A J-shaped relationship between caloric intake and survival in critically ill patients

The Impact of Higher Protein Intake in Patients with Prolonged Mechanical Ventilation

Prolonged mechanical ventilation (PMV) is associated with poor outcomes and a high economic cost. The association between protein intake and PMV has rarely been investigated in previous studies. This study aimed to investigate the impact of protein intake on weaning from mechanical ventilation. Patients with the PMV (mechanical ventilation ≥6 h/day for ≥21 days) at our hospital between December 2020 and April 2022 were included in this study. Demographic data, nutrition records, laboratory data, weaning conditions, and survival data were retrieved from the patient’s electronic medical records. A total of 172 patients were eligible for analysis. The patients were divided into two groups: weaning success (n = 109) and weaning failure (n = 63). Patients with daily protein intake greater than 1.2 g/kg/day had significant shorter median days of ventilator use than those with less daily protein intake (36.5 vs. 114 days, respectively, p < 0.0001). Daily protein intake ≥1.065 g/kg/day (odds ratio: 4.97, p = 0.033), daily protein intake ≥1.2 g/kg/day (odds ratio: 89.07, p = 0.001), improvement of serum albumin (odds ratio: 3.68, p = 0.027), and BMI (odds ratio: 1.235, p = 0.014) were independent predictor for successful weaning. The serum creatinine level in the 4th week remained similar in patients with daily protein intake either >1.065 g/kg/day or >1.2 g/kg/day (p = 0.5219 and p = 0.7796, respectively). Higher protein intake may have benefits in weaning in patients with PMV and had no negative impact on renal function.

Comparison of the effects of different calorie amounts of enteral nutrition in hypercatabolism associated with ghrelin-POMC in endotoxemic rats

Background

Hypercatabolism often occurs in critically ill patients, and it increases infection rates and mortality in these patients. Enteral nutrition (EN) is commonly used in case of hypercatabolism. However, the effect of amount of calories in EN on hypercatabolism remains unexplored.

Objective

Here, we compared the effect of low-calorie, medium-calorie and high-calorie EN on hypercatabolism in the acute phase of endotoxemia, which is associated with gastrointestinal hormones and hypothalamic neuropeptide proopiomelanocortin (POMC).

Methods

Overall 84 adult male Sprague–Dawley rats were used for research. A set of rats were divided into 5 groups, Control (NS) and lipopolysaccharide (LPS) groups were fed a standard chow diet; LPS + L (LPS + 40 kcal/kg/day EN), LPS + M (LPS + 80 kcal/kg/day EN) and LPS + H (LPS + 120 kcal/kg/day EN) groups received EN through a gastric tube for 3 days. Another set of rats were used for parallel control experiment and divided into 5 groups: NS + F (saline + fasting) and LPS + F (LPS + fasting) groups were given no food, NS + L (saline + 40 kcal/kg/day EN), NS + M (saline + 80 kcal/kg/day EN) and NS + H (saline + 120 kcal/kg/day EN) groups received EN through a gastric tube for 3 days. Hypercatabolism was evaluated by assessing skeletal muscle protein synthesis and atrophy, insulin resistance, and corticosterone levels. Moreover, serum inflammatory factors, gastrointestinal hormones, hypothalamic ghrelin, growth hormone secretagogue receptor-1α, hypothalamic neuropeptide, and intestinal injury indicators were detected.

Results

Low-calorie EN effectively increased serum and hypothalamic ghrelin possibly due to slight intestinal barrier damage, thereby decreasing hypothalamic POMC expression; consequently, it alleviated rat insulin resistance, reduced blood cortisol levels and muscle atrophy, and improved the survival rate of rats in the acute phase of endotoxemia. Interestingly, with an increase in calories in enteral nutrition, the aforementioned effects did not increase.

Conclusions

Low-calorie EN could effectively increase gastrointestinal hormone ghrelin by reducing intestinal damage and suppressing POMC expression to ameliorate hypercatabolism when compared with medium-calorie and high-calorie EN. Therefore Low-calorie EN may be preferred for providing EN in the acute stage of endotoxemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00663-7.

Effect of protein composition of enteral formula on gastric content volume during continuous feeding: A randomized controlled cross-over study in healthy adults

BACKGROUND & AIMS

Enteral nutrition with polymeric intact protein formula is the preferred medical nutrition strategy in critically ill patients when oral intake is insufficient. Enteral nutrition formulas are often rich in casein protein, which has coagulating properties. Coagulation in the stomach impedes gastric emptying and might result in high gastric residual volumes which are a clinical sign of gastrointestinal intolerance and a major reason to decrease or to discontinue enteral feeding. In this study the impact of protein composition of enteral formula on gastric content volume (GCV) during and after continuous feeding was tested in healthy volunteers in whom gastrointestinal conditions of critically ill patients were mimicked.

METHODS

An enteral formula including 4 proteins (P4) with non-coagulating properties was compared to a casein-dominant formula (Cas) with coagulating properties. Esomeprazole and codeine were administered to mimic stress ulcer prophylaxis and induce gastroduodenal motor dysfunction, both being hallmarks of critically ill patients. GCV was measured with magnetic resonance imaging during and after continuous enteral feeding (100 mL/h for 4h) in a randomized single-center cross-over study. Results are provided as mean (SD). Significance level of p < 0.05 was applied.

RESULTS

Twenty subjects completed the study (14 women, 6 men, 25.8 (4.6) years old, BMI: 22.5 (1.5) kg/m²). The GCV as change from baseline at T = 240 (primary endpoint) did not differ between study products (P4: 124.3 (83.4) vs. Cas: 137.1 (102.0) mL, 95% CI: -57.4, 27.0, p = 0.457). During feeding and after cessation of feeding, the area under the GCV-curve (AUC_0-360 GCV) for P4 and Cas was 44631.1 (15546.1) and 52822.2 (19686.1) mL∗min, respectively (p = 0.061). During feeding the GCV was lower at T = 180 min (175.4 (64.8) vs. 205.2 (75.4) mL, p = 0.038) and after cessation of feeding at T = 300 min (81.3 (71.1) vs. 116.3 (84.3) mL, p = 0.004) and T = 330 min (39.9 (53.9) vs. 73.6 (81.1) mL, p = 0.031). With P4 it took less time to reach half of the GCV at T = 240 min compared to Cas (52.8 (27.6) vs. 65.4 (29.9) min, p = 0.020).

CONCLUSIONS

In this study in which healthy volunteers received esomeprazole and codeine to mimic gastrointestinal conditions of critically ill patients, observations of secondary endpoints suggest faster gastric emptying with P4 compared to Cas, and less gastric accumulation, possibly due to the non-coagulating properties of the P4 protein blend. Considering the small effect and the possible clinical relevance of reduced intragastric accumulation of enteral nutrition, the potential impact of protein coagulation should be further investigated in relevant study populations. Registered under Netherlands Trial Register identifier no. NTR6423.

Metabolic Resuscitation Strategies to Prevent Organ Dysfunction in Sepsis

Significance: Sepsis is the main cause of death among patients admitted to the intensive care unit. As current treatment is limited to antimicrobial therapy and supportive care, mortality remains high, which warrants efforts to find novel therapies. Recent Advances: Mitochondrial dysfunction is emerging as a key process in the induction of organ dysfunction during sepsis, and metabolic resuscitation might reveal to be a novel cornerstone in the treatment of sepsis. Critical Issues: Here, we review novel strategies to maintain organ function in sepsis by precluding mitochondrial dysfunction by lowering energetic demand to allow preservation of adenosine triphosphate-levels, while reducing free radical generation. As the most common strategy to suppress metabolism, that is, cooling, does not reveal unequivocal beneficial effects and may even increase mortality, caloric restriction or modulation of energy-sensing pathways (i.e., sirtuins and AMP-activated protein kinase) may offer safe alternatives. Similar effects may be offered when mimicking hibernation by hydrogen sulfide (H₂S). In addition H₂S may also confer beneficial effects through upregulation of antioxidant mechanisms, similar to the other gasotransmitters nitric oxide and carbon monoxide, which display antioxidant and anti-inflammatory effects in sepsis. In addition, oxidative stress may be averted by systemic or mitochondria-targeted antioxidants, of which a wide range are able to lower inflammation, as well as reduce organ dysfunction and mortality from sepsis. Future Directions: Mitochondrial dysfunction plays a key role in the pathophysiology of sepsis. As a consequence, metabolic resuscitation might reveal to be a novel cornerstone in the treatment of sepsis.

Clinical Nutrition in Critical Care Medicine - Guideline of the German Society for Nutritional Medicine (DGEM)

PURPOSE

Enteral and parenteral nutrition of adult critically ill patients varies in terms of the route of nutrient delivery, the amount and composition of macro- and micronutrients, and the choice of specific, immune-modulating substrates. Variations of clinical nutrition may affect clinical outcomes. The present guideline provides clinicians with updated consensus-based recommendations for clinical nutrition in adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function.

METHODS

The former guidelines of the German Society for Nutritional Medicine (DGEM) were updated according to the current instructions of the Association of the Scientific Medical Societies in Germany (AWMF) valid for a S2k-guideline. According to the S2k-guideline classification, no systematic review of the available evidence was required to make recommendations, which, therefore, do not state evidence- or recommendation grades. Nevertheless, we considered and commented the evidence from randomized-controlled trials, meta-analyses and observational studies with adequate sample size and high methodological quality (until May 2018) as well as from currently valid guidelines of other societies. The liability of each recommendation was described linguistically. Each recommendation was finally validated and consented through a Delphi process.

RESULTS

In the introduction the guideline describes a) the pathophysiological consequences of critical illness possibly affecting metabolism and nutrition of critically ill patients, b) potential definitions for different disease phases during the course of illness, and c) methodological shortcomings of clinical trials on nutrition. Then, we make 69 consented recommendations for essential, practice-relevant elements of clinical nutrition in critically ill patients. Among others, recommendations include the assessment of nutrition status, the indication for clinical nutrition, the timing and route of nutrient delivery, and the amount and composition of substrates (macro- and micronutrients); furthermore, we discuss distinctive aspects of nutrition therapy in obese critically ill patients and those treated with extracorporeal support devices.

CONCLUSION

The current guideline provides clinicians with up-to-date recommendations for enteral and parenteral nutrition of adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function. The period of validity of the guideline is approximately fixed at five years (2018-2023).

ESPEN guideline on clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous guidelines to provide best medical nutritional therapy to critically ill patients have been updated. These guidelines define who are the patients at risk, how to assess nutritional status of an ICU patient, how to define the amount of energy to provide, the route to choose and how to adapt according to various clinical conditions. When to start and how to progress in the administration of adequate provision of nutrients is also described. The best determination of amount and nature of carbohydrates, fat and protein are suggested. Special attention is given to glutamine and omega-3 fatty acids. Particular conditions frequently observed in intensive care such as patients with dysphagia, frail patients, multiple trauma patients, abdominal surgery, sepsis, and obesity are discussed to guide the practitioner toward the best evidence based therapy. Monitoring of this nutritional therapy is discussed in a separate document.

Calorie intake and short-term survival of critically ill patients

BACKGROUND & AIMS

The association between calorie supply and outcome of critically ill patients is unclear. Results from observational studies contradict findings of randomized studies, and have been questioned because of unrecognized confounding by indication. The present study wanted to re-examine the associations between the daily amount of calorie intake and short-term survival of critically ill patients using several novel statistical approaches.

METHODS

9661 critically ill patients from 451 ICUs were extracted from an international database. We examined associations between survival time and three pragmatic nutritional categories (I: <30% of target, II: 30-70%, III: >70%) reflecting different amounts of total daily calorie intake. We compared hazard ratios for the 30-day risk of dying estimated for different hypothetical nutrition support plans (different categories of daily calorie intake during the first 11 days after ICU admission). To minimize indication bias, we used a lag time between nutrition and outcome, we particularly considered daily amounts of calorie intake, and we adjusted results to the route of calorie supply (enteral, parenteral, oral).

RESULTS

1974 patients (20.4%) died in hospital before day 30. Median of daily artificial calorie intake was 1.0 kcal/kg [IQR 0.0-4.1] in category I, 12.3 kcal/kg [9.4-15.4] in category II, and 23.5 kcal/kg [19.5-27.8] in category III. When compared to a plan providing daily minimal amounts of calories (category I), the adjusted minimal hazard ratios for a delayed (from day 5-11) or an early (from day 1-11) mildly hypocaloric nutrition (category II) were 0.71 (95% confidence interval [CI], 0.54 to 0.94) and 0.56 (95% CI, 0.38 to 0.82), respectively. No substantial hazard change could be detected, when a delayed or an early, near target calorie intake (category III) was compared to an early, mildly hypocaloric nutrition.

CONCLUSIONS

Compared to a severely hypocaloric nutrition, a mildly hypocaloric nutrition is associated with a decreased risk of death. In unselected critically ill patients, this risk cannot be reduced further by providing amounts of calories close to the calculated target.

STUDY REGISTRATION

ID number ISRCTN17829198, website http://www.isrctn.org.

Controversies Surrounding Critical Care Nutrition: An Appraisal of Permissive Underfeeding, Protein, and Outcomes

Over the past few years, numerous studies have called into question the optimal dose, timing, composition, and advancement rate of nutrition during the early acute phase of critical illness. These studies suggest permissive underfeeding with slow advancement may be more beneficial than aggressive full feeding. These counterintuitive results were possibly explained by enhanced autophagy, less hyperglycemia, or prevention of refeeding syndrome. This review underscores the controversies surrounding permissive underfeeding, aims to answer whether permissive underfeeding is appropriate for all critically ill patients, describes the impact of optimal protein delivery on critical care outcomes, discusses nutrition risk, and cogitates on the impact of nutrition on critical care outcomes.

Relationship of energy and protein adequacy with 60-day mortality in mechanically ventilated critically ill patients: A prospective observational study

BACKGROUND & AIMS

The effect of provision of full feeding or permissive underfeeding on mortality in mechanically ventilated critically ill patients in the intensive care unit (ICU) is still controversial. This study investigated the relationship of energy and protein intakes with 60-day mortality, and the extent to which ICU length of stay and nutritional risk status influenced this relationship.

METHODS

This is a prospective observational study conducted among critically ill patients aged ≥18 years, intubated and mechanically ventilated within 48 h of ICU admission and stayed in the ICU for at least 72 h. Information on baseline characteristics and nutritional risk status (the modified Nutrition Risk in Critically ill [NUTRIC] score) was collected on day 1. Nutritional intake was recorded daily until death, discharge, or until the twelfth evaluable days. Mortality status was assessed on day 60 based on the patient's hospital record. Patients were divided into 3 groups a) received <2/3 of prescribed energy and protein (both <2/3), b) received ≥2/3 of prescribed energy and protein (both ≥2/3) and c) either energy or protein received were ≥2/3 of prescribed (either ≥2/3). The relationship between the three groups with 60-day mortality was examined by using logistic regression with adjustment for potential confounders. Sensitivity analysis was performed to examine the influence of ICU length of stay (≥7 days) and nutritional risk status.

RESULTS

Data were collected from 154 mechanically ventilated patients (age, 51.3 ± 15.7 years; body mass index, 26.5 ± 6.7 kg/m²; 54% male). The mean modified NUTRIC score was 5.7 ± 1.9, with 56% of the patients at high nutritional risk. The patients received 64.5 ± 21.6% of the amount of energy and 56.4 ± 20.6% of the amount of protein prescribed. Provision of energy and protein at ≥2/3 compared with <2/3 of the prescribed amounts was associated with a trend towards increased 60-day mortality (Adjusted odds ratio [Adj OR] 2.23; 95% confidence interval [CI], 0.92-5.38; p = 0.074). No difference in mortality status was found between energy and protein provision at either ≥2/3 compared with <2/3 of the prescribed amounts (Adj OR 1.61, 95% CI, 0.58-4.45; p = 0.357). Nutritional risk status, not ICU length of stay, influenced the relationship between nutritional adequacy and 60-day mortality.

CONCLUSIONS

Energy and protein adequacy of ≥2/3 of the prescribed amounts were associated with a trend towards increased 60-day mortality among mechanically ventilated critically ill patients. However, neither energy nor protein adequacy alone at ≥ or <2/3 adequacy affect 60-day mortality. Increased mortality was associated with provision of energy and protein at ≥2/3 of the prescribed amounts, which only affected patients with low nutritional risk.

Major publications in the critical care pharmacotherapy literature in 2015

PURPOSE

Recently published practice guidelines and research reports on pharmacotherapy in critical care patient populations are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) Group is composed of over 50 experienced critical care pharmacists who evaluate 31 peer-reviewed journals monthly to identify literature pertaining to pharmacotherapy in critical care populations. Articles are chosen for summarization in a monthly CCPLU Group publication on the basis of applicability and relevance to clinical practice and strength of study design. From January to December 2015, a total of 121 articles were summarized; of these, 3 articles presenting clinical practice guidelines and 12 articles presenting original research findings were objectively selected for inclusion in this review based on their potential to change or reinforce current evidence-based practice. The reviewed guidelines address the management of intracranial hemorrhage (ICH), adult advanced cardiac life support (ACLS) and post-cardiac arrest care, and the management of supraventricular tachycardia (SVT). The reviewed research reports address topics such as nutrition in critically ill adults, administration of β-lactams for severe sepsis, anticoagulant selection in the context of continuous renal replacement therapy, early goal-directed therapy in septic shock, magnesium use for neuroprotection in acute stroke, and progesterone use in patients with traumatic brain injury.

CONCLUSION

Important recent additions to the critical care pharmacy literature include updated joint clinical practice guidelines on the management of spontaneous ICH, ACLS, and SVT.

Lower versus higher dose of enteral caloric intake in adult critically ill patients: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence about the relationship between the dose of enteral caloric intake and survival in critically ill patients. The objective of this systematic review and meta-analysis is to compare the effect of lower versus higher dose of enteral caloric intake in adult critically ill patients on outcome.

METHODS

We reviewed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from inception through November 2015. We included randomized and quasi-randomized studies in which there was a significant difference in the caloric intake in adult critically ill patients, including trials in which caloric restriction was the primary intervention (caloric restriction trials) and those with other interventions (non-caloric restriction trials). Two reviewers independently extracted data on study characteristics, caloric intake, and outcomes with hospital mortality being the primary outcome.

RESULTS

Twenty-one trials mostly with moderate bias risk were included (2365 patients in the lower caloric intake group and 2352 patients in the higher caloric group). Lower compared with higher caloric intake was not associated with difference in hospital mortality (risk ratio (RR) 0.953; 95 % confidence interval (CI) 0.838-1.083), ICU mortality (RR 0.885; 95 % CI 0.751-1.042), total nosocomial infections (RR 0.982; 95 % CI 0.878-1.077), mechanical ventilation duration, or length of ICU or hospital stay. Blood stream infections (11 trials; RR 0.718; 95 % CI 0.519-0.994) and incident renal replacement therapy (five trials; RR 0.711; 95 % CI 0.545-0.928) were lower with lower caloric intake. The associations between lower compared with higher caloric intake and primary and secondary outcomes, including pneumonia, were not different between caloric restriction and non-caloric restriction trials, except for the hospital stay which was longer with lower caloric intake in the caloric restriction trials.

CONCLUSIONS

We found no association between the dose of caloric intake in adult critically ill patients and hospital mortality. Lower caloric intake was associated with lower risk of blood stream infections and incident renal replacement therapy (five trials only). The heterogeneity in the design, feeding route and timing and caloric dose among the included trials could limit our interpretation. Further studies are needed to clarify our findings.

Significant Published Articles for Pharmacy Nutrition Support Practice in 2014 and 2015

PURPOSE

To assist the pharmacy clinician engaged in nutrition support in staying current with the most pertinent literature.

METHODS

Several experienced board-certified clinical pharmacists engaged in nutrition support therapy compiled a list of articles published in 2014 and 2015 that they considered to be important to their practice. Only those articles available in print format were considered for potential inclusion. Articles available only in preprint electronic format were not evaluated. The citation list was compiled into a single spreadsheet where the author participants were asked to ascertain whether they considered the paper important to nutrition support pharmacy practice. A culled list of publications was then identified whereby the majority of author participants (at least 5 out of 8) considered the paper to be important.

RESULTS

A total of 108 articles were identified; 36 of which were considered to be of high importance. An important guideline article published in early 2016, but not ranked, was also included. The top-ranked articles from the primary literature were reviewed.

CONCLUSION

It is recommended that the informed pharmacist, who is engaged in nutrition support therapy, be familiar with the majority of these articles.