Acute oral alkali citrate load in healthy humans — Response of blood and urinary citrate,mineral metabolism,and factors related to stone formation

Summary In ten healthy volunteers (/=5/5) the effects of two doses (2.5 and 5.0 g) of orally ingested alkali citrate (AC) on serum citrate, variables of mineral metabolism in serum, the urinary excretion of citrate, sodium and minerals were studied and compared with the effects of an oral vehicle load. Also, phosphate crystalluria and the supersaturation of several stone forming phases in urine were evaluated under all loads. The data allow to conclude that 1) the rise in serum citrate may result from citrate absorbed intestinally under AC;2) systemic metabolic alkalosis is not detectable with the chosen AC doses but may be reflected by the more alkaline urinary pH and a higher citrate excretion; 3) mineral metabolism, serum ionized calcium, parathormone, calcitonin and urinary cyclic AMP included, are more or less stable under acute loads of AC;4) postprandial phosphate crystalluria is more pronounced with increasing AC, but despite this the direct correlation with the supersaturation of hydroxyapatite is progressively weakened with both doses AC suggesting that the inhibitory effects of this drug may dominate over its effects upon initiation of precipitation.Parts of this work were presented at the European Urolithiasis Symposium, held in Vienna, from March 21 to 23, 1985     

The effect of LED on blood microcirculation during chronic wound healing in diabetic and non-diabetic patients—a prospective,double-blind randomized study

Chronic wounds, especially in diabetic patients, represent a challenging health issue. Since standard treatment protocols often do not provide satisfactory results, additional treatment methods—like phototherapy using low-level light therapy—are being investigated. The aim of our study was to evaluate the effect of phototherapy with light-emitting diodes on chronic wound treatment in diabetic and non-diabetic patients. Since a sufficient blood supply is mandatory for wound healing, the evaluation of microcirculation in the healthy skin at a wound’s edge was the main outcome measure. Forty non-diabetic patients and 39 diabetics with lower limb chronic wounds who were referred to the University Medical Center Ljubljana between October 2012 and June 2014 were randomized to the treated and control groups. The treated group received phototherapy with LED 2.4 J/cm² (wavelengths 625, 660, 850 nm) three times a week for 8 weeks, and the control group received phototherapy with broadband 580–900 nm and power density 0.72 J/cm². Microcirculation was measured using laser Doppler. A significant increase in blood flow was noted in the treated group of diabetic and non-diabetic patients (p?=?0.040 and p?=?0.033), while there was no difference in the control groups. Additional Falanga wound bed score evaluation showed a significant improvement in both treated groups as compared to the control group. According to our results, phototherapy with LED was shown to be an effective additional treatment method for chronic wounds in diabetic and non-diabetic patients.     

New blood volume monitoring method for hemodialysis: A-V pressure gradient measurement by synchronized one-point reading

Abstract:  During hemodialysis, rapid ultrafiltration often causes symptomatic hypotension. To predict the occurrence of volume-dependent hypotension as early as possible, continuous hematocrit monitoring with the Crit-Line noninvasive monitor has been widely used to measure blood volume changes during hemodialysis. As another potential method of monitoring blood volume variations, we studied blood viscosity, which is theoretically associated with the pressure gradient across the dialyzer. Blood viscosity (calculated by the Hugen-Poiseuille formula) is a major determinant of the blood flow rate and is associated with the pressure difference between the postpump arterial (A) and venous (V) pressures. The A-V pressure gradient fluctuates due to pump pulsation, so we minimized this noise by always reading the pressure gradient at the same point out of 1400 partitions on the rotary pump. To test this synchronized one-point reading method, the A-V pressure gradient was measured using 3 different xanthan gum solutions and was found to be linearly proportional to the model blood flow rate. In an experimental dialysis system using a xanthan gum solution (300 mg/L), the A-V pressure gradient showed a gradual linear increase along with the ultrafiltration rate up to 1 L/h as the viscosity slowly increased in the dialyzer. The changes of blood volume shown by this method were significantly correlated with data obtained using the Crit-Line in 8 patients undergoing hemodialysis. This simple and inexpensive method may allow monitoring of blood volume changes and thus provide data that are beneficial for fluid management in hemodialysis patients suffering from clinical dialysis intolerance.     

不同病种外科病人术前血浆量、红细胞量和血容量的测定

目的 研究不同外科疾病病人术前血浆量、红细胞量和血容量变化情况。方法 ５１例外科住院病人参加了本研究,术前分别测定其血浆量和红细胞量,二者相加得病人血容量值,与百科全书及生理教科书介绍的正常人资料对比。结果 （１）胆道疾病病人及胃、结肠癌病人每千克体重血浆量、红细胞量和血容量的测定值较正常人资料显著增高。结论 门静脉高压症病人的血浆量、红细胞量和血容量均较正常人资料显著增高,其它疾病病人则和正常人资料相近。     

A novel calculation to estimate blood volume and hematocrit during bypass

Patient blood volume impacts most facets of perfusion care, including volume management, transfusion practices, and pharmacologic interventions. Unfortunately, there is a wide variability in individual blood volumes, and experimental measurement is not practical in the clinical environment. The purpose of this study was to evaluate a mathematical algorithm for estimating individual blood volume. After institutional review board approval, volumetric and transfusion data were prospectively collected for 165 patients and applied to a series of calculations. The resultant blood volume estimate (BVE) was used to predict the first and last bypass hematocrit. The estimated hematocrits using both BVE and 65 mL/kg were compared with measured hematocrits using the Pearson moment correlation coefficient and the Bland Altman measures of accuracy and precision. There was a wide range of BVE (minimum, 35 mL/kg; mean +/- SD, 64 +/- 22 mL/kg; maximum, 129 mL/kg). Using BVE, the estimated hematocrit was similar to the measured first (24.7 +/- 6.4% vs. 24.5 +/- 6.2%, r = 0.9884, p > .05) and last (24.5 +/- 5.9% vs. 25.1 + 5.7%, r = 0.9001, p > .05) bypass hematocrit. Using 65 mL/kg resulted in a larger difference between estimated and measured hematocrits for the first (25.6 +/- 4.5% vs. 24.5 +/- 6.2%, r = 0.6885, p = .030) and last (23.8 +/- 3.6% vs. 25.1 +/-5.7%, r = 0.5990, p = .001) bypass hematocrits. Compared with using 65 mL/kg for blood volume, the BVE allowed for a more precise estimated hematocrit during CPB.     

Estimating allowable blood loss with correction for variations in blood volume

All the theoretical relationships between blood loss and change in haematocrit used for calculating the allowable pre-transfusion blood loss assume a strictly normovolaemic situation. In this study a formula was derived in which account was taken of the variation in blood volume. The formula was based on clinical data. Measurements of the blood loss, the blood haemoglobin concentration and the haematocrit (HCT) were performed on 230 occasions in the course of 35 transurethral prostatic resections. The change in blood volume was estimated by the haemoglobin dilution method and the value so obtained was compared to both the measured haematocrit and the theoretical value that would presumably have been recorded if there had been no change in blood volume. The relationship established from these comparisons was: blood loss = preoperative blood volume x [In preop HCT - In postop HCT (1 + 0.15 x blood volume change)].     

血液透析症状性低血压和难治性高血压患者相对血容量变化的比较

目的对症状性低血压(SH)和难治性高血压(RH)患者血透中相对血容量(RBV)的变化进行比较研究。方法选取SH患者15例和RH患者13例,通过血容量监测仪观察透析前和透析后每小时的RBV,BP,HR及超滤量(UV)。SH组共149次,RH组146次,比较两组各项指标的变化并分析各参数间的关系。结果SH组各小时RBV的变化均明显大于RH组(P<0.01)。SH组总的UV明显大于RH组。用体表面积校正后,UV分别为(2122.5±560.20)和(1389.83±615.59)ml/m2,P<0.01。用UV对RBV进行校正,RBV的变化在SH组仍明显大于RH组[分别为(-6.10±3.15),(-11.44±4.34),(15.62±5.30),(-18.83±7.43)%和(-2.94±3.23),(-6.91+4.99),(-11.04±5.82),(-14.87±6.16)%,P均<0.01]。RH组中有2例增加超滤量,干体重下降后,其平均动脉压(0h,1-3h)显著下降。RH组有58次在透后1h内RBV较开始时升高。结论在血透中,SH和RH患者间RBV的变化存在差异,这可能部分与两组患者的水化状态不同有关。对于SH患者,当RBV变化较大时要警惕发生低血压;对RH患者,当发现RBV变化较小时应当注意是否仍然存在水负荷过多。进一步降低原先认为已达临床估计目标的干体重值可能使部分RH患者血压得到进一步下降。     

大鼠椎骨错缝模型不同时间节点全血黏度变化的实验研究

目的：通过检测大鼠腰椎椎骨错缝模型不同时间点全血黏度的变化,研究石氏伤科气血理论及骨错缝、筋出槽学说,揭示慢性脊柱病损的病理生理学特征.方法：将36只350～450 g的SPF级雄性SD大鼠随机分为旋转固定组（RF组）、单纯固定组（SF组）和假手术组（Sham组）,每组12只.RF组和SF组大鼠腰椎L4-L6节段植入椎体外部连接固定装置,RF组大鼠使Ls棘突向右侧旋转,造成L5棘突与L4和Ls棘突的不共线;SF组大鼠单纯植入椎体外部连接固定装置不进行旋转.分别于固定后1、4、8和12周时,检测各组大鼠的全血黏度变化.结果：固定4、8周之后,RF组和SF组大鼠在高切（150/s）、中切（60/s）和低切变速率（10/s）下的全血黏度皆高于Sham组大鼠（P＜0.05）.固定1、12周后各组大鼠全血黏度比较差异无统计学意义（P＞0.05）.结论：椎体骨错缝、筋出槽可导致大鼠全血黏度升高,增加血脉瘀阻的程度,从而进一步诱发或加重脊柱病损的发生.     

超声测量下腔静脉内径快速评估老年患者术前血容量的价值

目的探讨应用超声测量下腔静脉(IVC)横切面内径及面积,快速评估老年患者术前血容量的价值。方法选择择期胃肠手术老年患者90例,男47例,女43例,年龄65～80岁,ASAⅠ—Ⅲ级,根据入室后CVP分为低血容量组(CVP5cmH_2O)和非低血容量组(CVP≥5cmH_2O)。采用超声测量患者剑突下呼气末IVC横切面的长径(LD)、短径(SD)及其横切面面积(Area),并计算IVC的内径形变指数(SCI),采用Pearson相关分析IVC各参数与CVP的相关性;绘制受试者工作特征(ROC)曲线确定IVC预测CVP5cmH_2O的效能。结果低血容量组呼气末LD、SD、Area均明显小于非低血容量组(P0.01),SCI明显高于非低血容量组(P0.01)。LD、SD、SCI、Area与CVP相关系数r分别为0.346、0.754、-0.679、0.534(P0.01)。ROC曲线预测CVP5cmH_2O时,SCI和SD曲线下面积(AUC)分别为0.925、0.893,明显优于LD、Area(0.669、0.717,P0.01);SCI和SD的AUC差异无统计学意义。结论超声测量IVC横切面SD、SCI和Area在一定程度上能够为老年患者术前血容量评估提供参考,且SD和SCI预测老年患者术前血容量的效能更高。     

Relationship between blood viscosity and cerebral ischemia after surgical treatment of ruptured intracranial aneurysms

To determine the role of blood viscosity after surgical treatment of ruptured intracranial aneurysms, the relationship between blood viscosity and clinical condition was examined in 17 patients. A total of 213 blood samples were analyzed. An inverse correlation was found between blood viscosity and level of consciousness; in addition, blood viscosity was higher when focal neurologic deficit was observed. Hematocrit was similarly related to clinical condition, although the correlations observed were less strong. Postoperative plasma viscosity was higher in patients with focal neurologic deficit. Regular blood viscosity measurements are of value in patients at risk for developing cerebral ischemia.     

成人原发性肾病综合征血容量与肾素,醛固酮,心钠素的关系

探讨成人原发性肾病综合征(NS)血容量与肾素、醛固酮及心钠素的关系。方法 应用~(113)mInCl标记转铁蛋白稀释法测定血容量,放免法测定血浆激素水平。对水肿期NS28例、正常26例及其中NS缓解期随访18例进行检测。结果 (1)水肿期NS血容量与正常组无差别,血浆肾素活性(PRA)、血管紧张素Ⅱ(ATⅡ)、醛固酮(Ald)、心钠素(ANP)水平均较正常组高,白蛋白、各激素水平与血容量无显著相关;(2)缓解期与水肿期比较,总的血容量无差异,Ald、ANP显著降低,PRA、ATⅡ则无明显差异;(3)Ald与24小时尿排钠(UNaV)显著负相关。结论 Ald和ANP是NS钠排泄的主要调节因子。     

Effects of PEEP on splanchnic hemodynamics and blood volume

The effects of intermittent positive pressure ventilation with PEEP on splanchnic circulation and hepatic oxygen supply were studied in six beagles. PEEP of 0, 0.5 and 1.0 kPa (0, 5, 10 cmH₂O, PEEP₀, PEEP₅ and PEEP₁₀, respectively) of 30 min duration was applied in a random sequence. Hepatic arterial blood flow and portal venous blood flow were measured by electromagnetic flow meters. Blood volume changes in the splanchnic area were assessed from hepatic and splenic dimensions determined by sonomicrometry. PEEP₅ and PEEP₁₀ were associated with proportional decreases in both hepatic blood flow and cardiac output, while mean arterial pressure remained unchanged. Reflecting the decrease in hepatic blood flow, the hepatic oxygen supply decreased with the level of PEEP, and hepatic venous hemoglobin oxygen saturation was significantly less during PEEP₁₀ (55.1 ± 14.3%) than during PEEP₅ (62.6 ± 17.4%) and PEEP₀ (62.3 ± 11.9%). Hepatic venous and portal venous pressure increased with the level of PEEP. Hepatic dimensions increased by 7–8% and 16–19% during PEEP₅ and PEEP₁₀, respectively, but no significant changes in splenic dimension were observed. We conclude that PEEP₅ and PEEP₁₀ are accompanied by a decrease in hepatic blood flow and oxygen supply along with hepatic congestion.