Nutrition delivery across hospitalisation in critically ill patients with COVID-19: An observational study of the Australian experience

BACKGROUND

Data on nutrition delivery over the whole hospital admission in critically ill patients with COVID-19 are scarce, particularly in the Australian setting.

OBJECTIVES

The objective of this study was to describe nutrition delivery in critically ill patients admitted to Australian intensive care units (ICUs) with coronavirus disease 2019 (COVID-19), with a focus on post-ICU nutrition practices.

METHODS

A multicentre observational study conducted at nine sites included adult patients with a positive COVID-19 diagnosis admitted to the ICU for >24 h and discharged to an acute ward over a 12-month recruitment period from 1 March 2020. Data were extracted on baseline characteristics and clinical outcomes. Nutrition practice data from the ICU and weekly in the post-ICU ward (up to week four) included route of feeding, presence of nutrition-impacting symptoms, and nutrition support received.

RESULTS

A total of 103 patients were included (71% male, age: 58 ± 14 years, body mass index: 30±7 kg/m2), of whom 41.7% (n = 43) received mechanical ventilation within 14 days of ICU admission. While oral nutrition was received by more patients at any time point in the ICU (n = 93, 91.2% of patients) than enteral nutrition (EN) (n = 43, 42.2%) or parenteral nutrition (PN) (n = 2, 2.0%), EN was delivered for a greater duration of time (69.6% feeding days) than oral and PN (29.7% and 0.7%, respectively). More patients received oral intake than the other modes in the post-ICU ward (n = 95, 95.0%), and 40.0% (n = 38/95) of patients were receiving oral nutrition supplements. In the week after ICU discharge, 51.0% of patients (n = 51) had at least one nutrition-impacting symptom, most commonly a reduced appetite (n = 25; 24.5%) or dysphagia (n = 16; 15.7%).

CONCLUSION

Critically ill patients during the COVID-19 pandemic in Australia were more likely to receive oral nutrition than artificial nutrition support at any time point both in the ICU and in the post-ICU ward, whereas EN was provided for a greater duration when it was prescribed. Nutrition-impacting symptoms were common.

High protein provision of more than 1.2 g/kg improves muscle mass preservation and mortality in ICU patients: A systematic review and meta-analyses

BACKGROUND

ICU patients lose muscle mass rapidly and maintenance of muscle mass may contribute to improved survival rates and quality of life. Protein provision may be beneficial for preservation of muscle mass and other clinical outcomes, including survival. Current protein recommendations are expert-based and range from 1.2 to 2.0 g/kg. Thus, we performed a systematic review and meta-analysis on protein provision and all clinically relevant outcomes recorded in the available literature.

METHODS

We conducted a systematic review and meta-analyses, including studies of all designs except case control and case studies, with patients aged ≥18 years with an ICU stay of ≥2 days and a mean protein provision group of ≥1.2 g/kg as compared to <1.2 g/kg with a difference of ≥0.2 g/kg between protein provision groups. All clinically relevant outcomes were studied. Meta-analyses were performed for all clinically relevant outcomes that were recorded in ≥3 included studies.

RESULTS

A total of 29 studies published between 2012 and 2022 were included. Outcomes reported in the included studies were ICU, hospital, 28-day, 30-day, 42-day, 60-day, 90-day and 6-month mortality, ICU and hospital length of stay, duration of mechanical ventilation, vomiting, diarrhea, gastric residual volume, pneumonia, overall infections, nitrogen balance, changes in muscle mass, destination at hospital discharge, physical performance and psychological status. Meta-analyses showed differences between groups in favour of high protein provision for 60-day mortality, nitrogen balance and changes in muscle mass.

CONCLUSION

High protein provision of more than 1.2 g/kg in critically ill patients seemed to improve nitrogen balance and changes in muscle mass on the short-term and likely 60-day mortality. Data on long-term effects on quality of life are urgently needed.

Safety of increasing protein delivery with an enteral nutrition formula containing very high protein (VHP) and lower carbohydrate concentrations compared to conventional standard (SF) and high protein (HP) formulas

BACKGROUND & AIMS

Studies demonstrate that caloric restriction in the first seven days in the ICU is safe. The amount of protein that should be delivered, however, is still unclear with clinical trials suggesting mixed results. Despite some capacity to customize the delivery of protein using supplemental modules, protein delivered is best determined by the concentration of protein contained in enteral formula (EF) ordered. This fact provides an opportunity to explore the potential clinical effects of protein delivery and lower carbohydrate intake on clinical outcomes compared with conventional enteral formulas.

METHODS

Retrospective analysis of clinical outcomes according to the amount of protein delivered in critically ill patients admitted to intensive care units at Geisinger Health System.

RESULTS

2000 encounters (1899 patients) in patients on enteral nutrition were divided into three groups receiving EF with either ≤20% protein (standard formula - SF), 21-25% protein (high protein - HP) or > 25% protein (VHP). Protein intake increased up to day 7 (p < 0.0001). Patients on VHP received more protein than other groups (p < 0.0001). Multivariable regression analysis showed no evidence of harm. In fact, we observed increased mortality with SF and HP formulas at 30-days post-discharge when compared to patients on VHP even when the effects of other variables (including age, BMI, sex, primary diagnosis, diabetes, history of dialysis, ICU days kept NPO) were taken into consideration.

CONCLUSIONS

Increasing protein intake while reducing carbohydrate intake appears to be safe. Further research aimed at defining a causative effect of increasing protein delivery while reducing carbohydrate load on outcomes is warranted.

Hypercatabolism and Anti-catabolic Therapies in the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome

Owing to the development of intensive care units, many patients survive their initial insults but progress to chronic critical illness (CCI). Patients with CCI are characterized by prolonged hospitalization, poor outcomes, and significant long-term mortality. Some of these patients get into a state of persistent low-grade inflammation, suppressed immunity, and ongoing catabolism, which was defined as persistent inflammation, immunosuppression, and catabolism syndrome (PICS) in 2012. Over the past few years, some progress has been made in the treatment of PICS. However, most of the existing studies are about the role of persistent inflammation and suppressed immunity in PICS. As one of the hallmarks of PICS, hypercatabolism has received little research attention. In this review, we explore the potential pathophysiological changes and molecular mechanisms of hypercatabolism and its role in PICS. In addition, we summarize current therapies for improving the hypercatabolic status and recommendations for patients with PICS.

Unraveling the Metabolic Hallmarks for the Optimization of Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients

The daily amount and quality of protein that should be administered by enteral nutrition in pre-dialysis chronic kidney disease (CKD) patients is a widely studied but still controversial issue. This is due to a compromise between the protein necessary to maintain muscular proteostasis avoiding sarcopenia, and the minimal amount required to prevent uremia and the accumulation of nitrogenous toxic substances in blood because of the renal function limitations. This review underlines some intracellular and extracellular features that should be considered to reconcile those two opposite factors. On one hand, the physiological conditions and usual side effects associated with CKD, mTOR and other proteins and nutrients involved in the regulation of protein synthesis in the muscular tissue are discussed. On the other hand, the main digestive features of the most common proteins used for enteral nutrition formulation (i.e., whey, casein and soy protein) are highlighted, due to the importance of supplying key amino acids to serum and tissues to maintain their concentration above the anabolic threshold needed for active protein synthesis, thereby minimizing the catabolic pathways leading to urea formation.

Colorectal Surgery in Critically Unwell Patients: A Multidisciplinary Approach

A proportion of patients require critical care support following elective or urgent colorectal procedures. Similarly, critically ill patients in intensive care units may also need colorectal surgery on occasions. This patient population is increasing in some jurisdictions given an aging population and increasing societal expectations. As such, this population often includes elderly, frail patients or patients with significant comorbidities. Careful stratification of operative risks including the need for prolonged intensive care support should be part of the consenting process. In high-risk patients, especially in setting of unplanned surgery, treatment goals should be clearly defined, and appropriate ceiling of care should be established to minimize care that is not in the best interest of the patient. In this article we describe approaches to critically unwell patients requiring colorectal surgery and how a multidisciplinary approach with proactive intensive care involvement can help achieve the best outcomes for these patients.

Current status of perioperative nutritional intervention and exercise in gastric cancer surgery: A review

Patients with gastric cancer are often malnourished or sarcopenic during tumor progression. Perioperative malnutrition, including sarcopenia, is strongly related to postoperative complications and long‐term outcomes. To improve outcomes, nutritional intervention is common for patients with gastric cancer, especially for those undergoing elective surgery. Several clinical trials evaluating perioperative nutritional intervention have set postoperative loss of body weight and lean body mass as endpoints; however, the results were inconsistent. Therefore, recently, perioperative multimodal interventions that are expected to have a synergistic effect between nutritional intervention and exercise have gained attention. Furthermore, supplementing with leucine, a branched‐chain amino acid, in addition to exercise, may be promising for preventing perioperative sarcopenia. However, whether perioperative nutritional intervention and exercise has clinical benefits in gastric surgery is unclear. With the aging of gastric cancer patients, measures to address sarcopenia will become more important in the future. Understanding the significance of nutritional intervention and exercise in patients undergoing gastric cancer surgery will help achieve good outcomes.

The purpose of this review was to summarize the current evidence for perioperative nutritional intervention and exercise for gastrectomy. The particular focus is on measures of preventing sarcopenia perioperatively.

Protein prescription and delivery practices in critically ill adults: A survey of Australian and New Zealand intensive care dietitians

BACKGROUND

Protein provision is thought to be integral to attenuating muscle wasting in critical illness, yet patients receive half of that prescribed. As international guidelines lack definitive evidence to support recommendations, understanding clinicians' views relating to protein practices is of importance.

OBJECTIVES

The objective of this study was to describe Australia and New Zealand intensive care unit (ICU) dietitians' protein prescription and perceived delivery practices in critically ill adults, including common barriers and associations between ICU clinical experience and protein prescriptions for different clinical conditions.

METHODS

A 42-item descriptive quantitative survey of Australian and New Zealand intensive care dietitians was disseminated through nutrition and ICU society e-mailing lists. Data were collected on respondent demographics and reported protein practices including questions related to a multitrauma case study. Data were analysed using descriptive and content analysis and reported as n (%). Fisher's exact tests were used to compare experience and protein prescriptions.

RESULTS

Of the 67 responses received (one excluded due to >50% missing data), more than 80% of respondents stated they would prescribe 1.2-1.5 g protein/kg bodyweight/day for most critically ill patients, most commonly using European Society of Clinical Nutrition and Metabolism (ESPEN) guidelines to support prescriptions (n = 61/66, 92%). Most respondents (n = 49/66, 74%) thought their practice achieved 61-80% of protein prescriptions, with frequently reported barriers including fasting periods (n = 59/66, 89%), avoiding energy overfeeding (n = 50/66, 76%), and gastrointestinal intolerance (n = 47/66, 71%). No associations between years of ICU experience and protein prescriptions for 14 of the 15 predefined clinical conditions were present.

CONCLUSIONS

Australian and New Zealand ICU dietitians use international guidelines to inform protein prescriptions of 1.2-1.5 g/kg/day for most clinical conditions, and protein prescriptions do not appear to be influenced by years of ICU experience. Key perceived barriers to protein delivery including avoidance of energy overfeeding and gastrointestinal intolerance could be explored to improve protein adequacy.

Effects on physical performance of high protein intake for critically ill adult patients admitted to the intensive care unit: A retrospective propensity-matched analysis

OBJECTIVES

This study aimed to examine the effects of protein intake on physical performance in critically ill adult patients admitted to the intensive care unit (ICU).

METHODS

This was a retrospective cohort study of adult patients mechanically ventilated over 48 h in the ICU who were classified into two groups based on the amount of protein intake: >1.0 g/kg/d (high-protein group) or <1.0 g/kg/d (low-protein group). After adjustment for possible confounding factors with propensity score matching, we compared muscle strength at the time of ICU discharge and the rate of recovery to independent walking between the two groups.

RESULTS

One-to-one propensity score matching created 20 pairs. The high-protein group had significantly higher muscle strength than the low-protein group at the time of discharge from the ICU. In addition, the rate of recovery to independent walking before hospital discharge was higher in the high-protein group than the low-protein group (16 of 20 patients [80%] vs. 8 of 20 patients [40%]; P = 0.032).

CONCLUSIONS

Our findings indicate that a sufficient amount of protein intake may lead to a higher rate of recovery to independent walking before discharge from the hospital in critically ill patients admitted to the ICU. This finding is likely related to preserved muscle strength at the time of ICU discharge.

Feasibility of achieving different protein targets using a hypocaloric high-protein enteral formula in critically ill patients

Background and aims

Combining energy and protein targets during the acute phase of critical illness is challenging. Energy should be provided progressively to reach targets while avoiding overfeeding and ensuring sufficient protein provision. This prospective observational study evaluated the feasibility of achieving protein targets guided by 24-h urinary nitrogen excretion while avoiding overfeeding when administering a high protein-to-energy ratio enteral nutrition (EN) formula.

Methods

Critically ill adult mechanically ventilated patients with an APACHE II score > 15, SOFA > 4 and without gastrointestinal dysfunction received EN with hypocaloric content for 7 days. Protein need was determined by 24-h urinary nitrogen excretion, up to 1.2 g/kg (Group A, N = 10) or up to 1.5 g/kg (Group B, N = 22). Variables assessed included nitrogen intake, excretion, balance; resting energy expenditure (REE); phase angle (PhA); gastrointestinal tolerance of EN.

Results

Demographic characteristics of groups were similar. Protein target was achieved using urinary nitrogen excretion measurements. Nitrogen balance worsened in Group A but improved in Group B. Daily protein and calorie intake and balance were significantly increased in Group B compared to Group A. REE was correlated to PhA measurements. Gastric tolerance of EN was good.

Conclusions

Achieving the protein target using urinary nitrogen loss up to 1.5 g/kg/day was feasible in this hypercatabolic population. Reaching a higher protein and calorie target did not induce higher nitrogen excretion and was associated with improved nitrogen balance and a better energy intake without overfeeding. PhA appears to be related to REE and may reflect metabolism level, suggestive of a new phenotype for nutritional status.

Trial registration 0795-18-RMC.

Chronic Critical Illness and PICS Nutritional Strategies

The nutritional hallmark of chronic critical illness (CCI) after sepsis is persistent inflammation, immunosuppression, and catabolism syndrome (PICS), which results in global resistance to the anabolic effect of nutritional supplements. This ultimately leaves these patients in a downward phenotypic spiral characterized by cachexia with profound weakness, decreased capacity for rehabilitation, and immunosuppression with the propensity for sepsis recidivism. The persistent catabolism is driven by a pathologic low-grade inflammation with the inability to return to homeostasis and by ongoing increased energy expenditure. Better critical care support systems and advances in technology have led to increased intensive care unit (ICU) survival, but CCI due to PICS with poor long-term outcomes has emerged as a frequent phenotype among ICU sepsis survivors. Unfortunately, therapies to mitigate or reverse PICS-CCI are limited, and recent evidence supports that these patients fail to respond to early ICU evidence-based nutrition protocols. A lack of randomized controlled trials has limited strong recommendations for nutrition adjuncts in these patients. However, based on experience in other conditions characterized by a similar phenotype, immunonutrients aimed at counteracting inflammation, immunosuppression, and catabolism may be important for improving outcomes in PICS-CCI patients. This manuscript intends to review several immunonutrients as adjunctive therapies in treating PICS-CCI.

Measures Derived from Panoramic Ultrasonography and Animal-Based Protein Intake Are Related to Muscular Performance in Middle-Aged Adults

Ultrasonography advantageously measures skeletal muscle size and quality, but some muscles may be too large to capture with standardized brightness mode (B-mode) imaging. Panoramic ultrasonography can capture more complete images and may more accurately measure muscle size. We investigated measurements made using panoramic compared to B-mode ultrasonography images of the rectus femoris with muscular performance. Concurrently, protein intake plays an important role in preventing sarcopenia; therefore, we also sought to investigate the association between animal-based protein intake (ABPI) and muscular performance. Ninety-one middle-aged adults were recruited. Muscle cross-sectional area (CSA) and thickness were obtained using B-mode and panoramic ultrasound and analyzed with Image J software. Muscular performance was assessed using isokinetic dynamometry, a 30-s chair test, and handgrip strength. Three-day food diaries estimated dietary intakes. Linear regression models determined relationships between measures from ultrasonography and muscular performance. Mixed linear models were used to evaluate the association between ABPI and muscular performance. Muscle CSA from panoramic ultrasonography and ABPI were positively associated with lower-body strength (β ± S.E.; CSA, 42.622 ± 20.024, p = 0.005; ABPI, 65.874 ± 19.855, p = 0.001), lower-body endurance (β ± S.E.; CSA, 595 ± 200.221, p = 0.001; ABPI, 549.944 ± 232.478, p = 0.020), and handgrip strength (β ± S.E.; CSA, 6.966 ± 3.328, p = 0.004; ABPI, 0.349 ± 0.171, p = 0.045). Panoramic ultrasound shows promise as a method for assessing sarcopenia. ABPI is related to better muscular performance.

Protein Intake and Human Health: Implications of Units of Protein Intake

Understanding the health effects of protein intake is bedeviled by a number of factors, including protein quality and source. In addition, different units, including grams, grams per kilogram body weight (g/kg BW), and percent energy, may contribute to confusion about protein's effects on health, especially BW-based units in increasingly obese populations. We aimed to review the literature and to conduct a modeling demonstration of various units of protein intake in relation to markers of cardiometabolic health. Data from the Framingham Heart Study Offspring (n = 1847; 60.3 y; 62.5% women) and Third Generation (n = 2548; 46.2 y; 55.3% women) cohorts and the NHANES 2003-04 (n = 1625; 46.2 y; 49.7% women) and 2005-06 (n = 1347; 43.7 y; 49.5% women) cycles were used to model cross-sectional associations between 7 protein units (grams, percent energy, g/kg ideal BW, g/kg actual BW, BW-adjusted g/kg actual BW, g/kg lean BW, and g/kg fat-free BW) and 9 cardiometabolic outcomes (fasting glucose, systolic and diastolic blood pressure, total and HDL cholesterol, triglycerides, BMI, waist circumference, and estimated glomerular filtration rate). The literature review indicated the use of myriad units of protein intake, with differential results on cardiometabolic outcomes. The modeling demonstration showed units expressed in BW were confounded by BW, irrespective of outcome. Units expressed in grams, percent energy, and ideal BW showed similar results, with or without adjustment for body size. After adjusting for BW, results of units expressed in BW aligned with results of grams, percent energy, and ideal BW. In conclusion, protein intake in cardiometabolic health appears to depend on protein's unit of expression. Authors should be specific about the use of WHO (g/kg ideal BW) compared with US (g/kg actual BW) units, and ideally use gram or percent energy in observational studies. In populations where overweight/obesity are prevalent, intake based on actual BW should be reevaluated.

Semi-elemental versus polymeric formula for enteral nutrition in brain-injured critically ill patients: a randomized trial

Background

The properties of semi-elemental enteral nutrition might theoretically improve gastrointestinal tolerance in brain-injured patients, known to suffer gastroparesis. The purpose of this study was to compare the efficacy and tolerance of a semi-elemental versus a polymeric formula for enteral nutrition (EN) in brain-injured critically ill patients.

Methods

Prospective, randomized study including brain-injured adult patients [Glasgow Coma Scale (GCS) ≤ 8] with an expected duration of mechanical ventilation > 48 h. Intervention: an enteral semi-elemental (SE group) or polymeric (P group) formula. EN was started within 36 h after admission to the intensive care unit and was delivered according to a standardized nurse-driven protocol. The primary endpoint was the percentage of patients who received both 60% of the daily energy goal at 3 days and 100% of the daily energy goal at 5 days after inclusion. Tolerance of EN was assessed by the rate of gastroparesis, vomiting and diarrhea.

Results

Respectively, 100 and 95 patients were analyzed in the SE and P groups: Age (57[44–65] versus 55[40–65] years) and GCS (6[3–7] versus 5[3–7]) did not differ between groups. The percentage of patients achieving the primary endpoint was similar (46% and 48%, respectively; relative risk (RR) [95% confidence interval (CI)] = 1.05 (0.78–1.42); p = 0.73). The mean daily energy intake was, respectively, 20.2 ± 6.3 versus 21.0 ± 6.5 kcal/kg/day (p = 0.42). Protein intakes were 1.3 ± 0.4 versus 1.1 ± 0.3 g/kg/day (p < 0.0001). Respectively, 18% versus 12% patients presented gastroparesis (p = 0.21), and 16% versus 8% patients suffered from diarrhea (p = 0.11). No patient presented vomiting in either group.

Conclusion

Semi-elemental compared to polymeric formula did not improve daily energy intake or gastrointestinal tolerance of enteral nutrition.

Trial registration

EudraCT/ID-RCB 2012-A00078-35 (registered January 17, 2012).

Use of a High-Protein Enteral Nutrition Formula to Increase Protein Delivery to Critically Ill Patients: A Randomized, Blinded, Parallel-Group, Feasibility Trial

BACKGROUND

International guidelines recommend critically ill adults receive more protein than most receive. We aimed to establish the feasibility of a trial to evaluate whether feeding protein to international recommendations would improve outcomes, in which 1 group received protein doses representative of international guideline recommendations (high protein) and the other received doses similar to usual practice.

METHODS

We conducted a prospective, randomized, blinded, parallel-group, feasibility trial across 6 intensive care units. Critically ill, mechanically ventilated adults expected to receive enteral nutrition (EN) for ≥2 days were randomized to receive EN containing 63 or 100 g/L protein for ≤28 days. Data are mean (SD) or median (interquartile range).

RESULTS

The recruitment rate was 0.35 (0.13) patients per day, with 120 patients randomized and data available for 116 (n = 58 per group). Protein delivery was greater in the high-protein group (1.52 [0.52] vs 0.99 [0.27] grams of protein per kilogram of ideal body weight per day; difference, 0.53 [95% CI, 0.38-0.69] g/kg/d protein), with no difference in energy delivery (difference, -26 [95% CI, -190 to 137] kcal/kg/d). There were no between-group differences in the duration of feeding (8.7 [7.3] vs 8.1 [6.3] days), and blinding of the intervention was confirmed. There were no differences in clinical outcomes, including 90-day mortality (14/55 [26%] vs 15/56 [27%]; risk difference, -1.3% [95% CI, -17.7% to 15.0%]).

CONCLUSION

Conducting a multicenter blinded trial is feasible to compare protein delivery at international guideline-recommended levels with doses similar to usual care during critical illness.

Review of evolution and current status of protein requirements and provision in acute illness and critical care

Nutrition therapy, by enteral, parenteral, or both routes combined, is a key component of the management of critically ill, surgical, burns, and oncology patients. Established evidence indicates overfeeding (provision of excessive calories) results in increased risk of infection, morbidity, and mortality. This has led to the practice of "permissive underfeeding" of calories; however, this can often lead to inadequate provision of guideline-recommended protein intakes. Acutely ill patients requiring nutritional therapy have high protein requirements, and studies demonstrate that provision of adequate protein can result in reduced mortality and improvement in quality of life. However, a significant challenge to adequate protein delivery is the current lack of concentrated protein solutions. Patients often have fluid administration restrictions and existing protein solutions are frequently not sufficiently concentrated to deliver a patient's protein requirements. This has led to the development of new enteral and parenteral nutrition solutions incorporating higher levels of protein in smaller volumes. This review article summarizes current evidence supporting the role of higher protein intakes, especially during the early phases of nutrition therapy in acute illness, methods for assessing protein requirements, as well as, the currently available high-protein enteral and parenteral nutrition solutions. There is sufficient evidence (albeit limited from true randomized, controlled studies) to indicate that earlier provision of guideline-recommended protein intakes may be key to improving patient outcomes and that nutritional therapy that tailors caloric and protein intake to the patients' needs should be considered a desired standard of care.

Prolonged Weaning: S2k Guideline Published by the German Respiratory Society

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by respiratory muscle insufficiency and/or lung parenchymal disease; that is, when other treatments such as medication, oxygen administration, secretion management, continuous positive airway pressure (CPAP), or nasal high-flow therapy have failed. MV is required for maintaining gas exchange and allows more time to curatively treat the underlying cause of respiratory failure. In the majority of ventilated patients, liberation or "weaning" from MV is routine, without the occurrence of any major problems. However, approximately 20% of patients require ongoing MV, despite amelioration of the conditions that precipitated the need for it in the first place. Approximately 40-50% of the time spent on MV is required to liberate the patient from the ventilator, a process called "weaning". In addition to acute respiratory failure, numerous factors can influence the duration and success rate of the weaning process; these include age, comorbidities, and conditions and complications acquired during the ICU stay. According to international consensus, "prolonged weaning" is defined as the weaning process in patients who have failed at least 3 weaning attempts, or require more than 7 days of weaning after the first spontaneous breathing trial (SBT). Given that prolonged weaning is a complex process, an interdisciplinary approach is essential for it to be successful. In specialised weaning centres, approximately 50% of patients with initial weaning failure can be liberated from MV after prolonged weaning. However, the heterogeneity of patients undergoing prolonged weaning precludes the direct comparison of individual centres. Patients with persistent weaning failure either die during the weaning process, or are discharged back to their home or to a long-term care facility with ongoing MV. Urged by the growing importance of prolonged weaning, this Sk2 Guideline was first published in 2014 as an initiative of the German Respiratory Society (DGP), in conjunction with other scientific societies involved in prolonged weaning. The emergence of new research, clinical study findings and registry data, as well as the accumulation of experience in daily practice, have made the revision of this guideline necessary. The following topics are dealt with in the present guideline: Definitions, epidemiology, weaning categories, underlying pathophysiology, prevention of prolonged weaning, treatment strategies in prolonged weaning, the weaning unit, discharge from hospital on MV, and recommendations for end-of-life decisions. Special emphasis was placed on the following themes: (1) A new classification of patient sub-groups in prolonged weaning. (2) Important aspects of pulmonary rehabilitation and neurorehabilitation in prolonged weaning. (3) Infrastructure and process organisation in the care of patients in prolonged weaning based on a continuous treatment concept. (4) Changes in therapeutic goals and communication with relatives. Aspects of paediatric weaning are addressed separately within individual chapters. The main aim of the revised guideline was to summarize both current evidence and expert-based knowledge on the topic of "prolonged weaning", and to use this information as a foundation for formulating recommendations related to "prolonged weaning", not only in acute medicine but also in the field of chronic intensive care medicine. The following professionals served as important addressees for this guideline: intensivists, pulmonary medicine specialists, anaesthesiologists, internists, cardiologists, surgeons, neurologists, paediatricians, geriatricians, palliative care clinicians, rehabilitation physicians, intensive/chronic care nurses, physiotherapists, respiratory therapists, speech therapists, medical service of health insurance, and associated ventilator manufacturers.

Assessment of muscle mass using ultrasound with minimal versus maximal pressure compared with computed tomography in critically ill adult patients

BACKGROUND

Preserved skeletal muscle mass identified using computed tomography (CT) predicts improved outcomes from critical illness; however, CT imaging have few limitations such that it involves a radiation dose and transferring patients out of the intensive care unit. This study aimed to assess in critically ill patients the relationship between muscle mass estimates obtained using minimally invasive ultrasound techniques with both minimal and maximal pressure compared with CT images at the third lumber vertebra level.

METHODS

All patients were treated in a single Australian intensive care unit. Eligible patients had paired assessments, within a 72-h window, of muscle mass by ultrasound (quadriceps muscle layer thickness in centimetres, with maximal and minimal pressure) and CT axial cross-sectional area (cm²). Data are presented as mean (standard deviation), median (interquartile range), and frequencies [n (%)].

RESULTS

Thirty-five patients [mean (standard deviation) age = 55 (16) years, median (interquartile range) body mass index = 27 (25-32) kg/m², and 26 (74%) men] contributed 41 paired measurements. Quadriceps muscle thickness measured using the maximal pressure technique was a strong independent predictor of lumbar muscle cross-sectional area. Within a multivariate mixed linear regression model and adjusting for sex, age, and body mass index, for every 1 cm increase in quadriceps muscle layer thickness, the lumbar muscle cross-sectional area increased by 35 cm² (95% confidence interval = 11-59 cm²). Similar univariate associations were observed using minimal pressure; however, as per multivariate analysis, there was no strength in this relationship [8 cm² (95% confidence interval = -5 to 22 cm²)].

CONCLUSION

Ultrasound assessment of the quadriceps muscle using maximal pressure reasonably predicts the skeletal muscle at the third lumbar vertebra level of critically ill patients. However, there is substantial uncertainty within these regression estimates, and this may reduce the current utility of this technique as a minimally invasive surrogate for CT assessment of skeletal muscle mass.

Value of the urea/creatinine index in isolated urine to estimate severe protein hypercatabolism in ventilated patients

Objective

To study the ability of the urea/creatinine index to identify severe protein catabolism from the isolated urine of critically ventilated patients.

Methods

This was a prospective, observational study. It included 52 patients without kidney failure. Variables: total urinary nitrogen estimated from the urea in 24-hour urine on the second (T1) and fourth days (T2) and urea/creatinine index in isolated urine before 24-hour urine collection.

Results

Severe protein hypercatabolism (estimated total urinary nitrogen > 15g) was present in 14 patients (26.9%) at T1 and in 29 (55.7%) at T2. Eighty-four percent of patients had low nutritional risk by the Nutrition Risk in the Critically Ill score. At T1, the Pearson correlation between the estimated total urinary nitrogen and the urea/creatinine index was 0.272 (p = 0.051), and at T2 it was 0.276 (p = 0.048). The urea/creatinine index at T2 had a tendency to better discriminate severe protein hypercatabolism than Acute Physiology and Chronic Health Evaluation II and Nutrition Risk in the Critically Ill (AUC 0.741 versus 0.669 and 0.656, 95%CI: 0.602 - 0.880; 0.519 - 0.818 and 0.506 - 0.806, respectively). The optimal cutoff value of the urea/creatinine index for the diagnosis of severe protein hypercatabolism was 16.15, with a sensitivity of 79.31% (95%CI: 59.74 - 91.29), specificity of 60.87% (95%CI: 38.78 - 79.53), positive predictive value 71.88% (95%CI: 53.02 - 85.60), negative predictive value 70.0% (95%CI: 45.67 - 87.18), LR (+) 2.03 (95%CI: 1.18 - 3.49), and LR (-) 0.34 (95%CI: 0.16 - 0.74).

Conclusion

The urea/creatinine index measured on the fourth day has a certain ability to estimate severe protein hypercatabolism (as defined by estimated total urinary nitrogen) but does not replace total urinary nitrogen in critically ventilated patients without kidney failure. Due to its reasonable sensitivity, it could be used as a screen to identify which patients to take a 24-hour urine sample from.

Protein delivery in intermittent and continuous enteral nutrition with a protein-rich formula in critically ill patients-a protocol for the prospective randomized controlled proof-of-concept Protein Bolus Nutrition (Pro BoNo) study

Background

Critically ill patients rapidly develop muscle wasting resulting in sarcopenia, long-term disability and higher mortality. Bolus nutrition (30–60 min period), whilst having a similar incidence of aspiration as continuous feeding, seems to provide metabolic benefits through increased muscle protein synthesis due to higher leucine peaks.

To date, clinical evidence on achievement of nutritional goals and influence of bolus nutrition on skeletal muscle metabolism in ICU patients is lacking. The aim of the Pro BoNo study (Protein Bolus Nutrition) is to compare intermittent and continuous enteral feeding with a specific high-protein formula. We hypothesise that target quantity of protein is reached earlier (within 36 h) by an intermittent feeding protocol with a favourable influence on muscle protein synthesis.

Methods

Pro BoNo is a prospective randomised controlled study aiming to compare the impact of intermittent and continuous enteral feeding on preventing muscle wasting in 60 critically ill patients recruited during the first 48 h after ICU admission. The primary outcome measure is the time until the daily protein target (≥ 1.5 g protein/kg bodyweight/24 h) is achieved. Secondary outcome measures include tolerance of enteral feeding and evolution of glucose, urea and IGF-1. Ultrasound and muscle biopsy of the quadriceps will be performed.

Discussion

The Basel Pro BoNo study aims to collect innovative data on the effect of intermittent enteral feeding of critically ill patients on muscle wasting.

Trial registration

ClinicalTrials.gov NCT03587870. Registered on July 16, 2018. Swiss National Clinical Trials Portal SNCTP000003234. Last updated on July 24, 2019.

Quantifying Response to Nutrition Therapy During Critical Illness: Implications for Clinical Practice and Research? A Narrative Review

Critical illness causes substantial muscle loss that adversely impacts recovery and health-related quality of life. Treatments are therefore needed that reduce mortality and/or improve the quality of survivorship. The purpose of this Review is to describe both patient-centered and surrogate outcomes that quantify responses to nutrition therapy in critically ill patients. The use of these outcomes in randomized clinical trials will be described and the strengths and limitations of these outcomes detailed. Outcomes used to quantify the response of nutrition therapy must have a plausible mechanistic relationship to nutrition therapy and either be an accepted measure for the quality of survivorship or highly likely to lead to improvements in survivorship. This Review identified that previous trials have utilized diverse outcomes. The variety of outcomes observed is probably due to a lack of consensus as to the most appropriate surrogate outcomes to quantify response to nutrition therapy during research or clinical practice. Recent studies have used, with some success, measures of muscle mass to evaluate and monitor nutrition interventions administered to critically ill patients.

Muscle Mass Loss in the Older Critically Ill Population: Potential Therapeutic Strategies

Skeletal muscle plays a critical role in everyday life, and its age-associated reduction has severe health consequences. The pre-existing presence of sarcopenia, combined with anabolic resistance, protein undernutrition, and the pro-catabolic/anti-anabolic milieu induced by aging and exacerbated in critical care, may accelerate the rate at which skeletal muscle is lost in patients with critical illness. Advancements in intensive care unit (ICU)-care provision have drastically improved survival rates; therefore, attention can be redirected toward other significant issues affecting ICU patients (e.g., length of stay, days on ventilation, nosocomial disease development, etc.). Thus, strategies targeting muscle mass and function losses within an ICU setting are essential to improve patient-related outcomes. Notably, loading exercise and protein provision are the most compelling. Many older ICU patients seldom meet the recommended protein intake, and loading exercise is difficult to conduct in the ICU. Nevertheless, the incorporation of physical therapy (PT), neuromuscular electrical stimulation, and early mobilization strategies may be beneficial. Furthermore, a number of nutrition practices within the ICU have been shown to improve patient-related outcomes ((e.g., feeding strategy [i.e., oral, early enteral, or parenteral]), be hypocaloric (∼70%-80% energy requirements), and increase protein provision (∼1.2-2.5 g/kg/d)). The aim of this brief review is to discuss the dysregulation of muscle mass maintenance in an older ICU population and highlight the potential benefits of strategic nutrition practice, specifically protein, and PT within the ICU. Finally, we provide some general guidelines that may serve to counteract muscle mass loss in patients with critical illness.

Translating the European Society for Clinical Nutrition and Metabolism 2019 guidelines into practice

PURPOSE OF REVIEW

To present a pragmatic approach to facilitate clinician's implementing the recent European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines on clinical nutrition in the intensive care unit.

RECENT FINDINGS

The ESPEN guidelines include 54 recommendations with a rationale for each recommendation. All data published since 1 January 2000 was reviewed and 31 meta-analyses were performed to inform these guidelines. An important aspect of the most recent ESPEN guidelines is an attempt to separate periods of critical illness into discrete - early acute, late acute and recovery - phases, with each exhibiting different metabolic profiles and requiring different strategies for nutritional and metabolic support.

SUMMARY

A pragmatic approach to incorporate the recent ESPEN guidelines into everyday clinical practice is provided.

Is Energy Delivery Guided by Indirect Calorimetry Associated With Improved Clinical Outcomes in Critically Ill Patients? A Systematic Review and Meta-analysis

Background:

Indirect calorimetry (IC) is recommended to guide energy delivery over predictive equations in critical illness due to its precision. However, the impact of using IC to measure energy expenditure on clinical outcomes is uncertain.

Objective:

To evaluate whether using IC to measure energy expenditure to inform energy delivery reduced hospital mortality and improved other important outcomes compared to using predictive equations in critically ill adults.

Methods:

A systematic literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Medline, Embase, CINAHL, and the Cochrane Library were searched for studies using IC to guide energy delivery compared to a predictive equation in adult critically ill patients with the primary outcome (hospital mortality) or any of the secondary outcomes reported (including but not limited to hospital and intensive care unit (ICU) length of stay (LOS) and duration mechanical ventilation (MV). Risk of bias within studies was assessed using the Cochrane “Risk of Bias” 1 tool. Random-effect meta-analyses were used when heterogeneity between studies existed (I² > 50%). Data are reported as median (interquartile range [IQR]), binomial outcomes as odds ratio (OR), 95% confidence interval (CI), and continuous outcomes as mean difference (MD).

Results:

Of 4060 articles, 4 randomized controlled trials were identified with 396 patients included in analysis. Three studies were considered low risk of bias and 1 as high risk. Two studies reported hospital mortality (n = 130 and 40 participants, respectively). When combined, no association between IC-guided energy delivery and hospital mortality was found (OR = 0.81, 95% CI = [0.25, 2.67], P = 0.73, I² = 52). No differences were reported with ICU mortality and hospital LOS between groups, but ICU LOS and duration of MV varied across all studies. According to the meta-analysis, no differences were observed in ICU LOS (MD = 1.39, 95% CI = [–5.01, 7.79], P = 0.67, I² = 81%), although the duration of MV was increased when energy delivery was guided by IC (MD = 2.01, 95% CI = [0.45, 3.57], P = 0.01, I² = 26%). In all 4 studies, prescribed energy targets were more closely met when energy delivery was informed by IC compared to a predictive equation. Three studies reported the percentage delivered versus the prescribed energy target, with the median (IQR) delta between the IC and predictive equation arms 19% (10%-32%).

Conclusion:

Limited data exist to assess the impact of using IC to inform energy delivery in comparison to predictive equations on hospital mortality. The association of IC use with other important outcomes, including duration of MV, needs to be further explored before definitive conclusions can be made.

Gut dysmotility in the ICU: diagnosis and therapeutic options

PURPOSE OF REVIEW

To provide a comprehensive update of diagnosis and treatment of gastrointestinal dysmotility in the critically ill, with a focus on work published in the last 5 years.

RECENT FINDINGS

Symptoms and clinical features consistent with upper and/or lower gastrointestinal dysmotility occur frequently. Although features of gastrointestinal dysmotility are strongly associated with adverse outcomes, these associations may be because of unmeasured confounders. The use of ultrasonography to identify upper gastrointestinal dysmotility appears promising. Both nonpharmacological and pharmacological approaches to treat gastrointestinal dysmotility have recently been evaluated. These approaches include modification of macronutrient content and administration of promotility drugs, stool softeners or laxatives. Although these approaches may reduce features of gastrointestinal dysmotility, none have translated to patient-centred benefit.

SUMMARY

'Off-label' metoclopramide and/or erythromycin administration are effective for upper gastrointestinal dysmotility but have adverse effects. Trials of alternative or novel promotility drugs have not demonstrated superiority over current pharmacotherapies. Prophylactic laxative regimens to prevent non-defecation have been infrequently studied and there is no recent evidence to further inform treatment of established pseudo-obstruction. Further trials of nonpharmacological and pharmacological therapies to treat upper and lower gastrointestinal dysmotility are required and challenges in designing such trials are explored.

Clinical nutrition for the gastroenterologist: bedside strategies for feeding the hospitalized patient

PURPOSE OF REVIEW

The timing, advancement, and use of appropriate monitors determine whether the hospitalized patient experiences the full benefit of nutritional therapy. This article reviews management strategies in delivering the optimal nutrition regimen capable of improving outcomes in the hospitalized patient.

RECENT FINDINGS

Enteral nutrition should be initiated in the first 24-36 h after admission. Determination of nutritional risk helps guide the urgency with which nutritional therapy is provided and predicts the likelihood for difficulties in delivering the prescribed regimen. Feeds should be advanced slowly over 3-4 days to meet 70-80% of goal for calories (20 kcal/kg/day) and 100% for protein (2.0 gm/kg/day). Reaching protein goals early on may be more important than achieving energy goals. Patients should be monitored for hemodynamic stability, evidence of refeeding syndrome, and tolerance in the setting of gastrointestinal dysfunction. Parenteral nutrition should be utilized in select high-risk patients where the feasibility of full enteral nutrition is questioned.

SUMMARY

Timing with early initiation of enteral nutrition, avoidance of overfeeding, and step-wise advancement of feeds are required to safely realize the benefits of such therapy.

Dietary management of blood glucose in medical critically ill patients with overweight/obesity

PURPOSE OF REVIEW

As the obesity epidemic continues, there is a greater proportion of patients with overweight, obesity, and other forms of adiposity-based chronic disease that require intensive care. Nutrition therapy in the ICU is a vital part of critical care but can be challenging in this setting because of the increased risk of stress hyperglycemia and adverse impact of obesity- and diabetes-related complications.

RECENT FINDINGS

Current guidelines favor early nutritional therapy with a hypocaloric, high-protein diet in patients with overweight/obesity. More aggressive protein intake may be useful in those with greater severity of overweight/obesity with an upper limit of 3 g/kg ideal body weight per day. Although there is no specific recommendation, choosing enteral formulas with higher fat content and slower digesting carbohydrates may assist with glucose control. Supplementation with immunonutrients is recommended, given their known benefits in obesity and in reducing inflammation, but must be done in an individualized manner.

SUMMARY

Aggressive nutritional therapy is crucial in patients with overweight/obesity to support ongoing metabolic demands. Although a hypocaloric high-protein feeding strategy is a starting point, nutritional therapy should be approached in an individualized manner taking into account age, weight and BMI, basal metabolism, nutrition status, complications, and comorbidities.

Narrowing the Protein Deficit Gap in Critically Ill Patients Using a Very High-Protein Enteral Formula

BACKGROUND

Protein deficits have been associated with longer intensive care unit (ICU) stays and increased mortality. Current view suggests if protein goals are met, meeting full energy targets may be less important and prevent deleterious effects of overfeeding. We proposed a very-high protein (VHP) enteral nutrition (EN) formula could provide adequate protein, without overfeeding energy, in the first week of critical illness.

METHODS

This was a retrospective study of medical/surgical ICU patients receiving EN exclusively for ≥5 days during the first week of ICU admission. Twenty participants received standard EN; 20 participants received the VHP-EN formula (1 kcal/mL, 37% protein). Protein and energy prescribed/received, gastrointestinal tolerance, and feeding interruptions were examined.

RESULTS

Forty ICU patients [average Acute Physiology and Chronic Health Evaluation II score of 20.1] were included. Protein prescribed and received was significantly higher in the VHP group vs the standard EN group (135.5 g/d ± 22.9 vs 111.4 g/d ± 25; P = .003 and 112.2 g/d ± 27.8 vs 81.7 g/d ± 16.7, respectively; P = .002). Energy prescribed and received was similar between groups (1696 kcal/d ± 402 vs 1893 kcal/d ± 341, respectively; P = .101 and 1520 kcal/d ± 346 vs 1506 ± 380 kcal/d; P = .901). There were no differences in EN tolerance (P = .065) or feeding interruptions (P = .336).

CONCLUSIONS

Use of a VHP formula in ICU patients resulted in higher protein intakes without overfeeding energy or use of modular protein in the first 5 days of exclusive EN.

Protein Requirements in Critical Illness: Do We Really Know Why to Give So Much?

The protein and energy requirements of critically ill patients treated in intensive care units (ICUs) have been actively discussed recently. Currently published clinical recommendations and reviews suggest significant increases of protein provision to 2-2.5 g/kg/d in some populations of ICU patients. However, a detailed analysis of the main sources of these recommendations reveals a number of serious contradictions, as well as an absence of obvious evidence supporting the allotment of high doses of protein. We went through these recommendations and reviewed cited articles and other studies, and we have separated our arguments against excessive protein provision into sections.

Chronic Critical Illness Patients Fail to Respond to Current Evidence-Based Intensive Care Nutrition Secondarily to Persistent Inflammation, Immunosuppression, and Catabolic Syndrome

BACKGROUND

Sepsis-induced multiple-organ failure (MOF) has plagued surgical intensive care units (ICUs) for decades. Early nutrition (principally enteral) improves hospital outcomes of high-risk ICU patients. The purpose of this study is to document how the growing epidemic of chronic critical illness (CCI) patients responds to adequate evidence-based ICU nutrition.

METHODS

This retrospective post hoc subgroup analysis of an ongoing sepsis database identified 56 CCI patients who received early, adequate nutrition per an established surgical ICU protocol compared with 112 matched rapid-recovery (RAP) patients.

RESULTS

The matched CCI and RAP groups had similar baseline characteristics. Serial biomarkers showed that CCI patients remained persistently inflamed with ongoing stress metabolism and that despite receiving evidence-based protocol nutrition, they had persistent catabolism and immunosuppression with more secondary infections. More CCI patients were discharged to poor nonhome destinations (ie, skilled nursing facilities, long-term acute care, hospice) (81% vs 29%, P < 0.05). At 12-month follow-up, CCI patients had worse functional status by Zubrod score (3.17 vs 1.62, P < 0.001) and Short Physical Battery Testing (4.78 vs 8.59, P < 0.02), worse health-related quality of life by EQ-5D-3L descriptive measures (9.07 vs 7.45, P < 0.003), and lower survival (67% vs 92%, P < 0.05).

CONCLUSIONS

Despite early, adequate, evidence-based ICU nutrition, septic surgical ICU patients who develop CCI exhibit persistent inflammation, immunosuppression, and catabolism with unacceptable long-term morbidity and mortality. Although current evidence-based ICU nutrition may improve short-term ICU outcomes, novel adjuncts are needed to improve long-term outcomes for CCI patients.

Amino Acid Availability of a Dairy and Vegetable Protein Blend Compared to Single Casein, Whey, Soy, and Pea Proteins: A Double-Blind, Cross-Over Trial

Protein quality is important for patients needing medical nutrition, especially those dependent on tube feeding. A blend of dairy and vegetable proteins (35% whey, 25% casein, 20% soy, 20% pea; P4) developed to obtain a more balanced amino acid profile with higher chemical scores, was compared to its constituent single proteins. Fourteen healthy elderly subjects received P4, whey, casein, soy, and pea (18 g/360 mL bolus) on five separate visits. Blood samples were collected at baseline until 240 min after intake. Amino acid availability was calculated using incremental maximal concentration (iCmax) and area under the curve (iAUC). Availability for P4 as a sum of all amino acids was similar to casein (iCmax and iAUC) and whey (iCmax) and higher vs. soy (iCmax and iAUC) and pea (iCmax). Individual amino acid availability (iCmax and iAUC) showed different profiles reflecting the composition of the protein sources: availability of leucine and methionine was higher for P4 vs. soy and pea; availability of arginine was higher for P4 vs. casein and whey. Conclusions: The P4 amino acid profile was reflected in post-prandial plasma levels and may be regarded as more balanced compared to the constituent single proteins.

Systematic Review With Meta-Analysis of Patient-Centered Outcomes, Comparing International Guideline-Recommended Enteral Protein Delivery With Usual Care

BACKGROUND

International guidelines recommend that protein be administered enterally to critically ill patients at doses between 1.2 and 2 g/kg per day Observational data indicate that patients frequently receive less protein. The aim of this systematic review was to evaluate patient-centered outcomes with guideline-recommended enteral protein compared with usual care.

METHODS

A systematic review was performed of randomized controlled trials including critically ill adult patients provided predominately enteral nutrition with mean protein at ≥1.2 g/kg per day (intervention) and <1.2 g/kg per day (comparator). Random-effects models were applied for outcomes reported in ≥3 trials.

RESULTS

Of 1375 abstracts, 69 full-text articles were reviewed, and 6 trials meet the inclusion criteria, including 511 patients. The intervention group received a mean (SD) of 1.3 (0.08) g/kg per day, and the comparator group received 0.75 (0.15) g/kg per day protein. Insufficient data were available for meta-analyses on the primary outcome (muscle mass or strength). According to our meta-analyses, mortality at 28 days (5 studies) (risk ratio 0.92 [95% Cl 0.63-1.35], P = .66) and the durations of intensive care unit (6 studies) and hospital admission (4 studies) were similar between the intervention and comparator, with some uncertainty due to sample sizes and heterogeneity.

CONCLUSION

There are insufficient data to conclude whether protein provision within the current international guideline recommendations improves outcomes. In a limited dataset, enteral protein intakes near the lower level of current recommendations do not appear to reduce admission duration or mortality when compared with usual care in critically ill.

Increasing Enteral Protein Intake in Critically Ill Trauma and Surgical Patients

BACKGROUND

Published guidelines recommend providing at least 2 g/kg/d of protein for critically ill surgical patients. It may be difficult to achieve this level of intake using standard enteral formulas, thus necessitating protein or amino acid supplementation. Herein, we report our approach to enteral protein supplementation and its relationship with urinary nitrogen excretion and serum transthyretin concentrations.

METHODS

This was a retrospective cohort study in which we reviewed critically ill trauma and surgical patients treated with supplemental enteral protein according to a protocol aiming to deliver a total of 2 g/kg/d of protein. We collected detailed nutrition data over a 2-week period after admission and obtained additional data through discharge to determine caloric and protein intake as well as complications. We also compared urine nitrogen excretion and transthyretin concentrations between these patients and a control group who did not receive supplemental protein.

RESULTS

Fifty-three subjects received early protein supplementation. Formula and protein supplement each provided ≈1.2 g/kg/d of protein by intensive care unit day 4. This resulted in a median total protein intake of 2.2 g/kg/d through day 14. One patient developed acute kidney injury, and 1 patient had 3 episodes of vomiting. By the third week, serum transthyretin concentrations increased to a median of 21 mg/dL compared with 13 mg/dL in subjects not receiving early supplementation.

CONCLUSION

It is safe to deliver supplemental protein enterally to critically ill surgical and trauma patients and reach 2 g/kg/d of protein intake during the first week of illness.

Relationship between Nutrition Intake and 28-Day Mortality Using Modified NUTRIC Score in Patients with Sepsis

In critically ill patients, malnutrition is known to increase morbidity and mortality. We investigated the relationship between nutritional support and 28-day mortality using the modified NUTrition RIsk in the Critically ill (NUTRIC) score in patients with sepsis. This retrospective cohort study included patients with sepsis admitted to the medical intensive care unit (ICU) between January 2011 and June 2017. Nutritional support for energy and protein intakes at day 7 of ICU admission were categorized into <20, 20 to <25, and ≥25 kcal/kg and <1.0, 1.0 to <1.2, and ≥1.2 g/kg, respectively. NUTRIC scores ≥4 were considered to indicate high nutritional risk. Among patients with low nutritional risk, higher intakes of energy (≥25 kcal/kg) and protein (≥1.2 g/kg) were not significantly associated with lower 28-day mortality. In patients with high nutritional risk, higher energy intakes of ≥25 kcal/kg were significantly associated with lower 28-day mortality compared to intakes of <20 kcal/kg (adjusted hazard ratio (aHR): 0.569, 95% confidence interval (CI): 0.339-0.962, p = 0.035). Higher protein intakes of ≥1.2 g/kg were also significantly associated with lower 28-day mortality compared to intakes of <1.0 g/kg (aHR: 0.502, 95% CI: 0.280-0.900, p = 0.021). Appropriate energy (≥25 kcal/kg) and protein (≥1.2 g/kg) intakes during the first week may improve outcomes in patients with sepsis having high nutritional risk.

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).

Achieving Protein Targets in the ICU Using a Specialized High-Protein Enteral Formula: A Quality Improvement Project

BACKGROUND

To meet protein needs in critical illness (CI), guidelines suggest ≥1.2-2.5 g protein/kg/d; however, most intensive care unit (ICU) patients receive ≤0.7 g/kg/d. Higher protein enteral nutrition (EN) formulas may be part of the solution to provide prescribed protein. Our objective was to demonstrate that an EN formula with 37% protein can deliver ≥80% of prescribed protein, without overfeeding calories within the first 5 days of feeding and to describe ICU clinicians' experience.

METHODS

This quality improvement (QI) project included patients requiring exclusive EN for up to 5 days from 6 Canadian ICUs. Rationale for choosing formula, patient's BMI (kg/m² ), nutrition targets, daily protein and energy delivered, feeding interruptions, and general tolerance were recorded.

RESULTS

Forty-four of 49 patients received the formula ≥2 days. Average protein prescribed was 137.5 g/d (82.5-200) or 1.9 g/kg/d (1.5-2.5). Average protein delivered was 116.9 g/d (33.5-180) or 1.6 g/kg/d (0.4-2.4). Seventy-five percent to 83% of patients received ≥80% prescribed protein on days 2-5. Average energy prescribed was 1638.6 kcal/d (990-2500) or 17.8 kcal/kg (11-26). Average energy delivered was 1523.9 kcal/d (693.0-2557.5) or 17.3 kcal/kg/d (1.35-64.7). The formula was well tolerated with no gastrointestinal symptoms reported in 38 (86%) patients. The most common reasons to prescribe the formula were obesity and use of fat-based medications.

CONCLUSIONS

We demonstrated in a QI study that a high-protein EN formula was tolerated in a small, heterogeneous group of ICU patients and effective in meeting protein targets without overfeeding.

Dietary Management of Blood Glucose in Medical Critically Ill Overweight and Obese Patients: An Open-Label Randomized Trial

BACKGROUND

Enteral nutrition (EN) increases hyperglycemia due to high carbohydrate concentrations while providing insufficient protein. The study tested whether an EN formula with very high-protein- and low-carbohydrate-facilitated glucose control delivered higher protein concentrations within a hypocaloric protocol.

METHODS

This was a multicenter, randomized, open-label clinical trial with parallel design in overweight/obese mechanically ventilated critically ill patients prescribed 1.5 g protein/kg ideal body weight/day. Patients received either an experimental very high-protein (37%) and low-carbohydrate (29%) or control high-protein (25%) and conventional-carbohydrate (45%) EN formula.

RESULTS

A prespecified interim analysis was performed after enrollment of 105 patients (52 experimental, 53 control). Protein and energy delivery for controls and experimental groups on days 1-5 were 1.2 ± 0.4 and 1.1 ± 0.3 g/kg ideal body weight/day (P = .83), and 18.2 ± 6.0 and 12.5 ± 3.7 kcals/kg ideal body weight/day (P < .0001), respectively. The combined rate of glucose events outside the range of >110 and ≤150 mg/dL were not different (P = .54, primary endpoint); thereby the trial was terminated. The mean blood glucose for the control and the experimental groups were 138 (-SD 108, +SD 177) and 126 (-SD 99, +SD 160) mg/dL (P = .004), respectively. Mean rate of glucose events >150 mg/dL decreased (Δ = -13%, P = .015), whereas that of 80-110 mg/dL increased (Δ = 14%, P = .0007). Insulin administration decreased 10.9% (95% CI, -22% to 0.1%; P = .048) in the experimental group relative to the controls. Glycemic events ≤80 mg/dL and rescue dextrose use were not different (P = .23 and P = .53).

CONCLUSIONS

A very high-protein and low-carbohydrate EN formula in a hypocaloric protocol reduces hyperglycemic events and insulin requirements while increasing glycemic events between 80-110 mg/dL.

Safety and efficacy of volume-based feeding in critically ill, mechanically ventilated adults using the 'Protein & Energy Requirements Fed for Every Critically ill patient every Time' (PERFECT) protocol: a before-and-after study

BACKGROUND

Underfeeding in critical illness is common and associated with poor outcomes. According to large prospective hospital studies, volume-based feeding (VBF) safely and effectively improves energy and protein delivery to critically ill patients compared to traditional rate-based feeding (RBF) and might improve patient outcomes. A before-and-after study was designed to evaluate the safety, efficacy and clinical outcomes associated with VBF compared to RBF in a single intensive care unit (ICU).

METHODS

The sample included consecutively admitted critically ill adults, mechanically ventilated for at least 72 h and fed enterally for a minimum of 48 h. The first cohort (n = 46) was fed using RBF, the second (n = 46) using VBF, and observed for 7 days, or until extubation or death. Statistical comparison of percentage feed volume, energy and protein delivered, plus indices of feed intolerance, were the primary outcomes of interest. Secondary observations included ventilation period, mortality, and length of ICU stay (LOICUS).

RESULTS

Groups were comparable in baseline clinical and demographic characteristics and nutrition practices. Volume delivered to the VBF group increased significantly by 11.2% (p ≤ 0.001), energy by 13.4% (p ≤ 0.001) and protein by 8.4% (p = 0.02), compared to the RBF group. In the VBF group, patients meeting > 90% of energy requirements increased significantly from 47.8 to 84.8% (p ≤ 0.001); those meeting > 90% of protein requirements changed from 56.5 to 73.9% (p = 0.134). VBF did not increase symptoms of feed intolerance. Adjusted binomial logistic regression found each additional 1% of prescribed feed delivered decreased the odds of vomiting by 0.942 (5.8%), 95% CI [0.900-0.985], p = 0.010. No differences in mortality or LOICUS were identified. Kaplan-Meier found a significantly increased extubation rate in patients receiving > 90% of protein requirements compared to those meeting < 80%, (p = 0.006). Adjusted Cox regression found the daily probability of being extubated tripled in patients receiving > 90% of their protein needs compared to the group receiving < 80%, hazard ratio 3.473, p = 0.021, 95% CI [1.205-10.014].

CONCLUSION

VBF safely and effectively increased the delivery of energy and protein to critically ill patients. Increased protein delivery may improve extubation rate which has positive patient-centred and financial implications, warranting larger confirmatory trials. This investigation adds weight to the ICU literature supporting VBF, and the growing evidence which advocates for enhanced protein delivery to improve patient outcomes.

New insights into the anorexia of ageing: from prevention to treatment

PURPOSE OF REVIEW

Undernutrition in older adults is associated with frailty, functional decline, and mortality. The 'anorexia of ageing' is the age-related appetite and weight loss underpinning such undernutrition. This review examines the latest evidence for its prevention and treatment.

RECENT FINDINGS

Existing nutritional therapies for the anorexia of ageing include supporting nutritional intake with fortified food or supplements, including protein, omega-3 fatty acids, multivitamins, and vitamin D. The Mediterranean diet provides high fat intake and nutrient density in a moderate volume of colourful and flavoursome food and is strengthening in evidence for healthy ageing. Studies of the gut microbiome, which potentially regulates normal appetite by acting on the brain-gut communication axis, are pertinent. Utilisation of the genetic profile of individuals to determine nutritional needs is an exciting advancement of the past decade and may become common practice.

SUMMARY

Prevention or early treatment of the anorexia of ageing in older adults is critical. Latest evidence suggests that once significant weight loss has occurred, aggressive nutritional support may not result in improved outcomes.

Association of protein intake with the outcomes of critically ill patients: a post hoc analysis of the PermiT trial

Background

The optimal amount of protein intake in critically ill patients is uncertain.

Objective

In this post hoc analysis of the PermiT (Permissive Underfeeding vs. Target Enteral Feeding in Adult Critically Ill Patients) trial, we tested the hypothesis that higher total protein intake was associated with lower 90-d mortality and improved protein biomarkers in critically ill patients.

Design

In this post hoc analysis of the PermiT trial, we included patients who received enteral feeding for ≥3 consecutive days. Using the median protein intake of the cohort as a cutoff, patients were categorized into 2 groups: a higher-protein group (>0.80 g · kg-1 · d-1) and a lower-protein group (≤0.80 g · kg-1 · d-1). We developed a propensity score for receiving higher protein. Primary outcome was 90-d mortality. We also compared serial values of prealbumin, transferrin, 24-h urinary nitrogen, and 24-h nitrogen balance on days 1, 7, and 14.

Results

Among the 729 patients included in this analysis, the average protein intake was 0.8 ± 0.3 g · kg-1 · d-1 [1.0 ± 0.2 g · kg-1 · d-1 in the higher-protein group (n = 365) and 0.6 ± 0.2 g · kg-1 · d-1 in the lower-protein group (n = 364); P < 0.0001]. There was no difference in 90-d mortality between the 2 groups [88/364 (24.2%) compared with 94/363 (25.9%), propensity score-adjusted OR: 0.80; 95% CI: 0.56, 1.16; P = 0.24]. Higher protein intake was associated with an increase in 24-h urea nitrogen excretion compared with lower protein intake, but without a significant change in prealbumin, transferrin, or 24-h nitrogen balance.

Conclusions

In the PermiT trial, a moderate difference in protein intake was not associated with lower mortality. Higher protein intake was associated with increased nitrogen excretion in the urine without a corresponding change in prealbumin, transferrin, or nitrogen balance. Protein intake needs to be tested in adequately powered randomized controlled trials targeting larger differences in protein intake in high-risk populations.

High protein intake during the early phase of critical illness: yes or no?

The rationale for the provision of nitrogen from proteins given via the enteral route or from intravenous amino acids is to boost the synthesis of muscle proteins, and thereby to limit the severity of intensive care unit-acquired weakness by the prevention of muscle loss. However, the optimal timing for supplemental nitrogen provision is a matter of debate and controversy. Indeed, consistent data from retrospective studies support an association between high early protein intakes and better outcomes, while recent post-hoc findings from prospective studies raise safety concerns. This pro–con paper details the arguments of both sides and highlights the need for large-scale prospective studies assessing the safety and efficacy of different levels of protein intake in combination with physical activity and summarizes the currently recruiting clinical trials.

Exploring the Potential Effectiveness of Combining Optimal Nutrition With Electrical Stimulation to Maintain Muscle Health in Critical Illness: A Narrative Review

Muscle wasting occurs rapidly within days of an admission to the intensive care unit (ICU). Concomitant muscle weakness and impaired physical functioning can ensue, with lasting effects well after hospital discharge. Early physical rehabilitation is a promising intervention to minimize muscle weakness and physical dysfunction. However, there is an often a delay in commencing active functional exercises (such as sitting on the edge of bed, standing and mobilizing) due to sedation, patient alertness, and impaired ability to cooperate in the initial days of ICU admission. Therefore, there is high interest in being able to intervene early through nonvolitional exercise strategies such as electrical muscle stimulation (EMS). Muscle health characterized as the composite of muscle quantity, as well as functional and metabolic integrity, may be potentially maintained when optimal nutrition therapy is provided in complement with early physical rehabilitation in critically ill patients; however, the type, dosage, and timing of these interventions are unclear. This article explores the potential role of nutrition and EMS in maintaining muscle health in critical illness. Within this article, we will evaluate fundamental concepts of muscle wasting and evaluate the effects of EMS, as well as the effects of nutrition therapy on muscle health and the clinical and functional outcomes in critically ill patients. We will also highlight current research gaps in order to advance the field forward in this important area.

Metabolic Support of the Patient on Continuous Renal Replacement Therapy

Continuous renal replacement therapy (CRRT) is the modality of choice in critically ill patients with hemodynamic instability requiring renal replacement therapy. The goal of this review is to discuss an overview of CRRT types, components, and important considerations for nutrition support provision. Evidence basis for guidelines and our recommendations are reviewed. Nutrition support-related implications include the possibility of calorie gain with citrate-based anticoagulation, calorie loss with glucose-free replacement fluids and dialysate, and significant amino acid losses in effluent. We challenge nutrition support clinicians to develop a keen understanding of the specific CRRT modalities that are employed in their intensive care units and to be able to determine how the CRRT prescription may impact a patient's nutrition support prescription.

Nutritional Composition Assessment of 3000 Individualized Parenteral Nutrition Bags in a Tertiary Referral Hospital: Current Prescribing Patterns

Individualized parenteral nutrition is the most specialized type of nutritional support in the hospital setting. The composition and prescribing patterns for parenteral nutrition have evolved due to new emerging scientific evidence. In the last few years, there has been a tendency to increase the nitrogen and lipid content and decrease the carbohydrate content. To assess the prescribing pattern in a tertiary referral hospital in Spain, the nutritional composition of individualized parenteral nutrition was evaluated retrospectively from January to December of 2016. A total of 3029 parenteral nutrition units were analysed, corresponding to 257 hospitalized adult patients. Medical specialists in General Surgery and Haematology were the most common petitioners. The three most frequently prescribed parenteral nutrition formulae contained 13.4 (28.8%), 15.7 (19.54%) and 17.9 (17.79%) g of nitrogen. The quantity of carbohydrates and lipids showed a mean non-protein calories-to-nitrogen ratio of approximately 78:1 and a carbohydrate-to-lipid ratio that was near 50:50 in most cases. These results suggest a trend towards the administration of parenteral nutrition with a high content of nitrogen and smaller proportion of the non-protein components.

Very high intact-protein formula successfully provides protein intake according to nutritional recommendations in overweight critically ill patients: a double-blind randomized trial

BACKGROUND

Optimal energy and protein provision through enteral nutrition is essential for critically ill patients. However, in clinical practice, the intake achieved is often far below the recommended targets. Because no polymeric formula with sufficient protein content is available, adequate protein intake can be achieved only by supplemental amino acids or semi-elemental formula administration. In the present study, we investigated whether protein intake can be increased with a new, very high intact-protein formula (VHPF) for enteral feeding.

METHODS

In this randomized, controlled, double-blind, multicenter trial, 44 overweight (body mass index ≥ 25 kg/m2) intensive care unit patients received either a VHPF (8 g/100 kcal) or a commercially available standard high protein formula (SHPF) (5 g/100 kcal). Protein and energy intake, gastrointestinal tolerance (gastric residual volume, vomiting, diarrhea, and constipation), adverse events, and serious adverse events were recorded. Total serum amino acid levels were measured at baseline and day 5.

RESULTS

The primary outcome, protein intake at day 5, was 1.49 g/kg body weight (95% CI 1.21-1.78) and 0.76 g/kg body weight (95% CI 0.49-1.03, P < 0.001) for VHPF and SHPF, respectively. Daily protein intake was statistically significantly higher in the VHPF group compared with the SHPF group from day 2 to day 10. Protein intake in the VHPF group as a percentage of target (1.5 g/kg ideal body weight) was 74.7% (IQR 53.2-87.6%) and 111.6% (IQR 51.7-130.7%) during days 1-3 and days 4-10, respectively. Serum amino acid concentrations were higher at day 5 in the VHPF group than in the SHPF group (P = 0.031). No differences were found in energy intake, measures of gastrointestinal tolerance, and safety.

CONCLUSIONS

Enteral feeding with VHPF (8 g/100 kcal) resulted in higher protein intake and plasma amino acid concentrations than an isocaloric SHPF (5 g/100 kcal), without an increase in energy intake. This VHPF facilitates feeding according to nutritional guidelines and is suitable as a first-line nutritional treatment for critically ill overweight patients.

TRIAL REGISTRATION

Netherlands Trial Register, NTR5643 . Registered on 2 February 2016.

Protein nutrition and exercise survival kit for critically ill

PURPOSE OF REVIEW

Protein delivery as well as exercise of critically ill in clinical practice is still a highly debated issue. Here we discuss only the most recent updates in the literature concerning protein nutrition and exercise of the critically ill.

RECENT FINDINGS

By lack of randomized controlled trial (RCTs) in protein nutrition we discuss four post-hoc analyses of nutrition studies and one experimental study in mice. Studies mainly confirm some insights that protein and energy effects are separate and that the trajectory of the patient in the ICU might change these effects. Exercise has been studied much more extensively with RCTs in the last year, although also here the differences between patient groups and timing of intervention might play their roles. Overall the effects of protein nutrition and exercise appear to be beneficial. However, studies into the differential effects of protein nutrition and/or exercise, and optimization of their combined use, have not been performed yet and are on the research agenda.

SUMMARY

Optimal protein nutrition, optimal exercise intervention as well as the optimal combination of nutrition, and exercise may help to improve long-term physical performance outcome in the critically ill patients.

Tuberculous Pleural Effusion: Clinical Characteristics of 320 Patients

OBJECTIVES

To analyze the clinical and radiological characteristics and features of pleural fluid (PF) in patients with tuberculous pleural effusion (TPE).

METHODS

Retrospective analysis of TPEs treated in our clinic over the last 23years.

RESULTS

We included 320 patients with TPE (70% men; median age 33years). Mycobacterium tuberculosis was identified in the sputum or PF of 36% of the patients by microscopic examination, solid and liquid media cultures, or nucleic acid amplification tests. The greatest percentage of positive microbiological findings were associated with human immunodeficiency virus (HIV) co-infection (OR: 3.27), and with the presence in PF of proteins <4g/dL (OR: 3.53), neutrophils >60% (OR: 3.23), and glucose <40mg/dL (OR: 3.17). Pleural adenosine deaminase <35U/L was associated with TPEs that occupied less than half of the hemithorax (OR: 6.36) and with PF lactate dehydrogenase levels <500U/L (OR: 8.09). Radiological pulmonary opacities (30%) were more common in TPE occupying less than half of the hemithorax (OR: 2.73), in bilateral TPE (OR: 4.48), and in older patients (OR: 1.02). Factors predicting mortality were: HIV co-infection (OR: 24), proteins in PF <5g/dL (OR: 10), and greater age (OR: 1.05).

CONCLUSIONS

Patients with TPE and HIV co-infection and those with lower concentrations of proteins in PF had higher rates of positive microbiological results and death. Moreover, older patients had more pulmonary opacities and a higher incidence of death.