Summary Background & aims This review aims to clarify the use of indirect calorimetry (IC) in nutritional therapy for critically ill and other patient populations. It features a comprehensive ...overview of the technical concepts, the practical application and current developments of IC. Methods Pubmed-referenced publications were analyzed to generate an overview about the basic knowledge of IC, to describe advantages and disadvantages of the current technology, to clarify technical issues and provide pragmatic solutions for clinical practice and metabolic research. The International Multicentric Study Group for Indirect Calorimetry (ICALIC) has generated this position paper. Results IC can be performed in in- and out-patients, including those in the intensive care unit, to measure energy expenditure (EE). Optimal nutritional therapy, defined as energy prescription based on measured EE by IC has been associated with better clinical outcome. Equations based on simple anthropometric measurements to predict EE are inaccurate when applied to individual patients. An ongoing international academic initiative to develop a new indirect calorimeter aims at providing innovative and affordable technical solutions for many of the current limitations of IC. Conclusion Indirect calorimetry is a tool of paramount importance, necessary to optimize the nutrition therapy of patients with various pathologies and conditions. Recent technical developments allow broader use of IC for in- and out-patients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Abstract
Gut microbiota plays an essential role in health and disease. It is constantly evolving and in permanent communication with its host. The gut microbiota is increasingly seen as an organ, and ...its failure, reflected by dysbiosis, is seen as an organ failure associated with poor outcomes. Critically ill patients may have an altered gut microbiota, namely dysbiosis, with a severe reduction in “health-promoting” commensal intestinal bacteria (such as Firmicutes or Bacteroidetes) and an increase in potentially pathogenic bacteria (e.g. Proteobacteria). Many factors that occur in critically ill patients favour dysbiosis, such as medications or changes in nutrition patterns. Dysbiosis leads to several important effects, including changes in gut integrity and in the production of metabolites such as short-chain fatty acids and trimethylamine N-oxide. There is increasing evidence that gut microbiota and its alteration interact with other organs, highlighting the concept of the gut–organ axis. Thus, dysbiosis will affect other organs and could have an impact on the progression of critical diseases. Current knowledge is only a small part of what remains to be discovered. The precise role and contribution of the gut microbiota and its interactions with various organs is an intense and challenging research area that offers exciting opportunities for disease prevention, management and therapy, particularly in critical care where multi-organ failure is often the focus. This narrative review provides an overview of the normal composition of the gut microbiota, its functions, the mechanisms leading to dysbiosis, its consequences in an intensive care setting, and highlights the concept of the gut–organ axis.
Summary Background Enteral nutrition (EN) is recommended for patients in the intensive-care unit (ICU), but it does not consistently achieve nutritional goals. We assessed whether delivery of 100% of ...the energy target from days 4 to 8 in the ICU with EN plus supplemental parenteral nutrition (SPN) could optimise clinical outcome. Methods This randomised controlled trial was undertaken in two centres in Switzerland. We enrolled patients on day 3 of admission to the ICU who had received less than 60% of their energy target from EN, were expected to stay for longer than 5 days, and to survive for longer than 7 days. We calculated energy targets with indirect calorimetry on day 3, or if not possible, set targets as 25 and 30 kcal per kg of ideal bodyweight a day for women and men, respectively. Patients were randomly assigned (1:1) by a computer-generated randomisation sequence to receive EN or SPN. The primary outcome was occurrence of nosocomial infection after cessation of intervention (day 8), measured until end of follow-up (day 28), analysed by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT00802503. Findings We randomly assigned 153 patients to SPN and 152 to EN. 30 patients discontinued before the study end. Mean energy delivery between day 4 and 8 was 28 kcal/kg per day (SD 5) for the SPN group (103% SD 18% of energy target), compared with 20 kcal/kg per day (7) for the EN group (77% 27%). Between days 9 and 28, 41 (27%) of 153 patients in the SPN group had a nosocomial infection compared with 58 (38%) of 152 patients in the EN group (hazard ratio 0·65, 95% CI 0·43–0·97; p=0·0338), and the SPN group had a lower mean number of nosocomial infections per patient (−0·42 −0·79 to −0·05; p=0·0248). Interpretation Individually optimised energy supplementation with SPN starting 4 days after ICU admission could reduce nosocomial infections and should be considered as a strategy to improve clinical outcome in patients in the ICU for whom EN is insufficient. Funding Foundation Nutrition 2000Plus, ICU Quality Funds, Baxter, and Fresenius Kabi.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background Methods to calculate energy expenditure (EE) based on CO2 measurements (EEVCO2) have been proposed as a surrogate to indirect calorimetry. This study aimed at evaluating whether EEVCO2 ...could be considered as an alternative to EE measured by indirect calorimetry. Methods Indirect calorimetry measurements conducted for clinical purposes on 278 mechanically ventilated ICU patients were retrospectively analyzed. EEVCO2 was calculated by a converted Weir's equation using CO2 consumption (VCO2) measured by indirect calorimetry and assumed respiratory quotients (RQ): 0.85 (EEVCO2_0.85) and food quotient (FQ; EEVCO2_FQ). Mean calculated EEVCO2 and measured EE were compared by paired t test. Accuracy of EEVCO2 was evaluated according to the clinically relevant standard of 5% accuracy rate to the measured EE, and the more general standard of 10% accuracy rate. The effects of the timing of measurement (before or after the 7th ICU day) and energy provision rates (<90 or ≥90% of EE) on 5% accuracy rates were also analyzed (chi-square tests). Results Mean biases for EEVCO2_0.85 and EEVCO2_FQ were -21 and -48 kcal/d (p = 0.04 and 0.00, respectively), and 10% accuracy rates were 77.7 and 77.3%, respectively. However, 5% accuracy rates were 46.0 and 46.4%, respectively. Accuracy rates were not affected by the timing of the measurement, or the energy provision rates at the time of measurements. Conclusions Calculated EE based on CO2 measurement was not sufficiently accurate to consider the results as an alternative to measured EE by indirect calorimetry. Therefore, EE measured by indirect calorimetry remains as the gold standard to guide nutrition therapy.
This review emphasizes the role of a timely supplemental parenteral nutrition (PN) for critically ill patients. It contradicts the recommendations of current guidelines to avoid the use of PN, as it ...is associated with risk. Critical illness results in severe metabolic stress. During the early phase, inflammatory cytokines and mediators induce catabolism to meet the increased body energy demands by endogenous sources. This response is not suppressed by exogenous energy administration, and the early use of PN to reach the energy target leads to overfeeding. On the other hand, early and progressive enteral nutrition (EN) is less likely to cause overfeeding because of variable gastrointestinal tolerance, a factor frequently associated with significant energy deficit. Recent studies demonstrate that adequate feeding is beneficial during and after the intensive care unit (ICU) stay. Supplemental PN allows for timely adequate feeding, if sufficient precautions are taken to avoid overfeeding. Indirect calorimetry can precisely define the adequate energy prescription. Our pragmatic approach is to start early EN to progressively test the gut tolerance and add supplemental PN on day 3 or 4 after ICU admission, only if EN does not meet the measured energy target. We believe that supplemental PN plays a pivotal role in the achievement of adequate feeding in critically ill patients with intolerance to EN and does not cause harm if overfeeding is avoided by careful prescription, ideally based on energy expenditure measured by indirect calorimetry.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK, VSZLJ
OBJECTIVES:To investigate if light sedation favorably affects subsequent patient mental health compared with deep sedation. Symptoms of posttraumatic stress disorder are common in patients after they ...have undergone prolonged mechanical ventilation and are associated with sedation depth.
DESIGN:Randomized, open-label, controlled trial.
SETTING:Single tertiary care center.
PATIENTS:Adult patients requiring mechanical ventilation.
INTERVENTIONS:Patients were randomized to receive either light (patient awake and cooperative) or deep sedation (patient asleep, awakening upon physical stimulation).
MEASUREMENTS AND MAIN RESULTS:Self-reported measures of posttraumatic stress disorder, anxiety, and depression were collected at intensive care unit discharge and 4 wks later. The primary outcomes were symptoms of posttraumatic stress disorder, anxiety, and depression 4 wks after intensive care unit discharge.A total of 137 patients were assigned to either the light (n = 69) or the deep sedation (n = 68) group. Seven patients withdrew consent and one patient was randomized in error, leaving 129 patients (n = 65 in light sedation and n = 64 in deep sedation) available for analysis. At the 4-wk follow-up, patients in the deep sedation group tended to have more posttraumatic stress disorder symptoms (p = .07); the deep sedation group had more trouble remembering the event (37% vs. 14%; p = .02) and more disturbing memories of the intensive care unit (18% vs. 4%; p = .05). Patients in the light sedation group had an average one day less being ventilated and 1.5 fewer days in the intensive care unit. There were no differences between the two groups in the occurrence of anxiety and depression, and also no difference in mortality or in the incidence of adverse events.
CONCLUSIONS:These data suggest that a strategy of light sedation affords benefits with regard to reduction of intensive care unit stay and duration of ventilation without negatively affecting subsequent patient mental health or patient safety.
The ICALIC project was initiated for developing an accurate, reliable and user friendly indirect calorimeter (IC) and aimed at evaluating its ease of use and the feasibility of the EE measurements in ...intensive care unit (ICU).
This was a prospective unblinded, observational, multi-center study. Simultaneous IC measurements in mechanically ventilated ICU patients were performed using the new IC (Q-NRG®) and currently used devices. Time required to obtain EE was recorded to evaluate the ease of use of Q-NRG® versus currently used ICs and EE measurements were compared. Conventional descriptive statistics were used: data as mean ± SD.
Six centers out of nine completed the required number of patients for the primary analysis. Mean differences in the time needed by Q-NRG® against currently used ICs were −32.3 ± 2.5 min in Geneva (vs. Deltatrac®; p < 0.01), −32.3 ± 3.1 in Lausanne (vs. Quark RMR®; p < 0.05), −33.7 ± 1.4 in Brussels (vs. V-Max Encore®; p < 0.05), −26.4 ± 7.8 in Tel Aviv (vs. Deltatrac®; p < 0.05), −28.5 ± 3.5 in Vienna (vs. Deltatrac®; p < 0.05), and 0.3 ± 1.2 in Chiba (vs. E-COVX®; p = 0.17). EE (kcal/day) measurements by the Q-NRG® were similar to the Deltatrac® in Geneva and Vienna (mean differences±SD: −63.1 ± 157.8 (p = 0.462) and −22.9 ± 328.2 (=0.650)), but significantly different in Tel Aviv (307.4 ± 324.5, p < 0.001). Significant differences were observed in Lausanne (Quark RMR®: −224.4 ± 514.9, p = 0.038) and in Brussels (V-max®: −449.6 ± 667.4, p < 0.001), but none was found in Chiba (E-COVX®; 55.0 ± 204.1, p = 0.165).
The Q-NRG® required a much shorter time than most other ICs to determine EE in mechanically ventilated ICU patients. The Q-NRG® is the only commercially available IC tested against mass spectrometry to ensure gas accuracy, while being very easy-to use.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Prolonged intensive care unit (ICU) stay is associated with physical, cognitive, and psychological disabilities. The impact of baseline frailty on long-stay ICU patients remains uncertain. ...This study aims to investigate how baseline frailty influences mortality and post-ICU disability 6 months after critical illness in long-stay ICU patients.
Methods
In this retrospective cohort study, we assessed patients hospitalized for ≥ 7 days in the ICU between May 2018 and May 2021, following them for up to 6 months or until death. Based on the Clinical Frailty Scale (CFS) at ICU admissions, patients were categorized as frail (CFS ≥ 5), pre-frail (CFS 3–4) and non-frail (CFS 1–2). Kaplan–Meier curves and a multivariate Cox model were used to examine the association between frailty and mortality. At the 6 month follow-up, we assessed psychological, physical, cognitive outcomes, and health-related quality of life (QoL) using descriptive statistics and linear regressions.
Results
We enrolled 531 patients, of which 178 (33.6%) were frail, 200 (37.6%) pre-frail and 153 (28.8%) non-frail. Frail patients were older, had more comorbidities, and greater disease severity at ICU admission. At 6 months, frail patients presented higher mortality rates than pre-frail and non-frail patients (34.3% (61/178)
vs.
21% (42/200)
vs
. 13.1% (20/153) respectively, p < 0.01). The rate of withdrawing or withholding of care did not differ significantly between the groups. Compared with CFS 1–2, the adjusted hazard ratios of death at 6 months were 1.7 (95% CI 0.9–2.9) for CFS 3–4 and 2.9 (95% CI 1.7–4.9) for CFS ≥ 5. At 6 months, 192 patients were seen at a follow-up consultation. In multivariate linear regressions, CFS ≥ 5 was associated with poorer physical health-related QoL, but not with poorer mental health-related QoL, compared with CFS 1–2.
Conclusion
Frailty is associated with increased mortality and poorer physical health-related QoL in long-stay ICU patients at 6 months. The admission CFS can help inform patients and families about the complexities of survivorship during a prolonged ICU stay.
The new decision support tool Glucosafe 2 (GS2) is based on a mathematical model of glucose and insulin dynamics, designed to assist caregivers in blood glucose control and nutrition. This study aims ...to assess end-user acceptance and usability of this bedside decision support tool in an adult intensive care setting. Caregivers were first trained and then invited to trial GS2 prototype on bedside computers. Data for qualitative analysis were collected through semi-structured interviews from twenty users after minimum three trial days. Most caregivers (70%) rated GS2 as convenient and believed it would help improving adherence to current guidelines (85%). Moreover, most nurses (80%) believed that GS2 would be timesaving. Nurses' risk perceptions and manual data entry emerged as central barriers to use GS2 in routine practice. Issues emerged from the caregivers were compiled into a list of 12 modifications of the GS2 prototype to increase end-user acceptance and usability. This usability study showed that GS2 was considered by ICU caregivers as helpful in daily clinical practice, allowing time-saving and better standardization of ICU patient’s care. Important issues were raised by the users with implications for the development and deployment of GS2. Integrating the technology into existing IT infrastructure may facilitate caregivers’ acceptance. Further clinical studies of the performance and potential health outcomes are warranted.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Current recommendations suggest starting enteral feeding as soon as possible whenever the gastrointestinal tract is functioning. The disadvantage of enteral support is that insufficient energy and ...protein coverage can occur. This review focuses on some recent findings regarding the nutritional support of critically ill patients and evaluates the data presented.
An increasing nutritional deficit during a long ICU stay is associated with increased morbidity (infection rate, wound healing, mechanical ventilation, length of stay, duration of recovery), and costs. Evidence shows that enteral nutrition can result in underfeeding and that nutritional goals are frequently reached only after 1 week. Contrary to former beliefs, recent meta-analyses of ICU studies showed that parenteral nutrition is not related to a surplus mortality and may even be associated with improved survival.
Early enteral nutrition is recommended for critically ill patients. Supplemental parenteral nutrition combined with enteral nutrition can be considered to cover the energy and protein targets when enteral nutrition alone fails to achieve the caloric goal. Whether such a combined nutritional support provides additional benefit on the overall outcome has to be proven in further studies on clinical outcome, including physical and cognitive functioning, quality of life, cost-effectiveness, and cost-utility.
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