Objective Routine perioperative intravenous antimicrobial agents,was administered as surgical prophylaxis.However,whether balanced ultrafiltration during extracorporeal circulation can remove antimicrobial agent remains unclear.The concentrations of antimicrobial agent in plasma and ultrafiltrate samples were measured in this pseudo-extracorporeal circulation model.Methods Extracorporeal circulation consisted of cardiotomy reservoir (Ningbo Fly Medical Healthcare CO.,LTD.Ningbo,China),D902 Lilliput 2 membrane oxygenator (Sorin Group Asia Pte Ltd,Beijing,China) and Capiox (R) AF02 pediatric arterial line filter (Terumo Corporation,Beijing,China).HEMOCONCENTRATOR BC 20 plus (MAQUET Cardiopulmonary AG,Hirrlingen,Germany) was placed between arterial purge line and oxygenator venous reservoir.Fresh donor human whole blood was added into the circuit and mixed with Ringer's solution to obtain a final hematocrit of 24％-28 ％.After 30 minutes of extracorporeal circulation,zero-balanced ultrafiltration was initiated and arterial line pressure was maintained at approximately 100 mm Hg(1 mm Hg =0.133 kPa) with Hoffman clamp.The rate of ultrafiltration (12 ml/min) was controlled by ultrafiltrate outlet pressure.Identical volume of plasmaslyte A was dripped into the circuit to maintain stable hematocrit during 45 minutes of experiment.Plasma and ultrafiltrate samples were drawn every 5 minutes and concentrations of antimicrobial agent (including Cefmetasole and cefotiam) were measured with high performance liquid chromatography.Results All these two antimicrobial agents were detected in ultrafiltrate,demonstrating hemoconcentration may remove antimicrobial agent.The concentration of plasma antimicrobial agent decreased lineally with the increase of ultrafiltrate volume.At end of balanced ultrafiltration,the concentration of plasma cefotiam was (104.96 ± 44.36) μg/ml,which is about (44.38 ± 7.42) ％ of the initial concentration (238.95 ± 101.12) μg/ml; the concentration of plasma cefmetazole decreased linearly to (25.76 ± 14.78) μg/ml,which is about (49.69 ± 10.49) ％ of the initial concentration (51.49 ± 28.03) μg/ml.The total amount of cefotiam in ultrafiltrate is (27.16 ± 12.17)％ of the total dose administered,whereas cefmetasole in ultrafiltrate is (7.74 ±4.17)％.Conclusion Balanced ultrafiltration may remove antimicrobial agent from serum and has significant influence on plasma concentration of antimicrobial agent.The strategy of surgical prophylaxis should consider this unique technique during extracorporeal circulation.

Objective To compare the results of the anterior approach (AA) with the conventional approach in the treatment of large hepatocellular carcinoma (HCC).Methods We searched the Medline,PubMed,Cochrane Library,Wanfang database on randomized clinical controlled trials and non-randomized clinical controlled trials comparing AA with the CA in right hepatic resection for large hepatocellular carcinoma.The data were analyzed with the RevMan5 software.Results Five non-randomized clinical controlled trials (NRCTs) and three randomized clinical controlled trials involving 615 patients (304 in the AA group,311 in the CA group) were enrolled into the analysis.There was no significant difference in the operation time between the two groups.Compared with the CA,the AA had lower intraoperative blood loss (WMD=-680.2 ml; 95％CI,-1023.97～-336.43;P=0.0001),blood transfusion rate (OR=0.38;95％ CI,0.25～0.59;P＜0.0001),intraoperative tumor rupture (OR=0.33;95％CI,0.11～0.97;P=0.04),surgical complication (OR=0.59;95％CI,0.38 ～ 0.93 ; P =0.02),hospital mortality (OR =0.37 ; 95 ％ CI,0.21 ～ 0.67 ; P =0.0009),and hospital stay (WMD=-4.75 d;95％CI,-7.82～-1.67;P=0.002).Conclusion AA is superior to CA in the treatment of larger.The operation time is the same for the 2 approaches.