From the Guidelines
Sodium sieving refers to the rapid removal of water from the blood relative to sodium during the initial phase of dialysis, resulting in a temporary increase in sodium concentration in the dialysate. This process is crucial in peritoneal dialysis, as it affects fluid balance and sodium levels in patients undergoing dialysis treatment 1. The sodium sieving effect is particularly significant in patients on automated peritoneal dialysis (APD), where short-duration cycles can lead to compromised blood pressure and volume control due to salt and water resorption during long day dwells 1.
Key aspects of sodium sieving include:
- The selective filtration of sodium ions during dialysis
- The impact on fluid balance and sodium levels in patients
- The need for individualized prescription and attention to ultrafiltration profiles to minimize sodium sieving during overnight dwells
- Possible maneuvers to minimize sodium sieving, such as using fewer overnight exchanges, shortening the day dwell, or substituting icodextrin for glucose solutions 1
In the context of peritoneal dialysis, understanding sodium sieving is essential for optimizing dialysis protocols and managing patients' electrolyte balance effectively. By recognizing the significance of sodium sieving, healthcare providers can take steps to mitigate its effects and improve patient outcomes, particularly in terms of blood pressure control and volume status 1.
From the Research
Definition of Sodium Sieving
- Sodium sieving is a measure of free water transport 2
- It is influenced by convective fluid loss, diffusion, and sieving due to free water transport, as predicted by the three-pore model of membrane function 3
Factors Affecting Sodium Sieving
- Sodium sieving is affected by the difference in sodium concentrations between plasma and dialysate 2
- It is also influenced by the diffusion rate, with high diffusion rates disturbing the assessment of sodium sieving 2
- The use of icodextrin as an adjuvant for higher daily ultrafiltration can increase solute clearance and remove more sodium 4
Measurement of Sodium Sieving
- Sodium sieving can be measured using a peritoneal equilibration test (PET) 2, 5
- The test involves measuring the dialysate sodium concentration at a specific time point, usually 60 minutes 5
- The reduction in dialysate sodium concentration at 60 minutes (ΔDNa60) can be used to predict the onset of encapsulating peritoneal sclerosis (EPS) 5
Clinical Significance of Sodium Sieving
- Sodium sieving is an important factor in peritoneal dialysis, as it affects the removal of sodium and water from the body 3, 4
- Accurate measurement of sodium sieving can help predict the onset of EPS and guide treatment decisions 5
- The use of sodium sieving as a screening tool can help identify patients at risk of developing EPS and improve patient outcomes 5