Hyponatremia in peritoneal dialysis patients

Geriatric Assessment, Falls and Rehabilitation in Patients Starting or Established on Peritoneal Dialysis

Individuals aged over 70 years at the time of starting dialysis have a varied and often challenging existence on dialysis. Canadian data suggest those starting dialysis between the ages of 75 and 79 years will have an average life expectancy of 3.2 years, while based on US data, patients can expect an average life expectancy of 25 months. A substantial proportion of these patients will, however, experience transient or permanent loss of personal independence within the first few months to years on dialysis. Preliminary data from patients recently started on peritoneal dialysis (PD) suggest patients and families adapt, but that the adaptation often involves limiting activities and altering the social role the patient has within the family. As data emerge, it will be possible to hypothesize whether this adaptation is beneficial in the long term, or whether these adaptations are permissive, allowing the patient to play a sick role leading to an accelerated transition to frailty and possibly death. Future research will hopefully inform us whether the functional dependency can be identified early and whether it is preventable. In the interim, repair rather than prevention is possible through rehabilitation. We therefore advocate that programs providing PD care consider the integration of protocols whereby patients may undergo formal evaluation to identify those who would benefit from walking or personal care aids, rehabilitation interventions, and, when needed, personal support.

Hyponatremia in peritoneal dialysis: epidemiology in a single center and correlation with clinical and biochemical parameters

BACKGROUND

Hyponatremia in peritoneal dialysis (PD) patients has previously been associated with water overload and weight gain, or with malnutrition and intracellular potassium depletion. Although there is a sizable literature about transmembrane sodium and water removal in PD, there are few reports about the incidence and characteristics of hyponatremia in the clinical setting.

AIM

We evaluated the incidence and factors associated with hyponatremia in PD patients in a single PD unit.

METHODS

We retrospectively evaluated the records of all patients (n = 198) who were treated with PD in the Home PD Unit of the University Health Network at Toronto General Hospital during 2010. We identified 166 patients who had a minimum follow-up of 60 days during 2010 and at least 2 consecutive sodium measurements at least a month apart. We examined baseline differences between patients who developed hyponatremia and those who did not, and clinical and biochemical factors that correlated with mean sodium values. In the 24 patients who developed hyponatremia, we examined paired differences between the normonatremic and hyponatremic periods. Finally, we investigated any possible correlations of change in serum sodium with clinical and biochemical characteristics before and during the hyponatremic period.

RESULTS

The incidence of hyponatremia was 14.5%. In multivariate analysis, serum sodium correlated significantly and independently with residual renal function (RRF: r = 0.463, p = 0.0001) and negatively with the daily volume of instilled icodextrin (r = -0.476, p = 0.0001). Residual renal function was significantly lower in patients with hyponatremia than in those with normal serum sodium (1.97 ± 2.3 mL/min vs 4.31 ± 5.01 mL/min, p = 0.033). The mean paired difference in body weight was -1.113 kg and the median difference was -0.55 kg (range: -8.5 kg to +4.2 kg). Impressively, hyponatremia was not associated with an increase in body weight in most patients who developed this complication (13 of 16 for whom comparative weights were known). Moreover, the mean paired change in serum sodium (ΔNa) from normonatremia to hyponatremia was, contrary to our expectations, significantly correlated with a decrease in body weight (r = 0.584, p = 0.017). The ΔNa was also significantly correlated with serum potassium (r = 0.526, p = 0.008), the greatest drop in serum sodium being associated with lower serum potassium in the hyponatremic period, as predicted.

CONCLUSIONS

Hyponatremia is seen more often than expected in a clinical setting. Serum sodium is strongly correlated with RRF, hyponatremia being associated with lower RRF. In patients who experienced hyponatremia, the fall in serum sodium was associated with a decrease, not an increase, in body weight and was correlated with serum potassium, suggesting that sodium and potassium depletion-and, by inference, malnutrition-may be important contributors in the clinical setting.

Current best evidence recommendations on measurement and interpretation of physical function in patients with chronic kidney disease

Chronic kidney disease (CKD) is becoming a serious health problem throughout the world and is one of the most potent known risk factors for cardiovascular disease. Deterioration of physical function is accelerated in patients with CKD to levels that significantly impact on clinically and patient-important outcomes such as morbidity, employment, quality of life and, ultimately, survival. However, meaningful interpretation of the existing physical function-related literature in adult patients with CKD is hindered, possibly due to inconsistent choice of methodology, assessment tools and reporting of data. The current comprehensive review of the literature aims to provide the theoretical rationale and framework for physical function assessment and to identify the prevailing approaches to (i) the characterization (classification and terminology), (ii) interpretation, and (iii) reporting of physical function assessment in people with CKD. Comprehensive assessment of physical function can provide important information about the presence of 'physiological impairment' at a body systems level (exercise tolerance under well controlled, laboratory-based procedures), 'functional limitations' (physical performance during tasks imitating usual daily, personal or occupational tasks) and 'functional disability' (via self-reported physical functioning in the context of a socio-cultural environment). The selection of physical function assessment tools should be guided by the primary purpose of the assessment (e.g. research or routine clinical monitoring), by the overall scientific 'soundness' of the chosen tool (e.g. validity, utility, reproducibility, responsiveness characteristics) and by operational factors (e.g. patient collaboration, cost, personnel expertise). Recommendations for tests, methods and protocols are therefore presented, for the assessment of cardiorespiratory and muscular fitness, physical performance and self-reported physical functioning. These recommendations are based on synthesis of available information as derived from controlled exercise training interventions in adult patients with CKD. Special considerations for physical function assessment and suggestions for future research are also addressed. Such an information synthesis might promote greater standardization of the physical function assessment of patients with CKD in routine clinical care or research settings. This would potentially lead to generation of adequate scientific decision-making criteria to help researchers and healthcare providers in selecting the most appropriate measures according to the physical function areas assessed, and to accurately and meaningfully characterize and compare patients' responses to therapeutic interventions.

Chronic kidney disease, exercise, and sports in children, adolescents, and adults

Individuals with chronic kidney disease have poor exercise tolerance and are easily fatigued compared with their healthy peers. The primary reasons for poor exercise tolerance include anemia, effects of chronic uremia and metabolic acidosis on the heart and skeletal muscles, and lower levels of physical activity. Studies suggest that regular and early implementation of both aerobic and resistance exercise programs in persons with chronic kidney disease have positive effects on muscle function, exercise tolerance, and quality of life. Before starting any exercise program, a medical assessment and exercise testing are generally recommended. No consensus exists regarding allowing young athletes with a solitary kidney who want to participate in contact or collision sports. Decisions to allow participation in different sports and leisure activities should be made on an individual basis, considering multiple factors. This article reviews factors that affect exercise tolerance in persons with chronic kidney disease, the effects of exercise, and exercise recommendations.

Rehabilitative training program for end-stage renal disease patients

A 4–5. (vég-)stádiumú és transzplantált vesebetegek izomereje, állóképessége, cardiovascularis kockázati tényezői, életminősége és a dialízishatásfoka is jelentősen javul a heti 3 × 30–60 perces, 45–60%-os intenzitású testmozgás során, amelyet többnyire a dialízis alatt végez a beteg. A korlátozó tényezők és ellenjavallatok figyelembevételével a vesebetegek többsége számára is kínálni kellene a rehabilitációs programokat.

Regular Exercise as a Part of Treatment for Patients With End-stage Renal Disease

Physical inactivity and its negative influence on health and the quality of life is a common problem generally, especially in patients with chronic illness and also in patients with end-stage renal disease. Motivation for regular physical exercise could be a problem. A supervised outpatient program in a rehabilitation center, a home exercise rehabilitation program and an exercise rehabilitation program during the first hours of the hemodialysis treatment with a bed bicycle ergometer in the renal unit could be carried out. Low intensity aerobic activity has a favorable effect on cardiovascular risk factor, and gymnastics to increase strength, flexibility and coordination, as well as relaxation techniques are very effective exercises in a rehabilitation program. The positive influence of individual regular exercise on health, quality of life, physical exercise capacity, endurance, muscle strength, social, professional and emotional status is also very high in patients. Side effects of exercise are very rare.

Intradialytic exercise as anabolic therapy in haemodialysis patients - a pilot study

Haemodialysis (HD) patients are characterized by muscle wasting and consequently decreased physical functioning and poor outcome. This pilot study investigated if a novel intradialytic exercise programme could increase lean mass via up-regulation of the insulin-like growth factor (IGF) system. Nine HD patients were assessed before (w-12) and after a 3-month control phase (w0), after a three-month intradialytic interval training programme using high intensity cycle exercise (w12), and after a withdrawal of treatment phase (w24). Body composition was determined by dual energy X-ray absorptiometry (DEXA) and bioelectrical impedance spectroscopy (BIS); physical functioning by knee extensor strength (KES) and 30-s sit stand test (SST); and IGF-I and IGFBP-3 in serum and muscle by radioimmunoassay. Despite significant increases in training load (+274%, P<0.001), peak power output (+71%, P<0.001) and physical function (KES: +19%, P<0.05; SST: +20%, P<0.05) following the intervention phase, lean masses by DEXA, intra cellular water by BIS (a surrogate measure of body cell mass) and serum and muscle IGFs remained unchanged following training. Although this novel exercise programme, utilizing high intensity interval training, was safe, clinically feasible and beneficial in terms of physical functioning, the 12 weeks of intradialytic cycle exercise failed to reverse the muscle atrophy characteristic of this population. Future studies, using primary outcome measures similar to those employed in the present study, should investigate other anabolic interventions to determine potential treatments for the muscle wasting associated with end stage renal disease.