The impact of the COVID-19 pandemic on gram-negative bacteria susceptibility patterns in respiratory samples of intensive care units in the Brussels Capital Region, 2010-2021.

BACKGROUND: The effect of the Coronavirus Disease 2019 (COVID-19) pandemic on gram-negative bacteria nonsusceptibility to antibiotics is unclear. METHODS: Between January 1, 2010, and December 31, 2021, the respiratory samples of intensive care unit patients at 3 University Hospitals in Brussels were retrieved. Based on the nonsusceptibility to antimicrobial classes, drug-resistance patterns were defined as multi-drug-resistant, extensively drug-resistant, and pan-drug-resistant. The study time frame was divided into 6 periods of 2 years each, and the impact of the COVID-19 pandemic (last period: 2020-2021) was assessed. RESULTS: During the current study, 10,577 samples were identified from 5,889 patients. While a significant augmentation of multi-drug-resistant isolates was noticed once comparing 2 prepandemic periods (2012-2013 and 2014-2015), all 3 patterns of nonsusceptibility significantly increased, comparing the years before and throughout the COVID-19 pandemic (2018-2019 and 2020-2021). Globally, the greatest increase in antimicrobial nonsusceptibility, comparing the last 2 periods, was reported for piperacillin-tazobactam (from 28% to 38%). Pseudomonas aeruginosa was the most isolated species, and the most involved in the appearance of resistance, with an augmentation of nonsusceptibility percentage to meropenem of 22% (from 25% to 47%), between the prepandemic and the pandemic periods. CONCLUSIONS: The COVID-19 pandemic was associated with increasing trends of antimicrobial resistance in respiratory samples of patients admitted to the intensive care units in university hospitals with well-implemented antibiotic stewardship programs.

Effective Treatment of Acute Tricyclic Antidepressant Poisoning with Cardiogenic Shock and Severe Rhabdomyolysis Using ECMO and CytoSorb® Adsorber.

BACKGROUND Tricyclic antidepressant (TCA) drugs are a common cause of fatal poisoning because of their cardiotoxic and arrhythmogenic effects. Classic supportive management includes sodium bicarbonate, gastrointestinal chelating agents, and vasopressors. Recently, intravenous lipid emulsion (supported by a low evidence level) has also been used. CASE REPORT We report the case of a 55-year-old woman admitted to our Intensive Care Unit (ICU) with acute imipramine self-poisoning. She arrived at the emergency department 7 hours after imipramine ingestion; she had severe rhabdomyolysis upon admission, with creatine phosphokinase levels at about 52 500 IU/L (normal, <200 IU/L). She quickly developed cardiogenic shock and malign arrhythmia requiring veno-arterial extra corporeal membrane oxygenation (VA-ECMO). Continuous renal replacement therapy (CRRT) with CytoSorb® (CytoSorbents, Monmouth Junction, New York, United Sates of America) was started 19 hours after admission. We performed serial blood measurements of imipramine and its active metabolite desipramine as well as viewing the levels on the CRRT-circuit monitor. Cardiac function improved and ECMO was explanted after 4 days. She also had severe acute respiratory distress syndrome, which resolved spontaneously. The neurologic outcome was favorable despite early myoclonus. The patient regained consciousness on the fifth day. Her clinical evolution was marked by acute ischemia of the lower left limb due to the arterial ECMO cannula. CONCLUSIONS These measurements document the efficacy of the CytoSorb® adsorber in removing a lipophilic drug from a patient's bloodstream. To our knowledge, this is the first published case of CytoSorb® extracorporeal blood purification therapy for acute TCA poisoning.

Parenteral Nutrition, Sepsis, Acute Heart Failure and Hepatotoxic Drugs Are Related to Liver Test Disturbances in Critically Ill Patients.

BACKGROUND: Parenteral nutrition (PN) is often associated with liver dysfunction in the ICU, although other factors such as sepsis, acute heart failure (AHF), and hepatotoxic drugs can be equally present. The relative impact of PN on liver dysfunction in critically ill patients is largely unknown. METHODS: We recorded the presence of pre-existing liver disturbances, AHF, sepsis, daily PN volume, and commonly used hepatotoxic drugs in adult ICU patients, together with daily aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkalic phosphatase (AP), total bilirubin (TB), and INR values in patients with three or more PN treatment days. A linear mixed-effects model was used to assess the relative contribution of each liver parameter. Nutritional adequacy was defined as intake/needs. RESULTS: We included 224 ICU patients with PN treatment lasting more than 3 days between 1 January 2017 and 31 December 2019. For AST, pre-existing liver disturbances (+180% ± 11%) and the presence of AHF (+75% ± 14%) were the main predictors of deterioration, whereas PN volume caused only a limited increase of 14% ± 1%/L. Similar results were observed for ALT. GGT, INR, and TB are mainly influenced by the presence of sepsis/septic shock and pre-existing liver disturbances, with no impact of PN or hepatotoxic drugs. Carbohydrate intake exceeded recommendations, and protein and lipid intake were insufficient in this study cohort. CONCLUSIONS: Liver test disturbances in ICU patients on PN are multifactorial, with sepsis and AHF having the highest influence, with only limited impact from PN and hepatotoxic drugs. Feeding adequacy can be improved.

Indirect Calorimetry in Spontaneously Breathing, Mechanically Ventilated and Extracorporeally Oxygenated Patients: An Engineering Review.

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), as well as to the sensors used in commercially available indirect calorimeters. The theoretical and technical aspects of IC in spontaneously breathing subjects and critically ill patients on mechanical ventilation and/or ECMO are covered and a critical review and comparison of the different techniques and sensors is provided. This review also aims to accurately present the physical quantities and mathematical concepts regarding IC to reduce errors and promote consistency in further research. By studying IC on ECMO from an engineering point of view rather than a medical point of view, new problem definitions come into play to further advance these techniques.

Medical nutrition therapy in patients receiving ECMO: Evidence-based guidance for clinical practice.

Patients receiving extracorporeal membrane oxygenation (ECMO) inherit substantial disease-associated metabolic, endocrinologic, and immunologic modifications. Along with the technical components of ECMO, the aforementioned alterations may affect patients' needs and feasibility of adequate macronutrient and micronutrient supply and intake. Thus, patients receiving ECMO are at increased risk for iatrogenic malnutrition and require targeted individual medical nutrition therapy (MNT). However, specific recommendations for MNT in patients receiving ECMO are limited and, with some exceptions, based on an evidence base encompassing general patients who are critically ill. Consequently, clinician decision-making for MNT in patients receiving ECMO is unguided, which may further increase nutrition risk, culminating in iatrogenic malnutrition and ultimately affecting patient outcomes. The purpose of this article is to provide educational background and highlight specific points for MNT in adult patients receiving ECMO, which might serve as evidence-based guidance to develop institutional standard operating procedures and nutrition protocols for daily clinical practice.

Digital tomography in the diagnosis of a posterior pneumothorax in the intensive care unit.

Portable chest radiography is a valuable tool in the intensive care unit. However, the supine position causes superposition of anatomical structures resulting in less reliable detection of certain abnormalities. Recently, a portable digital tomosynthesis (pDTS) prototype with a modified motorized X-ray device was developed. We aimed to compare the diagnostic value of pDTS to standard bedside chest radiography in the diagnosis of a posterior pneumothorax. A modified motorized X-ray device was developed to perform 15 radiographic projections while translating the X-ray tube 25 cm (10 cm ramp up and 15 cm during X-ray exposure) with a total radiation dose of 0.54 mSv. This new technique of pDTS was performed in addition to standard bedside chest X-ray in a patient with a confirmed posterior hydropneumothorax. The images were compared with the standard bedside chest X-ray and computed tomography (CT) images by two experienced radiologists. The posterior hydropneumothorax previously identified with CT was visible on tomosynthesis images but not with standard bedside imaging. Combining the digital tomosynthesis technique with the portable X-ray machine could increase the diagnostic value of bedside chest radiography for the diagnosis of posterior pneumothoraces while avoiding intrahospital transport and limiting radiation exposure compared to CT.

Performance of NUTRIC score to predict 28-day mortality in critically ill patients after replacing APACHE II with SAPS 3.

OBJECTIVES: The Nutrition Risk in the Critically Ill (NUTRIC) score has been advocated as a screening tool for nutrition risk assessment in critically ill patients. It was developed and validated to predict 28-day mortality using Acute Physiology and Chronic Health Evaluation II (APACHE II) score as one of its components. However, nowadays the Simplified Acute Physiology Score 3 (SAPS 3) demonstrates better performance. We aimed to test the performance of NUTRIC score in predicting 28-day mortality after replacement of APACHE II by SAPS 3, and the interaction between nutrition adequacy and mortality. METHODS: Adult patients who received nutrition therapy and remained >3 days in intensive care unit were retrospectively evaluated. In order to replace APACHE II component, we used ranges of SAPS 3 with similar predicted mortality. Discrimination between these tools in predicting 28-day mortality was assessed using the ROC curve, calibration was evaluated with calibration belt, and correlation with intraclass correlation. The relationship between nutritional adequacy and mortality was assessed in a subgroup with available data. RESULTS: 542 patients were analyzed (median age of 78 years old, 73.4% admitted for non-surgical reasons and 28-day mortality was 18.1%). Mortality prediction discrimination did not differ between tools (p>0.05), but showed a good agreement (intraclass correlation 0.86) with good calibration. In the subgroup analysis for nutritional adequacy (n = 99), no association with mortality was observed. CONCLUSION: Performance of NUTRIC score with SAPS 3 is similar to the original tool. Therefore, it might be used in settings where APACHE II is not available.

Bioenergetic Balance of Continuous Venovenous Hemofiltration, a Retrospective Analysis.

(1) Background: Nutrition therapy guided by indirect calorimetry (IC) is the gold standard and is associated with lower morbidity and mortality in critically ill patients. When performing IC during continuous venovenous hemofiltration (CVVH), the measured VCO2 should be corrected for the exchanged CO2 to calculate the 'true' Resting Energy Expenditure (REE). After the determination of the true REE, the caloric prescription should be adapted to the removal and addition of non-intentional calories due to citrate, glucose, and lactate in dialysis fluids to avoid over- and underfeeding. We aimed to evaluate this bioenergetic balance during CVVH and how nutrition therapy should be adapted. (2) Methods: This post hoc analysis evaluated citrate, glucose, and lactate exchange. Bioenergetic balances were calculated based on these values during three different CVVH settings: low dose with citrate, high dose with citrate, and low dose without citrate. The caloric load of these non-intentional calories during a CVVH-run was compared to the true REE. (3) Results: We included 19 CVVH-runs. The bioenergetic balance during the low dose with citrate was 498 ± 110 kcal/day (range 339 to 681 kcal/day) or 26 ± 9% (range 14 to 42%) of the true REE. During the high dose with citrate, it was 262 ± 222 kcal/day (range 56 to 262 kcal/day) or 17 ± 11% (range 7 to 32%) of the true REE. During the low dose without citrate, the bioenergetic balance was -189 ± 77 kcal/day (range -298 to -92 kcal/day) or -13 ± 8% (range -28 to -5%) of the true REE. (4) Conclusions: Different CVVH settings resulted in different bioenergetic balances ranging from -28% up to +42% of the true REE depending on the CVVH fluids chosen. When formulating a caloric prescription during CVVH, an individual approach considering the impact of these non-intentional calories is warranted.

Effect of extracorporeal carbon dioxide removal on respiratory quotient measured by indirect calorimetry: Unravelling the mystery.

NEW FINDINGS: What is the main observation in this case? Several studies have reported progressive hypoxaemia once extracorporeal carbon dioxide removal is started in patients with hypercapnic respiratory failure, possibly attributable to an altered respiratory quotient. What insights does it reveal? In this quality control report, we show that the respiratory quotient exhibits only minimal alteration when extracorporeal carbon dioxide removal is started and assume that the progressive hypoxaemia is attributable to an increase in intrapulmonary shunt. ABSTRACT: The use of extracorporeal carbon dioxide removal (ECCO2 R) has been proposed in patients with acute respiratory distress syndrome to achieve lung-protective ventilation and in patients with selective hypercapnic respiratory failure. However, several studies have reported progressive hypoxaemia, as expressed by a need to increase the inspired oxygen fraction (Fi O2 ) to maintain adequate oxygenation or by a decrease in the ratio of arterial oxygen tension (Pa O2 ) to Fi O2 once ECCO2 R is started. We present the case of a patient who was admitted to the intensive care unit for a coronavirus disease 2019 pneumonia and who was intubated because of hypercapnic respiratory insufficiency. Extracorporeal carbon dioxide removal was started, and the patient subsequently developed progressive hypoxaemia. To test whether the hypoxaemia was attributable to the ECCO2 R, blood samples were taken in different settings: (1) 'no ECCO2 R', blood flow 150 ml/min with a ECCO2 R gas flow of 0 L/min; and (2) 'with ECCO2 R', blood flow 400 ml/min with gas flow 12 L/min. We measured Pa O2 , alveolar oxygen tension, Pa O2 /Fi O2 , alveolar-arterial oxygen tension difference, arterial carbon dioxide tension and the respiratory quotient (RQ) by indirect calorimetry in each setting. The RQ was 0.60 without ECCO2 R and 0.57 with ECCO2 R. The alveolar oxygen tension was 220.4 mmHg without ECCO2 R and increased to 240.3 mmHg with ECCO2 R, whereas Pa O2 /Fi O2 decreased from 177 to 171. Our study showed only a minimal change in RQ when ECCO2 R was started. We were the first to measure the RQ directly, before and after the initiation of ECCO2 R, in a patient with hypercapnic respiratory failure.

Methodological Aspects of Indirect Calorimetry in Patients with Sepsis-Possibilities and Limitations.

The aim of the review was to analyse the challenges of using indirect calorimetry in patients with sepsis, including the limitations of this method. A systematic review of the literature was carried out. The analysis concerned the methodology and presentation of research results. In most studies assessing energy expenditure, energy expenditure was expressed in kcal per day (n = 9) and as the mean and standard deviation (n = 7). Most authors provided a detailed measurement protocol, including measurement duration (n = 10) and device calibration information (n = 7). Ten papers provided information on the day of hospitalisation when the measurements were obtained, nine on patient nutrition, and twelve on the criteria for inclusion and exclusion of participants from the study. Small study group sizes and study at a single centre were among the most cited limitations. Studies assessing energy expenditure in patients with sepsis by indirect calorimetry differ in the methodology and presentation of results, and their collective analysis is difficult. A meta-analysis of the results could enable multi-site and large patient evaluation. Standardisation of protocols and presentation of all collected data would enable their meta-analysis, which would help to achieve greater knowledge about metabolism in sepsis.

Cirrhosis and partial portal thrombosis leading to severe variceal bleeding, an unusual presentation of sarcoidosis.

INTRODUCTION: Sarcoidosis is a systemic granulomatous disease, characterized by the formation of non-necrotizing granulomas. Even though granulomas are frequently found in liver biopsy, related symptoms rarely occur. In the current article, a case report is pictured to increase the knowledge on portal hypertension in hepatic sarcoidosis. CLINICAL SITUATION: A 62-year-old female was diagnosed with variceal bleeding for which elastic banding was performed. The patient was admitted to the intensive care unit (ICU) as the bleeding persisted and she evolved in hemorrhagic shock. Liver ultrasound detected nodular hepatomegaly and partial portal thrombosis. Chest CT showed diffuse hilar adenopathies and interstitial micronodular lesion. Finally, PET-CT detected metabolic active liver, bone marrow, and upper and lower diaphragmatic adenopathies. CLINICAL RESOLUTION: Multidisciplinary discussion brought major advantages in rapid diagnosis and prompt effective treatment. Cirrhosis was diagnosed by liver nodularity on imaging and liver biopsy. Sarcoidosis diagnosis was supported by the biopsies of liver and lymph node, which yielded non-caseating granulomas infiltration. Chest CT scan and PET-CT were also consistent with this diagnosis. The complementary analysis excluded differential diagnosis. The patient was treated with high-dose methylprednisolone with notable clinical improvements and discharge from the ICU. CONCLUSION: Hepatic sarcoidosis can present as life-threatening bleeding due to variceal bleeding caused by portal hypertension. Differential diagnosis is broad when hepatic sarcoidosis is suspected. Therefore, a multidisciplinary discussion is warranted. Anatomopathological examination of two potentially involved organs should be considered to make the appropriate diagnosis. Further studies are requested to investigate the pathophysiological mechanism of portal hypertension.

Indirect calorimetry in critical illness: a new standard of care?

PURPOSE OF REVIEW: Review recent literature on the role of indirect calorimetry in critical care nutrition management. RECENT FINDINGS: Critical illness demands objective, targeted nutritional therapy to prevent adverse effects of underfeeding/over feeding. Thus, all recent societal guidelines recommend indirect calorimetry use to determine energy needs. Very recently, indirect calorimetry technology has finally evolved to allow for accurate, simple, and routine utilization in a wider range of ICU patients. Recent data continues to confirm poor correlation between measured and equation-predicted energy expenditure emphasizing need for indirect calorimetry to be standard of care. This may be particularly true in COVID-19, where significant progressive hypermetabolism and variability in energy expenditure has been shown. Metabolic physiology can change frequently during ICU stay in response to changes in clinical condition or care. Thus, repeated longitudinal indirect calorimetry measures are needed throughout ICU stay to optimize care, with initial data showing improved clinical outcomes when indirect calorimetry targets are utilized. SUMMARY: Personalized ICU care demands objective data to guide therapy. This includes use of indirect calorimetry to determine energy expenditure and guide ICU nutrition therapy. Long-awaited new innovations in indirect calorimetry technology should finally lead to indirect calorimetry to becoming a fundamental component of modern ICU standard of care and clinical research moving forward.

ESPEN guideline on clinical nutrition in hospitalized patients with acute or chronic kidney disease.

Acute kidney disease (AKD) - which includes acute kidney injury (AKI) - and chronic kidney disease (CKD) are highly prevalent among hospitalized patients, including those in nephrology and medicine wards, surgical wards, and intensive care units (ICU), and they have important metabolic and nutritional consequences. Moreover, in case kidney replacement therapy (KRT) is started, whatever is the modality used, the possible impact on nutritional profiles, substrate balance, and nutritional treatment processes cannot be neglected. The present guideline is aimed at providing evidence-based recommendations for clinical nutrition in hospitalized patients with AKD and CKD. Due to the significant heterogeneity of this patient population as well as the paucity of high-quality evidence data, the present guideline is to be intended as a basic framework of both evidence and - in most cases - expert opinions, aggregated in a structured consensus process, in order to update the two previous ESPEN Guidelines on Enteral (2006) and Parenteral (2009) Nutrition in Adult Renal Failure. Nutritional care for patients with stable CKD (i.e., controlled protein content diets/low protein diets with or without amino acid/ketoanalogue integration in outpatients up to CKD stages four and five), nutrition in kidney transplantation, and pediatric kidney disease will not be addressed in the present guideline.

Percutaneous tracheostomy for long-term ventilated COVID-19-patients: rationale and first clinical-safe for all-experience.

INTRODUCTION: COVID-19 infection has resulted in thousands of critically ill patients admitted to ICUs and treated with mechanical ventilation. Percutaneous tracheostomy is a well-known technique utilised as a strategy to wean critically ill patients from mechanical ventilation. Worldwide differences exist in terms of methods, operators, and settings, and questions remain regarding timing and indications. If tracheostomy is to be performed in COVID-19 patients, a safe environment is needed for optimal care. MATERIAL AND METHODS: We present a guidewire dilating forceps tracheostomy procedure in COVID-19 patients that was optimised including apnoea-moments, protective clothing, checklists, and clear protocols. We performed a retrospective analysis of the outcome after tracheostomy in COVID-19 patients between March 2020 and May 2020. RESULTS: The follow-up of the first 16 patients, median age 62 years, revealed a median intubation time until tracheostomy of 18 days and median cannulation time of 20 days. The overall perioperative complication rate and complication rate while cannulated was 19%, mainly superficial bleeding. None of the healthcare providers involved in performing the procedure developed any symptoms of the disease. CONCLUSIONS: This COVID-19-centred strategy based on flexibility, preparation, and cooperation between healthcare providers with different backgrounds facilitated percutaneous tracheostomy in COVID-19 patients without an increase in the overall complication rate or evidence of risk to healthcare providers. Our findings provide initial evidence that tracheostomy can be performed safely as a standard of care for COVID-19 patients requiring prolonged mechanical ventilation as was standard practice in ICU patients prior to the COVID-19 pandemic to promote ventilator weaning and patient recovery.

First international meeting of early career investigators: Current opportunities, challenges and horizon in critical care nutrition research.

BACKGROUND: Appropriate nutritional support is a key component of care for critically ill patients. While malnutrition increases complications, impacting long term outcomes and healthcare-related costs, uncertainties persist regarding optimal provision of nutritional support in this setting. METHODS: An international group of healthcare providers (HCPs) from critical care specialties and nutrition researchers convened to identify knowledge gaps and learnings from studies in critical care nutrition. Clinical research needs were identified in order to better inform future nutrition practices. RESULTS: Challenges in critical care nutrition arise, in part, from inconsistent outcomes in several large-scale studies regarding the optimal amount of calories and protein to prescribe, the optimal time to initiate nutritional support and the role of parental nutrition to support critically ill patients. Furthermore, there is uncertainty on how best to identify patients at nutritional risk, and the appropriate outcome measures for ICU nutrition studies. Given HCPs have a suboptimal evidence base to inform the nutritional management of critically ill patients, further well-designed clinical trials capturing clinically relevant endpoints are needed to address these knowledge gaps. CONCLUSIONS: The identified aspects for future research could be addressed in studies designed and conducted in collaboration with an international team of interdisciplinary nutrition experts. The aim of this collaboration is to address the unmet need for robust clinical data needed to develop high-quality evidence-based nutritional intervention recommendations to better inform the future management of critically ill patients.

An endotracheal tube providing "pressurized sealing" prevents fluid leakage in mechanically ventilated critically ill patients: a pilot study.

Microaspiration of bacteriologically contaminated oropharyngeal secretions alongside the cuff of an endotracheal tube (ETT) is a key mechanism for development of ventilator-associated pneumonia. We have constructed a prototype double-cuffed ETT equipped with a supplemental port in-between the cuffs through which continuous positive airway pressure (CPAP) is delivered. Pressure in the intercuff space propels secretions upwards and produces 100% tracheal sealing in an in vitro model. We conducted a 24 h study to investigate the sealing effect of this ETT in 12 critically ill mechanically ventilated patients. Methylene blue, instilled through a bronchoscope on top of the proximal cuff, was used as leakage tracer. Fiberoptic visualisation of the trachea was performed 1 h and 24 h thereafter. Leakage was confirmed if blue dye was detected on the tracheal mucosa beyond the tip of the ETT. In no patient, dye passed by the cuffs during the study period. Presence of the ETT did not interfere with ventilator settings, patient mobilization, physiotherapy, and technical acts. Overall, pressures in the intercuff space remained between 10 and 15 cmH2O. Excessive pressure swings were swiftly corrected by the CPAP system. A double-cuffed ETT, offering "pressurized sealing" of the trachea, safely and effectively prevented leakage during 24 h mechanical ventilation.

Cholestatic liver injury induced by food additives, dietary supplements and parenteral nutrition.

Cholestasis refers to the accumulation of toxic levels of bile acids in the liver due to defective bile secretion. This pathological situation can be triggered by drugs, but also by ingredients contained in food, food supplements and parenteral nutrition. This paper provides an overview of the current knowledge on cholestatic injury associated with such ingredients, with particular emphasis on the underlying mechanisms of toxicity.

Correction to: CO2 and O2 removal during continuous veno-venous hemofiltration: a pilot study.

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CO2 and O2 removal during continuous veno-venous hemofiltration: a pilot study.

BACKGROUND: Carbon dioxide (CO2) accumulation is a challenging issue in critically ill patients. CO2 can be eliminated by renal replacement therapy but studies are scarce and clinical relevance is unknown. We prospectively studied CO2 and O2 behavior at different sample points of continuous veno-venous hemofiltration (CVVH) and build a model to calculate CO2 removal bedside. METHODS: In 10 patients receiving standard CVVH under citrate anticoagulation, blood gas analysis was performed at different sample points within the CVVH circuit. Citrate was then replaced by NaCl 0.9% and sampling was repeated. Total CO2 (tCO2), CO2 flow (V̇CO2) and O2 flow (V̇O2) were compared between different sample points. The effect of citrate on transmembrane tCO2 was evaluated. Wilcoxon matched-pairs signed rank test was performed to evaluate significance of difference between 2 data sets. Friedman test was used when more data sets were compared. RESULTS: V̇CO2 in the effluent (26.0 ml/min) correlated significantly with transmembrane V̇CO2 (24.2 ml/min). This represents 14% of the average expired V̇CO2 in ventilated patients. Only 1.3 ml/min CO2 was removed in the de-aeration chamber, suggesting that CO2 was almost entirely cleared across the membrane filter. tCO2 values in effluent, before, and after the filter were not statistically different. Transmembrane tCO2 under citrate or NaCl 0.9% predilution also did not differ significantly. No changes in V̇O2 were observed throughout the CVVH circuit. Based on recorded data, formulas were constructed that allow bedside evaluation of CVVH-attributable CO2 removal. CONCLUSION: A relevant amount of CO2 is removed by CVVH and can be quantified by one simple blood gas analysis within the circuit. Future studies should assess the clinical impact of this observation. TRIAL REGISTRATION: The trial was registered at https://clinicaltrials.gov with trial registration number NCT03314363 on October 192,017.

Modification of Nutrition Therapy During Continuous Renal Replacement Therapy in Critically Ill Pediatric Patients: A Narrative Review and Recommendations.

INTRODUCTION: Nutrition is an important part of treatment in critically ill children. Clinical guidelines for nutrition adaptations during continuous renal replacement therapy (CRRT) are lacking. We collected and evaluated current knowledge on this topic and provide recommendations. METHODS: Questions were produced to guide the literature search in the PubMed database. RESULTS: Evidence is scarce and extrapolation from adult data was often required. CRRT has a direct and substantial impact on metabolism. Indirect calorimetry is the preferred method to assess resting energy expenditure (REE). Moderate underestimation of REE is common but not clinically relevant. Formula-based calculation of REE is inaccurate and not validated in critically ill children on CRRT. The nutrition impact of nonintentional calories delivered as citrate, lactate, and glucose during CRRT must be considered. Quantifying nitrogen balance is not feasible during CRRT. Protein delivery should be increased by 25% to compensate for losses in the effluent. Fats are not removed by CRRT and should not be adapted during CRRT. Electrolyte disturbances are frequently present and should be treated accordingly. Vitamins B1, B6, B9, and C are lost in the effluent and should be adapted to the effluent dose. Trace elements, with the exception of selenium, are not cleared in relevant quantities. Manganese accumulation is of concern because of potential neurotoxicity. CONCLUSION: Current recommendations regarding nutrition support in pediatric CRRT must be extrapolated from adult studies. Recommendations are provided, based on the weak level of evidence. Additional research on this topic is warranted.