Abstract:
Background: The ability of hemoglobin to bind and dissociate oxygen is crucial in delivering oxygen to tissues and is influenced by a range of physiological states, compensatory mechanisms, and pathological conditions. This may be illustrated by the oxyhemoglobin dissociation curve (ODC). The key parameter for evaluating the oxygen affinity to hemoglobin is p50. The aim of this study was to evaluate the impact of hemodialysis on p50 in a group of patients with chronic kidney disease (CKD). An additional goal was to assess the correlation between p50 and the parameters of erythropoiesis, point-of-care testing (POCT), and other laboratory parameters. Methods: One hundred and eighty patients (106 male, 74 female), mean age 62.5 ± 17 years, with CKD stage G4 and G5 were enrolled in this cross-sectional study. Patients were divided into two groups, including 65 hemodialysis (HD) patients and 115 patients not receiving dialysis (non-HD). During the standard procedure of arteriovenous fistula creation, blood samples from the artery (A) and the vein (V) were taken for POCT. The causes of CKD, as well as demographic and comorbidity data, were obtained from medical records and direct interviews. Results: The weekly dose of erythropoietin was higher in HD patients than in non-HD patients (4914 ± 2253 UI vs. 403 ± 798 UI, p < 0.01), but hemoglobin levels did not differ between these groups. In the group of non-HD patients, more advanced metabolic acidosis (MA) was found, compared to the group with HD. In arterial and venosus blood samples, the non-HD group had significantly lower pH, pCO2 and HCO3-. This group had a higher proportion of individuals with MA with HCO3- < 22 mmol/L (42% vs. 24%, p < 0.01). The absolute difference of p50 in arterial and venous blood was determined using the formula Δp50 = (p50-A) - (p50-V). Δp50 was significantly higher in the HD group in comparison to non-HD (0.08 ± 2.05 mmHg vs. -0.66 ± 1.93 mmHg, p = 0,02). There was a negative correlation between pH and the p50 value in arterial (pH-A vs. p50-A, r = -0.56, p < 0.01) and venous blood (pH-V vs. p50-V, r = -0.45, p < 0.01). In non-HD patients, hemoglobin levels correlated negatively with p50 (r = -0.29, p < 0.01), whereas no significant relation was found in HD patients. Conclusions: The ODC in pre-dialysis CKD (non-HD) patients is shifted to the right due to MA, and this is an additional factor influencing erythropoiesis. Hemodialysis restores the natural differences in hemoglobin\'s dissociation characteristics in the arterial and venous circulation.
摘要:
背景:血红蛋白结合和解离氧的能力在将氧输送到组织中是至关重要的,并且受到一系列生理状态的影响。补偿机制,和病理状况。这可以通过氧合血红蛋白解离曲线(ODC)来说明。评价对血红蛋白的氧亲和力的关键参数是p50。这项研究的目的是评估血液透析对一组慢性肾脏病(CKD)患者p50的影响。另一个目标是评估p50和红细胞生成参数之间的相关性,即时测试(POCT),和其他实验室参数。方法:一百八十例患者(男性106例,74名女性),平均年龄62.5±17岁,CKD分期G4和G5纳入本横断面研究.患者分为两组,包括65例血液透析(HD)患者和115例未接受透析(非HD)患者。在动静脉瘘创建的标准程序中,从动脉(A)和静脉(V)采集血样用于POCT。CKD的原因,以及人口和合并症数据,是从医疗记录和直接访谈中获得的。结果:HD患者的每周促红细胞生成素剂量高于非HD患者(4914±2253UIvs.403±798UI,p<0.01),但这些组间的血红蛋白水平没有差异.在非HD患者组中,发现了更晚期的代谢性酸中毒(MA),与HD组相比。在动脉和静脉血液样本中,非HD组的pH值明显降低,pCO2和HCO3-。该组中,HCO3-<22mmol/L的MA患者比例较高(42%vs.24%,p<0.01)。使用公式Δp50=(p50-A)-(p50-V)确定动脉和静脉血中p50的绝对差异。与非HD组相比,HD组的Δp50明显更高(0.08±2.05mmHg与-0.66±1.93mmHg,p=0,02)。动脉中pH值与p50值呈负相关(pH-A与p50-A,r=-0.56,p<0.01)和静脉血(pH-Vvs.p50-V,r=-0.45,p<0.01)。在非HD患者中,血红蛋白水平与p50呈负相关(r=-0.29,p<0.01),而在HD患者中没有发现显著的相关性。结论:透析前CKD(非HD)患者的ODC由于MA而向右移动,这是影响红细胞生成的另一个因素。血液透析恢复了动脉和静脉循环中血红蛋白解离特性的自然差异。