The role of nutritional support in the physical and functional recovery of critically ill patients

The lack of benefit from randomised controlled trials has resulted in significant controversy regarding the role of nutrition during critical illness in terms of long-term recovery and outcome | Critical Care

Although methodological caveats with a failure to adequately appreciate biological mechanisms may explain these disappointing results, it must be acknowledged that nutritional support during early critical illness, when considered alone, may have limited long-term functional impact.

This narrative review focuses specifically on recent clinical trials and evaluates the impact of nutrition during critical illness on long-term physical and functional recovery.

Specific focus on the trial design and methodological limitations has been considered in detail. Limitations include delivery of caloric and protein targets, patient heterogeneity, short duration of intervention, inappropriate clinical outcomes and a disregard for baseline nutritional status and nutritional intake in the post-ICU period.

With survivorship at the forefront of critical care research, it is imperative that nutrition studies carefully consider biological mechanisms and trial design because these factors can strongly influence outcomes, in particular long-term physical and functional outcome. Failure to do so may lead to inconclusive clinical trials and consequent rejection of the potentially beneficial effects of nutrition interventions during critical illness.

Full reference: Bear, D.E. et al. (2017) The role of nutritional support in the physical and functional recovery of critically ill patients: a narrative review. Critical Care. Vol. 21 (no. 226)


NutritionDay ICU: A 7 year worldwide prevalence study of nutrition practice in intensive care

Introduction:  To determine the nutrition practice in intensive care units and the associated outcome across the world, a yearly 1 day cross sectional audit was performed from 2007 to 2013. The data of this initiative called “nutrition Day ICU” were analyzed.

Material and methods:  A questionnaire translated in 17 languages was used to determine the unit’s characteristics, patient’s condition, nutrition condition and therapy as well as outcome. All the patients present in the morning of the 1 day prevalence study were included from 2007 to 2013.

Results:  9777 patients from 46 countries and 880 units were included. Their SAPS 2 was median 38 (IQR 27-51), predicted mortality was 30.7% ± 26.9, and their SOFA score 4.5 ± 3.4 with median 4 (IQR 2-7). Administration of calories did not appear to be related to actual or ideal body weight within all BMI groups. Patients with a BMI 40 received slightly less calories than all other BMI groups. Two third of the patients were either ventilated or were in the ICU for longer than 24 h at nutrition.  Day. Routes of feeding used were the oral, enteral and parenteral routes. More than 40% of the patients were not fed during the first day. The mean energy administered using enteral route was 1286 ± 663 kcal/day and using parenteral nutrition 1440 ± 652 kcal/day. 60 days mortality was 26.0%.

Discussion:  This very large collaborative cohort study shows that most of the patients are underfed during according to actual recommendations their ICU stay. Prescribed calories appear to be ordered regardless to the ideal weight of the patient. Nutritional support is slow to start and never reaches the recommended targets. Parenteral nutrition prescription is increasing during the ICU stay but reaching only 20% of the population studied if ICU stay is one week or longer. The nutritional support worldwide does not seem to be guided by weight or disease but more to be standardized and limited to a certain level of calories. These observations are showing the poor observance to guidelines.

This research by Bendavid and colleagues was published in the Clinical Nutrition August issue.  Library members can order the full text of this and other articles via the Rotherham NHS Foundation Trust Library and Knowledge Service website using the article requests online via this link

Disturbed Microbiome Clinically Detrimental in ICU

Patients in the intensive care unit with an imbalanced microbiome are at increased risk for complications and longer ICU stays, according to findings presented at Clinical Nutrition Week 2017 | Anesthesiology News

B0011080 Bacterial microbiome mapping, bioartistic experiment

Image source: François-Joseph Lapointe, Université de Montréal – Wellcome Images // CC BY 4.0

Image shows bacterial microbiome mapping – a bioartistic experiment.

Paul Wischmeyer, MD, professor of anesthesiology and surgery and director of perioperative research at Duke Clinical Research Institute, in Durham, N.C., who also is part of the ICU Microbiome Project, told meeting attendees that ICU patients experience significant microbiome perturbations and added complications, including acute respiratory distress syndrome (ARDS).

“ICU patients have massive loss of health-promoting bacteria and higher levels of pathogenic species, compared with healthy patients,” Dr. Wischmeyer said. “It is astonishing how rapidly pathogenic bacteria flourish and how this shift to dysbiosis appears to affect a variety of outcomes.”

Dr. Wischmeyer and his colleagues have been examining fecal and oral microbiome samples from 115 ICU patients treated at four hospitals and comparing them with samples from healthy people participating in the American Gut project. In previous research, they found decreases in populations of Bacteroides and Firmicutes, as well as the healthy bacterium, Faecalibacterium prausnitzii, which produces short-chain fatty acids that help preserve normal gut barrier function (mSphere 2016;1[4]. pii:e00199-16). Meanwhile, they discovered increases in the relative abundance of Proteobacteria, a phylum of gram-negative bacteria linked to infections in ICU and hospitalized patients.

ICU patients also tended to lose overall fecal microbiota diversity, with some patients having only one organism compose 95% of their fecal bacteria after a short time in the ICU, he explained.

Muscle mass and physical recovery in ICU

We have significantly improved hospital mortality from sepsis and critical illness in last 10 years; however, over this same period we have tripled the number of ‘ICU survivors’ going to rehabilitation | Current Opinion in Critical Care


Furthermore, as up to half the deaths in the first year following ICU admission occur post-ICU discharge, it is unclear how many of these patients ever returned home or a meaningful quality of life. For those who do survive, recent data reveals many ‘ICU survivors’ will suffer significant functional impairment or post-ICU syndrome (PICS). Thus, new innovative metabolic and exercise interventions to address PICS are urgently needed. These should focus on optimal nutrition and lean body mass (LBM) assessment, targeted nutrition delivery, anabolic/anticatabolic strategies, and utilization of personalized exercise intervention techniques, such as utilized by elite athletes to optimize preparation and recovery from critical care.

New data for novel LBM analysis technique such as computerized tomography scan and ultrasound analysis of LBM are available showing objective measures of LBM now becoming more practical for predicting metabolic reserve and effectiveness of nutrition/exercise interventions. 13C-Breath testing is a novel technique under study to predict infection earlier and predict over-feeding and under-feeding to target nutrition delivery. New technologies utilized routinely by athletes such as muscle glycogen ultrasound also show promise. Finally, the role of personalized cardiopulmonary exercise testing to target preoperative exercise optimization and post-ICU recovery are becoming reality.

Full reference: Wischmeyer, P.E. et al. (2017) Muscle mass and physical recovery in ICU: innovations for targeting of nutrition and exercise. Current Opinion in Critical Care: Published online: June 7, 2017

Electrolyte abnormalities in critically ill patients with end-stage renal disease receiving parenteral nutrition

Dotson, B & Vulaj, V. Journal of Critical Care | Published online: 27 April 2017

Malnutrition is common in patients who are critically ill and is associated with increased morbidity and mortality. For patients unable to receive enteral nutrition, the use of parenteral nutrition (PN) can be life-saving. PN is a complex formulation containing macronutrients, electrolytes, and micronutrients, and critical care clinicians are frequently involved in writing PN orders for patients in the intensive care unit (ICU).

Read the abstract here

Nurses’ prioritization of enteral nutrition in intensive care units

Bloomer, M. J et al. Nursing in Critical Care. Published online: 30 January 2017


Background: Enteral nutrition is important in critically ill patients to improve patient outcomes, with nurses playing a pivotal role in the delivery and ongoing care of enteral nutrition. A significant deficit in nurses’ knowledge and education relating to enteral nutrition has been identified, leading to iatrogenic malnutrition and potentially compromising patient care. Enteral nutrition appears to be prioritized lower than many other aspects of care. However, there is scant research to show how nurses prioritize enteral nutrition.

Conclusion:Respondents relied on their clinical judgement to inform decisions in relation to enteral nutrition in critically ill patients. Most respondents agreed that enteral nutrition was an important aspect of patient care, but acknowledged that other aspects of care were prioritized more highly. Despite this, some delays to enteral nutrition were perceived to be avoidable, and nurses recognized a need to advocate on the patient’s behalf to increase the visibility of enteral nutrition.

Relevance to clinical practice: The findings of this study demonstrate that enteral nutrition is often prioritized lower than other competing care needs in the critically ill patient. Given the importance of enteral nutrition to patient recovery, changes to clinical practice to improve enteral nutrition management are necessary.

Read the full abstract here

Parental nutrition in the critically ill.

Gunst, Jan; Van den Berghe, Greet. Parenteral nutrition in the critically ill. Current Opinion in Critical Care. January 2017

Purpose of review: Feeding guidelines have recommended early, full nutritional support in critically ill patients to prevent hypercatabolism and muscle weakness. Early enteral nutrition was suggested to be superior to early parenteral nutrition. When enteral nutrition fails to meet nutritional target, it was recommended to administer supplemental parenteral nutrition, albeit with a varying starting point. Sufficient amounts of amino acids were recommended, with addition of glutamine in subgroups. Recently, several large randomized controlled trials (RCTs) have yielded important new insights.
This review summarizes recent evidence with regard to the indication, timing, and dosing of parenteral nutrition in critically ill patients.

Recent findings: One large RCT revealed no difference between early enteral nutrition and early parenteral nutrition. Two large multicenter RCTs showed harm by early supplementation of insufficient enteral nutrition with parenteral nutrition, which could be explained by feeding-induced suppression of autophagy. Several RCTs found either no benefit or harm with a higher amino acid or caloric intake, as well as harm by administration of glutamine.

Summary: Although unanswered questions remain, current evidence supports accepting low macronutrient intake during the acute phase of critical illness and does not support use of early parenteral nutrition. The timing when parenteral nutrition can be initiated safely and effectively is unclear.