Nutrition support in critically ill septic patients

Change of serum prealbumin levels and serum protein markers between egg white powder and casein protein additives in standard enteral feeding formulas in critically ill patients with acute respiratory failure

Background

Protein deficiency is a major problem in critically ill patients. Egg white powder recently became a standard additive for protein supplementation in our unit. However, clinical data are not available to support egg white powder supplementation compared to standard protein casein supplementation. This study aimed to determine the change of serum prealbumin (PAB) levels of egg white powder compared to casein additive in standard enteral feeding in critically ill patients with respiratory failure.

Methods

A prospective double-blind, randomized, non-inferiority study was conducted in patients with acute respiratory failure in the medical intensive care unit and respiratory care unit. These patients randomly received 1500 kcal/day of enteral nutrition support with 40 g/day of protein additives by either egg white protein powder or casein protein for 7 days. The serum PAB and C-reactive protein (CRP) levels were measured on days 1, 3, 5, and 7. Repeated-measures ANOVA determined the group effects displayed by serum PAB and CRP levels. p values <0.05 were considered statistically significant.

Results

Thirty-four patients were in two groups: 17 in the casein protein group and 17 in the egg white powder group. The clinical characteristics, baseline nutritional status, and biochemistries were not significantly different between the groups. No statistically significant differences were seen in the serum PAB and serum CRP levels between the two groups. The average mean ± SEM difference of serum PAB level between the groups was 2.3 ± 2.5 mg% (p = 0.58).

Conclusions

The levels of PAB between the egg white protein additive and casein protein additive were not significantly different and less than the non-inferior margin.

Trial registration

Thai Clinical Trials Registry TCTR20160126002

Providing optimal nutritional support on the intensive care unit: key challenges and practical solutions

Many patients in the intensive care unit are malnourished or unable to eat. Feeding them correctly has the potential to reduce morbidity and even mortality but is a very complex procedure. The inflammatory response induced by surgery, trauma or sepsis will alter metabolism, change the ability to utilise nutrients and can lead to rapid loss of lean mass. Both overfeeding and underfeeding macronutrients can be harmful but generally it would seem optimal to give less during metabolic stress and immobility and increase in recovery. Physical intolerance of feeding such as diarrhoea or delayed gastric emptying is common in the intensive care unit. Diarrhoea can be treated with fibre or peptide feeds and anti-diarrhoeal drugs; however, the use of probiotics is controversial. Gastric dysfunction problems can often be overcome with prokinetic drugs or small bowel feeding tubes. New feeds with nutrients such as n-3 fatty acids that have the potential to attenuate excessive inflammatory responses show great promise in favourably improving metabolism and substrate utilisation. The importance of changing nutrient provision according to metabolic and physical tolerance cannot be understated and although expert groups have produced many guidelines on nutritional support of the critically ill, correct interpretation and implementation can be difficult without a dedicated nutrition health care professional such as a dietitian or a multidisciplinary nutritional support team.

Nutrition assessment: the reproducibility of subjective global assessment in patients requiring mechanical ventilation

Background/Objective

The detection of malnutrition in the intensive care unit (ICU) is critical to appropriately address its contribution on outcomes. The primary objective of this investigation was to determine if nutritional status could be reliably classified using Subjective Global Assessment (SGA) in mechanically ventilated (MV) patients.

Subjects/Methods

Fifty-seven patients requiring MV greater than 48 hours in a university-affiliated medical ICU were evaluated in this cross-sectional study over a 3 month period. Nutritional status was categorized independently by two Registered Dietitians using SGA. Frequencies, means (± standard deviations), Chi square and T tests were used to describe the population characteristics; agreement between raters was evaluated using the κ statistic.

Results

On admission, the average patient was 50.4 (± 14.2) years of age, overweight (body mass index: 29.0 ± 9.2), had an APACHE II score of 24 (± 10) and respiratory failure. Fifty percent (n=29) of patients were categorized as malnourished. Agreement between raters was 95% prior to consensus, reflecting near perfect agreement (κ =0.90) and excellent reliability. Patients categorized as malnourished were more often admitted to the hospital floor prior to the ICU (n=32; 56%), reported decreased dietary intake (69% vs. 46%, p=0.02) and exhibited signs of muscle wasting (45% vs. 7%, p<0.001, respectively) and fat loss (52% vs. 7%, p<0.001, respectively) on physical exam when compared to normally nourished individuals.

Conclusions

SGA can serve as a reliable nutrition assessment technique for detecting malnutrition in patients requiring MV. Its routine use should be incorporated into future studies and clinical practice.

[The Latin-American survey on nutrition in Pediatric Intensive Care (ELAN-CIP)]

INTRODUCTION

Artificial Nutrition Support (ANS) is an important therapeutic technique in the care of the critically ill child that is not always implemented appropriately and correctly. There are also different ways of applying it which varies between the different centres and, even among the different health professionals.

MATERIAL METHODS

A cross-sectional multicentre survey.

RESULTS

A total of 24 PICUs took part in 14 countries, the majority multidisciplinary and belonging to public and university hospitals. The preferred ANS was enteral, administrated by the gastric route and started within the first 72h after admission. The administration techniques and monitoring of the ANS, enteral and parenteral, were variable but generally consistent with the world-wide accept recommendations.

CONCLUSIONS

Latin-American PICUs prefer enteral ANS administered by gastric feed soon after admission.

Effect of Enteral Versus Parenteral Nutrition on LPS-Induced Sepsis in a Rat Model

BACKGROUND

The purpose of the present study was to determine whether total enteral nutrition (TEN) or total parenteral nutrition (TPN) differ in their modulation of ghrelin production and cardiac dysfunction induced by lipopolysaccharide (LPS).

MATERIALS AND METHODS

Vascular catheters or gastrostomy tubes were surgically placed into rats who received isocaloric parenteral or enteral nutrition postoperatively. After 7 d, the rats were injected intravenously with LPS (2.5 mg/kg). Serum ghrelin levels were determined by enzyme-linked immunosorbent assay and myocardiac function was assessed via the Langendorff isolated heart technique.

RESULTS

Before and after the administration of LPS, TEN was found to be more effective at increasing the plasma ghrelin levels than TPN. After LPS administration, left-ventricular developed pressure decreased in animals receiving TPN when compared with animals receiving TEN. Animals receiving TPN also had significant reductions in their maximal rates of increase (+dp/dt max) and decrease (-dp/dt max) in left ventricular pressure when compared with animals receiving TEN (unpaired t-test, P < 0.05). Upon reperfusion after 30 min of ischemia, the left ventricular resting tension decreased in animals receiving TPN compared with animals receiving TEN. Thereafter, left-ventricular developed pressure, +dp/dt max, and -dp/dt max decreased in the TEN recipients in comparison to the TPN-receiving animals.

CONCLUSIONS

We conclude that TEN more effectively increases plasma ghrelin levels than TPN. The maintenance of higher ghrelin levels in TEN-fed rats is associated with maintaining cardiac function during LPS-induced septic shock.

Early enteral nutrition in the critically ill: do we need more evidence or better evidence?

PURPOSE OF REVIEW

Nutritional support of the critically ill is accepted as a standard of care. Recommendations for early enteral nutrition are based on reasonable evidence but only 50% of eligible patients receive enteral nutrition within 48 h of admission to the intensive care unit. The purpose of this review is to determine how recent developments advance the current state of knowledge.

RECENT FINDINGS

The benefits of early enteral nutrition are supported by two recent evidence-based guidelines initiatives. Early (< 48 h after intensive care unit admission) enteral nutrition may decrease hospital discharge mortality by 8-12% (grade B+ evidence-based recommendation). Five recent level II clinical trials, two of which contain major methodological flaws, are consistent with this recommendation.

SUMMARY

Higher levels of evidence, demonstrating benefit to a patient-oriented outcome, are more likely to change practice. The addition of more level II trials to a meta-analysis composed of level II trials may not convince clinicians to change practice. A level I trial (equivalent to a phase III Food and Drug Administration licensing trial) is required to convince more clinicians to provide early enteral nutrition. A level I trial would also provide an important opportunity to validate changes in disease-oriented outcomes (measures of nutritional status) against improvements in patient-oriented outcomes.

Nutrition support for patients in the intensive care unit

Enteral nutrition (EN) is the mainstay of nutrition delivery within intensive care seeking to capitalise on its benefits for the gastrointestinal tract and associated immune system, but this has brought new challenges in delivery to the sick. The hoped for benefit has led to the mistaken belief by some that parenteral nutrition (PN) is no longer required. However, a greater appreciation of the risks of EN delivery in the sick patient combined with improvements in PN formulation and use help explain why PN is not as risky as some have believed. Real outcome benefits have been described with the new glutamine containing PN formulations. PN remains important in the presence of gastrointestinal feed intolerance or failure.

Muscle glutamine depletion in the intensive care unit

Glutamine is primarily synthesized in skeletal muscle and enables transfer of nitrogen to splanchnic tissues, kidneys and immune system. Discrepancy between increasing rates of glutamine utilization at whole body level and relative impairment of de novo synthesis in skeletal muscle leads to systemic glutamine deficiency and characterizes critical illness. Glutamine depletion at whole body level may contribute to gut, liver and immune system disfunctions, whereas its intramuscular deficiency may directly contribute to lean body mass loss. Severe intramuscular glutamine depletion also develops because of outward transport system upregulation, which is not counteracted by increased de novo synthesis. The negative impact of systemic glutamine depletion on critically ill patients is suggested both by the association between a lower plasma glutamine concentration and poor outcome and by a clear clinical benefit after glutamine supplementation. Enteral glutamine administration preferentially increases glutamine disposal in splanchnic tissues, whereas parenteral supplementation provides glutamine to the whole organism. Nonetheless, systemic administration was ineffective in preventing muscle depletion, due to a relative inability of skeletal muscle to seize glutamine from the bloodstream. Intramuscular glutamine depletion could be potentially counteracted by promoting de novo glutamine synthesis with pharmacological or nutritional interventions.

Clinical evaluation of hormonal stress state in medical ICU patients: a prospective blinded observational study

OBJECTIVE

To evaluate whether classification of patients as having low, moderate, or high stress based on clinical parameters is associated with plasma levels of stress hormone.

DESIGN AND SETTING

Prospective, blinded, observational study in an 18-bed medical ICU.

PATIENTS

Eighty-eight consecutive patients.

INTERVENTIONS

Patients were classified as low (n=28), moderate (n=33) or high stress (n=27) on days 0 and 3 of ICU stay, based on 1 point for each abnormal parameter: body temperature, heart rate, systemic arterial pressure, respiratory rate, physical agitation, presence of infection and catecholamine administration. The stress categories were: high: 4 points or more, moderate 2-3 points, low 1 point. Plasma growth hormone (GH), insulin-like growth factor 1 (IGF-1), insulin, glucagon, cortisol were measured on days 0 and 3.

MEASUREMENTS AND RESULTS

Plasma cortisol and glucagon were significantly higher and IGF-1 lower in high vs. low stress patients on days 0 and 3. High stress patients were more likely to have high cortisol levels (odds ratio 5.8, confidence interval 1.8-18.9), high glucagon (8.7, 2.1-36.1), and low IGF-1 levels (5.9, 1.8-19.0) than low stress patients on day 0. Moderate stress patients were also more likely to have high cortisol and glucagon levels than low stress patients. Insulin and GH did not differ significantly. Results were similar for day 3.

CONCLUSIONS

Moderate and severe stress was significantly associated with high catabolic (cortisol, glucagon) and low anabolic (IGF-1) hormone levels. The hormonal stress level in ICU patients can be estimated from simple clinical parameters during routine clinical evaluation.

The role of the dietitian in the intensive care unit

PURPOSE OF REVIEW

The role of the intensive care unit registered dietitian has evolved over the past few years to become a vital component of the intensivist-led multidisciplinary intensive care unit team. The purpose of this review is to define the level of clinical practice and skill set of the intensive care unit dietitian, which defines them as a clinician, educator and researcher worthy to practice alongside their colleagues on the intensive care unit team.

RECENT FINDINGS

An intensive care unit registered dietitian must be a dedicated professional with advanced training in critical care nutrition, the ability to read critically and evaluate new literature, a willingness to think 'outside the box', the fortitude to be an active participant in the intensive care unit team, the aptitude to educate colleagues and students from all disciplines, and the desire to participate in clinical research. Intensive care unit registered dietitians have published research concerning the nutritional assessment of the critically ill patient, the route of nutritional support, nutritional access, fluid and electrolyte issues, speciality enteral products, and optimal blood glucose control. They continue to attain skills and knowledge to extend their scope of practice and improve the quality of care in the intensive care unit. Recent guidelines adapted to the nutritional care of critically ill patients have been published for guidance.

SUMMARY

The scope of practice of intensive care dietitians defines them as clinicians, educators and researchers. Their skill set is a unique and vital component of the intensivist-led multidisciplinary intensive care unit team.

Nutrition and the chronically critically ill patient

PURPOSE OF REVIEW

It has been recently recognized that patients of chronic critical illness (CCI) - those who have stabilized after an acute critical illness but remain dependent on life-support - manifest a distinct set of clinical attributes. This unique patient population is often dismissed as hopeless, with aggressive medical therapies considered futile. In fact, with meticulous care, many CCI patients can be liberated from mechanical ventilation and graduated to a rehabilitation program. The nutritional approach to CCI patients is presented here as part of a comprehensive metabolic program to increase their survival and quality of life.

RECENT FINDINGS

Both theory-driven and data-driven advances to our knowledge of CCI syndrome have appeared in the literature over the past year. Recurrent activation of the immune-neuroendocrine axis may induce allostatic overload in CCI. Experimental studies with hypothalamic releasing factors and intensive insulin therapy demonstrate that mechanisms perpetuating the CCI state can be abrogated. Recent studies and consensus opinions support the use of aggressive nutrition support.

SUMMARY

Nutritional assessment and support of the CCI patient must be implemented upon admission to the respiratory care unit (RCU). Enteral nutrition (EN) with semi-elemental formulas is preferred. Parenteral nutrition is used to supplement EN when necessary. Overfeeding is avoided and tight glycemic control maintained. Diarrhea is aggressively managed. By correcting proximal etiologic events (infection, inflammatory, injuries), avoiding iatrogenic complications and devoting careful attention to nutritional status, CCI patients can potentially overcome their pulmonary compromise and debilitated state, to fully recover.

Is parenteral nutrition really that risky in the intensive care unit?

PURPOSE OF REVIEW

Although enteral nutrition is now the mainstay of nutrition delivery within intensive care, there is a blind faith in its benefits and a disregard of its risks. This has led to the belief that parenteral nutrition is no longer required as it is fraught with risks to the patient. This review attempts to dispel these myths and compares and contrasts the risks of enteral nutrition with those of parenteral nutrition in the critically ill.

RECENT FINDINGS

A greater appreciation of the failings and risks associated with the delivery of enteral nutrition combined with improvements in the formulation and use of parenteral nutrition help explain why parenteral nutrition is not as risky as some have believed. Recent evidence has suggested that enteral nutrition in a few selected circumstances may even carry a higher mortality risk. Real outcome benefits have been described with the new glutamine-containing parenteral nutrition formulations.

SUMMARY

Parenteral nutrition remains a valuable yet challenging weapon in our therapeutic armoury in the presence of gastrointestinal feed intolerance or failure. However, it should be used wisely and not indiscriminately because the majority of intensive care unit patients with a fully functional gastrointestinal tract may be fed safely with enteral nutrition.

Can it all be done by enteral nutrition?

PURPOSE OF REVIEW

During recent years techniques and metabolic considerations have been discussed intensively. One contributing reason is that results have not always been easy to interpret and introduce into clinical practice. Nutrition through the enteral and parenteral route has classically been compared, and this is the topic of this review.

RECENT FINDINGS

During the past 2 years a growing number of studies have focused on the amount and type of nutrition that is possible to give by enteral nutrition to intensive care unit patients. How to handle the clinical problem with paralysis and gastroparesis has also been studied. Basic research has shown a link between the gastrointestinal tract, immunocompetence and nutritional status. More evidence now exists that this is also clinically valid.

SUMMARY

Recent research has shown that enteral nutrition alone does not cover the total nutritional needs of intensive care unit patients. Enteral nutrition given early in a high dose is associated with a higher risk of complications. Metabolism in intensive care unit patients is different from the perioperative condition, which has been highlighted in recent studies with important clinical implications. The final solution has not been found yet, if it exists at all, and research in this field will continue. As the situation in biology and in real intensive care unit life is neither black nor white, it would be most beneficial for the intensive care unit patient if enteral nutrition and parenteral nutrition joined together in a good balance in order to avoid underload and overload.

Current concepts in the diagnosis and management of trauma-related sepsis

Traumatic injury is common, and accounts for a large health care burden. Trauma and in particular haemorrhagic shock are closely related to the onset of multiple organ failure, the systemic inflammatory response and sepsis. Despite overall improvements in the care of septic critically ill patients there has been little impact on morbidity and mortality. In recent years our understanding of sepsis both as an illness and at a molecular level has led to the development of a number of therapeutic interventions. This article outlines the current evidence for such interventions and points to possible future research that is required in the diagnosis and management of trauma-related sepsis.