Experience with a low volume ultrafiltration cell in small children*

Area of Science:

• Pediatric Nephrology
• Critical Care Medicine
• Renal Replacement Therapy

Background:

• Fluid overload is a critical issue in pediatric patients, often requiring renal support.
• Effective and safe fluid management strategies are essential for critically ill children.

Purpose of the Study:

• To evaluate the feasibility and safety of a low volume (16 ml) ultrafiltration cell for plasma water removal in fluid-overloaded children.
• To assess the efficacy of controlled fluid removal using this device.

Main Methods:

• Ultrafiltration was performed ten times in two pediatric patients using a 16 ml ultrafiltration cell.
• Slow blood flow rates (25-50 ml/min) and low transmembrane pressures (10-30 mm Hg) were employed.
• Ultrafiltrate composition, including solutes and proteins, was analyzed.

Main Results:

• Controlled removal of excess plasma water was achieved.
• No major complications were observed, but hypothermia and hypotension occurred at high ultrafiltrate flux rates (>0.5 ml/kg/min).
• Ultrafiltrate solute concentration mirrored plasma; no significant electrolyte shifts were induced. Protein concentration in ultrafiltrate was notably high (64–2,760 mg/dl).

Conclusions:

• Low volume ultrafiltration is a potentially safe and effective method for fluid management in pediatric patients.
• Careful monitoring of blood flow rates and transmembrane pressures is crucial to mitigate risks like hypothermia and hypotension.
• The high protein concentration in the ultrafiltrate warrants further investigation.