Objective: To comprehensively evaluate the clinical efficacy of a single dose of tranexamic acid (TXA) in reducing perioperative blood loss in patients undergoing craniomaxillofacial plastic and cosmetic surgery through meta-regression analysis. Methods: Embase, PubMed, Wanfang Data, VIP database, China National Knowledge Infrastructure (CNKI), the Chinese Clinical Trial Registry (ChiCTR) and Cochrane Central Register of Controlled Trials (CENTRAL) were electronically retrieved to collect clinical studies evaluating efficacy of perioperative TXA administration in patients undergoing craniomaxillofacial plastic and cosmetic surgery, from inception to August 2024. Quality assessment of randomized controlled trials (RCTs) was performed using Cochrane Collaboration's Risk of Bias Tool. Based on the results of methodological heterogeneity, corresponding meta-analyses were conducted using either random-effects or fixed-effects models in R programming software. Results: Thirty-one articles were included, involving 2 072 patients who underwent craniomaxillofacial plastic and cosmetic surgeries. Among these patients, 1 051 were in the TXA treatment group, and 1 021 were in the control group. The paired meta-analysis showed that compared with the control group, the use of TXA significantly reduced bleeding volume in perioperative patients [standardized mean difference (SMD)=-1.13; 95%CI (-1.47, -0.80), P<0.001]. Subgroup analysis revealed that TXA significantly reduced intraoperative bleeding volume in patients across different surgeries, with the order of efficacy as follows: orthognathic surgery [SMD=-1.44; 95%CI (-2.07, -0.80), P<0.001], cleft palate repair [SMD=-1.32; 95%CI (-2.14, -0.50), P<0.001], rhinoplasty [SMD=-0.97; 95%CI (-1.63, -0.30), P<0.001], and craniosynostosis [SMD=-0.96; 95%CI (-1.40, -0.53), P=0.040]. The result of the meta regression showed there was no significant difference in the hemostatic effect of TXA on patients with increasing doses (5, 10, 15, 20, 25 mg/kg) (P=0.650). Sensitivity analysis verified that the pooled values were stable and reliable. The Egger's test indicated a certain degree of publication bias (Z=-3.40, P<0.001). Conclusion: Existing evidence suggests that TXA effectively reduces perioperative blood loss in patients undergoing craniofacial plastic surgery, regardless of its dosage administered.

OBJECTIVEDust sample mass gain is too smaller to satisfy the limit of detection (LOD) even in most cases during dust sampling at workplaces nowdays, especially for respirable fraction. Therefore, it is aimed to solve the problem by increasing sample load with high flow rate samplers.

METHODSIn A and B two shipyards respirable welding fume was sampled by high flow rate cyclone samplers of FSP-10 (10 L/min) for 2-2.5 hours and normal flow rate FSP-2 (2 L/min) for 3-4 hours with a stratigy of parallele sampling at the same workpalce, in order to compare their mass gain, coincidence rate with LOD, and airborn dust concentration.

RESULTSSample mass gain of 0.97±0.40 mg and 1.61±0.86 mg respectively in the two factories by FSP-10 was significantly higher than that of 0.29±0.12 mg and 0.51±0.27 mg by FSP-2 (t-test, P<0.05 in both cases) , increasing herewith the coincidence rate with LOD from 26.8% (when sampling with FSP-2, calculated together with samples of the two factories) to 89.7%. However there was no significant difference in dust concentrations by the two different samplers, 0.53±1.88 vs 0.73±1.61 mg/m(3) by FSP-2 and FSP-10 in the shipyard A and 1.14±1.78 vs 1.01±1.63 mg/m(3) in the factory B (t-test, P>0.05 in every case) . In addtion, sample loading by FSP-2 was found to be correlated to sampling time (R(2)=0.7906, y=0.002 6x) , therefore, it has to sample for ≥192.3 min to meet the LOD (0.5 mg) in case of normal flow rate.

CONCLUSIONBy using of high flow rate cyclone FSP-10 the problem of LOD could be solved, along with increased sample mass and similar respirable dust concentration by the two samplers. Some techincal improvements of FSP-10 and increasing of LOD coincidence rate by other methods was also disscussed.

Air Pollutants, Occupational ; analysis ; Construction Industry ; Dust ; analysis ; Environmental Monitoring ; instrumentation ; Occupational Exposure ; Ships ; Workplace