Plasma glutamine status at intensive care unit admission: an independent risk factor for mortality in critical illness

Abstract

Background A plasma glutamine concentration outside the normal range at Intensive Care Unit (ICU) admission has been reported to be associated with an increased mortality rate. Whereas hypoglutaminemia has been frequently reported, the number of patients with hyperglutaminemia has so far been quite few. Therefore, the association between hyperglutaminemia and mortality outcomes was studied in a prospective, observational study. Patients and methods Consecutive admissions to a mixed general ICU were eligible. Exclusion criteria were < 18 years of age, readmissions, no informed consent, or a ‘do not resuscitate’ order at admission. A blood sample was saved within one hour from admission to be analysed by high-pressure liquid chromatography for glutamine concentration. Conventional risk scoring (Simplified Acute Physiology Score and Sequential Organ Failure Assessment) at admission, and mortality outcomes were recorded for all included patients. Results Out of 269 included patients, 26 were hyperglutaminemic (≥ 930 µmol/L) at admission. The six-month mortality rate for this subgroup was 46%, compared to 18% for patients with a plasma glutamine concentration < 930 µmol/L (P = 0.002). A regression analysis showed that hyperglutaminemia was an independent mortality predictor that added prediction value to conventional admission risk scoring and age. Conclusion Hyperglutaminemia in critical illness at ICU admission was an independent mortality predictor, often but not always, associated with an acute liver condition. The mechanism behind a plasma glutamine concentration outside normal range, as well as the prognostic value of repeated measurements of plasma glutamine during ICU stay, remains to be investigated.

Tissue-Specific and Interorgan Metabolic Reprogramming Maintains Tolerance to Sepsis

“…Glutamine in the context of sepsis-induced critical illness has been investigated thoroughly 9,10,36–38 , and so far the few consensus opinions are that glutamine supplementation appears ineffective at reducing skeletal muscle proteolysis 39 , and that it should not be administered in critically ill patients 40 , especially in light of the evidence from the REDOXs randomized controlled trial, in which investigators demonstrated that glutamine supplementation worsened survival in patients with sepsis, though it should be kept in mind only nearly half of these patients had confirmed microbial identification, so the influence of viral versus bacterial versus fungal infections cannot be determined 2 . A key insight that has been largely missing from prior studies is an answer to: what is the fate of glutamine within the tissue/cell during critical illness?…”

An analysis of urine and serum amino acids in critically ill patients upon admission by means of targeted LC–MS/MS: a preliminary study

“…Smedberg et al results confirmed our observation that hyperglutaminemia present at ICU admission was an independent mortality predictor for critically ill patients. Authors concluded that the mechanism behind a serum Gln concentration out of the normal range is likely multifactorial, and still obscure 42 .…”

Immunmodulation durch Ernährung bei kritisch kranken Patienten

“…Eine deutlich erhöhte Zufuhr von Glutamin könnte den kritisch kranken Patienten immunologisch durch eine übermäßige Stärkung proinflammatorischer Prozesse weiter kompromittieren. Entsprechend sind auch erhöhte Glutaminspiegel ein unabhängiger Risikofaktor für Mortalität und korrelieren mit einem schlechteren intensivmedizinischen Outcome [181].…”