Serum glutamine and hospital-acquired infections after aneurysmal subarachnoid hemorrhage.

Objective To understand nutritional and inflammatory factors contributing to serum glutamine levels and their relationship to hospital-acquired infections (HAIs) after aneurysmal subarachnoid hemorrhage (SAH). Methods A prospective observational study of patients with SAH who had measurements of daily caloric intake and C-reactive protein, transthyretin, tumor necrosis factor a receptor 1a (TNF alpha R1a), glutamine, and nitrogen balance performed within 4 preset time periods during the 14 days after SAH. Factors associated with glutamine levels and HAIs were analyzed with multivariable regression. HAIs were tracked daily for time-to-event analyses. Outcome 3 months after SAH was assessed by the Telephone Interview for Cognitive Status and modified Rankin Scale. Results There were 77 patients with an average age of 55 +/- 15 years. HAIs developed in 18 (23%) on mean SAH day 8 +/- 3. In a multivariable linear regression model, negative nitrogen balance (p = 0.02) and elevated TNFaR1a (p = 0.04) were independently associated with higher glutamine levels during the study period. The 14-day mean glutamine levels were lower in patients who developed HAI (166 +/- 110 vs 236 +/- 81 mu g/mL, p = 0.004). Poor admission Hunt and Hess grade (p = 0.04) and lower glutamine levels (p = 0.02) predicted time to first HAI. Low 14-day mean levels of glutamine were associated with a poor recovery on the Telephone Interview for Cognitive Status score (p = 0.03) and modified Rankin Scale score (p = 0.04) at 3 months after injury. Conclusions Declining glutamine levels in the first 14 days after SAH are influenced by inflammation and associated with an increased risk of HAI.