TICACOS international: A multi-center, randomized, prospective controlled study comparing tight calorie control versus Liberal calorie administration study

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.

Effects of Energy Delivery Guided by Indirect Calorimetry in Critically Ill Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The utility of using indirect calorimetry (IC) to estimate energy needs and methods for its application to this purpose remain unclear. This systematic review investigated whether using IC to estimate energy expenditure in critically ill patients is more meaningful for improving survival than other estimation methods.

METHODS

Comprehensive searches were conducted in MEDLINE using PubMed, Cochrane Central Register of Controlled Trials, and Igaku-Chuo-Zasshi up to March 2023.

RESULTS

Nine RCTs involving 1178 patients were included in the meta-analysis. The evidence obtained suggested that energy delivery by IC improved short-term mortality (risk ratio, 0.86; 95% confidence interval [CI], 0.70 to 1.06). However, the use of IC did not appear to affect the length of ICU stay (mean difference [MD], 0.86; 95% CI, -0.98 to 2.70) or the duration of mechanical ventilation (MD, 0.66; 95% CI, -0.39 to 1.72). Post hoc analyses using short-term mortality as the outcome found no significant difference by target calories in resting energy expenditure, whereas more frequent IC estimates were associated with lower short-term mortality and were more effective in mechanically ventilated patients.

CONCLUSIONS

This updated meta-analysis revealed that the use of IC may improve short-term mortality in patients with critical illness and did not increase adverse events.

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.

Clinical practice guidelines for nutritional assessment and monitoring of adult ICU patients in China

The Chinese Society of Critical Care Medicine (CSCCM) has developed clinical practice guidelines for nutrition assessment and monitoring for patients in adult intensive care units (ICUs) in China. This guideline focuses on nutrition evaluation and metabolic monitoring to achieve optimal and personalized nutrition therapy for critically ill patients. This guideline was developed by experts in critical care medicine and evidence-based medicine methodology and was developed after a thorough review of the system and a summary of relevant trials or studies published from 2000 to July 2023. A total of 18 recommendations were formed and consensus was reached through discussions and reviews by expert groups in critical care medicine, parenteral and enteral nutrition, and surgery. The recommendations are based on currently available evidence and cover several key fields, including screening and assessment, evaluation and assessment of enteral feeding intolerance, metabolic and nutritional measurement and monitoring during nutrition therapy, and organ function evaluation related to nutrition supply. Each question was analyzed according to the Population, Intervention, Comparison, and Outcome (PICO) principle. In addition, interpretations were provided for four questions that did not reach a consensus but may have potential clinical and research value. The plan is to update this nutrition assessment and monitoring guideline using the international guideline update method within 3-5 years.

Measurement and estimation of energy in the critically ill

PURPOSE OF REVIEW

Recent changes in guidelines recommendation during early phase of critical illness and use of indirect calorimetry. The aim of this review is to discuss methods of determining energy requirements in the critically ill and highlight factors impacting resting energy expenditure.

RECENT FINDING

An appraisal of recent literature discussing indirect calorimetry guided-nutrition potential benefits or pitfalls. Recent attempts to devise strategy and pilot indirect calorimetry use in the critically ill patients requiring continuous renal replacement therapy or extracorporeal membrane oxygenation are also discussed. Additionally, we briefly touched on variability between guidelines recommended energy target and measured energy expenditure for adult critically ill patients with obesity.

SUMMARY

While energy requirement in the critically ill continues to be an area of controversy, recent guidelines recommendations shift toward providing less aggressive calories during acute phase of illness in the first week of ICU.Use of indirect calorimetry may provide more accurate energy target compared to the use of predictive equations. Despite the absence of literature to support long term mortality benefits, there are many potential benefits for the use of indirect calorimetry when available.

Survey on Nutrition in Neurological Intensive Care Units (SONNIC)-A Cross-Sectional Survey among German-Speaking Neurointensivists on Medical Nutritional Therapy

Medical nutritional therapy (MNT) in neurointensive care units (NICUs) is both particularly relevant and challenging due to prolonged analgosedation, immobilization, disorders of consciousness, and the high prevalence of dysphagia. Moreover, current guideline recommendations predominantly address the general intensive care unit (ICU) population, overlooking specific characteristics of neurological patients. We, therefore, conducted a web-based, cross-sectional survey for German-speaking neurointensivists mapping the clinical practices of MNT on NICUs to identify research gaps and common grounds for future clinical trials. A total of 25.9% (56/216) NICU representatives responded to our questionnaire. A total of 78.2% (43/55) were neurologist and 63% (34/54) held a leadership role. Overall, 80.4% (41/51) had established a standard operating procedure (SOP), largely based on the DGEM-Guideline (53.7%; 22/41), followed by the ESPEN-Guideline (14.6%; 6/41). Upon admission, 36% (18/50) conducted a risk stratification, with 83.3% primarily relying on past medical history (15/18) and clinical gestalt (15/18). Energy expenditure (EE) was measured or calculated by 75% (36/48), with 72.2% (26/36) using pragmatic weight-based equations. Indirect calorimetry was used by 19.4% (7/36). A total of 83.3% (30/36) used the patient's serum glucose level as the primary biomarker to monitor metabolic tolerance. SOPs regarding ICU-Acquired Weakness (ICUAW) were found in 8.9% (4/45) of respondents. Overall, guideline adherence was 47%. In summary, this is, to the best of our knowledge, the first study systematically describing the currently applied concepts of MNT on NICUs. The data reveal great variations in the implementation of guideline recommendations, indicating the need for further research and tailored approaches to optimize nutritional therapy in neurointensive care settings.

In critically ill adult patients with COVID-19, lower energy and higher protein intake are associated with fewer mechanical ventilation and antibiotic days but not with ICU length of stay

BACKGROUND

Coronavirus disease 2019 (COVID-19) nutrition management guidelines recommend hypocaloric, high-protein feeding in the acute phase of critical illness. This study aimed to determine, among critically ill adults with COVID-19, whether nutrition support affects outcomes in nonobese patients when providing a mean energy intake of ≥20 kcal/kg/day vs <20 kcal/kg/day and protein intake of ≥1.2 g/kg/day vs <1.2 g/kg/day, using actual body weight, and in patients with obesity when providing ≥20 kcal/kg/day vs <20 kcal/kg/day and a protein intake of ≥2 g/kg/day vs <2 g/kg/day using ideal body weight.

METHODS

This retrospective study included adults with COVID-19 on mechanical ventilation (MV) admitted to the intensive care unit (ICU) from 2020 to 2021. Clinical and nutrition parameters were recorded the first 14 days of ICU stay.

RESULTS

One hundred four patients were included: 79 (75.96%) were male and had a median age of 51 years and body mass index of 29.65 kg/m2 . ICU length of stay (LOS) was not affected by nutrition intake, but patients receiving <20 kcal/kg/day had fewer MV days (P = 0.029). In a subgroup analysis, MV days were lower in the nonobese group receiving <20 kcal/kg/day (P = 0.012). In the obese group, those receiving higher protein intake had fewer antibiotic days (P = 0.013).

CONCLUSION

In critically ill patients with COVID-19, lower energy and higher protein intake were respectively associated with fewer MV days and, in patients with obesity, fewer antibiotic days, but they had no effect on ICU LOS.

Implementation of the ESPEN guideline on clinical nutrition in the intensive care unit (ICU): It is time to move forward!: A position paper from the 'nutrition in the ICU' ESPEN special interest group

Nutritional assessment and provision of nutritional therapy are a core part of intensive care unit (ICU) patient treatment. The ESPEN guideline on clinical nutrition in the ICU was published in 2019. However, uncertainty and difficulties remain regarding its full implementation in daily practice. This position paper is intended to help ICU healthcare professionals facilitate the implementation of ESPEN nutrition guidelines to ensure the best care for their patients. We have aimed to emphasize the guideline recommendations that need to be implemented in the ICU, are advised, or are optional, and to give practical directives to improve the guideline recommendations in daily practice. These statements were written by the members of the ICU nutrition ESPEN special interest group (SIG), based on a survey aimed at identifying current practices relating to key issues in ICU nutrition. The ultimate goal is to improve the ICU patients quality of care.

DYNAMIC METABOLIC CHANGES OBSERVED IN AN LPS-INDUCED SYSTEMIC INFLAMMATION RAT MODEL USING CONTINUOUS LONG-TERM INDIRECT CALORIMETRY EXPERIMENTS

ABSTRACT

Background : Nutritional management is crucial for severely ill patients. Measuring metabolism is believed to be necessary for the acute sepsis phase to accurately estimate nutrition. Indirect calorimetry (IDC) is assumed to be useful for acute intensive care; however, there are few studies on long-term IDC measurement in patients with systemic inflammation. Methods : Rats were categorized into the LPS received or control groups; LPS rats were categorized into underfeeding (UF), adjusted feeding (AF), and overfeeding (OF) groups. Indirect calorimetry measurement was performed until 72 or 144 h. Body composition was measured at -24 and 72 or 144 h, and tissue weight was measured at 72 or 144 h. Results : Low energy consumption and loss of diurnal variation of resting energy expenditure were observed in the LPS group compared with the control group until 72 h, after which the LPS group recovered. The resting energy expenditure in the OF group was higher than that in the UF and AF groups. In the first phase, low energy consumption was observed in all groups. In the second and third phases, higher energy consumption occurred in the OF group than in the UF and AF groups. In the third phase, diurnal variation recovered in all groups. Muscle atrophy caused body weight loss, but fat tissue loss did not occur. Conclusions : We observed metabolic changes with IDC during the acute systemic inflammation phase owing to differences in calorie intake. This is the first report of long-term IDC measurement using the LPS-induced systemic inflammation rat model.

Inadequate Energy Delivery Is Frequent among COVID-19 Patients Requiring ECMO Support and Associated with Increased ICU Mortality

BACKGROUND

Patients receiving extracorporeal membrane oxygenation (ECMO) support are at high risk for malnutrition. There are currently no general nutrition guidelines for coronavirus disease 2019 (COVID-19) patients during ECMO therapy.

METHODS

We conducted a retrospective analysis of COVID-19 patients requiring venovenous ECMO support at a large tertiary hospital center. Nutrition goals were calculated using 25 kcal/kg body weight (BW)/day. Associations between nutrition support and outcome were evaluated using Kaplan-Meier and multivariable Cox regression analyses.

RESULTS

Overall, 102 patients accounted for a total of 2344 nutrition support days during ECMO therapy. On 40.6% of these days, nutrition goals were met. Undernutrition was found in 40.8%. Mean daily calorie delivery was 73.7% of calculated requirements, mean daily protein delivery was 0.7 g/kg BW/d. Mean energy intake of ≥70% of calculated targets was associated with significantly lower ICU mortality independently of age, disease severity at ECMO start and body mass index (adjusted hazard ratio: 0.372, p = 0.007).

CONCLUSIONS

Patients with a mean energy delivery of ≥70% of calculated targets during ECMO therapy had a better ICU survival compared to patients with unmet energy goals. These results indicate that adequate nutritional support needs to be a major priority in the treatment of COVID-19 patients requiring ECMO support.

Current insights in ICU nutrition: tailored nutrition

PURPOSE OF REVIEW

To summarize recent research on critical care nutrition focusing on the optimal composition, timing, and monitoring of enteral feeding strategies for (post)-ICU patients. We provide new insights on energy and protein recommendations, feeding intolerance, and describe nutritional practices for coronavirus disease 2019 ICU patients.

RECENT FINDINGS

The use of indirect calorimetry to establish individual energy requirements for ICU patients is considered the gold standard. The limited research on optimal feeding targets in the early phase of critical illness suggests avoiding overfeeding. Protein provision based upon the absolute lean body mass is rational. Therefore, body composition measurements should be considered. Body impedance analysis and muscle ultrasound seem reliable, affordable, and accessible methods to assess body composition at the bedside. There is inadequate evidence to change our practice of continuous enteral feeding into intermittent feeding. Finally, severe acute respiratory syndrome coronavirus 2 patients are prone to underfeeding due to hypermetabolism and should be closely monitored.

SUMMARY

Nutritional therapy should be adapted to the patient's characteristics, diagnosis, and state of metabolism during ICU stay and convalescence. A personalized nutrition plan may prevent harmful over- or underfeeding and attenuate muscle loss. Despite novel insights, more research is warranted into tailored nutrition strategies during critical illness and convalescence.

The epigenetic legacy of ICU feeding and its consequences

PURPOSE OF REVIEW

Many critically ill patients face physical, mental or neurocognitive impairments up to years later, the etiology remaining largely unexplained. Aberrant epigenetic changes have been linked to abnormal development and diseases resulting from adverse environmental exposures like major stress or inadequate nutrition. Theoretically, severe stress and artificial nutritional management of critical illness thus could induce epigenetic changes explaining long-term problems. We review supporting evidence.

RECENT FINDINGS

Epigenetic abnormalities are found in various critical illness types, affecting DNA-methylation, histone-modification and noncoding RNAs. They at least partly arise de novo after ICU-admission. Many affect genes with functions relevant for and several associate with long-term impairments. As such, de novo DNA-methylation changes in critically ill children statistically explained part of their disturbed long-term physical/neurocognitive development. These methylation changes were in part evoked by early-parenteral-nutrition (early-PN) and statistically explained harm by early-PN on long-term neurocognitive development. Finally, long-term epigenetic abnormalities beyond hospital-discharge have been identified, affecting pathways highly relevant for long-term outcomes.

SUMMARY

Epigenetic abnormalities induced by critical illness or its nutritional management provide a plausible molecular basis for their adverse effects on long-term outcomes. Identifying treatments to further attenuate these abnormalities opens perspectives to reduce the debilitating legacy of critical illness.

Energy Guidance Using Indirect Calorimetry for Intestinal Failure Patients with Home Parenteral Nutrition: The Right Bag Right at the Start

Intestinal failure is defined as the inability to absorb the minimum of macro and micronutrients, minerals and vitamins due to a reduction in gut function. In a subpopulation of patients with a dysfunctional gastrointestinal system, treatment with total or supplemental parenteral nutrition is required. The golden standard for the determination of energy expenditure is indirect calorimetry. This method enables an individualized nutritional treatment based on measurements instead of equations or body weight calculations. The possible use and advantages of this technology in a home PN setting need critical evaluation. For this narrative review, a bibliographic search is performed in PubMed and Web of Science using the following terms: 'indirect calorimetry', 'home parenteral nutrition', 'intestinal failure', 'parenteral nutrition', 'resting energy expenditure', 'energy expenditure' and 'science implementation'. The use of IC is widely embedded in the hospital setting but more research is necessary to investigate the role of IC in a home setting and especially in IF patients. It is important that scientific output is generated in order to improve patients' outcome and develop nutritional care paths.

Nutrition after severe burn injury

PURPOSE OF REVIEW

Severe burn injury causes significant metabolic changes and demands that make nutritional support particularly important. Feeding the severe burn patient is a real challenge in regard to the specific needs and the clinical constraints. This review aims to challenge the existing recommendations in the light of the few recently published data on nutritional support in burn patients.

RECENT FINDINGS

Some key macro- and micro-nutrients have been recently studied in severe burn patients. Repletion, complementation or supplementation of omega-3 fatty acids, vitamin C, vitamin D, antioxidant micronutrients may be promising from a physiologic perspective, but evidence of benefits on hard outcomes is still weak due to the studies' design. On the contrary, the anticipated positive effects of glutamine on the time to discharge, mortality and bacteremias have been disproved in the largest randomized controlled trial investigating glutamine supplementation in burns. An individualized approach in term of nutrients quantity and quality may proof highly valuable and needs to be validated in adequate trials. The combination of nutrition and physical exercises is another studied strategy that could improve muscle outcomes.

SUMMARY

Due to the low number of clinical trials focused on severe burn injury, most often including limited number of patients, developing new evidence-based guidelines is challenging. More high-quality trials are needed to improve the existing recommendations in the very next future.

Potential benefits of using an energy-dense, high-protein formula enriched with β-hydroxy-β-methylbutyrate, fructo-oligosaccharide, and vitamin D for enteral feeding in the ICU: A pilot case-control study in COVID-19 patients

OBJECTIVES

The aim of this study was to investigate the potential benefits of using an energy-dense, high-protein (HP) formula enriched with β-hydroxy-β-methylbutyrate (HMB), fructo-oligosaccharide (FOS), and vitamin D (VitD) for enteral feeding in the intensive care unit (ICU).

METHODS

This was a nested case-control multicenter study. Mechanically ventilated patients with COVID-19 in whom enteral nutrition was not contraindicated and receiving an energy-dense, HP-HMB-FOS-VitD formula (1.5 kcal/mL; 21.5% of calories from protein; n = 53) were matched (1:1) by age (±1 y), sex, body mass index (±1 kg/m²) and Sequential Organ Failure Assessment score (±1 point) and compared with patients fed with a standard HP, fiber-free formula (1.25-1.3 kcal/mL; 20% of calories from protein; n = 53). The primary end point was daily protein intake (g/kg) on day 4. Protein-calorie intake on day 7, gastrointestinal intolerance, and clinical outcomes were addressed as secondary end points.

RESULTS

The use of a HP-HMB-FOS-VitD formula resulted in higher protein intake on days 4 and 7 (P = 0.006 and P = 0.013, respectively), with similar energy intake but higher provision of calories from enteral nutrition at both times (P <0 .001 and P = 0.017, respectively). Gastrointestinal tolerance was superior, with fewer patients fed with a HP-HMB-FOS-VitD formula reporting at least one symptom of intolerance (55 versus 74%; odds ratio [OR], 0.43; 95% confidence interval [CI], 0.18-0.99; P = 0.046) and constipation (38 versus 66%; OR, 0.27; 95% CI, 0.12-0.61; P = 0.002). A lower rate of ICU-acquired infections was also observed (42 versus 72%; OR, 0.29; 95% CI, 0.13-0.65; P = 0.003), although no difference was found in mortality, ICU length of stay, and ventilation-free survival.

CONCLUSIONS

An energy-dense, HP-HMB-FOS-VitD formula provided a more satisfactory protein intake and a higher provision of caloric intake from enteral nutrition than a standard HP formula in mechanically ventilated patients with COVID-19. Lower rates of gastrointestinal intolerance and ICU-acquired infections were also observed.

Toward nutrition improving outcome of critically ill patients: How to interpret recent feeding RCTs?

Although numerous observational studies associated underfeeding with poor outcome, recent randomized controlled trials (RCTs) have shown that early full nutritional support does not benefit critically ill patients and may induce dose-dependent harm. Some researchers have suggested that the absence of benefit in RCTs may be attributed to overrepresentation of patients deemed at low nutritional risk, or to a too low amino acid versus non-protein energy dose in the nutritional formula. However, these hypotheses have not been confirmed by strong evidence. RCTs have not revealed any subgroup benefiting from early full nutritional support, nor benefit from increased amino acid doses or from indirect calorimetry-based energy dosing targeted at 100% of energy expenditure. Mechanistic studies attributed the absence of benefit of early feeding to anabolic resistance and futile catabolism of extra provided amino acids, and to feeding-induced suppression of recovery-enhancing pathways such as autophagy and ketogenesis, which opened perspectives for fasting-mimicking diets and ketone supplementation. Yet, the presence or absence of an anabolic response to feeding cannot be predicted or monitored and likely differs over time and among patients. In the absence of such monitor, the value of indirect calorimetry seems obscure, especially in the acute phase of illness. Until now, large feeding RCTs have focused on interventions that were initiated in the first week of critical illness. There are no large RCTs that investigated the impact of different feeding strategies initiated after the acute phase and continued after discharge from the intensive care unit in patients recovering from critical illness.

Early caloric deficit is associated with a higher risk of death in invasive ventilated COVID-19 patients

BACKGROUND & AIMS

The aim of this study was to evaluate the nutritional support management in mechanically ventilated coronavirus disease 2019 (COVID-19) patients and explore the association between early caloric deficit and mortality, taking possible confounders (i.e. obesity) into consideration.

METHODS

This was a prospective study carried out during the first pandemic wave in the intensive care units (ICUs) of two referral University Hospitals in Lombardy, Italy. Two hundred twenty-two consecutive mechanically ventilated COVID-19 patients were evaluated during the ICU stay. In addition to major demographic and clinical data, we recorded information on the route and amount of nutritional support provided on a daily basis.

RESULTS

Among patients still in the ICUs and alive on day 4 (N = 198), 129 (65.2%) and 72 (36.4%) reached a satisfactory caloric and protein intake, respectively, mainly by enteral route. In multivariable analysis, a satisfactory caloric intake on day 4 was associated with lower mortality (HR = 0.46 [95%CI, 0.42-0.50], P < 0.001). Mild obesity (body mass index [BMI] ≥30 and < 35 kg/m²) was associated with higher mortality (HR = 1.99 [95%CI, 1.07-3.68], P = 0.029), while patients with moderate-severe obesity (BMI≥35 kg/m²) were less likely to be weaned from invasive mechanical ventilation (HR = 0.71 [95%CI, 0.62-0.82], P < 0.001).

CONCLUSIONS

This study confirmed the negative prognostic and clinical role of obesity in mechanically ventilated COVID-19 patients and suggested that early caloric deficit may independently contribute to worsen survival in this patients' population. Therefore, any effort should be made to implement an adequate timely nutritional support in all COVID-19 patients during the ICU stay.

Clinical nutrition issues in 2022: What is missing to trust supplemental parenteral nutrition (SPN) in ICU patients?

A multidisciplinary group of international physicians involved in the medical nutrition therapy (MNT) of adult critically ill patients met to discuss the value, role, and open questions regarding supplemental parenteral nutrition (SPN) along with oral or enteral nutrition (EN), particularly in the intensive care unit (ICU) setting. This manuscript summarizes the discussions and results to highlight the importance of SPN as part of a comprehensive approach to MNT in critically ill adults and for researchers to generate new evidence based on well-powered randomized controlled trials (RCTs). The experts agreed on several key points: SPN has shown clinical benefits, resulting in this strategy being included in American and European guidelines. Nevertheless, its use is heterogeneous across European countries, due to the persistence of uncertainties, such as the optimal timing and the risk of overfeeding in absence of indirect calorimetry (IC), which results in divergent opinions and barriers to SPN implementation. Education is also insufficient. The experts agreed on actions needed to increase evidence quality on SPN use in specific patients at a given time point during acute critical illness or recovery.

Do we need different predictive equations for the acute and late phases of critical illness? A prospective observational study with repeated indirect calorimetry measurements

BACKGROUND

Predictive equations (PEs) for estimating resting energy expenditure (REE) that have been developed from acute phase data may not be applicable in the late phase and vice versa. This study aimed to assess whether separate PEs are needed for acute and late phases of critical illness and to develop and validate PE(s) based on the results of this assessment.

METHODS

Using indirect calorimetry, REE was measured at acute (≤5 days; n = 294) and late (≥6 days; n = 180) phases of intensive care unit admission. PEs were developed by multiple linear regression. A multi-fold cross-validation approach was used to validate the PEs. The best PEs were selected based on the highest coefficient of determination (R²), the lowest root mean square error (RMSE) and the lowest standard error of estimate (SEE). Two PEs developed from paired 168-patient data were compared with measured REE using mean absolute percentage difference.

RESULTS

Mean absolute percentage difference between predicted and measured REE was <20%, which is not clinically significant. Thus, a single PE was developed and validated from data of the larger sample size measured in the acute phase. The best PE for REE (kcal/day) was 891.6(Height) + 9.0(Weight) + 39.7(Minute Ventilation)-5.6(Age) - 354, with R² = 0.442, RMSE = 348.3, SEE = 325.6 and mean absolute percentage difference with measured REE was: 15.1 ± 14.2% [acute], 15.0 ± 13.1% [late].

CONCLUSIONS

Separate PEs for acute and late phases may not be necessary. Thus, we have developed and validated a PE from acute phase data and demonstrated that it can provide optimal estimates of REE for patients in both acute and late phases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03319329.

A guide to enteral nutrition in intensive care units: 10 expert tips for the daily practice

The preferential use of the oral/enteral route in critically ill patients over gut rest is uniformly recommended and applied. This article provides practical guidance on enteral nutrition in compliance with recent American and European guidelines. Low-dose enteral nutrition can be safely started within 48 h after admission, even during treatment with small or moderate doses of vasopressor agents. A percutaneous access should be used when enteral nutrition is anticipated for ≥ 4 weeks. Energy delivery should not be calculated to match energy expenditure before day 4–7, and the use of energy-dense formulas can be restricted to cases of inability to tolerate full-volume isocaloric enteral nutrition or to patients who require fluid restriction. Low-dose protein (max 0.8 g/kg/day) can be provided during the early phase of critical illness, while a protein target of > 1.2 g/kg/day could be considered during the rehabilitation phase. The occurrence of refeeding syndrome should be assessed by daily measurement of plasma phosphate, and a phosphate drop of 30% should be managed by reduction of enteral feeding rate and high-dose thiamine. Vomiting and increased gastric residual volume may indicate gastric intolerance, while sudden abdominal pain, distension, gastrointestinal paralysis, or rising abdominal pressure may indicate lower gastrointestinal intolerance.

Safety and efficacy of therapeutic endoscopic retrograde cholangiopancreatography for patients over 90 years of age

AIMS

This study aimed to explore the safety and efficacy of endoscopic retrograde cholangiopancreatography (ERCP) in patients over 90 years of age.

METHODS

The study included 176 patients aged over 85 years who received their ERCP from February 2002 to January 2021. In the case group (super-elderly group), 44 patients were 90 years old or above. In the control group (younger group), there were 132 patients aged 85-89 years. The control group was matched according to patient gender and the same indications of ERCP at a 1:3 ratio. Logistic regression models were employed to evaluate all complications.

RESULTS

The case group had higher acute physiology and chronic health evaluation scoring system (APACHE-II) scores and rate of hypoalbuminemia. APACHE-II scores (≥6 or 7) were significantly more common in the case group. The rates of technical success and complete success in the case group were 100% and 100% respectively, which were similar to the rates in the control group, namely a technical success rate of 98.5% and a complete success rate of 98.5%. The rate of complication in the case group was 9.1%, which was slightly lower than that of the control group (15.2%, P > 0.05). ERCP-related death occurred in one patient in the control group, who had malignant biliary obstruction and died from cholangitis. There was no significant difference in the incidence of complications such as pancreatitis, hemorrhage, and infection between the two groups. In the multivariate analysis, the independent risk factor was Charlson Comorbidity Index (CCI) for overall complication.

CONCLUSIONS

ERCP can be performed safely and successfully in patients aged ≥90 years. Geriatr Gerontol Int 2021; ••: ••-••.

Immediate vs. gradual advancement to goal of enteral nutrition after elective abdominal surgery: A multicenter non-inferiority randomized trial

BACKGROUND & AIMS

The strategy of increasing the postoperative enteral nutrition dose to the target goal has not yet been clarified. This study aimed to determine whether an immediate goal-dose enteral nutrition (IGEN) strategy is non-inferior to a gradual goal-dose enteral nutrition (GGEN) strategy in reducing infections in patients undergoing abdominal surgery involving the organs of the digestive system.

METHODS

This randomized controlled trial enrolled postoperative patients with nutritional risk screening 2002 scores ≥3 from 11 Chinese hospitals. Energy targets were calculated as 25 kcal/kg and 30 kcal/kg of ideal body weight for women and men, respectively. Patients were randomly assigned 1:1 to IGEN or GGEN group after enteral tolerance was confirmed (30% of the target on day 2). The IGEN group immediately started receiving 100% of the caloric requirements on day 3, while the GGEN group received 40% progressing to 80% of target on day 7. The primary endpoint was the infection rate until discharge, based on the intention-to-treat population.

RESULTS

A total of 411 patients were enrolled and randomized to the IGEN and GGEN groups, and five patients did not receive the allocated intervention. A total of 406 patients were included in the primary analysis, with 199 and 207 in the IGEN and GGEN groups, respectively. Infection was observed in 17/199 (8.5%) in the IGEN group and 19/207 (9.2%) in the GGEN group, respectively (difference, -0.6%; [95% confidence interval (CI), -6.2%-4.9%]; P = 0.009 for non-inferiority test). There were significantly more gastrointestinal intolerance events with IGEN than with GGEN (58/199 [29.1%] vs. 32/207 [15.5%], P < 0.001). All other secondary endpoints were non-significant.

CONCLUSIONS

Among postoperative patients at nutritional risk, IGEN was non-inferior to GGEN in regards to infectious complications. IGEN was associated with more gastrointestinal intolerance events. It showed that IGEN cannot be considered to be clinically directive. ClinicalTrials.gov (#NCT03117348).

Albumin-Globulin Ratio Is an Independent Determinant of 28-Day Mortality in Patients with Critical Illness

Background

Critical illness in the intensive care unit (ICU) has been a global health priority. Systemic nutritional status has turned out to be related to the prognosis of critically ill patients. The albumin-globulin ratio (AGR) has been reported to be a novel prognostic factor of many diseases. This study is aimed at investigating whether the AGR could predict the mortality risk in critically ill patients.

Methods

We enrolled 582 adult patients admitted to the respiratory intensive care unit (RICU). We collected the clinical and laboratory data. X-tile software was used to determine the optimal cut-off values for the AGR. Patients were divided into three groups according to the AGR (low AGR group with AGR < 0.8, medium AGR group with AGR ranging from 0.8 to 1.1, and high AGR group with AGR > 1.1). Kaplan-Meier analysis was used for survival analysis. A Cox proportional hazard model was applied to the univariate and multivariate analyses for the potential predictors associated with survival.

Results

Our present study showed that the AGR was related to the 28-day survival of critically ill patients in the RICU. The rate of pneumonia in the low AGR group was significantly higher than that in the other groups. Patients with a lower AGR present an increased risk of 28-day mortality compared to patients with a higher AGR. Cox regression analysis showed that the AGR might be an independent predictor of prognosis to 28-day survival in critically ill patients in the RICU. Medium and high AGR values remained independently associated with better 28-day survival than low AGR values (HR: 0.484 (0.263-0.892) (p = 0.02); HR: 0.332 (0.166-0.665) (p = 0.002)).

Conclusion

The AGR might be an independent predictor of prognosis in critically ill patients.

The effect of indirect calorimetry guided isocaloric nutrition on mortality in critically ill patients-a systematic review and meta-analysis

Indirect calorimetry (IC)-guided nutrition might positively affect the clinical outcome of critically ill patients. In this systematic review and meta-analysis, our objective was to assess the benefit of isocaloric nutrition guided by IC, compared to hypocaloric nutrition, for critically ill patients admitted to the intensive care unit (ICU). We performed a systematic review of all randomized controlled trials published through January 2021, assessing the benefit of isocaloric nutrition guided by IC. The primary outcome was 28-day all-cause mortality. Secondary outcomes were ICU and 90-day all-cause mortality, rate of nosocomial infections, and adverse events. Four trials evaluating 1052 patients were included. Patients treated with isocaloric nutrition had a lower 28-day mortality rate (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.63-0.99, P = 0.04). No between-group difference was found in ICU and 90-day mortality (RR 0.92, 95% CI 0.68-1.23, P = 0.56 and RR 0.88, 95% CI 0.72-1.07; P = 0.2, respectively) and in the rate of nosocomial infections (RR 1.15, 95% CI 0.77-1.72, P = 0.51). A pooled analysis of studies that evaluated the benefit of isocaloric nutrition guided by IC, for critically ill patients in the ICU, has shown reduced 28-day mortality. However, there was no difference in 90-day mortality and nosocomial infection rate.

Point-Counterpoint: Indirect Calorimetry Is not Necessary for Optimal Nutrition Therapy in Critical Illness

Clinicians have widely recognized that indirect calorimetry (IC) is the "gold standard" for measuring energy expenditure (EE) and thus would intuitively anticipate that its use would be needed to provide optimal nutrition support in critical illness. Recent studies in the literature as well as dramatic changes in clinical practice over the past decade, though, would suggest that such a precise measure by IC to set energy goals is not required to maximize clinical benefit from early feeding in the intensive care unit (ICU). Results from randomized controlled trials evaluating permissive underfeeding, use of supplemental parenteral nutrition to achieve tight calorie control, and caloric density of formulas to increase energy delivery have provided an important perspective on 3 pertinent issues. First, a simple weight-based predictive equation (25 kcal/kg/day) provides a clinically useful approximation of EE. Second, a precise measure of EE by IC does not appear to improve outcomes compared with use of this less accurate estimation of energy requirements. And third, providing some percentage of requirements (50%-80%), achieves similar clinical benefit to full feeding (100%) in the early phases of critical illness. The value from IC use lies in the determination of caloric requirements in conditions for which weight-based equations are rendered inaccurate (anasarca, amputation, severe obesity) or the clinical state is markedly altered (such as the prolonged hyperinflammatory state of coronavirus disease 2019 [COVID-19]). In most other circumstances, routine use of IC would not be expected to change clinical outcomes from early nutrition therapy in the ICU.

Energy delivery guided by indirect calorimetry in critically ill patients: a systematic review and meta-analysis

BACKGROUND

The use of indirect calorimetry (IC) is increasing due to its precision in resting energy expenditure (REE) measurement in critically ill patients. Thus, we aimed to evaluate the clinical outcomes of an IC-guided nutrition therapy compared to predictive equations strategy in such a patient population.

METHODS

We searched PubMed, EMBASE, and Cochrane library databases up to October 25, 2020. Randomized controlled trials (RCTs) were included if they focused on energy delivery guided by either IC or predictive equations in critically ill adults. We used the Cochrane risk-of-bias tool to assess the quality of the included studies. Short-term mortality was the primary outcome. The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.

RESULTS

Eight RCTs with 991 adults met the inclusion criteria. The overall quality of the included studies was moderate. Significantly higher mean energy delivered per day was observed in the IC group, as well as percent delivered energy over REE targets, than the control group. IC-guided energy delivery significantly reduced short-term mortality compared with the control group (risk ratio = 0.77; 95% CI 0.60 to 0.98; I² = 3%, P = 0.03). IC-guided strategy did not significantly prolong the duration of mechanical ventilation (mean difference [MD] = 0.61 days; 95% CI - 1.08 to 2.29; P = 0.48), length of stay in ICU (MD = 0.32 days; 95% CI - 2.51 to 3.16; P = 0.82) and hospital (MD = 0.30 days; 95% CI - 3.23 to 3.83; P = 0.87). Additionally, adverse events were similar between the two groups.

CONCLUSIONS

This meta-analysis indicates that IC-guided energy delivery significantly reduces short-term mortality in critically ill patients. This finding encourages the use of IC-guided energy delivery during critical nutrition support. But more high-quality studies are still needed to confirm these findings.

Energy expenditure and indirect calorimetry in critical illness and convalescence: current evidence and practical considerations

The use of indirect calorimetry is strongly recommended to guide nutrition therapy in critically ill patients, preventing the detrimental effects of under- and overfeeding. However, the course of energy expenditure is complex, and clinical studies on indirect calorimetry during critical illness and convalescence are scarce. Energy expenditure is influenced by many individual and iatrogenic factors and different metabolic phases of critical illness and convalescence. In the first days, energy production from endogenous sources appears to be increased due to a catabolic state and is likely near-sufficient to meet energy requirements. Full nutrition support in this phase may lead to overfeeding as exogenous nutrition cannot abolish this endogenous energy production, and mitochondria are unable to process the excess substrate. However, energy expenditure is reported to increase hereafter and is still shown to be elevated 3 weeks after ICU admission, when endogenous energy production is reduced, and exogenous nutrition support is indispensable. Indirect calorimetry is the gold standard for bedside calculation of energy expenditure. However, the superiority of IC-guided nutritional therapy has not yet been unequivocally proven in clinical trials and many practical aspects and pitfalls should be taken into account when measuring energy expenditure in critically ill patients. Furthermore, the contribution of endogenously produced energy cannot be measured. Nevertheless, routine use of indirect calorimetry to aid personalized nutrition has strong potential to improve nutritional status and consequently, the long-term outcome of critically ill patients.

How Differences in the Disease Process of the COVID-19 Pandemic Pose Challenges to the Delivery of Critical Care Nutrition

PURPOSE OF REVIEW

The COVID-19 pandemic is a unique disease process that has caused unprecedented challenges for intensive care specialists. The hyperinflammatory hypermetabolic nature of the disease and the complexity of its management create barriers to the delivery of nutritional therapy. This review identifies the key differences which characterize this pandemic from other disease processes in critical illness and discusses alternative strategies to enhance success of nutritional support.

RECENT FINDINGS

Prolonged hyperinflammation, unlike any previously described pattern of response to injury, causes metabolic perturbations and deterioration of nutritional status. High ventilatory demands, hypercoagulation with the risk of bowel ischemia, and threat of aspiration in patients with little or no pulmonary reserve, thwart initial efforts to provide early enteral nutrition (EN). The obesity paradox is invalidated, tolerance of EN is limited, intensivists are reluctant to add supplemental parenteral nutrition (PN), and efforts to give sufficient nutritional therapy remain a low priority. The nature of the disease and difficulties providing traditional critical care nutrition lead to dramatic deterioration of nutritional status. Institutions should not rely on insufficient gastric feeding alone but focus instead on redoubling efforts to provide postpyloric deep duodenal/jejunal EN or re-examine the role of supplemental PN in this population of patients with such severe critical illness.

Full Versus Trophic Feeds in Critically Ill Adults with High and Low Nutritional Risk Scores: A Randomized Controlled Trial

Although energy intake might be associated with clinical outcomes in critically ill patients, it remains unclear whether full or trophic feeding is suitable for critically ill patients with high or low nutrition risk. We conducted a prospective study to determine which feeding energy intakes were associated with clinical outcomes in critically ill patients with high or low nutrition risk. This was an investigator-initiated, single center, single blind, randomized controlled trial. Critically ill patients were allocated to either high or low nutrition risk based on their Nutrition Risk in the Critically Ill score, and then randomized to receive either the full or the trophic feeding. The feeding procedure was administered for six days. No significant differences were observed in hospital, 14-day and 28-day mortalities, the length of ventilator dependency, or ICU and hospital stay among the four groups. There were no associations between energy and protein intakes and hospital, 14-day and 28-day mortalities in any of the four groups. However, protein intake was positively associated with the length of hospital stay and ventilator dependency in patients with low nutrition risk receiving trophic feeding. Full or trophic feeding in critically ill patients showed no associations with clinical outcomes, regardless of nutrition risk.