the head-elevated position as a starting intubating position for all patients undergoing anaesthesia in view of its many benefits and the lack of proven adverse consequences. Protocol Registration: This systematic review was registered prospectively in PROSPERO (CRD42019128962).