A double blind, randomised, controlled trial of glutamine supplementation in parenteral nutrition

Randomized, double-blind, controlled trial in consenting adult hospital patients who required parenteral nutrition because enteral feeding was not feasible. The active glutamine arm included 83 participants, with 85 participants in the control arm.

Adults receiving parenteral nutrition were given 20 g of free glutamine per parenteral feed, continued for the duration of parenteral feeding during the hospital admission. The glutamine-containing feeds also supplied the remainder of the estimated nitrogen requirement as Eloamin.

Glutamine supplementation did not improve outcomes for the overall trial population, and routine use was not recommended. Hospital mortality was 16.9% with glutamine versus 24% with control (p=0.28), and median length of stay was 32 (23-52) days versus 35 (25-55) days. Septic complications were similar, with at least one positive culture in 37 glutamine and 38 control patients, and six month mortality was nearly identical between groups. A possible subgroup benefit was noted in some surgical patients and in haematological malignancy, but the main conclusion remained that overall benefit was not demonstrated.

The trial was relatively small for detecting differences in mortality and other clinical outcomes, and subgroup findings were exploratory rather than definitive. Frequency of dosing and allocation ratio were not stated, and several baseline characteristics were not reported per arm. The overall null result limits confidence that any observed subgroup signal is generalizable.