Early Enteral Nutrition (within 48 h) for Patients with Sepsis or Septic Shock: A Systematic Review and Meta-Analysis.

OBJECTIVE: Medical nutrition therapy provides the opportunity to compensate for muscle wasting and immune response activation during stress and trauma. The objective of this systematic review is to assess the safety and effectiveness of early enteral nutrition (EEN) in adults with sepsis or septic shock. METHODS: The MEDLINE, Embase, CENTRAL, CINAHL, ClinicalTrials.gov, and ICTRP tools were searched from inception until July 2023. Conference proceedings, the reference lists of included studies, and expert content were queried to identify additional publications. Two review authors completed the study selection, data extraction, and risk of bias assessment; disagreements were resolved through discussion. Inclusion criteria were randomized controlled trials (RCTs) and non-randomized studies (NRSs) comparing the administration of EEN with no or delayed enteral nutrition (DEE) in adult populations with sepsis or septic shock. RESULTS: Five RCTs (n = 442 participants) and ten NRSs (n = 3724 participants) were included. Low-certainty evidence from RCTs and NRSs suggests that patients receiving EEN could require fewer days of mechanical ventilation (MD -2.65; 95% CI, -4.44-0.86; and MD -2.94; 95% CI, -3.64--2.23, respectively) and may show lower SOFA scores during follow-up (MD -1.64 points; 95% CI, -2.60--0.68; and MD -1.08 points; 95% CI, -1.90--0.26, respectively), albeit with an increased frequency of diarrhea episodes (OR 2.23, 95% CI 1.115-4.34). Even though the patients with EEN show a lower in-hospital mortality rate both in RCTs (OR 0.69; 95% CI, 0.39-1.23) and NRSs (OR 0.89; 95% CI, 0.69-1.13), this difference does not achieve statistical significance. There were no apparent differences for other outcomes. CONCLUSIONS: Low-quality evidence suggests that EEN may be a safe and effective intervention for the management of critically ill patients with sepsis or septic shock.

Hydromediastinum and hydrothorax as delayed complications of peripherally inserted central catheter used for total parenteral nutrition: A case report.

INTRODUCTION: Central venous catheters (CVCs) and peripherally inserted central catheters (PICCs) may cause delayed complications, such as venous erosion, hydrothorax, or hydromediastinum. Vascular erosion is most frequently associated with left-sided CVC insertions. We report a case of hydropneumomediastinum and hydropneumothorax as a delayed complication of right-sided PICC used for total parenteral nutrition. PRESENTATION OF CASE: A 77-year-old man with muscle-invasive urothelial bladder cancer underwent pelvic lymphadenectomy and radical cystectomy with uretero-ileostomy reconstruction (Bricker). The patient developed postoperative ileus, and thus, a right PICC was inserted for total parenteral nutrition. On postoperative day 8, he developed bilateral hydromediastinum, and bilateral thoracentesis was performed. After the procedure, he presented with respiratory and hemodynamic deterioration and was transferred to the intensive care unit for 12 days. The patient was eventually discharged and followed-up at the outpatient department. DISCUSSION: Ruptured SVC has been predominantly described in left-sided CVCs at the right angle of the junction of the left brachiocephalic vein and SVC. However, our patient is the second documented case of bilateral hydropneumothorax and hydropneumomediastinum as a delayed complication of a PICC used to administer total parenteral nutrition. Catheters may migrate from their initial position due to breathing, bloodstream flow dynamics, postural rotation, and neck movements. Chemical irritation of the vessel wall may be caused by hyperosmolar hyperalimentation fluid. CONCLUSION: A right-sided vascular approach is preferred to avoid friction complications, and the tip should be placed at the lower third of the vena cava to prevent vascular erosion.

Experimental and Outcome-Based Approaches to Protein Requirements in the Intensive Care Unit.

Insight into protein requirements of intensive care unit (ICU) patients is urgently needed, but at present, it is unrealistic to define protein requirements for different diagnostic groups of critical illness or at different stages of illness. No large randomized controlled trials have randomized protein delivery, adequately addressed energy intake, and evaluated relevant clinical outcomes. As a pragmatic approach, experimental studies have focused on protein requirements of heterogeneous ICU patients. Data are scarce and the absolute value of protein requirements therefore is an approximation. Experimental studies indicate a protein requirement of >1.2 g/kg protein, which is supported by several outcome-based observational studies. Protein intake levels of up to 2.0-2.5 g/kg appear to be safe. A higher level of personalized treatment, within 1.2 and 2.5 g/kg, must involve identification of patients with low muscle protein mass that might benefit most from adequate protein nutrition in the ICU.

Protein Kinetics and Metabolic Effects Related to Disease States in the Intensive Care Unit.

Evaluating protein kinetics in the critically ill population remains a very difficult task. Heterogeneity in the intensive care unit (ICU) population and wide spectrum of disease processes creates complexity in assessing protein kinetics. Traditionally, protein has been delivered in the context of total energy. Focus on energy delivery has recently come into question, as the importance of supplemental protein in patient outcomes has been shown in several recent trials. The ICU patient is prone to catabolism, immobilization, and impaired immunity, which is a perfect storm for massive loss of lean body tissue with a unidirectional flow of amino acids from muscle to immune tissue for immunoglobulin production, as well as liver for gluconeogenesis and acute phase protein synthesis. The understanding of protein metabolism in the ICU has been recently expanded with the discovery of how the mammalian target of rapamycin complex 1 is regulated. The concept of "anabolic resistance" and identifying the quantity of protein required to overcome this resistance is gaining support among critical care nutrition circles. It appears that a minimum of at least 1.2 g/kg/d with levels up to 2.0 g/kg/d of protein or amino acids appears safe for delivery in the ICU setting and may yield a better clinical outcome.

Summary Points and Consensus Recommendations From the International Protein Summit.

The International Protein Summit in 2016 brought experts in clinical nutrition and protein metabolism together from around the globe to determine the impact of high-dose protein administration on clinical outcomes and address barriers to its delivery in the critically ill patient. It has been suggested that high doses of protein in the range of 1.2-2.5 g/kg/d may be required in the setting of the intensive care unit (ICU) to optimize nutrition therapy and reduce mortality. While incapable of blunting the catabolic response, protein doses in this range may be needed to best stimulate new protein synthesis and preserve muscle mass. Quality of protein (determined by source, content and ratio of amino acids, and digestibility) affects nutrient sensing pathways such as the mammalian target of rapamycin. Achieving protein goals the first week following admission to the ICU should take precedence over meeting energy goals. High-protein hypocaloric (providing 80%-90% of caloric requirements) feeding may evolve as the best strategy during the initial phase of critical illness to avoid overfeeding, improve insulin sensitivity, and maintain body protein homeostasis, especially in the patient at high nutrition risk. This article provides a set of recommendations based on assessment of the current literature to guide healthcare professionals in clinical practice at this time, as well as a list of potential topics to guide investigators for purposes of research in the future.

How Many Nonprotein Calories Does a Critically Ill Patient Require? A Case for Hypocaloric Nutrition in the Critically Ill Patient.

Calculation of energy and protein doses for critically ill patients is still a matter of controversy. For more than 40 years of nutrition support, the total amount of nutrients to be delivered to these patients has been calculated based on expert recommendations, and this calculation is based on the administration of nonprotein calories in one attempt to ameliorate catabolic response and avoid the weight loss. New evidence suggests protein delivery is the most important intervention to improve clinical and metabolic outcomes. This article describes the metabolic rationale and the new evidence supporting a change in the approach of metabolic support of the critically ill, proposing a physiological-based intervention supported by the recognition of ancillary characteristics of the metabolic response to trauma and injury. A moderate dose of calories around 15 kcal/kg/d with a delivery of protein of 1.5 g/kg/d appears to be the new recommendation for many hypercatabolic patients in the first week following injury.

How Much and What Type of Protein Should a Critically Ill Patient Receive?

Protein loss, manifested as loss of muscle mass, is observed universally in all critically ill patients. Depletion of muscle mass is associated with impaired function and poor outcomes. In extreme cases, protein malnutrition is manifested by respiratory failure, lack of wound healing, and immune dysfunction. Protecting muscle loss focused initially on meeting energy requirements. The assumption was that protein was being used (through oxidation) as an energy source. In healthy individuals, small amounts of glucose (approximately 400 calories) protect muscle loss and decrease amino acid oxidation (protein-sparing effect of glucose). Despite expectations of the benefits, the high provision of energy (above basal energy requirements) through the delivery of nonprotein calories has failed to demonstrate a clear benefit at curtailing protein loss. The protein-sparing effect of glucose is not clearly observed during illness. Increasing protein delivery beyond the normal nutrition requirements (0.8 g/k/d) has been investigated as an alternative solution. Over a dozen observational studies in critically ill patients suggest that higher protein delivery is beneficial at protecting muscle mass and associated with improved outcomes (decrease in mortality). Not surprisingly, new Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition guidelines and expert recommendations suggest higher protein delivery (>1.2 g/kg/d) for critically ill patients. This article provides an introduction to the concepts that delineate the basic principles of modern medical nutrition therapy as it relates to the goal of achieving an optimal management of protein metabolism during critical care illness, highlighting successes achieved so far but also placing significant challenges limiting our success in perspective.