Relation of interdialytic water retention with apparent bicarbonate space, HCO3-, and pH in hemodialyzed uremic patients.

This study determines the relationship between interdialytic water retention (IWR) and acid-base homeostasis in uremic patients under regular hemodialysis (HD). To this aim, in 33 regular bicarbonate HD sessions of 11 uremic patients (three HD sessions of 1 week for each patient), blood samples were received from arterial line immediately pre- and post-HD anaerobically in heparinized syringes and the HCO3-, pH, and pco2 were determined. Also in the studied HD sessions, the IWR was estimated and the apparent bicarbonate space percentage (ABS%) pre- and post-HD was calculated by Fernandez et al. (Eq. 1). The mean +/- SD values pre-HD (ABS% = 54.15 +/- 1.49, HCO3- = 18.54 +/- 2.0 mmol/L, pH = 7.32 +/- 0.02, pco2 = 35.44 +/- 3.10 mmHg) and post-HD (ABS% = 49.88 +/- 0.6, HCO3- = 26.33 +/- 1.6 mmol/L, pH = 7.44 +/- 0.02, pco2 = 37.69 +/- 3.00 mmHg) show metabolic acidosis pre-HD and slight alkalosis post-HD. There was a significant positive correlation between IWR and ABS% pre-HD (r = 0.650, p < .0001) and post-HD (r = 0.655, p < .0001), but a significant negative correlation between IWR and HCO3- pre-HD (r = -0.502, p < .003) and post-HD (r = -0.700, p < .001), as well as between IWR and pH pre-HD (r = -0.516, p < .002) and post-HD (r = -0.377, p < .03). In addition, there was a significantly negative correlation between IWR and pco2 post-HD (r = -0.656, p < .001), but not pre-HD (r = 0.0136, PNS). The significantly positive relationship between IWR and ABS% pre- and post-HD, in combination with the significantly negative correlation between HCO3- and pH pre- and post-HD, indicates that the IWR negatively influences the acid-base homeostasis in hemodialysis patients without residual renal function, and may worsen the cardiovascular physiology and tissue oxygenation of these patients.

Pre-HD dilution acidosis, without post-HD contraction alkalosis in uremic patients.

The aim of this study was to verify if the degree of pre-HD acidosis and its correction post-HD is related to body fluid expansion during the interdialytic period. Twelve uremic patients without major problems, with stable hematocrit, with regular and similar HD-session characteristics, but widely varying amounts of body fluid expansion in the interdialytic period were included. Blood samples were collected from arterial line pre- and post-HD, anaerobically in heparinized syringes, for determination of HCO3-, pH and PaCO2 (radiometer Copenhagen ABL 300 Acid-Base Laboratory), in two similar HD-sessions for each patient (12 patients, 24 HD-sessions). The percentage (%) of body weight gain in the interdialytic period was also estimated. For each patient, the mean value of parameters studied in the two HD-sessions was used for the evaluation of findings. According to mean values (+/-SD) of HCO3-, pH and PaCO2 Pre-HD (18.26+/-1.99 mmol/L, 7.31+/-0.03, 36.27+/-2.5 mmHg respectively) and post-HD (26.37+/-1.7, 7.43+/-0.03, 38.43+/-2.10 respectively) patients are acidotic pre-HD and slightly alkalemic post-HD. Correlation between the percentage (%) of interdialytic body weight gain (IBWG) and the values of HCO3-, pH and PaCO2, Pre-HD (r=-0.814, p<0.001; r=-0.931, p<0.001; r=0, 100 NS; respectively) and post-HD (r=-0.958, p<0.001; r=-0.937, p<0.001; r=-0.504 NS; respectively) indicates a significant and negative relationship of IBWG% with HCO3- and pH pre- and post-HD, but not with PCO2. In conclusion, the negative relationship of IBWG% with HCO3- and pH pre- and post-HD indicates that the body fluid expansion during the interdialytic period contributes to a dilutional acidosis pre-HD, but not to a contraction alkalosis post-HD, by the elimination of fluid during the HD-session.

Relationship between interdialytic weight gain and acid-base status in hemodialysis by bicarbonate.

The aim of this study was to determine the relationship between interdialytic weight gain and acid-base balance pre- and posthemodialysis in uremic patients undergoing hemodialysis with a high bicarbonate dialysate (39 mmol/L). To this end we studied 8 stable uremic patients on regular hemodialysis thrice weekly who had stable hematocrit values for at least 3 months, similar clinical characteristics including dry weight but widely varying interdialytic weight gain. Arterial line blood samples were collected anaerobically in heparinized syringes pre- and posthemodialysis in 4 consecutive hemodialysis sessions for the determination of pH, Paco2, and HCO3. Prehemodialysis values (mean +/- SD) were pH = 7.34 +/- 0.03, Paco2 = 36.43 +/- 1.4, and Hco3 = 20.1 +/- 1.55. Posthemodialysis values were pH= 7.47 +/- 0.02, Paco2 = 38.72 +/- 2.0, and HCO3 = 27.73 +/- 1.72. In other words, patients were moderately acidemic prior to and moderately alkalemic after the hemodialysis session. Of note, a significant negative correlation was revealed between the interdialytic weight gain and the values of prehemodialysis blood pH (r = -0.721, p < 0.001) and HCO3 (r = -0.836, p < 0.001) and posthemodialysis pH (r = -0.533, p < 0.001), Paco2 (r = -0.623, p < 0.001) and HCO3 (r = -0.815, p < 0.001), suggesting an important role of the interdialytic weight gain on acid-base equilibrium of uremic patients undergoing hemodialysis. Thus, patients with high interdialytic weight gains may require higher bicarbonate concentrations to achieve normal acid-base status whereas patients with low interdialyic weight gains may require lower bicarbonate concentrations to prevent alkalemia at the end of dialysis.

Relation between echinocytosis and erythrocyte calcium content in hemodialyzed uremic patients.

A rise in intracellular calcium concentration in erythrocytes has multiple effects on these cells. The purpose of this study was to determine the changes of calcium content in red blood cells (RBCs) and of echinocyte percentages in uremic patients during hemodialysis sessions. In 30 uremic patients under hemodialysis, the calcium content of RBCs and echinocyte percentages were determined in 3 blood samples collected at 0 min hemodialysis (prehemodialysis), 45 min hemodialysis, and 240 min hemodialysis (end hemodialysis) for a 4 h hemodialysis session. Calcium content of RBCs and echinocytes were also determined in 22 normal subjects (controls). The findings of the present study were that the mean values (+/-SD) of calcium content of RBCs in patients at 0 min hemodialysis, 45 min hemodialysis, and 240 min hemodialysis were 2.00 +/- 1.0, 2.66 +/- 0.87, and 1.62 +/- 0.66 microg/ml respectively and 0.65 +/- 0.07 microg/ml in controls. These values show that the calcium content of RBCs in uremic patients at 0 min hemodialysis, 45 min hemodialysis, and 240 hemodialysis was significantly higher than in controls (p < 0.0001), and that RBC calcium content at 45 min hemodialysis was significantly higher in comparison to that at 0 min hemodialysis (p < 0.001) and to that at 240 min hemodialysis (p < 0.0001), while that at 240 min hemodialysis was significantly lower than at 0 min hemodialysis (p < 0.05). The mean values (+/-SD) of echinocyte percentages in patients at 0 min hemodialysis, 45 min hemodialysis, and 240 hemodialysis were 11.93 +/- 6.18, 17.23 +/- 4.1, and 7.96 +/- 5.67% respectively, and in controls ranged from 0 to 1%. The values in uremic patients show a transient increase of echinocyte percentages at 45 min hemodialysis, which is significant in comparison to that at 0 min hemodialysis (p < 0.001) and to that at 240 min hemodialysis (p < 0.0001). Echinocyte percentages at 240 min hemodialysis were significantly lower to those at 0 min hemodialysis (p < 0.001). Correlation between calcium content of erythrocytes and echinocyte percentages shows a significantly positive relationship at 45 min hemodialysis (r = 0.368, p < 0.05) but no significant relationship at 0 min hemodialysis and 240 min hemodialysis. In conclusion, uremic patients under hemodialysis present with high calcium content in erythrocytes and abnormal erythrocytes like echinocytes. A rapid and transient increase of erythrocyte calcium is also accompanied by transient elevation of echinocytes in the first hour of hemodialysis (45 min hemodialysis), which returns after hemodialysis to lower than prehemodialysis levels.

Alterations in echinocyte transformation and erythrocyte sedimentation rate during hemodialysis.

In 18 uremic patients under regular hemodialysis (HD) with bicarbonate dialysate, the echinocytes and erythrocyte sedimentation rates (ESR) were determined in 4 blood samples collected from the arterial line at 0, 45, 120, and 240 min (end-HD) in one HD session by a bioincompatible dialyzer and in another by a biocompatible one. In the HD session by a bioincompatible dialyzer, the mean values (+/- SEM) of echinocytes (%) at 0, 45, 120, and 240 min were 8.89 +/- 1.15, 20.77 +/- 2.35, 7.39 +/- 1.1, 5.27 +/- 0.66 and of ESR (mm/h) were 65.00 +/- 6.26, 47.05 +/- 3.89, 66.72 +/- 6.00, 68.44 +/- 5.92, respectively. According to these findings, echinocytes show a transient significant increase at 45 min HD in comparison to those at 0 (p < 0.001), 120 (p < 0.001), and 240 (p < 0.001) min while ESR shows a transient significant decrease at 45 min HD compared with the rates at 0 (p < 0.05), 120 (p < 0.05) and 240 (p < 0.01) min. In the HD sessions with the biocompatible dialyzer, the mean values (+/- SEM) of echinocytes at the aforementioned 4 time points were 8.55 +/- 1.10, 17.05 +/- 2.40, 17.05 +/- 1.19, and 5.11 +/- 0.75%, and the ESR values were 60.89 +/- 6.08, 44.33 +/- 4.18, 62.94 +/- 6.55, and 65.61 +/- 6.13 mm/h, respectively. These values also show a transient significant increase of echinocytes at 45 min HD in comparison with those at 0 (p < 0.01), 120 (p < 0.01), and 240 (p < 0.001) min, with a parallel transient decrease of ESR at 45 min HD as compared to the ones at 0 (p < 0.05), 120 (p < 0.05), and 240 (p < 0.05) min. Although the echinocytosis at 45 min HD was more prominent in HD by the bioincompatible than by the biocompatible dialyzer, the comparison between these values indicates no significant difference in the echinocytes or the ESR. In conclusion, uremic patients receiving HD exhibit echinocytes, the percentage of which shows a transient increase at 45 min HD that returns to about baseline at 120 min HD. In parallel with the changes in echinocytes, the ESR shows an inverse change at 45 min HD which returns to baseline at 120 min HD.

Echinocytic transformation and aggregation of red cells in uremic patients.

Isolated rabbit lungs were perfused with washed and resuspended human red blood cells (RBCs) in the presence of drugs known to change the shape and deformability of RBCs. With sodium salicylate (0.5-2 g/l), which causes echinocytosis and increases RBC deformability, lung diffusing capacity for O2 (DLO2) increased by 21%. When chlorpromazine, which induces stomatocytosis and stiffens RBCs, was given (50 mg/l), DLO2 decreased by 18% under chlorpromazine. Comparative experiments with hemoglobin solutions did not reveal any effect of those two drugs either on DLO2 or on pulmonary arterial pressure, which indicates that the effects of sodium salicylate and chlorpromazine were due to changes in RBC shape and deformability. It is concluded that RBC shape and deformability affect pulmonary artery pressure and oxygen diffusing capacity, which may have an influence on oxygen transfer to tissue and hence be of clinical relevance.

Serum transferrin and ceruloplasmin in patients with cancer of the gastrointestinal and other systems.

Serum transferrin and ceruloplasmin were determined in 20 healthy subjects, 23 patients with cancer of the gastro-intestinal system (G.I.S) and 22 patients with other types of cancer. Serum transferrin in patients with cancer of the G.I.S. was significantly decreased in comparison to that of healthy subjects (p < 0.05) and to that of other cancer patients (p < 0.005), but no significant difference was found between the values of healthy subjects and those with other types of cancer. Serum ceruloplasmin was significantly increased in patients with cancer of the G.I.S. (p < 0.01) and other types (p < 0.05) in comparison to that of healthy subjects. No significant difference was found between patients with cancer of the G.I.S. and those with other cancer types. In conclusion, transferrin was significantly decreased in the serum of patients with cancer of the G.I.S. while ceruloplasmin was significantly increased in both groups of patients with G.I.S. and other types of cancer.

Changes of serum transferrin and ceruloplasmin after radiation therapy in women with cervical or uterine carcinoma.

Serum transferrin and ceruloplasmin were measured in 27 healthy women as well as in 21 women who received fractionated radiation therapy (RT) after undergoing surgery for cervical or uterine carcinoma. Although no significant difference in the mean values of transferrin was found between the healthy women and the patients before the initiation of RT, a significantly lower concentration of transferrin after the end of RT (p < 0.001) was observed in comparison to that of controls and of patients before RT. On the contrary, a significantly higher serum concentration of ceruloplasmin was found in patients before and after RT compared to that in healthy women (p < 0.001). The observed increase of ceruloplasmin after RT was not found to be significantly different from the mean value before RT. In conclusion serum transferrin is reduced by RT, while ceruloplasmin which is higher in patients before RT shows a tendency for increase following RT.

Influence of radiation treatment on serum transferrin and tumor necrosis factor-alpha.

This study deals with the effect of radiation treatment (RT) on serum transferrin and tumor necrosis factor-alpha (TNF-alpha) in patients with malignant tumors. In 21 patients who received 36-60 Gy in 20 to 30 sessions of RT, serum transferrin and TNF-alpha were determined pre-RT, after 10 to 15 sessions (middle of RT) and after 20 to 30 sessions (end of RT). The values of serum transferrin pre-RT were significantly higher than those in the middle and at the end of RT (p < 0.001). The values of TNF-alpha were increased by RT and were significantly higher at the end of RT as compared to the pre-RT values (p < 0.05). The values of serum transferrin and TNF-alpha show a tendency to negative correlation, either as a whole or separately pre- and under-RT. However, no correlation was statistically significant.