Current Fluid Management Practice in Critically Ill Adults on Continuous Renal Replacement Therapy: A Binational,...

Area of Science:

• Critical care medicine
• Nephrology
• Intensive care unit (ICU) management

Background:

• Positive fluid balance (FB) in critically ill patients undergoing continuous renal replacement therapy (CRRT) is associated with adverse outcomes.
• Current FB management strategies in CRRT patients are not well understood.
• This study aimed to investigate FB and its components in CRRT patients in British and Australian ICUs.

Purpose of the Study:

• To analyze fluid balance (FB) and its contributing factors in critically ill patients receiving continuous renal replacement therapy (CRRT).
• To identify characteristics and outcomes of CRRT patients with positive FB.
• To inform the design of future clinical trials targeting fluid management in CRRT.

Main Methods:

• Retrospective analysis of electronic health records from three tertiary ICUs in the UK and Australia.
• Inclusion of 1,616 patients undergoing CRRT.
• Collection of hourly fluid-related variables and cumulative FB for the first 7 days of CRRT.

Main Results:

• The mean cumulative FB became negative within 31 hours and reached a nadir of -4.1 L after 7 days.
• Net ultrafiltration (NUF) was the primary driver of negative FB, but urine output, crystalloid administration, and nutritional input also contributed.
• A positive FB at 72 hours was independently associated with increased hospital mortality (OR 1.70, p=0.004) and linked to greater illness severity and vasopressor use.

Conclusions:

• Most CRRT patients in the studied ICUs achieved a negative FB, predominantly influenced by NUF.
• Positive FB at 72 hours in CRRT patients correlated with higher illness severity and hemodynamic instability.
• Establishing equipoise for trials targeting early negative FB in CRRT patients may be challenging due to observed patient characteristics and outcomes.