Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.).

Increased inflammatory cytokine levels and intestinal epithelial cell apoptosis leading to disruption of epithelial integrity are major pathologic factors in inflammatory bowel diseases. The probiotic bacterium Lactobacillus rhamnosus GG (LGG) and factors recovered from LGG broth culture supernatant (LGG-s) prevent cytokine-induced apoptosis in human and mouse intestinal epithelial cells by regulating signaling pathways. Here, we purify and characterize 2 secreted LGG proteins that regulate intestinal epithelial cell antiapoptotic and proliferation responses. LGG proteins were purified from LGG-s, analyzed, and used to generate polyclonal antibodies for immunodepletion of respective proteins from LGG-conditioned cell culture media (CM). Mouse colon epithelial cells and cultured colon explants were treated with purified proteins in the absence or presence of tumor necrosis factor (TNF). Akt activation, proliferation, tissue injury, apoptosis, and caspase-3 activation were determined. We purified 2 novel proteins, p75 (75 kilodaltons) and p40 (40 kilodaltons), from LGG-s. Each of these purified protein preparations activated Akt, inhibited cytokine-induced epithelial cell apoptosis, and promoted cell growth in human and mouse colon epithelial cells and cultured mouse colon explants. TNF-induced colon epithelial damage was significantly reduced by p75 and p40. Immunodepletion of p75 and p40 from LGG-CM reversed LGG-CM activation of Akt and its inhibitory effects on cytokine-induced apoptosis and loss of intestinal epithelial cells. p75 and p40 are the first probiotic bacterial proteins demonstrated to promote intestinal epithelial homeostasis through specific signaling pathways. These findings suggest that probiotic bacterial components may be useful for preventing cytokine-mediated gastrointestinal diseases.

Risk factors for nosocomial pneumonia, such as gastro-oesophageal reflux and subsequent aspiration, can be reduced by semirecumbent body position in intensive-care patients. The objective of this study was to assess whether the incidence of nosocomial pneumonia can also be reduced by this measure. This trial was stopped after the planned interim analysis. 86 intubated and mechanically ventilated patients of one medical and one respiratory intensive-care unit at a tertiary-care university hospital were randomly assigned to semirecumbent (n=39) or supine (n=47) body position. The frequency of clinically suspected and microbiologically confirmed nosocomial pneumonia (clinical plus quantitative bacteriological criteria) was assessed in both groups. Body position was analysed together with known risk factors for nosocomial pneumonia. The frequency of clinically suspected nosocomial pneumonia was lower in the semirecumbent group than in the supine group (three of 39 [8%] vs 16 of 47 [34%]; 95% CI for difference 10.0-42.0, p=0.003). This was also true for microbiologically confirmed pneumonia (semirecumbent 2/39 [5%] vs supine 11/47 [23%]; 4.2-31.8, p=0.018). Supine body position (odds ratio 6.8 [1.7-26.7], p=0.006) and enteral nutrition (5.7 [1.5-22.8], p=0.013) were independent risk factors for nosocomial pneumonia and the frequency was highest for patients receiving enteral nutrition in the supine body position (14/28, 50%). Mechanical ventilation for 7 days or more (10.9 [3.0-40.4], p=0.001) and a Glasgow coma scale score of less than 9 were additional risk factors. The semirecumbent body position reduces frequency and risk of nosocomial pneumonia, especially in patients who receive enteral nutrition. The risk of nosocomial pneumonia is increased by long-duration mechanical ventilation and decreased consciousness.

We undertook this study to test the hypothesis that perioperative total parenteral nutrition (TPN) decreases the incidence of serious complications after major abdominal or thoracic surgical procedures in malnourished patients. We studied 395 malnourished patients (99 percent of them male) who required laparotomy or noncardiac thoracotomy. They were randomly assigned to receive either TPN for 7 to 15 days before surgery and 3 days afterward (the TPN group) or no perioperative TPN (the control group). The patients were monitored for complications for 90 days after surgery. The rates of major complications during the first 30 days after surgery in the two groups were similar (TPN group, 25.5 percent; control group, 24.6 percent), as were the overall 90-day mortality rates (13.4 percent and 10.5 percent, respectively). There were more infectious complications in the TPN group than in the controls (14.1 vs. 6.4 percent; P = 0.01; relative risk, 2.20; 95 percent confidence interval, 1.19 to 4.05), but slightly more noninfectious complications in the control group (16.7 vs. 22.2 percent; P = 0.20; relative risk, 0.75; 95 percent confidence interval, 0.50 to 1.13). The increased rate of infections was confined to patients categorized as either borderline or mildly malnourished, according to Subjective Global Assessment or an objective nutritional assessment, and these patients had no demonstrable benefit from TPN. In contrast, severely malnourished patients who received TPN had fewer noninfectious complications than controls (5 vs. 43 percent; P = 0.03; relative risk, 0.12; 95 percent confidence interval, 0.02 to 0.91), with no concomitant increase in infectious complications. The use of preoperative TPN should be limited to patients who are severely malnourished unless there are other specific indications.