重新审视婴幼儿心肺转流中改良超滤的使用

改良超滤(MUF)技术作为心肺转流中节约用血的重要手段之一,具有浓缩血液、清除炎性介质、减轻组织水肿等优点,但随着微小化体外循环技术的应用,MUF在临床应用中的获益性和必要性开始受到各中心的重新审视。本文对近年来MUF的临床使用进展予以综述。     

改良超滤和无血预充技术在儿童体外循环中的应用

目的：在儿童体外循环中应用改良超滤和无血预充技术，探讨其节约用血和减少术后并发症的作用。方法：40例接近室间隔缺损修补术的儿童根据在手术中是否应用改良超滤和无血预充技术，随机分为（实验组）20例与（对照组）20例，观察两组病人的用血量、手术前后红细胞压积（HCT）变化、速尿用量和血钾变化、术后呼吸机使用时间等指标。结果：实验组围手术期用血量明显减少，术后速用量减少、低血钾发生率降低，术后呼吸机使用时间缩短；而术后24hHCT、平均住院日两组无显著性差异。结果：在儿童体外循环手术中联合应用改良超滤和无血预充技术可明显减少围手术期库血用量而不会降低术后病人红细胞只；有效降低低低血钾的发生率。     

Fluconazole dosing in continuous veno-venous haemofiltration (CVVHF): need for a high daily dose of 800 mg

To cover intermediate sensitive Candida glabrata in ICU patients,fluconazole plasma peak levels at least in the range of 16–32µg/ml appear necessary for treatment. Previous studiesdid not reach these fluconazole levels under continuous veno-venoushaemofiltration (CVVHF) with dosages of 200–600 mg fluconzoledaily. In the present study, nine patients simultaneously requiringCVVHF for treatment of acute oligoanuric renal failure and antimycotictherapy of Candida septicemia received fluconazole 800 mg/day.Fluconazole plasma levels were determined to evaluate whetherthis dosage is adequate to reach the advised fluconazole levels.Patients were dialysed on two consecutive days with an ultrafiltrationrate (UF) of 1000 ml/h or 2000 ml/h, respectively, in a randomizedorder. The predilution was 800 ml/h and 1800 ml/h, respectively.The treatment was tolerated without adverse effects. All patientsreached plasma fluconazole concentrations between 16 and 32µg/ml, remaining in this range for a minimum of 1 up to24 h with a mean of 9.6 h and a UF rate of 2000 ml/h, and 15.7h with a UF rate of 1000 ml/h. So far, there are no in vivodata on the fluconazole plasma concentrations required for effectivetreatment. However, our data demonstrate, that at least thefluconazole concentrations desirable on the basis of in vitrosusceptibility testing can be reached in critically ill patientson CVVHF in an ICU setting. However, in these patients, 800mg fluconazole/day are necessary to achieve fungicidal drugconcentrations.     

改良超滤技术在体外循环中的应用

目的　观察改良动、静脉超滤技术在体外循环 (CPB)中作用及效果。方法　 4 8例病人随机分为两组 ,各 2 4例 ,超滤组于CPB停机后 ,待血液动力学基本稳定时 ,使体内血液经动脉供血管经超滤器超滤后进入右房。对照组不行改良动、静脉超滤。结果　术后输入库血量对照组 5 90ml,超滤组 310ml(P <0 .0 1)。超滤组平均滤出液5 4 0ml,术后血细胞比容、血小板、血浆蛋白、纤维蛋白与超滤前比速度增高 (P <0 .0 1)。结论　改良动、静脉超滤技术有利于术后多余水分排出 ,可减少术后并发症和输血量 ,适用于小体重、血液稀释度大的婴幼儿和长时间CPB者。     

Palliative treatment of malignant ascites by intraperitoneal bleomycin after dialytic ultrafiltration with haemofilter

Dialytic ultrafiltration with haemofilter was performed in 16 patients with malignant ascites refractory to treatment with sodium restriction, diuretic and systemic chemotherapy. A continuous flow of ascitic fluid at a rate of 300–400 ml/min through a haemofilter was maintained by a blood pump. The protein-rich ascitic fluid was re-infused into the peritoneal cavity with sodium and water removed. An average of 5.2 1 of filtrate was removed over a mean interval of 3.5 h. Bleomycin (60 mg) was administered intraperitoneally following the procedure. Complete response was observed in six patients (37.25%) and partial response occurred in four (25%). The remaining patients showed no response. Complications of the dialytic ultrafiltration procedure and toxicity of intraperitoneal administration of bleomycin were minimal. The technique of dialytic ultrafiltration is simple, safe and cost-effective and could be used as an adjuvant therapy for intraperitoneal chemotherapy.     

Modified Ultrafiltration Attenuates Dilutional Coagulopathy in Pediatric Open Heart Operations

Background. Extreme hemodilution caused by relatively large prime volumes required for cardiopulmonary bypass in infants causes a dilutional coagulopathy, characterized by low concentrations of fibrinogen and other circulating coagulation factors. Modified ultrafiltration results in hemoconcentration and is associated with decreases in postoperative bleeding and transfusion requirements in children. This study was undertaken to quantify the effect of modified ultrafiltration on concentrations of fibrinogen, plasma proteins, and platelets in infants and small children.

Methods. Twenty patients less than 15 kg were studied. Cardiopulmonary bypass circuits were primed with crystalloid solutions. Red blood cells were added during cardiopulmonary bypass for hematocrits less than 15%. Colloid solutions were not administered. Concentrations of fibrinogen, plasma proteins, and platelets, and hematocrit were measured before cardiopulmonary bypass, before modified ultrafiltration, and after modified ultrafiltration.

Results. Modified ultrafiltration was associated with significant (p < 0.001) increases in hematocrit (19% ± 6% to 31% ± 9%), fibrinogen (65 ± 29 to 101 ± 45 mg/dL), and total plasma proteins (2.7 ± 0.3 to 4.9 ± 0.7 g/dL), but no change (p = 0.129) in platelet count.

Conclusions. We conclude that modified ultrafiltration significantly attenuates the dilutional coagulopathy associated with cardiopulmonary bypass in infants.     

酵母抽提物超滤制备海藻糖工艺条件的优化

利用响应面分析法对影响酵母抽提液中总氮截留率和海藻糖透过率的主要因素进行分析,优化超滤工艺,得到最佳超滤条件:料液质量浓度10 g／dL,料液温度42℃,操作压力0.31MPa,在最佳超滤条件下得到酵母抽提物蛋白质截留率96.5%,海藻糖透过率94.8%,所得RSA图可直观地反映各因素与蛋白氮截留率和海藻糖透过率的关系.     

超滤膜分离技术在植酸酶浓缩中的应用

目的 利用超滤法在低温下操作,生物活性物质不易失活的特点,探讨超滤法代替薄膜蒸发法浓缩植酸酶发醇液的技术可行性,以降低能耗。方法 采用截留分子量为２００００的ＰＵ－２０Ｋ－ＰＳ管式超滤膜系统浓缩１～５批次的植酸酶发醇液,测定浓缩倍数、浓缩收率和截留率并观察超滤过程的膜通量及其变化。结果 植酸酶的浓缩倍数为６．５３倍,浓缩收率为９９．６９％,截留率为９９．９３％,系统可以在植酸酶的工艺条件下连续浓缩〉１０ｈ,且经过简单清洗后,膜通量基本恢复。结论 用ＰＵ－２０Ｋ－ＰＳ管式超滤膜系统缩植酸酶发醇液在技术上可行。     

腹腔巨噬细胞产生一氧化氮对腹膜透析失超滤的作用

目的 研究腹腔巨噬细胞产生的一氧化氮（ＮＯ）对腹膜淋巴孔的作用,探讨腹膜淋巴孔的淋巴重吸收对长期腹膜透析失超滤的影响。方法 应用腹透液建立腹宁的小鼠模型,用全自动酶标仪动态测定怛,用扫描电镜观察不同时间点腹膜间皮超微病理变化,使用计算机与扫描电镜联机的图象处理系统,测定不同腹膜透析时间点腹膜淋巴孔的变化。结果 腹腹膜管析时程延长,透析组有大量巨噬细胞从腹膜淋巴孔游出,在腹膜表面形成许多乳斑。巨噬细     

丙烯腈/丙烯酰胺/苯乙烯三元共聚超滤膜材料的制备和表征

以偶氮二异丁腈为引发剂,采用溶液聚合法制备了丙烯腈、丙烯酰胺、苯乙烯三元共聚物,并用红外光谱(IR)、示差扫描量热(DSC)、热重分析(TG)等手段对共聚物进行了结构和性能表征。结果表明:苯乙烯的加入使得参加环化反应的氰基和酰胺基的数目减少,保留了更多作为功能基团的酰胺基。用相转化法制备得到超滤平板膜,膜的渗透通量为2.63 mL/(cm2.h),对聚乙二醇20000(PEG 20000)的截留率为96.95%。