Plasma glutamine concentration after intensive care unit discharge: an observational study

Area of Science:

• Critical Care Medicine
• Nutritional Biochemistry

Background:

• Low plasma glutamine is linked to poor outcomes in intensive care unit (ICU) patients.
• The predictive value of plasma glutamine levels post-ICU discharge for patient outcomes remains unclear.
• Previous trials suggest glutamine supplementation may improve survival during ICU stays.

Purpose of the Study:

• To investigate if plasma glutamine levels drop at ICU discharge, indicating sustained deficiency.
• To determine the relationship between post-ICU glutamine levels and patient mortality.

Main Methods:

• Study A: Monitored plasma glutamine levels every 5-7 days post-ICU discharge in 63 fully fed patients receiving glutamine supplementation.
• Study B: Assessed the association between plasma glutamine levels 24-72 hours post-ICU discharge and 12-month all-cause mortality in 100 patients.

Main Results:

• Post-ICU plasma glutamine levels were within the normal range and did not predict mortality.
• Plasma glutamine levels at ICU discharge were higher in non-survivors compared to survivors.
• Discharge plasma glutamine levels added predictive value to SOFA scores for post-ICU mortality.

Conclusions:

• Post-ICU plasma glutamine levels do not appear to reflect glutamine depletion.
• The complex relationship between plasma glutamine and availability during critical illness requires further investigation.
• The potential role of glutamine supplementation in critical care needs more research.