血液滤过对犬脑损伤后外周血细胞因子的影响

目的探讨血液滤过(CHF)用于脑损伤后治疗的可行性和作用机制。方法 12只健康犬随机分为2组:治疗组(6只),对照组(6只)。采用改进的Feeney法自由落体致犬脑损伤,治疗组在伤后6小时后采用血液滤过治疗,血流量为90～100ml,置换液为500～800ml/h。持续监测生命体征,每2小时检测血气分析,乳酸和细胞因子;伤后24小时动物处死做脑水含量和组织学检查。结果研究期间,治疗组动物无死亡,犬肛温可在15～18分钟后下降并维持29～32℃之间;与对照组比较,血浆乳酸、IL-1β、IL6、TNF-α水平显著低于对照组(P<0.05～0.01),脑组织含水量明显低于对照组。结论血液滤过可用于脑损伤后亚低温治疗;同时,血液滤过能较好地调节内环境、清除体内细胞因子和乳酸等炎性介质,这对减少脑组织的继发性损伤有益。     

Renal replacement therapies in pediatric multiorgan dysfunction syndrome

Both peritoneal dialysis (PD) and continuous hemodiafiltration (CHDF) techniques are used in children who develop acute renal failure as part of multiorgan dysfunction syndrome (MODS). An important goal of renal support in MODS is treatment and prevention of fluid overload. This report describes an experience with PD and CHDF in children with MODS and presents an analysis of fluid balance for each modality. Medical records of patients with MODS treated with PD/CHDF were reviewed. Fluid balance was studied only in patients with documented fluid overload treated with PD/CHDF for more than 24 h. Successful fluid control was defined as more fluid output than input over the course of PD/CHDF. CHDF was used in 37 patients, median age 47 months (range 0.2–284 months), for a mean of 110 h (range 4–733 h). PD was initiated in 25 patients, median age 4 months (range 0.1–156 months), for a mean of 145 h (range 7–992 h). Successful fluid control was achieved in 17 of 26 (65%) CHDF patients and in 5 of 14 (36%) PD patients (P<0.01, chi-squared). In conclusion, CHDF is more effective than PD in treating and preventing fluid overload in children with MODS. Received: 14 July 1998 / Revised: 13 January 1999 / Accepted: 13 January 1999     

连续性血液净化在急性重症中毒抢救中的应用

目的探讨连续性血液净化(CBP)在急性重症中毒患者抢救治疗中的作用。方法总结我院2004年8月～2006年10月急诊ICU收治的接受CBP治疗的32例重症中毒患者的临床资料,对接受不同的连续性血液净化疗法患者治疗前后的凝血指标、肝肾功能、血清酶学、氧合等指标的变化进行对照研究。结果CBP治疗后,除血小板轻度减低外,患者的凝血指标、肝肾功能、血清酶学等指标较治疗前均明显降低,活化部分凝血活酶时间明显缩短,生命体征明显改善。结论CBP对于急性重症中毒的救治具有重要作用,能明显改善患者的中毒症状、肝肾功能、血清酶学及凝血指标,稳定机体的内环境,从而利于改善中毒患者的预后。     

持续高容量血液滤过对急性呼吸窘迫综合征患者呼吸力学和血流动力学的影响

目的 探讨持续高容量血液滤过(HVHF)对急性呼吸窘迫综合征(ARDS)患者呼吸力学和血流动力学的影响. 方法 选择由各种病因导致的ARDS患者22例,全部病例均在呼吸机支持下给予48 h的HVHF,在HVHF治疗前及治疗后12、24和48 h监测并记录气道峰压、动态肺顺应性、平均肺动脉压(MPAP)、肺动脉楔压(PAWP)、心排血量(CO)、外周循环阻力(SVR)、肺循环阻力(PVR)和血气分析. 结果 HVHF治疗后48 h,气道峰压、动态肺顺应性、MPAP、PAWP、CO、PVR、SVR、氧合指数分别为(31.32±2.23)cm H2O(1 cm H2O=0.098 kPa)、(26.18±3.54)ml/cm H2O、(32.05±1.99)mm Hg(1 mnl Hg=0.133 kPa)、(12.14±1.78)mm Hg,(6.18±0.91)L/min、(194.95±11.51)dyn·s·cm-5、(1071.55±66.50)dyn·s·cm-5、(220.41±21.41)mm Hg,均得到明显改善(P＜0.01). 结论 HVHF可明显改善ARDS患者的呼吸力学和血流动力学.     

连续性血液滤过对多器官功能障碍患者炎性介质的影响

目的 探讨连续性静脉-静脉血液滤过（CVVH）在治疗多器官功能障碍综合征（MODS）患者过程中对其炎性介质的影响。方法 选择30例危重患者，诊断符合MODS标准，分为实验组和对照组；实验组进行常规综合治疗和CVVH治疗，对照组患者采用常规综合治疗，观察2组患者血液及滤液中的白介素-1（IL-1β）、肿瘤坏死因子（TNF-α）、C反应蛋白（CRP）的变化。结果实验组CVVH前后IL-1β无变化（P〉0．05），血TNF-α、CRP在CVVH后呈降低趋势（P〈0．01）；临床症状也明显改善；对照组无明显变化，且有轻度升高。结论 对MODS患者应用CVVH治疗，可以清除炎症介质，减少其对组织器官的损害；并通过稳定内环境，调节水、电解质及酸碱平衡，进而达到改善临床症状提高生存率的目的。     

透析机自产回输液行血液滤过及透析滤过的临床研究

目的评价透析机自产回输液（ｏｎ－ｌｉｎｅ）行血液滤过（ＨＦ）及血液透析滤过（ＨＤＦ）对尿毒症患者不同分子量物质的清除及治疗的安全性、心血管稳定性。方法４０例患者随机分为前稀释ＨＦ、前稀释ＨＤＦ、后稀释ＨＤＦ及ＨＤ四组。观察ＫＴ／Ｖ及血清肌酐（Ｃｒ）、β２微球蛋白（β２－ｍ）、甲状旁腺激素（ＰＴＨ）、α１微球蛋白（α１－ｍ）下降率，评价治疗中低血压及发热反应发生率。结果与ＨＤ相比，ＨＦ或ＨＤＦ治疗中发热反应发生率没有增加；ＨＦ及前稀释ＨＤＦ的超滤量（ＵＦＶ）明显高于ＨＤ，但低血压的发生率并未增加；ＨＦ或ＨＤＦ治疗后血清Ｃｒ、β２－ｍ、ＰＴＨ水平显著降低；后稀释ＨＤＦ的ＫＴ／Ｖ及Ｃｒ下降率均明显高于ＨＤ、前稀释ＨＦ及ＨＤＦ，而前稀释ＨＤＦ的ＫＴ／Ｖ明显高于ＨＤ及ＨＦ。结论ｏｎ－ｌｉｎｅＨＦ及ＨＤＦ治疗安全可靠，能有效地清除ＰＴＨ及β２－ｍ。后稀释ＨＤＦ对小分子物质的清除及治疗中的ＫＴ／Ｖ均较理想，而ＨＦ及前稀释ＨＤＦ更适用于ＨＤ中易出现低血压的血透患者，其长期疗效还有待进一步观察。     

Present Status of the Hemofiltration/Molecular Separation Artificial Kidney

The hemofiltration/molecular separation (HFMS) artificial kidney concept, first proposed over a decade ago, involves continuous ultrafiltration from the blood stream followed by cleansing of the filtrate, with subsequent return to the body. Thus, the system is completely self-contained and portable. During recent preclinical trials on nephrectomized canines, HFMS was better than hemodialysis (HD) in several important ways. First, the removal or clearance of middle molecules was better with 0.34 m(2) HFMS than with 1 m(2) HD. Significant phosphate clearance was achieved, and the removal rate for creatinine was the same as that for urea. This uniform clearance extends to even higher molecular weight solutes and could potentially result in improved patient response. It mimics the real kidney, whereas membrane-limited dialysis undergoes a logarithmic decrease of clearance with molecular weight. This is due to the fact that solute transport through the membrane involves solution into its matrix followed by diffusion, and solute diffusivity decreases with molecular volume. In order to achieve this potential for hemofiltration-based systems, however, there are stringent requirements on both the membrane and the plasma proteins allowed to accumulate on the membrane surface.     

Estimation of Theophylline Clearance During Continuous Arteriovenous Hemofiltration

Pharmacologic agents and other non-protein-bound compounds smaller than 5,000 daltons have the potential to be removed by continuous arteriovenous hemofiltration (CAVH). A proposed method for estimating drug clearance by CAVH (ClCAVH) equates ultrafiltrate clearance to the product of the sieving coefficient and the average ultrafiltration rate. This simplified approach for estimating ClCAVH would be a clinically useful method for calculating replacement doses, as it economizes on the sampling and analytical requirements associated with the conventional method. Presented are some theoretical considerations and a brief evaluation of the accuracy of this proposed method. The evaluation was conducted using an animal model whereby CAVH was performed in four male beagles. During the hemofiltration period, an i.v. bolus of theophylline, 6 mg/kg, was administered over 15 s. Samples for analysis of theophylline were collected from the arterial, venous, and ultrafiltrate ports at 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 360, and 480 min following dosage administration. The volume of ultrafiltrate produced during each collection interval was measured. Theophylline serum concentrations were determined by a high performance liquid chromatography assay. Statistically, the simplified method was found to result in significantly (p less than 0.05) larger estimates of ultrafiltrate clearance when compared to the conventional method. However, the average magnitude of difference was only 9% and does not constitute a clinically significant margin between the two methods.     

Effects of ultrafiltration, dialysis, and temperature on gas exchange during hemodiafiltration: a laboratory experiment

To study gas exchange in the filter during continuous venovenous hemodiafiltration (CVVHDF), an air-tight heated mixing chamber with adjustable CO2 supply was constructed and connected to a CVVHDF monitor. Bicarbonate-free crystalloid (Part 1) and packed red blood cell (Part 2) solutions were circulated at 150 ml x min(-1). Gas exchange expressed as pre-postfilter difference in CO2 and O2 contents was measured at different CVVHDF settings and temperatures of circulating and dialysis solutions. Ultrafiltration was most efficacious for CO2 removal (at 1,000 ml x h(-1) ultrafiltration CO2 losses reached 13% of prefilter CO2 content). Addition of dialysis (1,000 ml x h(-1)) increased CO2 loss to 17% and at maximal parameters (filtration 3,000 ml x h(-1), dialysis 2,500 ml x h(-1)), the loss of CO2 amounted to 35% of prefilter content. Temperature changes of circulating and/or dialysis fluids had no significant impact on CO2 losses. The O2 exchange during CVVHDF was negligible. Currently used CVVHDF is only marginally effective in CO2 removal. Higher volume ultrafiltration combined with dialysis can be expected to reach clinical significance.     

持续高通量静—静脉血液滤过在治疗多脏器功能障碍综合征的作用

目的：探讨持续高通量静－静脉血液滤过（HV－CVVH）治疗多脏器功能障碍综合征（MODS）的效果。方法：观察6例HV－CVVHF治疗MODS患者治疗前后血液动力学、脉搏、血氧饱和度（SaO2）和血浆尿素氮、肌酐、电解质及β2MG变化。结果：HV－CVVH后1h平均动脉压（MAP）、SaO2明显上升,心率明显降低（P＜0．05）;2小时后血钾、血磷、尿素氮、肌酐明显降低（P＜0．05）;4小时后β2微球蛋白开始下降（P＜0．05）。结论：HV－CVVH可有效清除尿素氮、肌酐、β2MG,调整酸碱及电解质紊乱,改善血氧饱和度,使血流动力学稳定。