Timing of parenteral nutrition in ICU patients: A transatlantic controversy

Nutrition considerations for patients with persistent critical illness: A narrative review

Critically ill patients experience high rates of malnutrition and significant muscle loss during their intensive care unit (ICU) admission, impacting recovery. Nutrition is likely to play an important role in mitigating the development and progression of malnutrition and muscle loss observed in ICU, yet definitive clinical trials of nutrition interventions in ICU have failed to show benefit. As improvements in the quality of medical care mean that sicker patients are able to survive the initial insult, combined with an aging and increasingly comorbid population, it is anticipated that ICU length of stay will continue to increase. This review aims to discuss nutrition considerations unique to critically ill patients who have persistent critical illness, defined as an ICU stay of >10 days. A discussion of nutrition concepts relevant to patients with persistent critical illness will include energy and protein metabolism, prescription, and delivery; monitoring of nutrition at the bedside; and the role of the healthcare team in optimizing nutrition support.

Nutrition in the intensive care unit: from the acute phase to beyond

Recent randomized controlled trials (RCTs) have shown no benefit but  dose-dependent harm by early full nutritional support in critically ill patients. Lack of benefit may be explained by anabolic resistance, suppression of cellular repair processes, and aggravation of hyperglycemia and insulin needs. Also early high amino acid doses did not provide benefit, but instead associated with harm in patients with organ dysfunctions. However, most studies focused on nutritional interventions initiated during the first days after intensive care unit admission. Although the intervention window of some RCTs extended into the post-acute phase of critical illness, no large RCTs studied nutritional interventions initiated beyond the first week. Hence, clear evidence-based guidance on when and how to initiate and advance nutrition is lacking. Prolonged underfeeding will come at a price as there is no validated metabolic monitor that indicates readiness for medical nutrition therapy, and an adequate response to nutrition, which likely varies between patients. Also micronutrient status cannot be assessed reliably, as inflammation can cause redistribution, so that plasma micronutrient concentrations are not necessarily reflective of total body stores. Moreover, high doses of individual micronutrients have not proven beneficial. Accordingly, current evidence provides clear guidance on which nutritional strategies to avoid, but the ideal nutritional regimen for individual patients remains unclear. In this narrative review, we summarize the findings of recent studies, discuss possible mechanisms explaining the results, point out pitfalls in interpretation of RCTs and their effect on clinical practice, and formulate suggestions for future research.

Parenteral Nutrition in the Critically Ill Adult: A Narrative Review

Malnutrition in adult intensive care unit patients is associated with poor clinical outcomes. Providing adequate nutritional support to the critically ill adult should be an important goal for the intensivist. This narrative review aims to delineate the role of parenteral nutrition (PN) in meeting nutritional goals. We examined the data regarding the safety and efficacy of PN compared to enteral nutrition. In addition, we describe practical considerations for the use of PN in the ICU including patient nutritional risk stratification, nutrient composition selection for PN, route of PN administration, and biochemical monitoring.

How to avoid harm with feeding critically ill patients: a synthesis of viewpoints of a basic scientist, dietitian and intensivist

The optimal feeding strategy in critically ill patients is a matter of debate, with current guidelines recommending different strategies regarding energy and protein targets. Several recent trials have added to the debate and question our previous understanding of the provision of nutrition during critical illness. This narrative review aims to provide a summary of interpretation of recent evidence from the view of basic scientist, critical care dietitian and intensivist, resulting in joined suggestions for both clinical practice and future research. In the most recent randomised controlled trial (RCT), patients receiving 6 versus 25 kcal/kg/day by any route achieved readiness for ICU discharge earlier and had fewer GI complications. A second showed that high protein dosage may be harmful in patients with baseline acute kidney injury and more severe illness. Lastly, a prospective observational study using propensity score matched analysis suggested that early full feeding, especially enteral, compared to delayed feeding is associated with a higher 28-day mortality. Viewpoints from all three professionals point to the agreement that early full feeding is likely harmful, whereas important questions regarding the mechanisms of harm as well as on timing and optimal dose of nutrition for individual patients remain unanswered and warrant future studies. For now, we suggest giving low dose of energy and protein during the first few days in the ICU and apply individualised approach based on assumed metabolic state according to the trajectory of illness thereafter. At the same time, we encourage research to develop better tools to monitor metabolism and the nutritional needs for the individual patient accurately and continuously.

[Nutrition practices in intensive care units: nutritionDay from 2007-2021]

In intensive care units (ICU), patients who are not able to eat or are considered at nutritional risk typically receive medical nutrition therapy based on partially contradictory guidelines as well as the strategies used in large randomized trials. The aim of this study is to analyze patient data from the nutritionDay project in intensive care to describe current clinical approaches to nutrition support worldwide, in Europe and in the group of German-speaking countries, the DACH (i.e., Germany, Austria, Switzerland) region. From 2007-2021, data of 18,918 adult patients in 1595 ICUs from 63 different countries were included in this cross-sectional study. The aim was to recruit all patients present in ICUs. Median stay in the ICU was 4 days on nutritionDay. Little difference in patient characteristics were observed between worldwide, Europe, and the DACH region. Patient were 64 years old, 40% female, 50% ventilated, 29% sedated, and 10% needed renal replacement therapy. A quarter of the patients died in hospital within 60 days and about half of the patients had been discharged home. Enteral nutrition was given twice as frequently as parenteral nutrition (48% versus 24%). Many patients received oral nutrition (39%) and a substantial number received no nutrition support (10%). Parenteral nutrition was used more frequently in Europe than in other world regions, the lowest use being observed in North America. The amount of nutrition given is very similar in all regions regardless of the nutrition route with about 1500 kcal and 60 g of protein per day. A clear association with body weight was not observed and the variation around the median was very large with half of patients receiving amounts 25% below or above the median. Upon completion of data entry, the nutritionDay project allows each ICU to download a unit report summarizing data that allows comparison with worldwide data in numeric and graphical form to permit easy benchmarking of medical nutrition therapy.

Intravenous amino acids may mediate the adverse effect of early parenteral nutrition on mortality in critically ill patients requiring mechanical ventilation: A post hoc analysis of the NEED trial

BACKGROUND

There is controversy regarding the optimal timing of initiating parenteral nutrition (PN) in critically ill patients. We aimed to evaluate the association between early PN and clinical outcomes and explore the mediation effects of different macronutrients in a cohort of mechanically ventilated patients.

METHODS

This is a post hoc analysis of the NEED trial aiming to investigate the effect of implementing an evidence-based feeding guideline in newly-admitted critically ill patients. All eligible patients were divided into those who received early PN within the first 3 days of enrollment (early PN) or those who did not (non-early PN). Propensity score matching with a one-to-one nearest neighbor-matching algorithm was applied to control potential confounders. Mediation analysis was used to test the indirect effect of different macronutrients from PN on the relationship between early PN and 28-day mortality.

RESULTS

The propensity score matching created 370 matched pairs of 1154 patients that met the eligibility criteria. Compared with non-early PN, patients receiving early PN had significantly higher 28-day mortality (19.7% vs 12.4%; hazard ratio = 1.904; 95% CI, 1.063-3.410; P = 0.03). Mediation analysis showed that amino acids from early PN mediated 65% (mediation effect = 0.07; 95% CI, 0.02-0.13; P = 0.01) of the detrimental effect of early PN on the 28-day mortality.

CONCLUSION

Early PN is associated with increased 28-day mortality in critically ill patients requiring invasive mechanical ventilation. The detrimental effect may be mediated by intravenous amino acids from early PN.

Tranexamic acid administration practice in otolaryngology head & neck surgery; international survey

PURPOSE

Tranexamic acid (TXA) is a potent pro-coagulation drug. Pre-operative, preventive TXA administration and TXA use for active bleeding are established treatments in many medical situations; yet, less is known about its use in otolaryngology head and neck surgery practice. The primary study goals were: MATERIALS AND METHODS: This is an international survey exploring TXA administration strategy. The electronic, anonymous, questionnaire was emailed to all registered Israeli and American Otolaryngology Head and Neck Surgery (OHNS) physicians, investigating TXA administration: RESULTS: Overall, 317 otolaryngologists participated in the study. TXA was administered to 40.5 % of the pediatric population and 50 % of the adult patients when needed. Epistaxis was the most common indication for TXA administration (48-55 %). A small number of otolaryngologists, 4-13 %, recommended preventive TXA for various operations. More surgeons include TXA in their practice and adjusted the dose according to renal function in academic compared to non-academic medical centers and among otolaryngologists practicing in Israel compared to the United States.

CONCLUSIONS

TXA is provided by many otolaryngologists to treat active epistaxis but to a substantially lesser extent as a preventive measure. TXA is given to children and adults, some with substantial comorbidities. Treatment is more common among surgeons working in academic institutes and medical centers in Israel.