Role of Different Blood Purification Nursing Models in Uremic Patients: A Preliminary Report.

BACKGROUND Accumulation of uremic toxins is closely associated with chronic kidney disease (CKD)-related complications such as cerebrovascular accidents and cardiovascular diseases. Clinical nursing is accepted as a critical clinical prognosis factor for hospitalized patients. The present study was designed to compare the effects of different blood purification nursing models on clinical outcomes in patients with uremia. MATERIAL AND METHODS A total of 68 patients with uremia were selected and divided to control and intervention groups. The patients in the control group received traditional nursing model care, while the patients in intervention group received comprehensive high-quality nursing care for 6 months. RESULTS After 6 months of treatment, the quality of life, anxiety, and depression were obviously ameliorated in both groups. The levels of blood urea nitrogen (BUN), parathyroid hormone (PTH), creatinine, ß2-microglobulin (ß2-MG), total cholesterol (TC), albumin (ALB), interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), 8-isoprostane, and malondialdehyde (MDA), as well as superoxide dismutase (SOD) and catalase (CAT) activities were all significantly improved in both groups of patients, but the intervention group exhibited better results than the control group. CONCLUSIONS Our results demonstrated that comprehensive high-quality nursing care rectified the metabolic disorders and inhibited systematic inflammatory factors, and oxidative stress, which may be responsible for better amelioration of quality of life in patients with uremia.

Depressive Symptoms in Dialysis: Prevalence and Relationship with Uremia-Related Biochemical Parameters.

BACKGROUND: Depression is the most common psychiatric disorder in long-term dialysis patients and a risk factor for morbidity and mortality. Although there is a relevance of the issue in the dialysis setting, we still know little about possible relationships between depression and uraemia-related biochemical abnormalities. Our aims were to evaluate (1) the prevalence of depression in our haemodialysis (HD) and peritoneal dialysis (PD) population using a validated and easy-to-implement screening tool and (2) the association between depression and the main uraemia-related clinical and biochemical parameter changes. METHODS: In this monocentric cross-sectional study, all patients of our centre with at least 3 months of dialysis were screened by Patient Health Questionnaire-9 (PHQ-9), a self-administered depression-screening questionnaire validated in dialysis setting. The impact of depressive symptoms on daily life was also assessed. We then analysed relationships between the PHQ-9-derived depressive score, functional impairment score, demographic, clinical and laboratory variables. RESULTS: In our cohort of 145 patients, depressive symptoms were found in 69 patients (46%). Stratifying for severity, mild, moderate and severe grade accounted for 31, 13 and 2% respectively. Depressive symptoms affected 36% of patients on PD versus 52% of patients on HD. Moreover, the PD patients had significantly less functional impairment derived from depressive symptoms than the HD patients. Simple and multiple regression analysis identified serum phosphorus as the only uraemia-related laboratory parameter that was high statistically associated with depressive score. CONCLUSIONS: Using a reliable, simple and fast tool, we found that depressive symptoms affect almost half of dialysis patients, particularly so the HD cohort. Severity of depressive symptoms seems related to serum levels of phosphorus possibly because depression affects compliance to therapy.

Prevalence and Associated Factors of Uraemic Pruritus in Continuous Ambulatory Peritoneal Dialysis Patients.

OBJECTIVE: Uraemic pruritus is a distressing symptom that has a negative impact on the quality of life for dialysis patients. The pathophysiology of pruritus in peritoneal dialysis (PD) patients is still poorly understood. The present study aims to investigate the prevalence and related risk factors of pruritus in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: In total, 362 CAPD cases were investigated from January 2012 to April 2013. Pruritus was assessed by visual analogue scale. RESULTS: The prevalence of severe pruritus and mild to moderate pruritus was 12.7% and 52.5%, respectively. The patients with severe pruritus had the longest duration of PD (p<0.001), Pittsburgh Sleep Quality Index (PSQI) score (p<0.001), Beck Depression Inventory (BDI) score (p=0.003), intact parathyroid hormone (iPTH) level (p=0.009), and the lowest Medical Outcomes Short Form 36 Health Survey, Physical Component Score (SF-36 PCS) (p<0.001) among the three groups. The patients with mild to moderate pruritus had a significantly higher iPTH level (p=0.004) compared with the patients without pruritus. A multivariate logistic regression for pruritus showed that higher PSQI score [odds ratio (OR)=1.305, p=0.001], higher BDI score (OR=1.429, p=0.002), longer vintage (OR=1.039, p=0.004), and higher iPTH level (OR=1.317, p=0.014) were independently associated with pruritus. CONCLUSION: The prevalence of uraemic pruritus was 65.2% in CAPD patients. Sleep disorder, depression, longer vintage, and a higher iPTH level were independent associated factors for pruritus in CAPD patients.

Effect of individualized exercise during maintenance haemodialysis on exercise capacity and health-related quality of life in patients with uraemia.

OBJECTIVE: To investigate the effect of individualized exercise on exercise capacity and health-related quality of life (HRQoL) in uraemic patients during maintenance haemodialysis (MHD). METHODS: Patients receiving MHD were divided randomly into a test group, who underwent recumbent cycling exercise during dialysis, and a control group, who performed simple stretching exercises. The same dialysis protocol was used for all study participants. At study start and after 12 weeks, exercise capacity was measured using tests of physical ability; HRQoL was measured using the kidney disease quality of life score (KDQOL-SF™). RESULTS: A total of 65 patients were included in the study: 33 in the control group and 32 in the test group. There were no significant differences in patient characteristics between the two groups at baseline. After 12 weeks, there were significant improvements in exercise capacity and in many of the items of the KDQOL-SF™ in the test group compared with the control group. CONCLUSION: Individualized exercise during MHD significantly improved the exercise capacity and HRQoL for uraemic patients within a short time period, and could therefore be used as a simple, cost-effective therapeutic approach.

Uraemic pruritus markedly affects the quality of life and depressive symptoms in haemodialysis patients with end-stage renal disease.

Little is known about the influence of uraemic pruritus on patients' wellbeing. The aim of our study was to evaluate the impact of uraemic pruritus on quality of life and depressive symptoms in patients with end-stage renal disease. A total of 200 haemodialysis patients were included into the study. The prevalence of uraemic pruritus was 38%. Patients with uraemic pruritus had significantly lower quality of life according to SF-36 questionnaire compared to the remaining of analysed subjects. Among patients with uraemic pruritus, 64.5% individuals also showed impaired skin-related quality of life evaluated with Dermatology Life Quality Index. The quality of life impairment correlated with uraemic pruritus intensity assessed with VAS and the 4-item itch questionnaire. Depression level significantly correlated with quality of life and severity of depressive symptoms was significantly associated with uraemic pruritus intensity. Our study underscores that uraemic pruritus should be regarded as an important health problem among haemodialysis patients.

Effect of exercise training and dopamine agonists in patients with uremic restless legs syndrome: a six-month randomized, partially double-blind, placebo-controlled comparative study.

BACKGROUND: Restless Legs Syndrome is very common in hemodialysis patients however there are no comparative studies assessing the effectiveness of a non-pharmacological treatment to a classical treatment on parameters related to syndromes' severity and quality of life. METHODS: In this randomized, partially double blind, placebo controlled trial, thirty two hemodialysis patients with restless legs syndrome were randomly assigned into three groups: 1) the exercise training group (N = 16), 2) the dopamine agonists group (ropinirole 0.25 mg/d) (N = 8) and 3) the placebo group (N = 8). The intervention programs lasted 6 months. Restless Legs Syndrome severity was assessed using the international severity scale, physical performance by a battery of tests, muscle size and composition by computed tomography, body composition by Dual Energy X Ray Absorptiometry, while depression score, sleep quality, daily sleepiness and quality of life were assessed through questionnaires. RESULTS: Exercise training and dopamine agonists were effective in reducing syndrome's symptoms by 46% (P = 0.009) and 54% (P = 0.001) respectively. Within group changes revealed that both approaches significantly improved quality of life (P < 0.05), however, only the dopamine agonists significantly improved sleep quality (P = 0.009). Within group changes showed a tendency for lean body mass improvements with dopamine agonists, this reached statistical significance only with the exercise training (P = 0.014), which also reduced fat infiltration in muscles (P = 0.044) and improved physical performance (P > 0.05) in various tests. Between group changes detect significant improvements with both exercise and dopamine agonists in depression score (P = 0.003), while only the dopamine agonist treatment was able to significantly improve sleep quality, compared to exercise and placebo (P = 0.016). CONCLUSIONS: A 6-month exercise training regime was as effective as a 6-month low dosage dopamine agonist treatment in reducing restless legs syndrome symptoms and improving depression score in uremic patients. Further research is needed in order to show whether a combination treatment could be more beneficial for the amelioration of RLS. TRIAL REGISTRATION: NCT00942253.

Acupuncture and moxibustion treatment for hypersexuality in a patient who was uraemic: a case report.

This report concerns a case that shows the apparent successful use of acupuncture and moxibustion in treating hypersexuality. The patient was a 60-year-old Chinese woman with a history of uraemia for 4 years and hypersexuality for 7 months, the latter being a rare condition. The presenting symptoms were persistent sexual desires and fantasies, in addition to being irritated when her continuous sexual urges could not be satisfied. In order to control her sexual desire the patient had tried almost all viable therapeutic methods, including use of sedatives, but the symptoms could not be mitigated any further even after consulting eight different hospital departments. However, after 10 days of acupuncture and moxibustion, all her symptoms related to the problem were resolved. A year later, she presented with a slight relapse with similar symptoms and was again treated with acupuncture and moxibustion, with subsequent resolution of symptoms. Over the following 2 years, such symptoms have not recurred. Based on the findings from this case, we conclude that use of acupuncture and moxibustion may be an effective treatment for hypersexuality in clinical practice.

A pilot investigation of cognitive improvement across a single hemodialysis treatment.

BACKGROUND: Uremia has long been associated with cognitive deficits. This study explored the importance of the time of measurement of neurocognitive functioning, by directly comparing changes in neurocognitive functioning from immediately after hemodialysis treatment to immediately before treatment. METHODS: Twenty-five hemodynamically stable hemodialysis patients and 6 peritoneal dialysis controls completed 2 computer-based assessment batteries (ANAM), one immediately before dialysis and the second upon completion of that dialysis session. Paired sample t-tests were used to compare postdialysis with predialysis neurocognitive functioning scores for both a composite measure of global functioning and the neurocognitive subtests. RESULTS: There was significant improvement in global neuropsychological functioning from predialysis to postdialysis (t (24) = -7.5, p<0.001), showing an average of 18% improvement in the hemodialysis group, with no significant change in the peritoneal dialysis group. CONCLUSION: This study suggests that computer-based testing can offer information on the cognitive fluctuations of medically complex populations and suggests that the end of the session may be a better time to discuss important and complex health messages with hemodialysis patients. It further implies that some of the neurocognitive impairment that is associated with end-stage renal disease is a consequence of uremia and is improved by hemodialysis.

Association between uremic toxins and depression in patients with chronic kidney disease undergoing maintenance hemodialysis.

OBJECTIVE: Patients with chronic kidney disease (CKD) who are undergoing maintenance hemodialysis have a higher prevalence of depression than the general population. The underlying cause of this association is unknown, but may be related to accumulation of uremic toxins. Little is known about the association of accumulation of uremic toxins and depression in hemodialysis patients. METHOD: We conducted a cross-sectional study of 209 CKD patients from a single institution to evaluate the associations of a soluble small uremic toxin (urea), a soluble large uremic toxin (ß2 microglobulin) and two protein-bound uremic toxins [total p-cresol sulfate (PCS) and indoxyl sulfate (IS)] with the presence of depression. RESULTS: A total of 47 patients (22.4%) had depression. Depressive patients had lower body mass index, lower serum creatinine, lower serum albumin and lower total IS. Univariate and multivariate logistic regression analyses that adjusted for age, gender and other statistically significant variables indicated that depression was significantly and independently associated with lower serum albumin and lower total IS. The levels of urea, ß2 microglobulin and PCS were not significantly associated with depression. CONCLUSION: Our results indicate that depression in patients with CKD was significantly and independently associated with lower serum albumin and lower total IS. However, the pathological mechanisms underlying these associations are unknown.

Uremic versus idiopathic restless legs syndrome: impact on aspects related to quality of life.

Restless legs syndrome (RLS) affects both the general population and patients with chronic renal failure. Even though it has been suggested that all forms of RLS share a common pathophysiology, not much evidence exists on how RLS of different etiology could affect aspects related to quality of life (QoL). The aim of this study was to investigate whether patients with uremic RLS (uRLS) experience lower QoL, mental health, and sleep quality, compared with their idiopathic RLS (iRLS) counterparts. Fifteen iRLS patients, 26 uRLS patients, and 15 age-matched healthy individuals participated in the study. The RLS diagnosis and severity, the depression levels, the perception of sleep, and perceived health-related QoL levels were assessed through validated questionnaires. Sleep status was not different between the two RLS groups. In contrast, the uRLS patients scored higher in RLS symptoms severity, depression, while they scored lower in QoL levels compared with iRLS patients. QoL levels were significantly lower in both RLS groups compared with healthy individuals. In conclusion, the uRLS patients experienced lower QoL levels and more severe RLS symptoms, compared with the idiopathic group, possibly leading to the observed higher depression symptoms score.

Uremic pruritus.

Uremic pruritus remains one of the most frustrating and potentially disabling symptoms in patients with end-stage renal disease. It affects up to 90% of patients on dialysis. Several hypotheses have been postulated for the possible underlying etiology, but none is conclusive. Aside from kidney transplantation, which is the only definitive treatment, therapeutic approaches have largely been empirical, and no firm evidence-based treatments are available. The main goal of therapy remains to minimize the severity of pruritus and improve the quality of life especially among those who are not transplantation candidates or are waiting for surgery.

Combination of maintenance hemodialysis with hemoperfusion: a safe and effective model of artificial kidney.

OBJECTIVE: To investigate whether the combination of maintenance hemodialysis (MHD) with hemoperfusion (HP) could improve the clearance rate of middle and large molecule uremic toxins so as to improve the quality of life of MHD patients and reduce their mortality rate. METHODS: This study was a prospective, randomized, controlled clinical trial. 100 MHD patients were selected and then randomly divided into two groups after four weeks of run-in period. Group 1 received HD alone 2 times a week and the combined treatment of HD with HP (HD+HP) once a week, whereas Group 2 was given HD alone 3 times a week. This study was followed up for a mean of 2 years. The primary outcome was the death of patients. Secondary end points included normal clinical data, leptin, high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), ß(2) microglobulin (ß(2)-MG), immunoreactive parathyroid hormone (iPTH), tumor necrosis factor-α (TNF-α) and the index of dimensions of Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36 Chinese Edition ). RESULTS: At the end of the two-year observation, the serum concentration of leptin, hsCRP, iPTH, IL-6, ß(2)-MG and TNF-α, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), cardiothoracic ratio, left ventricular mass index (LVMI), the EPO doses and the types of antihypertensive drugs used were lower with Group 1 than with Group 2 (p<0.05); Group 1 had higher hemoglobin (Hb), ejection fraction (EF), and body mass index (BMI) (p<0.05). No statistical difference between the two groups was observed in terms of serum albumin, serum iron (SI), total iron binding capacity (TIBC), cardiac output (CO), Kt/V, early/atrial mitral inflow velocities (E/A) (p>0.05). Besides, the SF-36 indicated that the total score of overall dimentions of Group 1 was higher than Group 2 (p<0.05) and the quality of life of Group 1 was evidently better than Group 2. The Kaplan-Meier Survival Curves for the 2-year observation period showed that patients in Group 1 had obvious survival advantage while Log-rank test results showed p<0.05. No serious adverse incidents occurred during the HD+HP treatment. CONCLUSIONS: HD+HP was superior to HD in regularly eliminating middle and large molecule uremic toxins accumulated in the body. These findings suggest a potential role for HD+HP in the treatment to improve the quality of life and survival rate of MHD patients.

Quality of life in patients with uraemic xerosis and pruritus.

A total of 334 end-stage renal disease patients with moderate-to-severe uraemic xerosis were surveyed for quality of life assessment, using the generic Short-Form (SF-12) scale and the Dermatology Life Quality Index (DLQI). In parallel, the intensity of xerosis at four sites (the two lower legs, chest, forearm without arterio-venous shunt) was assessed, using a five-point lesional intensity score. Pruritus was auto-assessed by the patients, using a 100-mm visual analogue scale. Uraemic xerosis patients had a marked deterioration in the Physical Component Summary of SF-12 (mean ± SD: 34.92 ± 9.98) and DLQI (5.06 ± 4.73). Younger age (r = -0.20), xerosis intensity (r = 0.14), and the presence of pruritus (p < 0.0001) and its intensity (r = 0.50) were shown to be significant worsening factors of DLQI. Because a low, but significant, correlation between the intensity of xerosis and pruritus was also demonstrated (r = 0.18), the direct contribution of age, xerosis and pruritus on DLQI was analysed in a multiple linear regression model. Age and pruritus intensity, but not xerosis intensity, were found to be independent contributors to DLQI deterioration (p < 0.0005). On the other hand, uraemic xerosis without associated pruritus still resulted in DLQI alteration (3.24 ± 3.99). It was concluded that young age and intensity of uraemic pruritus compromise quality of life in uraemic xerosis patients. Some characteristics of uraemic xerosis other than xerosis intensity may also be involved in quality of life alteration.

Restless legs syndrome in hemodialysis patients: association with depression and quality of life.

PURPOSE: The prevalence of restless legs syndrome (RLS) ranging from 6.6% to 83% has been reported in different case series. The pathophysiology of RLS in uremia is still unclear. The aim of this study was to assess the frequency of RLS in the hemodialysis patients and to explore depression and associated detrimental impact on quality of life. METHODS: The diagnosis of RLS was made using the criteria of the International Restless Legs Study Group. The polyneuropathy was diagnosed according to clinical signs and symptoms. Each subject completed three questionnaires: Beck Depression Inventory, Short Form-36 Quality of Life Scale, and the Epworth Sleepiness Scale (ESS). Biochemical parameters including hemoglobin, serum ferritin, and Kt/V index were collected. The data of the patients with and without RLS or clinical polyneuropathy (PNP) were compared. RESULTS: There were 41 male and 40 female patients. RLS, PNP, and high ESS scores were seen in 12%, 47%, and 7% of hemodialysis patients, respectively. Beck depression inventory scores were high in patients with RLS when compared to those without (28.9 ± 9, p = 0.007). General health score in the RLS patients, physical functioning score in the PNP patients were significantly lower (GH, 20.7; p = 0.036; PF, 10.5; p < 0.005). We did not observe any association between hemoglobin, ferritin levels, and Kt/V index in the RLS patients. However, Kt/V index in the PNP patients were low. CONCLUSIONS: The frequency of RLS in hemodialysis patients was lower than that reported from similar studies in other countries. The presence of RLS and PNP in hemodialyzed patients negatively affects quality of life, and RLS contributes to occurrence of depression.

Enhanced degradation of tryptophan in patients on hemodialysis.

BACKGROUND: Hemodialysis patients often present with increased concentrations of tryptophan catabolites perhaps related to an enhanced activity of tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) that is inducible by pro-inflammatory stimuli. The often chronic inflammation and immune activation status in dialysis patients may accelerate tryptophan degradation, which could influence patients' psychological performance. PATIENTS AND METHODS: In this study, plasma concentrations of kynurenine and tryptophan were determined by HPLC in 75 dialysis patients, aged 65.3 ± 15.0 years. Forty patients were female, 35 male; 21 (28%) had diabetes mellitus Type 1 or 2 and 32 (43%) suffered from sleep disturbances and/or depression. Their dialysis vintage was 4.26 ± 4.72 years. HPLC results were compared to concentrations obtained from 40 healthy blood donors, to immune activation marker neopterin, and to psychological test results based on INTERMED scores. RESULTS: Compared to those in healthy controls, tryptophan concentrations were decreased in patients. Neopterin, kynurenine and the kynurenine to tryptophan ratio (kyn/trp, an index of tryptophan degradation) were increased in patients (all p < 0.01). Kyn/trp correlated with neopterin concentrations (rs = 0.393, p < 0.01). INTERMED scores were 21.0 + 8.4 and slightly higher in females (U = -1.831, p < 0.07); they correlated with tryptophan concentrations (rs = -0.227, p < 0.05) but with no other parameter studied. Data point to a possible relationship between tryptophan metabolic disturbances and psychologic presentation of patients, although only a rather weak relationship was found. CONCLUSION: We conclude that tryptophan degradation is increased in dialysis patients. The association with increased neopterin concentrations indicates activated IDO.

A longitudinal study of uremic pruritus in hemodialysis patients.

BACKGROUND AND OBJECTIVES: Although uremic pruritus (UP) is a highly prevalent complication of chronic kidney disease, it remains poorly characterized. There have been no longitudinal studies of natural history, and no health-related quality of life (HR-QOL) instruments have been developed for UP. The objectives of this study were to describe the natural history of UP, to compare rating scales of itching intensity, and to assess usefulness and validity of HR-QOL instruments for UP. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The intensity, severity, and effects of pathologic itching on HR-QOL were assessed prospectively in 103 patients with UP on chronic hemodialysis. Outcome measures were obtained at scheduled intervals over 3.5 months. RESULTS: Itching daily or nearly daily was reported by 84% of patients and had been ongoing for >1 year in 59%. In 83%, pruritus involved large, nondermatomal areas with striking bilateral symmetry. Two thirds of the patients were using medications such as antihistamines, steroids, and various emollients without satisfactory relief of itching. Statistically significant associations were found among itching intensity, severity, and HR-QOL measures in domains such as mood, social relations, and sleep. Among patients with moderate-to-severe UP, changes in itching intensity of 20% or greater were associated with significant reductions in HR-QOL measures. CONCLUSIONS: This first longitudinal study of UP describes key features of UP and its effect on HR-QOL. The assessment instruments we have developed are easily used, are responsive to changes in UP intensity, and should facilitate clinical evaluation and research to meet the needs of afflicted patients.

Sexual dysfunction in uraemic patients undergoing haemodialysis: predisposing and related conditions.

Chronic kidney disease and sexual dysfunction are common entities in clinical practice in haemodialysis (HD) units. This article is a review of some articles that focus on sexual dysfunction in patients undergoing HD and its possible relationship in multiple ways.

Analysis of sexual functions in male nondiabetic hemodialysis patients and renal transplant recipients.

SUMMARY: Disturbance of sexual functions among hemodialysis patients and renal transplant recipients (RTRs) is controversial. Diabetes mellitus (DM) is known to have a significant negative impact on sexual functions. Most previous studies concerning the issue of disturbance of sexual functions among hemodialysis patients and renal transplant recipients have included diabetic patients also, which might have influenced their results. The aim of this study was to evaluate sexual functions of nondiabetic male (NDM) dialysis patients and RTRs, and to compare our findings with those of the others. Twenty-five nondiabetic male RTRs, 25 age-matched NDM hemodialysis patients, and 25 age-matched NDM controls were the subjects of this study. Sexual functions of all subjects were assessed using the International Index of Erectile Function (IIEF) questionnaire. Statistical analysis was performed using appropriate statistical tests with the level of significance set at P < 0.05. Data were described using mean, standard deviation (SD), median and interquartile range (IQR). Renal transplant recipients (RTRs) and hemodialysis patients had depressed erectile function (EF) and Intercourse satisfaction (IS) function, but normal orgasmic (OF) function. Sexual desire (SxD) function of RTRs group, although subnormal, was better than that of hemodialysis patients. Overall satisfaction (OS) of RTRs, unlike that of hemodialysis patients, was normal. Sexual dysfunction is prevalent even in NDM hemodialysis patients and RTRs. Although ED is equally prevalent among these two groups, it is more profound among the former one. OF is spared in these patients. Renal transplantation seems to normalize OS and improve SxD function of nondiabetic male renal transplant recipients (NDM RTRs).

[Mood disorders in patients with chronic kidney disease. Diagnosis, screening and treatment of depression]. / Hangulatzavarok krónikus vesebetegek körében. A depresszió diagnosztikája, szurése és terápiája.

Depression is a common co-morbid condition in patients suffering from a variety of chronic medical conditions. In spite of this, mental health of patients with chronic kidney disease is understudied. Accurate estimation of the prevalence of depressive disorders in this population is difficult due to the different definitions and assessment techniques and the overlap of depressive symptomatology with symptoms of uremia. Several potential pathways link depression and chronic kidney disease. The association between the two conditions is probably bidirectional. Consequently, treatment of mood disorders could impact medical outcome. Very little has been published about the therapeutic options for depression in patients with chronic kidney disease. Available data, however, suggest that several antidepressant medications and psychotherapeutic methods are likely to be safe and effective also in this population. In this review, which is the second of a series of reviews on this topic, we provide an overview of the literature concerning the diagnosis, screening and therapy of depressive disorders in patients with chronic kidney disease.

Guanidino compounds as uremic (neuro)toxins.

Neurological and vascular impairment are important sources of morbidity in patients with renal failure. A portion of patients still suffers from uremic encephalopathy or other signs of nervous system impairment. Several reports demonstrate increased incidence of cardiac infarction and cerebrovascular accidents in chronic renal failure patients, even in those otherwise adequately dialyzed. Epileptic and cognitive symptoms are among the most typical manifestations of uremic encephalopathy. Several guanidino compounds (GCs) may play an important role in the etiology of uremic encephalopathy. Four GCs appeared to be substantially increased as well in serum, cerebrospinal fluid, and brain of uremic patients. These compounds, "uremic" GCs, are creatinine, guanidine (G), guanidinosuccinic acid (GSA), and methylguanidine. All four compounds are experimental convulsants in concentrations similar to those found in uremic brain. We described a possible mechanism for the contribution of GCs to uremic hyperexcitability, referring to the in vitro effects of uremic GCs on inhibitory and excitatory amino acid receptors. It was demonstrated that the excitatory effects of uremic GCs on the central nervous system can be explained by the activation of N-methyl-d-aspartate receptors by GSA, concomitant inhibition of gamma-aminobutyric acid type A receptors by uremic GCs, and other depolarizing effects. These effects might also indicate the putative contribution of uremic GCs to the etiology of uremic encephalopathy. In this article, we review the uremic GCs with particular attention to their neurotoxicity. We elaborate in detail on the mechanisms of action of the neurotoxic uremic GCs and summarize the kinetics of these toxins.