Efficacy and Safety of Glutamine-supplemented Parenteral Nutrition in Surgical ICU Patients

Abstract

Objective To determine whether glutamine (GLN)-supplemented parenteral nutrition (PN) improves clinical outcomes in surgical ICU (SICU) patients. Summary Background Data GLN requirements may increase with critical illness. GLN-supplemented PN may improve clinical outcomes in SICU patients, but data in patient subgroups are limited. Methods A parallel-group, multicenter, double blind, randomized, controlled clinical trial in adults after gastrointestinal, vascular, or cardiac surgery who required PN and SICU care. Subjects were without significant renal or hepatic failure or shock at entry. All received isonitrogenous, isocaloric PN [1.5 g/kg/d amino acids (AA) and energy at 1.3 × estimated basal energy expenditure]. Controls (n = 75) received standard GLN-free PN (STD-PN); the GLN group (n = 75) received PN containing alanyl-GLN dipeptide (0.5 g/kg/d), proportionally replacing AA in control PN (GLN-PN). Enteral nutrition (EN) was advanced and PN weaned as indicated. Hospital mortality and infections were primary endpoints. Results Baseline characteristics, days on study PN and daily energy and amino acid/protein intakes via PN and EN were similar between groups. There were 11 hospital deaths (14.7%) in the GLN-PN group and 13 deaths in the STD-PN group and (17.3%; difference, −2.6%; 95% confidence interval −14.6 to 9.3%; P = 0.66). The 6-month cumulative all-cause mortality was 31.4% in the GLN-PN group and 29.7% in the STD-PN group (P = 0.88). Incident bloodstream infection rate was 9.6 and 8.4 per 1000 hospital days in the GLN-PN and STD-PN groups, respectively (P= 0.73). Other clinical outcomes and adverse events were similar. Conclusions PN supplemented with GLN dipeptide was safe but did not alter clinical outcomes among SICU patients.

Effect of Previous High Glutamine Infusion on Inflammatory Mediators and Mortality in an Acute Pancreatitis Model

“…With consideration of systemic disturbances that could culminate in multiple organ failure, our AP model did not confirm this harmful effect, despite our parenteral infusion of high glutamine doses. The most recent multicentric trial showed that parenteral glutamine infusion did not change the mortality rate of patients in the surgical intensive care unit but also did not improve clinical outcomes [37]. In our study, the mortality rate was lower and death occurred later in animals in the glutamine group compared with the other groups, although these differences were not significant.…”

Glutamine Administration in Early or Late Septic Phase Downregulates Lymphocyte PD‐1/PD‐L1 Expression and the Inflammatory Response in Mice With Polymicrobial Sepsis

“…A recent clinical trial performed in the United States found that supplementation with parenteral GLN is safe but did not influence the clinical outcomes of the ICU patients. 37 Furthermore, a systematic review reported by Wischmeyer et al 38 concluded that parenteral GLN supplementation reduces hospital mortality and length of stay when administered following resolution of shock and multiorgan failure. In this study, midgrade sepsis was induced and antibiotic was used to control the infection.…”

The gut microbiome and the mechanism of surgical infection

“…In the absence of significant knowledge and consideration of the role of the intestinal microbiome to modify, and be modified by, foodstuffs as they pass through the intestinal bioreactor, surgeons have over the years attempted to modify the metabolic response to injury with nutrients. Failure to enhance recovery after surgery was witnessed, including trials of glutamine, branched‐chain amino acids, arginine and various fat emulsions. Viewing the gut as a mere conduit for nutrient absorption led to missteps and miscalculations that nutrients in their most elemental form could be delivered parenterally and would be sufficient to reprogramme the immune system to enhance recovery.…”