Respiratory complications and sleep disorders in children with chronic kidney disease: A correlation often underestimated.

Chronic Kidney Disease (CKD) is characterized by a progressive and irreversible loss of kidney function which gradually leads to end-stage kidney disease (ESKD). Virtually all the organs are damaged by the toxicity of uremic compounds. The lungs may be affected and the impaired pulmonary function may be the direct result of fluid retention and metabolic, endocrine and cardiovascular alterations, as well as systemic activation of the inflammation. An increased prevalence in sleep disorders (SD) is also reported in patients with CKD, leading to a further negative impact on overall health and quality of life. While these complex relationships are well documented in the adult population, these aspects remain relatively little investigated in children. The aim of this review is to provide a brief overview of the pathophysiology between lung and kidney and to summarize how CKD may affect respiratory function and sleep in children.

Blood pressure management in children on dialysis.

Hypertension is a leading cause of cardiovascular complications in children on dialysis. Volume overload and activation of the renin-angiotensin-aldosterone system play a major role in the pathophysiology of hypertension. The first step in managing blood pressure (BP) is the careful assessment of ambulatory BP monitoring. Volume control is essential and should start with the accurate identification of dry weight, based on a comprehensive assessment, including bioimpedance analysis and intradialytic blood volume monitoring (BVM). Reduction of interdialytic weight gain (IDWG) is critical, as higher IDWG is associated with a worse left ventricular mass index and poorer BP control: it can be obtained by means of salt restriction, reduced fluid intake, and optimized sodium removal in dialysis. Optimization of peritoneal dialysis and intensified hemodialysis or hemodiafiltration have been shown to improve both fluid and sodium management, leading to better BP levels. Studies comparing different antihypertensive agents in children are lacking. The pharmacokinetic properties of each drug should be considered. At present, BP control remains suboptimal in many patients and efforts are needed to improve the long-term outcomes of children on dialysis.

Assessment of nutritional status in children with chronic kidney disease.

The achievement of a normal nutritional status, that is a normal body composition and a normal pattern of growth, is a cornerstone in the management of children with chronic kidney disease (CKD). Protein-energy wasting (PEW) which indicates the state of decreased body protein mass and fuel reserves (body protein and fat mass), is a common condition in this population, and a source of morbidity and mortality. For the diagnosis of this condition, a lot of methods have been proposed, but due to the clinical characteristics of children with CKD, the intrinsic limits of the available indices and some methodological issues concerning published pediatric studies, none of these parameters could be considered as the gold standard. Given these limitations, a general consensus exists according to which only the combination of more indices integrated in a multidisciplinary approach can give the idea of the individual nutritional status. Among these indices, recent guidelines recommend dietary intake (by means of 3-day diary or 24-hour recall), anthropometric parameters (weight, height, height velocity, body mass index, head circumference) and, only for adolescent on hemodialysis, normalized protein catabolic rate as the most accurate ones. Other methods, such as mid-arm anthropometry, bioimpedance analysis, biochemical indices, and dual-energy X-ray absorptiometry could certainly help in the nutritional evaluation, taking into account the advantages and drawbacks of each method.