Disorders of water and electrolyte balance are common in intensive care medicine and are prognostically relevant. In the intensive care unit (ICU) setting, the underlying causes are often multifactorial and are substantially influenced by reduced kidney function, iatrogenic fluid and electrolyte administration and organ support treatment. This article provides a practice-oriented overview of the diagnostics and management of hyponatremia and hypernatremia as well as disturbances of potassium, magnesium and phosphate balance. In hyponatremia, symptom severity and the temporal course determine the need for acute treatment. The diagnostic evaluation should be primarily based on laboratory results and rely on serum and urine osmolality as well as urine sodium, as the clinical assessment of volume status is often unreliable. Most cases of hypotonic hyponatremia are caused by dysregulation of the arginine-vasopressin axis, particularly in syndrome of inappropriate antidiuresis (SIAD) or conditions with reduced effective circulating volume. Hypernatremia in the intensive care unit is frequently iatrogenic and associated with increased mortality, with urine osmolality guiding further diagnostic and treatment decisions. Potassium, magnesium, and phosphate disturbances are common and require an early cause-directed management and close monitoring to prevent severe complications.
The management of end-stage renal disease and kidney failure in patients transitioning to the immediate need for a renal replacement procedure is one of the most important tasks for nephrologists. A timely, structured and patient-centered approach is crucial for improving the clinical prognosis and preserving the quality of life. This includes an early systematic assessment of risk and progression, taking factors such as proteinuria, the decline of the estimated glomerular filtration rate (eGFR-slope) and cardiovascular comorbidities into account, in order to determine the optimal timing for an intensive counselling. In the evaluation of older adults, numerous geriatric nephrological aspects must be incorporated and weighed up. Shared decision-making is always central to this, which fully informs patients and relatives about all therapeutic options, conservative therapy, hemodialysis, peritoneal dialysis and kidney transplantation, and actively incorporates their preferences into the treatment plan. The option of pre-emptive kidney transplantation should be presented early, and by the time dialysis is started, a timely registration on the transplant waiting list should be ensured for eligible patients. In treatment management, patient-centered home dialysis modalities should, whenever possible, be placed clearly at the forefront, especially given their advantages with respect to sustainability and demographic trends. This also applies to older patients, although center-based dialysis as well as continuation of treatment within a conservative management framework remain highly valuable.
Fluid management is a fundamental component of intensive care treatment and has a major impact on the hemodynamics, organ perfusion, tissue oxygenation and prognosis of critically ill patients. This review article outlines the current diagnostic strategies for assessing the volume status using clinical parameters, laboratory markers, imaging techniques and advanced hemodynamic monitoring. In addition to static measurements, dynamic tests such as the passive leg raising test, fluid challenges, respiratory-induced stroke volume variations and end-expiratory occlusion maneuvers for identification of fluid responsiveness are presented. Furthermore, evidence-based recommendations on disease and phase -oriented fluid therapy are discussed. Particular emphasis is placed on the selection of infusion solutions. Balanced crystalloids are recommended as first-line therapy due to their physiological composition and favorable outcome data compared with 0.9% saline. The role of human albumin, especially in septic shock and patients with liver cirrhosis, is critically reviewed based on recent trials. Synthetic colloids are not recommended because of their side effect profile. An optimal fluid management in the ICU requires continuous reassessment, the integration of dynamic monitoring tools and adherence to patient-centered, evidence-based choice of infusion fluid and its amount to improve outcomes in critically ill patients.
Background Prevention of progression of chronic kidney disease (CKD) is one of the main tasks in nephrology. Question Available scientific evidence for drug treatment to halt CKD progression is discussed. Material and methods Structured literature search in PubMed. Results There is strong evidence supporting the use of angiotensin-converting enzyme (ACE) inhibitors/angiotensin II type 1 (AT1) receptor blockers in patients with confirmed CKD. Sodium-glucose transporter 2 (SGLT-2) inhibitors are particularly beneficial in proteinuric patients. The newer glucagon-like peptide 1 (GLP-1)/glucose-dependent insulinotropic polypeptide (GIP) receptor agonists and finerenone have also been shown to be effective in patients with type 2 diabetes and diabetic kidney damage. Conclusion The pharmacotherapeutic options for slowing CKD progression have expanded considerably in recent years. This is particularly true for patients with type 2 diabetes mellitus. It remains to be seen to what extent CKD patients with other underlying kidney diseases will benefit from GLP-1/GIP receptor agonists and finerenone. The role of combination therapy (fantastic four) also needs to be evaluated. Furthermore, new biomarkers are needed that can predict CKD progression better and thus enable individualized treatment.
