Objectives: Adverse physiology and antibiotic exposure devastate the intestinal microbiome in critical illness. Time and cost implications limit the immediate clinical potential of microbial sequencing to identify or treat intestinal dysbiosis. Here, we examined whether metabolic profiling is a feasible method of monitoring intestinal dysbiosis in critically ill children. Design: Prospective multicenter cohort study. Setting: Three U.K.-based PICUs. Patients: Mechanically ventilated critically ill (n = 60) and age-matched healthy children (n = 55). Interventions: Collection of urine and fecal samples in children admitted to the PICU. A single fecal and urine sample was collected in healthy controls. Measurements and Main Results: Untargeted and targeted metabolic profiling using 1H-nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry or urine and fecal samples. This was integrated with analysis of fecal bacterial 16S ribosomal RNA profiles and clinical disease severity indicators. We observed separation of global urinary and fecal metabolic profiles in critically ill compared with healthy children. Urinary excretion of mammalian-microbial co-metabolites hippurate, 4-cresol sulphate, and formate were reduced in critical illness compared with healthy children. Reduced fecal excretion of short-chain fatty acids (including butyrate, propionate, and acetate) were observed in the patient cohort, demonstrating that these metabolites also distinguished between critical illness and health. Dysregulation of intestinal bile metabolism was evidenced by increased primary and reduced secondary fecal bile acid excretion. Fecal butyrate correlated with days free of intensive care at 30 days (r = 0.38; p = 0.03), while urinary formate correlated inversely with vasopressor requirement (r = –0.2; p = 0.037). Conclusions: Disruption to the functional activity of the intestinal microbiome may result in worsening organ failure in the critically ill child. Profiling of bacterial metabolites in fecal and urine samples may support identification and treatment of intestinal dysbiosis in critical illness.

Changes in the microbiome in response to environmental influences can affect the overall health. Critical illness is considered one of the major environmental factors that can potentially influence the normal gut homeostasis. It is associated with pathophysiological effects causing damage to the intestinal microbiome. Alteration of intestinal microbial composition during critical illness may subsequently compromise the integrity of the intestinal epithelial barrier and intestinal mucosa absorptive function. Many factors can impact the microbiome of critically ill patients including ischemia, hypoxia and hypotension along with the iatrogenic effects of therapeutic agents and the lack of enteral feeds. Factors related to disease state and medication are inevitable and they are part of the intensive care unit (ICU) exposure. However, a nutritional intervention targeting gut microbiota might have the potential to improve clinical outcomes in the critically ill population given the extensive vascular and lymphatic links between the intestines and other organs. Although nutrition is considered an integral part of the treatment plan of critically ill patients, still the role of nutritional intervention is restricted to improve nitrogen balance. What is dismissed is whether the nutrients we provide are adequate and how they are processed and utilised by the host and the microbiota. Therefore, the goal of nutrition therapy during critical illness should be extended to provide good quality feeds with balanced macronutrient content to feed up the entire body including the microbiota and host cells. The main aim of this review is to examine the current literature on the effect of critical illness on the gut microbiome and to highlight the role of nutrition as a factor affecting the intestinal microbiome-host relationship during critical illness.

Background and Aims: Achieving optimal nutrition prescription is challenging in critically ill patients. Many factors can hinder the adequate delivery of enteral nutrition (EN) in intensive care units (ICUs). In this study, we aim to describe EN barriers and compare the perceptions of health care practitioners working in adult and paediatric ICUs regarding these barriers. Methods: In this cross-sectional study, data were collected via online survey. All physicians, dietitians, and nurses working in adult or paediatric ICUs across Saudi Arabia were eligible to participate. The survey contained 24 potential EN barriers and participants were asked to rate their importance on a scale from 1 to 5. A total Likert rating score of the 24 items was later calculated. Results: We recruited 244 health care providers working in adult and paediatric ICUs. The most important perceived barriers were “Delay in physician ordering EN initiation” (3.33 ± 1.32), and ‘Waiting for dietitians to assess patients’ (3.22 ± 1.20). There was a statistical difference between the responses of health care providers based on their work settings for the following items; “Nurses failing to progress feeds according to feeding protocol” (p=0.006) and ‘Feeding being held too far prior procedures or operating-room visits’ (p=0.021). Profession significantly influenced the total Likert rating score of the 24 items (r=− 0.234, p=0.001). Conclusion: This study identified some barriers of EN delivery in ICUs and showed that participants’ perceptions regarding these barriers were influenced by their roles. These findings shed light on the nutritional practices in Saudi hospitals and identify areas of improvement in EN practice and advancements in the field of critical care nutrition in the region.

Background: The management process of Enteral Nutrition (EN) typically involves the interaction between a team of health care practitioners. Nurses being the closest to the patients, have crucial responsibilities and play a major role in feeding delivery along with other medical treatments. This study was conducted to investigate the perception of the nurses working in adult and paediatric intensive care Units (ICUs) regarding the EN barriers and identify the factors that influenced their perception. Methods: The data in this cross-sectional study was collected via online survey between 15 October 2021 and January 2022. All nurses working in adult or paediatric ICUs across Saudi Arabia were eligible to participate. The tool used for the data collection was adapted from Cahill et al. (2016) and then reviewed and modified by the researchers. The survey collected information about the demographics of the nurses, and it included 24 potential EN barriers where the participants were asked to rate their importance on a scale from 1 to 5. Descriptive statistics were performed to describe the variables, univariant analysis were performed to compare the perceptions of the nurses regarding the EN barriers based on their characteristics followed by stepwise linear regression analysis. Results: A total of 136 nurses working in adult and paediatric ICUs were included in this study. The results showed that the most important barriers as perceived by the nurses was “Frequent displacement of feeding tube, requiring reinsertion” [3.29 ± 1.28], “Delays in initiating motility agents in patients not tolerating enteral nutrition” [3.27 ± 1.24] and “Enteral formula not available on the unit”. [3.27 ± 1.24]. Our results showed that the responses of the participants statistically varied based on their work settings, gender, region, and educational level for some items in the survey (P-value ≤ 0.05). In the regression analysis, gender was the only variable statistically influenced the total Likert rating scores of the participants (r = -0.213, p-value = 0.013). Conclusion: This study identified several barriers that exist in the nursing practice of EN in critical care settings. There are distinct differences in the perception of the nurses to these barriers based on their characteristics. Understanding such differences is important for implementing future strategies for units that needed the most help in prioritizing EN delivery.

Biochemical assessment is considered a useful tool in assessing the patient’s nutritional status and intake. However, during critical illness, nutritional biomarkers, such as albumin, and haemoglobin (HB) may reflect the severity of acute illness. The aim of this study is to assess the relationship between energy and protein delivery with the change in albumin, HB, “mean corpuscular volume”(MCV), and “mean corpuscular haemoglobin concentration” (MCHC) levels in critically ill patients. In this prospective observational study we monitored the intake of energy and protein in a group critically ill patients for 6 consecutive days. Biochemical data including albumin, HB, MCV and MCHC was measured on admission and on day 6 of the follow-up. The variation in the biomarkers between admission and day 6 was calculated as the follow-up reading minus the reading obtained upon admission to (Intensive Care Unit) ICU. This study included 43 patients. There was a significant difference in the albumin and HB levels between admission and follow up readings. No statistical association was recorded between the intake and the changes in albumin, MCV and MCHC level during ICU stay. The results showed a significant association between the intake of energy (R = 0.393), and protein (R = 0.385), with the increase in HB level during hospitalisation. Overall, this study showed that most nutritional biomarkers were not influenced by nutritional therapy during the acute phase of illness. These findings may directly undermine the usefulness of the serial measurements of these biomarkers in the early phase of ICU admission.