Effects of Modified Ultrafiltration on Coagulation Factors in Pediatric Cardiac Surgery

Purpose. Modified ultrafiltration (MUF) after cardiopulmonary bypass (CPB) in children has been reported to reduce the need for postoperative blood transfusion and minimize postoperative blood loss. This study was undertaken to quantify the effects of MUF on coagulation factors in pediatric patients. Methods. Seven children scheduled to undergo open-heart surgery for congenital heart defects were studied. CPB cir-cuits were primed with crystalloid solutions and no blood transfusions were performed. Hematocrit, platelet count, total plasma proteins, albumin, fibrinogen, prothrombin, factor VII, factor IX, and factor X were measured preoperatively, at the termination of cardiopulmonary bypass, and at the end of modified ultrafiltration. Results. MUF was associated with significant (P < 0.05) increases in hematocrit (17.6% ± 1.6% to 21.6% ± 2.4%), platelet count 11.1 ± 2.5 to 12.8 ± 2.4 × 10⁴/mm³), total plasma proteins (2.7 ± 0.3 to 3.4 ± 0.4 g/dl), and albumin (1.6 ± 0.2 to 2.1 ± 0.2 g/dl). Fibrinogen, prothrombin, and factor VII also increased significantly (P < 0.05) during MUF, but factor IX and factor X did not change. Conclusion. We conclude that MUF attenuates the dilutional coagulopathy that occurs during CPB in children. There were slight improvements in the coagulation factors when MUF was employed. Received: October 5, 2000 / Accepted: September 11, 2001     

超滤法-HPLC法测定灯盏花素脂质体包封率

目的对灯盏花素脂质体进行质量评价,测定灯盏花素脂质体包封率。方法采用超滤法分离脂质体与游离药物;采用Kromasil ODS柱(200 mm×4.6 mm,5μm),流动相为甲醇乙腈20 mmol.L-1磷酸盐缓冲液(pH值为2.5)(体积比为17∶17∶66),流速为0.8 mL.min-1,检测波长为334 nm,测定药物含量,计算包封率。结果超滤法能很好的将脂质体与游离药物分离,游离药物的平均回收率在95.9%~97.6%,加样回收率在96.4%~97.1%,脂质体不能透过超滤膜;该色谱条件下,灯盏乙素得到良好分离,辅料不干扰测定,灯盏乙素在1.0~40.0 mg.L-1内线性关系良好(r=0.999 9),日内和日间RSD均小于2.0%(n=5),加样回收率在99.7%~100.1%之间,RSD小于1.23%。结论该方法可用于灯盏花素脂质体的质量控制。     

改良超滤在10kg以下婴幼儿体外循环中的应用

目的:观察改良超滤(MUF)技术对10kg以下婴幼儿体外循环(CPB)心脏手术的影响.方法:2002年10月～2004年11月,共进行10kg以下小儿先天性心脏病(CHD)心内直视手术102例,所有病例均在手术中应用动-静脉MUF 技术.结果:超滤时间5～20(11.9±2.8)min,超滤流量10～15 ml/kg,超滤量200～950(586.97.5)ml,CPB中红细胞压积(HCT)为18～30(22.5±2)%,MUF结束时HCT为32～38(35.8±1.4)%.术后平均用血(230±60)ml,全组患儿未出现与MUF相关的并发症.结论:在婴幼儿体外循环心脏手术中采用改良超滤技术,能有效地清除体内多余的水分,减轻心、脑、肺等脏器水肿;能快速地浓缩血液,减少输血和术后出血;同时能滤出CPB引起的多种有害的炎性因子,减轻炎性反应,促进术后器官功能的恢复.     

膜法分级纯化姬松茸子实体多糖的研究

目的通过微滤和超滤对姬松茸子实体粗多糖分级纯化,获得最佳试验操作条件,考察各级相对分子质量范围内的多糖分布情况及所得制品的纯度。方法使用微滤和不同截留相对分子质量的超滤串联工艺。结果试验按相对分子质量将其分成>3×105、3×105~8×104,8×104~1×104以及<1×1044个级别,所得多糖质量分布比例约为5∶1∶3∶1。试验确定操作条件为室温,操作压力0.08~0.1MPa,微滤和各级超滤分别将各级多糖最高浓缩至45、35和25g/L。在低温下干燥制备的姬松茸多糖制品,质量分数高于70%,多糖总回收率高达83.7%。结论该工艺简单可行,姬松茸子实体多糖相对分子质量主要分布于>3×105和8×104~1×105。     

透析用水纯化与除菌方案实践及验证

目的:建立一个合理的透析用水纯化与除菌方案,并对该方案的实际运行进行验证。方法:对透析用水系统的各个环节进行多指标监测。结果:透析用水系统中的制水系统、贮水系统、超滤系统、管路系统的多指标监测合格。结论:透析用水系统方案布置监测维护合理,符合使用要求。     

Transcapillary ultrafiltration and peritoneal equilibration test in pediatric patients

The usefulness of the peritoneal equilibration test (PET) in children is unknown. The relationship between transcapillary ultrafiltration and PET was investigated in order to evaluate the usefulness of PET in children. PET was performed on 14 patients undergoing peritoneal dialysis. Their age and bodyweight ranged from 3.8 to 23.6 years and 10.2 to 55.8 kg, respectively. The patients were divided into two groups according to bodyweight; group A patients weighed ≤ 40 kg (n = 7) and group B patients weighed > 40 kg (n = 7). There was no significant difference in the mean infusion volume per bodyweight between the two groups, but the mean infusion volume per body surface area was smaller in group A than in group B. Group A showed a more rapid equilibration of dialysate glucose and creatinine than group B. Higher normalized mass transfer area coefficients were evident in group A. In spite of the lower effective glucose gradient in group A, the transcapillary ultrafiltration capacity (TUFC) showed no difference between the two groups. When the slope indices of the regression equations between the two groups were compared, the slopes of the regression in the relationship between TUFC and dialysate (D) ratios D/D₀ glucose or D/P creatinine in group A were steeper than those in group B. Results of the present study indicate that the larger peritoneal area to infusion volume in patients with smaller body size results in both a rapid equilibration of solutes and sufficient transcapillary ultrafiltration.     

婴儿心脏直视手术中两种超滤法应用的对比研究

目的　比较常规超滤 (CUF)和CUF加改良超滤 (MUF)在婴儿心脏直视手术中应用及效果。方法　选取 4 0例单纯室间隔缺损 (VSD)行修补术的婴儿随机均分为两组 ,C组采用CUF ,M组采用CUF +MUF ,两组用相同的方法进行体外循环 (CPB)。观察 :⑴CPB预充总量、手术总用血量、CPB总入量、红细胞压积 (Hct)、超滤量、尿量、残血量等 ;⑵术前、术毕、术后 4h、术后 2 4h血浆白细胞介素 (IL) - 6 ,IL - 8、肿瘤坏死因子 (TNF -α)水平 ;⑶术后血管活性药物的应用、机械通气时间、ICU停留时间。结果　⑴两组预充总量、手术总用血量、CPB总入量、尿量无统计学差异 ,超滤量M组 (4 36± 82 )ml显著多于C组 (347± 5 7)ml,P <0 .0 5 ;残血量M组 (135± 2 3)ml少于C组(16 8± 32ml) ,P <0 .0 1;术毕HctM组 (0 .36± 0 .0 4 )高于C组 (0 .32± 0 .0 5 ) ,P <0 .0 5。⑵术毕TNF -αM组 (97.6± 18.4 )pg/ml显著高于C组 (83.1± 16 .5 )pg/ml,P <0 .0 5 ;余各时点、各指标 2组间均无统计学差别。⑶术后血管活性药物的使用、机械通气时间、ICU停留时间 2组间无显著差异 ,胸腔引流量M组 (96 .4± 2 8.7)ml少于C组(117.3± 32 .6 )ml,P <0 .0 5 ;术后输血量 (4 6 .4± 17.1)ml少于C组 (6 1.5± 2 5 .0 )ml,P <0 .0 5。结论　与CUF     

Transglomerular Transport of DEAE Dextran in the Isolated Perfused Kidney

Objective: The renal fractional clearance of [³H]DEAE dextran has been widely used to substantiate the charge selective model for renal permselectively, although there has only been one reported study on this type of clearance. This study sets out to examine the fractional clearance and glomerular processing of DEAE dextran. Methods: Fractional clearance studies were performed using isolated perfused rat kidneys. The glomerular processing of DEAE dextran was assessed by examining the kinetics of DEAE dextran uptake in glomerluli isolated post perfusion. Results: The fractional clearance of DEAE dextran used in the concentration range of 15–150 μg/ml in the perfusate of the isolated perfused kidney did not produce the classical in vivo facilitated transport of DEAE dextran as compared to dextran as observed by Bohrer et al. The fractional clearance curve displays retarded clearance of low molecular weight (small radii) DEAE dextran, giving the appearance of a ‘flat curve’. Similar results were obtained when an oxygen free radical scavenger cocktail was included in the perfusate. These results may be due to the fact that DEAE dextran binds to the glomeruli (at an order of magnitude greater than dextran sulfate). Perfused kidneys with [³H]DEAE dextran for 1 h followed by a five minute perfusion with unlabelled DEAE dextran revealed no significant change in the glomerular levels of [³H]DEAE dextran (unlike dextran sulfate). Perfusion of rat kidneys with 15 μg/ml DEAE dextran produced no changes in the electron microscopical morphology of the glomerulus and no changes in the fractional clearance of dextran. Conclusions: These results do not support the glomerular charge selectivity model that involves a non-binding electrostatic interaction of the charged dextran with the fixed anion charges of the glomerular capillary wall.     

The Effect of Hemofiltration on Fiber Platelet Concentration

Experimental methods and apparatus were developed to measure platelet concentration in an ultrafiltering hollow fiber with blood and ultrafiltrative flow rates that are characteristic of current hemofiltration practice. Values are presented for the adjusted local platelet concentration, which allows for the expected increase due to loss of ultrafiltrate volume. Platelet concentrations in fiber samples are of interest since ultrafiltration can create platelet polarization in a fashion similar to the concentration polarization that occurs for proteins. For many combinations of inlet flow rate, ultrafiltrative flow rate, and fiber dimension, there are significant elevations in adjusted fiber platelet concentration. The adjusted platelet concentrations of the outflow samples are nominally equal to those of the feed (reservoir) samples; thus, reaction and adhesion of platelets is not a significant source of fiber concentration. Experiments with fibers of different diameters indicate that, as expected in concentration polarization, the excess platelets are located near the wall. Data for the fiber platelet concentration depend in a complex fashion upon the inlet wall shear rate and ultrafiltrative velocity. For certain fixed ultrafiltrative velocities, a maximum fiber platelet concentration occurs at an intermediate inlet wall shear rate. The data are qualitatively explained by an extension of a published model involving diffusive, ultrafiltrative, and wall-induced fluxes of red cells and platelets.     

Protein binding of salicylate in cutaneous hepatic porphyria

Summary (1) Plasma protein binding of salicylate was studied in 14 patients with cutaneous hepatic porphyria (CHP) and 11 normal subjects using ultrafiltration with centrifugation (membrane cones) and continuous ultrafiltration. (2) Albumin and haemoglobin levels were significantly reduced in patients with CHP, and salicylate binding by ultrafiltration/centrifugation was 65% compared with 84% in normal subjects. (3) Plasma porphyrin levels were raised, but did not correlate with salicylate binding, and protoporphyrin or uroporphyrin added to plasma did not alter the amount of drug bound. (4) Palmitate added to plasma reduced salicylate binding by 9 to 20% but a crossover of patient and normal plasma proteins and ultrafiltrates confirmed that no other ultrafiltrable metabolites present in patient plasma appeared to cause decreased binding. (5) Scatchard plots obtained by continuous ultrafiltration for normal and patient plasma showed a reduction in the number of primary and secondary binding sites and an increase in the intrinsic association constants for both these sites. (6) It was concluded that the decreased salicylate binding in CHP was due to a reduced albumin concentration and altered salicylate albumin interaction.