Volume Balance in Chronic Kidney Disease: Evaluation Methodologies and Innovation Opportunities.

BACKGROUND: Patients affected by chronic kidney disease are at a risk of cardiovascular morbidity and mortality. Body fluids unbalance is one of the main characteristics of this condition, as fluid overload is highly prevalent in patients affected by the cardiorenal syndrome. SUMMARY: We describe the state of the art and new insights into body volume evaluation. The mechanisms behind fluid balance are often complex, mainly because of the interplay of multiple regulatory systems. Consequently, its management may be challenging in clinical practice and even more so out-of-hospital. Availability of novel technologies offer new opportunities to improve the quality of care and patients' outcome. Development and validation of new technologies could provide new tools to reduce costs for the healthcare system, promote personalized medicine, and boost home care. Due to the current COVID-19 pandemic, a proper monitoring of chronic patients suffering from fluid unbalances is extremely relevant. Key Message: We discuss the main mechanisms responsible for fluid overload in different clinical contexts, including hemodialysis, peritoneal dialysis, and heart failure, emphasizing the potential impact provided by the implementation of the new technologies.

Severe cyclophosphamide-related hyponatremia in a patient with acute glomerulonephritis.

Cyclophosphamide is frequently used to treat cancer, autoimmune and renal diseases, such as rapidly progressive glomerulonephritis. Its side effects are well-known, including bone marrow depression, infections, alopecia, sterility, bladder malignancy and hemorrhagic cystitis. Moreover, in some cases cyclophosphamide use has been related to the onset of hyponatremia, by development of a syndrome of inappropriate antidiuresis. Indeed, severe hyponatremia has been previously reported in patients treated with high-dose or moderate-dose of intravenous cyclophosphamide, while only few cases have been reported in patients treated with low dose. Here, we discuss a case of a syndrome of inappropriate antidiuresis followed to a single low-dose of intravenous cyclophosphamide in a patient with a histological diagnosis of acute glomerulonephritis, presenting as acute kidney injury. After cyclophosphamide administration (500 mg IV), while renal function gradually improved, the patient developed confusion and headache. Laboratory examinations showed serum sodium concentration dropped to 122 mmol per liter associated with an elevated urinary osmolality of 199 mOsm/kg, while common causes of acute hyponatremia were excluded. He was successfully treated with water restriction and hypertonic saline solution infusion with the resolution of the electrolyte disorder. This case, together with the previous ones already reported, highlights that electrolyte profile should be strictly monitored in patients undergoing cyclophosphamide therapy in order to early recognize the potentially life-threatening complications of acute water retention.

[Spontaneous rupture of a simple renal cyst: clinical management]. / Rottura spontanea di cisti renale semplice: gestione clinica.

Spontaneous renal bleeding mainly occurs in patients with polycystic kidney diseases or cancer. Indeed, despite the high prevalence of simple cysts, their spontaneous atraumatic rupture is a rare event. Underlying mechanisms may involve the increase of intracystic pressure and/or the development of a haemorrhage into the cyst. Management of this condition includes surgery, interventional radiology or conservative strategies. Here, we report a case of spontaneous rupture of a simple renal cyst, successfully managed with conservative treatment.

["Deep" purple urine bag syndrome: physiopathology and clinical implications]. / La Sindrome delle urine viola: patogenesi e significato clinico.

Urinalysis is a key part of the clinical evaluation of patients with kidney disease. It can provide several useful information for the diagnosis and management of diseases of kidneys and urinary tract. In particular, urine color can be affected by the presence of blood, infection and endogenous metabolites, such as bilirubin, or exogenous, for instance those derived from drugs. Therefore, the analysis of urine color may be helpful in identifying different clinical conditions. Here we report a case of a patient who presented purple-colored urine, the so-called " Purple urine bag syndrome", discussing the predisposing factors and the pathogenesis of this condition. We believe that this information can be useful to clinicians who might face this particular situation.