Nutrition and infection in the intensive care unit: what does the evidence show?

Impact of early enteral nutrition on ventilator associated pneumonia in intubated severe trauma patients: A propensity score-matched study

Background

Early enteral nutrition (EN) is recommended for critically ill patients. However, the impact of early EN on intubated severe trauma patients remains unclear.

Methods

Severely traumatized adult patients who received invasive mechanical ventilation (MV) for more than 48 h during intensive care unit (ICU) stay at our institution between 2017 and 2022 were retrospectively included. Early EN was defined as EN initiation ≤48 h from ICU admission and late EN >48 h. Propensity score matching (PSM) analysis was used to compare outcomes between the groups. The primary endpoint was the incidence of ventilator-associated pneumonia (VAP). Multivariable logistic regression analysis was performed to identify independent predictors of delayed EN.

Results

For final analysis, 337 intubated severe trauma patients were available, including 204 (60.5%) in the early EN group and 133 (39.5%) in the late EN group. After PSM, early EN patients had a lower incidence of VAP (12.9 vs. 25.8%, p = 0.026) and a shorter length of hospital stay (21 vs. 24 days, p = 0.015) compared to late EN patients. There was no demonstrable difference in mortality between the two groups. Abdominal trauma, massive blood transfusion, and serum albumin were identified as independent risk factors for delayed EN.

Conclusion

Early EN decreased the VAP rate and reduced the length of hospital stay in invasively ventilated patients with severe trauma. Abdominal injury, massive blood transfusion and low albumin were associated with delayed EN.

Alcohol use disorder increases the risk of necrotizing fasciitis: A nationwide retrospective cohort study

This nationwide retrospective cohort study determined the association between alcohol use disorder (AUD) and the risk of necrotizing fasciitis (NF).This study used health insurance claims data of 52,212 in-patients with AUD and 208,848 controls randomly frequency-matched by age and sex at a 1:4 ratio. The AUD cohort included patients newly diagnosed with AUD between January 1, 2000 and December 31, 2008. The NF event occurrence was observed until December 31, 2011. We used the Kaplan-Meier method to present the cumulative incidence curve and Cox proportional hazard models to depict the risk of NF in patients with AUD.The incidence of NF was 19.4 per 10,000 person-years in the AUD cohort, which was nearly 7.73-fold higher than that in the comparison cohort (2.54 per 10,000 person-years). After adjustment for age, sex, and comorbidities, the patients with AUD exhibited a 3.55-fold higher risk of NF than did the controls (hazard ratio [HR] = 3.55, 95% confidence interval [CI] = 3.00-4.20). Nevertheless, in the AUD groups without any comorbidity, patients with AUD exhibited a significant 15.2-fold higher risk of NF than did the comparison cohort (HR = 15.2, 95% CI = 10.9-21.3). Moreover, the adjusted HRs of NF risk with respect to the severity of AUD were 2.15 (95% CI = 1.76-2.62), 4.54 (95% CI = 3.67-5.62), and 10.7 (95% CI = 8.66-13.2) for mild, moderate, and severe AUD, respectively.This study indicated that AUD should be considered an independent and significant risk factor for NF.

Assay of the multiple energy-producing pathways of mammalian cells

BACKGROUND

To elucidate metabolic changes that occur in diabetes, obesity, and cancer, it is important to understand cellular energy metabolism pathways and their alterations in various cells.

METHODOLOGY AND PRINCIPAL FINDINGS

Here we describe a technology for simultaneous assessment of cellular energy metabolism pathways. The technology employs a redox dye chemistry specifically coupled to catabolic energy-producing pathways. Using this colorimetric assay, we show that human cancer cell lines from different organ tissues produce distinct profiles of metabolic activity. Further, we show that murine white and brown adipocyte cell lines produce profiles that are distinct from each other as well as from precursor cells undergoing differentiation.

CONCLUSIONS

This technology can be employed as a fundamental tool in genotype-phenotype studies to determine changes in cells from shared lineages due to differentiation or mutation.

Chylothorax after surgery on congenital heart disease in newborns and infants -risk factors and efficacy of MCT-diet

Objectives

To analyze risk factors for chylothorax in infants after congenital heart surgery and the efficacy of median chain triglyceride diet (MCT). To develop our therapeutic pathway for the management of chylothorax.

Patients and methods

Retrospective review of the institutional surgical database and patient charts including detailed perioperative informations between 1/2000 and 10/2006. Data analyzing with an elimination regression analysis.

Results

Twenty six out of 282 patients had chylothorax (=9.2%). Secondary chest closure, low body weight, small size, longer cardiopulmonary bypass (242 ± 30 versus 129 ± 5 min) and x-clamp times (111 ± 15 versus 62 ± 3 min) were significantly associated with chylothorax (p < 0.05). One patient was cured with total parenteral nutrition (TPN) and one without any treatment. 24 patients received MCT-diet alone, which was successful in 17 patients within 10 days. After conversion to regular alimentation within one week only one chylothorax relapsed. Out of 7 patients primarily not responsive to MCT-diet, 2 were successfully treated by lysis of a caval vein thrombosis, 2 by TPN + pleurodesis + supradiaphragmatic thoracic duct ligation, one by octreotide treatment, and two patients finally died.

Conclusions

Chylothorax may appear due to injury of the thoracic duct, due to venous or lymphatic congestion, central vein thrombosis, or diffuse injury of mediastinal lymphatic tissue in association with secondary chest closure. Application of MCT alone was effective in 71%, and more invasive treatments like TPN should not be used in primary routine. After resolution of chylothorax, MCT-diet can be converted to regular milk formula within one week and with very low risk of relapse.

Metabolic effects of enteral versus parenteral alanyl-glutamine dipeptide administration in critically ill patients receiving enteral feeding: a pilot study

BACKGROUND

Glutamine (Gln) may become conditionally indispensable during critical illness. The short-term metabolic effects of enteral versus parenteral Gln supplementation are unknown in this clinical setting.

OBJECTIVES

We studied metabolic effects of intravenous (i.v.) alanyl-Gln dipeptide (AG) supplementation and enteral (e.n.) AG supplementation on plasma Gln concentration, antioxidant status, plasma lymphocyte subset number, gut permeability and nitrogen balance in adult critically ill patients requiring tube feeding compared to a control group not receiving Gln supplementation.

METHODS

In a double-blind, pilot clinical trial, 44 medical and surgical ICU patients received identical Gln-free tube feedings 24 h/day and were randomized to either isonitrogenous control (n=15), e.n. AG (n=15) or i.v. AG (n=14) groups (AG). Twelve patients were discontinued from the study. The goal AG dose was 0.5 g/kg/day. Biochemical and metabolic endpoints were measured at baseline and on day 9 (plasma Gln, antioxidant indices, lymphocyte subsets; serum IGF-1 and IGF-binding protein-3; intestinal permeability). Nitrogen balance was determined between study days 6 and 8.

RESULTS

Illness severity indices, clinical demographics, enteral energy and nitrogen intake and major biochemical indices were similar between groups during study. Plasma Gln was higher in the i.v. AG (565+/-119 microM, mean+/-SEM) vs the e.n. AG (411+/-27 microM) group by day 9 (p=0.039); however, subjects in the i.v. AG group received a higher dose of AG (i.v. AG 0.50 versus e.n. AG 0.32+/-0.02 g/kg/day; p<0.001). E.n. AG subjects showed a significant increase in plasma alpha-tocopherol levels over time and maintained plasma gamma-tocopherol concentrations. There were no differences between groups for plasma concentrations of vitamin C, glutathione, malondialdehyde (MDA), T-lymphocyte subsets, intestinal permeability or nitrogen balance.

CONCLUSIONS

This study showed that alanyl-Gln administration by enteral or parenteral routes did not appear to affect antioxidant capacity or oxidative stress markers, T-lymphocyte subset (CD-3, CD-4, CD-8) number, gut barrier function or whole-body protein metabolism compared to unsupplemented ICU patients requiring enteral tube feeding. Enteral Gln appeared to maintain plasma tocopherol levels in this pilot metabolic study.

Immune-modulating enteral formulations: optimum components, appropriate patients, and controversial use of arginine in sepsis

Nutrients have traditionally been viewed as a means to provide basic calories to sustain homeostasis. However, critically ill, surgical, and trauma patients are in a constant dynamic state between systemic inflammatory response (SIRS) and compensatory anti-inflammatory response (CARS). Results from ongoing research strongly support the use of specific nutrients to modulate the immune and/or metabolic response. These agents can now be considered therapeutic tools in the management of complex hypermetabolic diseases. The principle of using nutrients as a therapeutic strategy rather than just as "nutritional support" requires a shift in the current dogma. The most common nutrients found in currently available enteral immune-modulating formulas are omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid), antioxidants, nucleotides, glutamine, and arginine. Multiple individual reports and at least five meta-analyses using combinations of immune-modulating nutrients have reported almost uniform beneficial results. However, certain conflicting hypotheses continue to revolve around the use of arginine in septic patients.