Critical care in the Emergency Department: organ donation.

Organ transplantation is associated with improved outcomes for some patients with end-stage organ failure; however, the number of patients awaiting a transplant exceeds the available organs. Recently, an extended role has been proposed for EDs in the recognition and management of potential donors. The present review presents an illustrative case report and considers current transplantation practice in the UK. Ethical and legal considerations, the classification of deceased donors and future developments promising greater numbers of organs are discussed.

An increase in selenium intake improves immune function and poliovirus handling in adults with marginal selenium status.

BACKGROUND: Dietary selenium intakes in many countries, including the United Kingdom, are lower than international recommendations. No functional consequences of these lower intakes have been recognized, although experimental studies suggest that they might contribute to reduced immune function, increased cancer incidence, and increased susceptibility to viral disease. OBJECTIVE: The objective was to assess whether administration of small selenium supplements to otherwise healthy UK subjects leads to functional changes in immune status and the rates of clearance and mutation of a picornavirus: live attenuated polio vaccine. DESIGN: Twenty-two adult UK subjects with relatively low plasma selenium concentrations (<1.2 micromol/L, approximately 60% of those screened) received 50 or 100 microg Se (as sodium selenite) or placebo daily for 15 wk in a double-blind study. All subjects received an oral live attenuated poliomyelitis vaccine after 6 wk and enriched stable (74)Se intravenously 3 wk later. RESULTS: Selenium supplementation increased plasma selenium concentrations, the body exchangeable selenium pool (measured by using (74)Se), and lymphocyte phospholipid and cytosolic glutathione peroxidase activities. Selenium supplements augmented the cellular immune response through an increased production of interferon gamma and other cytokines, an earlier peak T cell proliferation, and an increase in T helper cells. Humoral immune responses were unaffected. Selenium-supplemented subjects also showed more rapid clearance of the poliovirus, and the poliovirus reverse transcriptase-polymerase chain reaction products recovered from the feces of the supplemented subjects contained a lower number of mutations. CONCLUSIONS: The data indicate that these subjects had a functional selenium deficit with suboptimal immune status and a deficit in viral handling. They also suggest that the additional 100 microg Se/d may be insufficient to support optimal function.

Infection, multiple organ failure, and survival in the intensive care unit: influence of glutamine-supplemented parenteral nutrition on acquired infection.

OBJECTIVE: We investigated the effect of a glutamine-supplemented parenteral nutrition on intensive-care-acquired infection (ICAI) and its relation to outcome. METHODS: We analyzed new data prospectively collected during a double-blind, randomized, and controlled trial in an adult general intensive care unit previously reported (Nutrition 1997;13:295). Eighty-four patients were randomized to receive glutamine-supplemented total parenteral nutrition or an isonitrogenous, isoenergetic control. Sepsis was present on admission in 71% of the patients. Clinical and microbiological data were collected on all new infective episodes and associated treatment decisions. Data were analyzed blind to the randomization and study outcome. RESULTS: There was no significant difference in the number of patients developing new infections or in the number occurring during the first 5 d. There was a non-significant trend to increased numbers of infections in those patients receiving the control feed for at least 5 d. In these patients the glutamine recipients showed significantly fewer catheter-related infections: 21 versus 12 (P = 0.026). The difference in overall 6-mo mortality was almost completely described by those patients fed for at least 5 d: 9 of 25 versus 18 of 27 using the control nutrition (P = 0.05). Of the deaths in the intensive care unit due to multiple organ failure, 8 of 8 in the glutamine group and 14 of 16 in the control group sustained one or more ICAI and accounted for 38% versus 74%, respectively, of the ICAIs occurring in those patients. In those patients, despite a similar high incidence of colonization with Candida, those receiving glutamine developed fewer Candida infections and none died, whereas six control patients who developed Candida infections died from multiple organ failure (P = 0.02). Survival was not related to the reduced occurrence of the first acquired infection; however, binary logistic regression analysis of glutamine and the incidence of ICAI after starting total parenteral nutrition to outcome showed that only glutamine was significantly associated with improved 6-mo survival (P = 0.027). CONCLUSIONS: In these severely ill patients, parenteral nutrition containing glutamine may not reduce the overall incidence of ICAI, but it may reduce the risk of dying from acquired infections. The improved survival seen at 6 mo appeared related mostly to reduced mortality in the intensive care unit from multiple organ failure in those patients in whom acquired infections are common.

Glutamine-enhanced nutrition in the critically ill patient.

It is well established that critically ill patients have a deficiency of the amino acid glutamine. This article reviews the evidence for supplemental glutamine in the critically ill, focusing on the benefits in terms of reduced mortality and infectious morbidity.

Glutamine: essential for immune nutrition in the critically ill.

Critically ill patients on intensive care units are at an increased risk of sepsis, which is a major cause of mortality in these patients. Recent evidence suggests that impairment of the functioning of the immune system contributes to the development of sepsis in such patients. In particular, monocytes show reduced expression of HLA-DR antigen, associated with impaired antigen presenting capability and decreased phagocytic activity; lymphocytes show decreased proliferation in response to mitogens and T-helper cells show a shift in the Th1/Th2 ratio consistent with impaired immunity. The amino acid glutamine becomes conditionally essential in the critically ill, yet such patients frequently have a marked deficiency of glutamine; the reasons for this are still unclear. Glutamine is required by the cells of the immune system both as a primary fuel and as a carbon and nitrogen donor for nucleotide precursor synthesis. In vivo studies have demonstrated that glutamine is essential for optimal immune cell functioning for monocytes, lymphocytes and neutrophils. A number of trials of patients fed by the enteral or parenteral route have shown improved infectious morbidity when supplemented with glutamine. However, the exact mechanism of glutamine action in these patients remains to be determined.