Residual Daily Urine Volume Association with Inflammation and Nutrition Status in Maintenance Hemodialysis Patients

Delayed Graft Function After Kidney Transplantation: The Role of Residual Diuresis and Waste Products, as Oxalic Acid and Its Precursors

Delayed graft function (DGF) after kidney transplantation heralds a worse prognosis. In patients with hyperoxaluria, the incidence of DGF is high. Oxalic acid is a waste product that accumulates when kidney function decreases. We hypothesize that residual diuresis and accumulated waste products influence the DGF incidence. Patients transplanted between 2018-2022 participated in the prospective cohort study. Pre-transplant concentrations of oxalic acid and its precursors were determined. Data on residual diuresis and other recipient, donor or transplant related variables were collected. 496 patients were included, 154 were not on dialysis. Oxalic acid, and glyoxylic acid, were above upper normal concentrations in 98.8%, and 100% of patients. Residual diuresis was ≤150 mL/min in 24% of patients. DGF occurred in 157 patients. Multivariable binary logistic regression analysis demonstrated a significant influence of dialysis type, recipient BMI, donor type, age, and serum creatinine on the DGF risk. Residual diuresis and glycolic acid concentration were inversely proportionally related to this risk, glyoxylic acid directly proportionally. Results in the dialysis population showed the same results, but glyoxylic acid lacked significance. In conclusion, low residual diuresis is associated with increased DGF incidence. Possibly accumulated waste products also play a role. Pre-emptive transplantation may decrease the incidence of DGF.

Residual Kidney Function in Hemodialysis: Its Importance and Contribution to Improved Patient Outcomes

Individuals afflicted with advanced kidney dysfunction who require dialysis for medical management exhibit different degrees of native kidney function, called residual kidney function (RKF), ranging from nil to appreciable levels. The primary focus of this manuscript is to delve into the concept of RKF, a pivotal yet under-represented topic in nephrology. To begin, we unpack the definition and intrinsic nature of RKF. We then juxtapose the efficiency of RKF against that of hemodialysis in preserving homeostatic equilibrium and facilitating physiological functions. Given the complex interplay of RKF and overall patient health, we shed light on the extent of its influence on patient outcomes, particularly in those living with advanced kidney dysfunction and on dialysis. This manuscript subsequently presents methodologies and measures to assess RKF, concluding with the potential benefits of targeted interventions aimed at preserving RKF.

Incremental hemodialysis in pediatric patients

BACKGROUND

Incremental hemodialysis follows the concept of adjusting dialysis dose according to residual kidney function. Data on incremental hemodialysis in pediatric patients is lacking.

METHODS

We conducted a retrospective analysis of children initiating hemodialysis between January 2015 and July 2020 in a single tertiary center, comparing the characteristics and outcomes of those who commenced with incremental hemodialysis vs with conventional thrice-weekly regimen.

RESULTS

Data on forty patients, 15 (37.5%) on incremental hemodialysis and 25 (63%) on thrice-weekly hemodialysis were analyzed. No differences in age, estimated glomerular filtration rate and metabolic parameters were noted between groups at baseline, but there were more males (73 vs 40%, p = 0.04), more patients with congenital anomalies of kidney and urinary tract (60 vs 20%, p = 0.01), higher urine output (2.5 ± 1 vs 1 ± 0.8 ml/kg/h, p < 0.001), lower use of antihypertensive medications (20 vs 72%, p = 0.002) and lower prevalence of left ventricular hypertrophy (6.7 vs 32%, p = 0.003) in the incremental hemodialysis group vs thrice-weekly hemodialysis. During follow up, 5 (33%) incremental hemodialysis patients were transplanted, 1 (7%) remained on incremental hemodialysis at 24 months, and 9 (60%) transitioned to thrice-weekly hemodialysis at a median (IQR) time of 8.7 (4.2, 11.8) months. At last follow up, fewer patients who initiated incremental hemodialysis had left ventricular hypertrophy (0 vs 32%, p = 0.016) and urine output < 100 ml/24 h (20 vs 60%, p = 0.02) compared to thrice-weekly hemodialysis, with no significant differences in metabolic or growth parameters.

CONCLUSION

Incremental hemodialysis is a viable option for initiating dialysis in selected pediatric patients, that may help improve patients' quality of life and reduce dialysis burden without compromising clinical outcome.

On the importance of the interplay of residual renal function with clinical outcomes in end-stage kidney disease

Chronic kidney disease (CKD) is one of the most important public health concerns of the century, and is associated with high rates of morbidity, mortality and social costs. CKD evolving towards end-stage kidney disease (ESKD) is on the rise resulting in a greater number of patients requiring peritoneal dialysis (PD) and hemodialysis (HD). The aim of this manuscript is to review the current literature on the interplay of residual renal function (RRF) with clinical outcomes in ESKD. The persistence of RRF is one of the most important predictors of decreased morbidity, mortality, and better quality of life in both PD and HD patients. RRF contributes to the well-being of ESKD patients through various mechanisms including higher clearance of solutes, maintenance of fluid balance, removal of uremic toxins and control of electrolytes. Furthermore, RRF has beneficial effects on inflammation, anemia, malnutrition, diabetes mellitus, obesity, changes in the microbiota, and cardiac diseases. Several strategies have been proposed to preserve RRF, such as blockade of the renin-angiotensin-aldosterone system, better blood pressure control, incremental PD and HD. Several clinical trials investigating the issue of preservation of RRF are ongoing. They are needed to broaden our understanding of the interplay of RRF with clinical outcomes in ESKD.

Relationship between residual kidney function and symptom burden in haemodialysis patients

BACKGROUND

Residual kidney function (RKF) has been associated with improved solute clearance and survival in haemodialysis (HD) patients. However, whether RKF impacts symptom burden in HD patients is unknown.

AIMS

To determine the prevalence of RKF in HD patients and to explore associations between higher levels of RKF with symptom burden, as well as clinical and biochemical parameters.

METHODS

This is a single-centre, retrospective, observational study. RKF was assessed as urea clearance (KRU) by interdialytic urine collection. Symptom burden was measured using the palliative care outcome scale renal questionnaire.

RESULTS

A total of 90 maintenance HD patients was recruited; 31.9% had KRU ≥1 mL/min/1.73 m² . Patients with KRU ≥1 mL/min/1.73 m² reported fewer symptoms (5.3 ± 3.5 vs 7.7 ± 3.8) (P = 0.011), including less shortness of breath (15% vs 55%) (P = 0.0013) and vomiting (0% vs 30%) (P = 0.0016). Higher RKF was associated with lower β₂ -microglobilin (P < 0.0001), and lower serum potassium (P = 0.02), but no difference in phosphate, haemoglobin, C-reactive protein or serum albumin.

CONCLUSION

Higher RKF was significantly associated with fewer symptoms, and lower serum β₂ -microglobulin and potassium, suggesting that strategies to preserve RKF may be beneficial.

Factors associated with residual urine volume preservation in patients undergoing hemodialysis for end-stage kidney disease in Kinshasa

BACKGROUND

Decreased residual urine volume (RUV) is associated with higher mortality in hemodialysis (HD). However, few studies have examined RUV in patients on HD in Sub-Saharan Africa. The aim of this study was to identify predictors of RUV among incident hemodialysis patients in Kinshasa.

METHODS

This historical cohort study enrolled 250 patients with ESRD undergoing hemodialysis between January 2007 and July 2013 in two hemodialysis centers in Kinshasa. RUV were collected over 24 h at the initiation of HD and 6 and 12 months later during the interdialytic period. We compared the baseline characteristics of the patients according to their initial RUV (≤ 500 ml/day vs >  500 ml/day) using Student's t, Mann-Whitney U and Chi2 tests. Linear mixed-effects models were used to search for predictors of decreased RUV by adding potentially predictive baseline covariates of the evolution of RUV to the effect of time: age, sex, diabetes mellitus, hypertension, diastolic blood pressure, diuretics, angiotensin conversion enzyme inhibitors (ACEI), angiotensin receptor blockers, hypovolemia, chronic tubulointerstitial nephropathy, left ventricular hypertrophy and initial hemodialysis characteristic. A value of p < 0.05 was considered the threshold of statistical significance.

RESULTS

The majority of hemodialysis patients were male (68.8%, sex ratio 2.2), with a mean age of 52.5 ± 12.3 years. The population's RUV decreased with time, but with a slight deceleration. The mean RUV values were 680 ± 537 ml/day, 558 ± 442 ml/day and 499 ± 475 ml/day, respectively, at the initiation of HD and at 6 and 12 months later. The use of ACEI at the initiation of HD (beta coefficient 219.5, p < 0.001) and the presence of chronic tubulointerstitial nephropathy (beta coefficient 291.8, p = 0.007) were significantly associated with RUV preservation over time. In contrast, the presence of left ventricular hypertrophy at the initiation of HD was significantly associated with decreased RUV over time (beta coefficient - 133.9, p = 0.029).

CONCLUSIONS

Among incident hemodialysis patients, the use of ACEI, the presence of chronic tubulointerstitial nephropathy and reduced left ventricular hypertrophy are associated with greater RUV preservation in the first year of dialysis.

[Predictors of physical incapacity degree to chronic hemodialysis patients in Kinshasa : Key role of the residual diuresis]

OBJECTIVE

Identifying predictors of physical incapacity degree in patients on chronic hemodialysis in Kinshasa.

METHODS

Bicentric analytical study, between January 2007 and July 2013. Degree of physical handicap was evaluated at 6months of hemodialysis based on the scale of Rosser. Logistic regression sought the predictors of no or light physical incapacity (Rosser<3) vs. moderate to maximum (Rosser≥3). P was set at 0.05.

RESULTS

One hundred twenty-seven patients (127) patients received at least 6months of hemodialysis (53.3±11years; 73.2 % male), 79 (62.2 %) had no or light incapacity and 48 (37.8 %) moderate to maximum. Predictors of lower physical incapacity in univaried analysis were: secured funding, high socioeconomic level, lack of diabetes mellitus, high body weight, normal systolic and diastolic blood pressure, residual diuresis 3months later, hemoglobin and hematocrit, low comorbidity, arteriovenous fistula, erythropoietin, at least 12hours of hemodialysis per week and lack of intradialytic complications. After logistic regression, a high residual diuresis 3months of hemodialysis has proved an independent predictor of lower physical Incapacity (aOR 0.998; P=0.024) next to the lack of diabetes mellitus (aOR 0.239; P=0.024), good control of systolic (aOR 0.958; P=0.013) and diastolic (aOR 1.089; P=0.003) blood pressure and the use of erythropoietin (aOR 5.687; P=0.004).

CONCLUSION

Preserving residual diuresis is associated with lower physical incapacity and must be integrated in the management in hemodialysis.

Association Between Hemodiafiltration and Hypoalbuminemia in Middle-Age Hemodialysis Patients

The advantage of hemodiafiltration (HDF) is well known. One of the disadvantages of HDF is loss of serum albumin, but this issue is still obscure. Some risk factors associated with mortality were age dependent. Studies on serum albumin/hypoalbuminemia and HDF in different age stratification were limited. The aim of this cross-sectional study was to assess the role of HDF and other clinical variables on serum albumin values in maintenance hemodialysis (MHD) patients of different age groups. We recruited a total of 1216 patients on MHD. Patients were divided into 4 groups by age stratification of youth (<30 years old), young-middle age (30-44 years old), middle age (45-64 years old), and old age (≥65  years old). Biochemical, hematological, nutritional, inflammatory parameters, and receiving HDF or not were recorded. The associations between age groups, HDF, and variables mentioned above were analyzed. Only in middle-age group, patients with HDF was significantly (P = 0.013) associated with serum albumin <4 g/dL. In middle-age group, a multivariate-forward logistic regression analysis showed that male sex (2.169 [1.029, 4.574], P = 0.042), inflammation (4.167 [2.043, 8.498], P < 0.001), cardiovascular disease (2.92 [1.019, 8.402], P = 0.046), serum creatinine level (0.639 [0.538, 0.758], P < 0.001), and cholesterol level (0.984 [0.975, 0.993], P = 0.001) were associated with serum albumin level <3.6 g/dL. Hepatitis C virus infection (1.911 [1.186, 3.077], P = 0.008), HDF (2.143 [1.298, 3.540], P = 0.003), inflammation (2.309 [1.549, 3.440], P < 0.001), use of arterio-venous fistula (0.518 [0.327, 0.820], P = 0.005), Kt/V (0.395 [0.193, 0.809], P = 0.011), nonanuria (0.542 [0.337, 0.870], P = 0.011), serum creatinine level (0.744 [0.669, 0.828], P < 0.001), and cholesterol level (0.993 [0.987, 0.998], P = 0.013) were associated with serum albumin level <4 g/dL. HDF can predict serum albumin level <4 g/dL in middle-age HD patients. The effect of age needs to be taken into consideration when interpreting the correlation between hypoalbuminemia and HDF.

Preservation of residual renal function with limited water removal in hemodialysis patients

Residual renal function (RRF) is of paramount importance for hemodialysis (HD) adequacy, morbidity, and mortality. Some studies have shown that overhydration is beneficial for preservation of RRF, but it can also increase the probability of adverse events such as hypertension and heart failure in HD patients. To determine the optimal amount of dehydration, we performed HD with limited water removal in HD patients. Eighteen HD patients included in this self-controlled study underwent HD with limited water removal. Water removal volume was determined by a previous volume as follows. Total water removal volume was divided into levels: ≤3.0, 3.0-9.0, and >9.0 L per week. Water removal was performed to obtain dry weight in the last dialysis, and was performed three times with a ratio of 1:1:2 and 2:2:3, respectively. Urine volume, endogenous creatinine clearance rate, Kt/V, hemoglobin, and serum albumin were recorded before and after the study at 3, 6, 9, and 12 months. The follow-up period was 12 months. Ten patients withdrew from the study because of adverse events including hypertension (n = 3), heart failure (n = 3), angina (n = 1), polycystic kidney rupture (n = 1), obvious edema (n = 1), and one patient had too much interdialytic weight gain to continue. As a result, we stopped this study after 1 month. Our data suggest that the preservation of RRF with limited water removal in HD patients must be interpreted with caution.

Definite and probable septic pericarditis in hemodialysis

INTRODUCTION

Although the incidence of septic pericarditis in hemodialysis populations is less frequent in the modern antibiotic era, it is still a cause of death partly because diagnosis is sometimes difficult and uncertain.

METHODS

From 2002 to 2006, 12 out of a total of 12,213 maintenance hemodialysis patients were referred for management of septic pericarditis. Patients were diagnosed as either definite or probable septic pericarditis. A definite diagnosis of septic pericarditis is based on the discovery of pathogenic bacteria in pericardial effusion, whereas a probable diagnosis is based on the proof of bacterial infection elsewhere in a patient with otherwise unexplained pericarditis, or appropriate response to a trial of systemic antibiotics.

RESULTS

Four (33.3%) patients were diagnosed as definite pericarditis, whereas eight (66.7%) patients as probable pericarditis. It was found that although oxacillin-resistant Staphylococcus aureus (ORSA) (4/12 or 33.3%) and tuberculous (4/12 or 33.3%) pericarditis were common, salmonella pericarditis (2/12 or 16.7%) was also not uncommon. Pericardiocentesis, or pericardial window with pericardiectomy, was performed in three (25%) and two (16%) of patients with cardiac tamponade, respectively. Two patients died because of severe ORSA (1/12 or 8%) and salmonella (1/12 or 8%) sepsis. Finally, there were four (33%) patients who developed constrictive pericarditis after follow-up.

CONCLUSIONS

These data are important because the spectrum of septic pericarditis was clearly different between Taiwan and other developed countries. Furthermore, it is the only report in which patients were diagnosed as either definite or probable septic pericarditis, therefore improving the sensitivity of diagnosis as in the case of tuberculous pericarditis.

An evaluation of serum albumin, root caries, and other covariates in Gullah African Americans with type-2 diabetes

OBJECTIVES

Associations between dental conditions and overall health have been previously reported. Investigators have also shown significant inverse relationships between serum albumin (a general health status marker) and root caries. This relationship was explored among a study population of Gullah African Americans (who have a considerably lower level of non-African genetic admixture when compared to other African American populations) with type-2 diabetes (T2DM) and self-reported history of normal kidney function (N=280).

METHODS

Root caries indices were defined as total decayed and/or filled root surfaces. The coronal caries index [total decayed, missing, and/or filled coronal surfaces (DMFS)], level of glycemic control, total number of teeth, and other covariates were also evaluated. Logistic regression models were used to evaluate the associations between these factors and hypoalbuminemia (serum albumin concentrations <4 g/dl).

RESULTS

Serum albumin concentrations ranged 2.4-4.5 g/dl (mean=3.8, SD=0.3), with 70.4% exhibiting hypoalbuminemia. Root caries totals ranged 0-38 (mean=1.3, SD=4.5) surfaces decayed/filled, while total teeth ranged 1-28 (mean=19.4, SD=6.2). DMFS totals ranged 2-116 (mean=55.2, SD=28.0). We failed to detect significant associations for root caries; however, the final multivariable logistic regression models showed significant associations between hypoalbuminemia and total teeth [odds ratio (OR)=0.93, P=0.01], poor glycemic control (OR=2.49, P<0.01), elevated C-reactive protein (OR=1.57, P<0.01), glomerular filtration rates ≥60 (OR=0.31, P=0.03), and age (OR=0.97, P=0.03).

CONCLUSIONS

Previously reported inverse relationships between serum albumin and root caries were not evident in our study population. We propose that these null findings are because of the considerably lower level of root caries as well as other differing characteristics (including oral health status, the chronic presence of T2DM, and predominantly younger age) within our study population compared to these previously assessed groups.