Optimal nutrition during the period of mechanical ventilation decreases mortality in critically ill, long-term acute female patients: a prospective observational cohort study

Indirect calorimetry and nitrogen balance guided nutrition therapy in ICU patients with acute kidney injury

Data on the benefits of early integration of indirect calorimetry (IC) for caloric guidance and maintaining a positive nitrogen balance in critically ill patients with acute kidney injury (AKI) are scarce. This study aimed to evaluate the impact of the nutritional therapeutic approach on mortality and renal outcomes in these patients. We conducted an open-label randomized controlled trial, Intensive Care Unit (ICU)-admitted patients on mechanical ventilation who were diagnosed with AKI within 72 h after admission were enrolled and assigned to receive either early goal nutrition therapy (caloric dosing guided by IC and protein delivery guided by nitrogen balance, maximum 1.3 g/kg/day) or conventional nutrition therapy for 14 days. The primary outcome was all-cause 28-day mortality. Secondary outcomes included 14-day mortality, an incidence of renal replacement therapy (RRT) initiation, and safety. A total of 80 patients were enrolled, with 40 participants in each group. At 28 days, mortality in the early goal group was 17.5% (7 out of 40), compared to 40% (16 out of 40) in the conventional group, resulting in a difference of 22.5% points (P = 0.03). The incidence of RRT initiation and adverse events was similar. In conclusion, among critically ill patients with AKI, early goal nutrition therapy is safe. However, renal and mortality outcomes do not allow for a conclusion since the unequal in disease severity between groups. Larger randomized controlled trials are required to confirm findings.

Longitudinal analysis of caloric requirements in critically ill trauma patients: a retrospective cohort study

PURPOSE

Nutrition is of paramount importance in critically ill trauma patients. However, adequate supply is difficult to achieve, as caloric requirements are unknown. This study investigated caloric requirements over time, based on indirect calorimetry, in critically ill trauma patients.

METHODS

Retrospective cohort study at a tertiary trauma center including critically ill trauma patients who underwent indirect calorimetry 2012-2019. Caloric requirements were assessed as resting energy expenditure (REE) during the intensive care unit stay up to 28 days and analyzed in patient-clustered linear regression analysis.

RESULTS

A total of 129 patients were included. Median REE per day was 2376 kcal. The caloric intake did not meet REE at any time with a median daily deficit of 1167 kcal. In univariable analysis, ISS was not significantly associated with REE over time (RC 0.03, p = 0.600). Multivariable analysis revealed a significant REE increase (RC 0.62, p < 0.001) and subsequent decrease (RC - 0.03, p < 0.001) over time. Age < 65 years (RC 2.07, p = 0.018), male sex (RC 4.38, p < 0.001), and BMI ≥ 35 kg/m2 (RC 6.94, p < 0.001) were identified as independent predictors for higher REE over time. Severe head trauma was associated with lower REE over time (RC - 2.10, p = 0.030).

CONCLUSION

In critically ill trauma patients, caloric requirements significantly increased and subsequently decreased over time. Younger age, male sex and higher BMI were identified as independent predictors for higher caloric requirements, whereas severe head trauma was associated with lower caloric requirements over time. These results support the use of IC and will help to adjust nutritional support in critically ill trauma patients.

Obesity and septic patient outcomes: Shaping the puzzle through age and sex perspectives

BACKGROUND & AIMS

While obesity has been reported as a protective factor in septic patients, little is known about the potential modifying effects of age and sex. The objective of this study is to investigate age and sex-specific associations between obesity and the prognosis of septic patients.

METHODS

A retrospective analysis was conducted on a cohort of 15,464 septic patients, categorized by body mass index (BMI) into four groups: underweight (<18.5 kg/m2, n = 483), normal (18.5-24.9 kg/m2, n = 4344), overweight (25-29.9 kg/m2, n = 4949) and obese (≥30 kg/m2, n = 5688). Multivariable logistic regression and inverse probability weighting were employed to robustly confirm the protective effect of a higher BMI on 28-day mortality, with normal weight serving as the reference category. Subgroup analyses based on age (young: 18-39, middle-aged: 40-64 and elderly: ≥65) and sex were performed.

RESULTS

The findings demonstrate that high BMI independently confers a protective effect against 28-day mortality in septic patients. However, the relationship between BMI and 28-day mortality exhibits a non-linear trend, with a BMI of 34.5 kg/m2 displaying the lowest odds ratio. Notably, the survival benefits associated with a high BMI were not observed in the young group. Moreover, being underweight emerges as an independent risk factor for middle-aged and elderly female patients, while in males it is only a risk factor in the elderly group. Interestingly, being overweight and obese were identified as independent protective factors in middle-aged and elderly male patients, but not in females.

CONCLUSIONS

The effect of BMI on mortality in septic patients varies according to age and sex. Elderly individuals with sepsis may derive more prognostic benefits from obesity.

Association of longitudinal changes in skeletal muscle mass with prognosis and nutritional intake in acutely hospitalized patients with abdominal trauma: a retrospective observational study

BACKGROUND

The objective of this study was to explore whether longitudinal changes in skeletal muscle mass, from hospital admission to 3  weeks post-trauma, are associated with poor prognosis and nutritional intake in acutely hospitalized patients with abdominal trauma.

METHODS

A single-center retrospective observational review was conducted on 103 patients with abdominal trauma admitted to the Affiliated Jinling Hospital, Medical School of Nanjing University between January 2010 and April 2020. Skeletal muscle mass was assessed by abdominal computed tomography (CT) performed within 14 days before surgery and on post-trauma days 1-3 (week 0), 7-10 (week 1), 14-17 (week 2), and 21-24 (week 3). The skeletal muscle index (SMI) at L3, change in SMI per day (ΔSMI/day), and percent change in SMI per day (ΔSMI/day [%]) were calculated. The receiver-operating characteristic (ROC) curve was used to evaluate the discriminatory performance of ΔSMI/day (%) for mortality. Linear correlation analysis was used to evaluate the associations between ΔSMI/day (%) and daily caloric or protein intake.

RESULTS

Among the included patients, there were 91 males and 12 females (mean age ± standard deviation 43.74 ± 15.53 years). ΔSMI4-1/d (%) had a ROC-area under the curve of 0.747 (p = 0.048) and a cut-off value of -0.032 for overall mortality. There were significant positive correlations between ΔSMI4-1/d (%) and daily caloric intake and protein intake (Y = 0.0007501*X - 1.397, R2 = 0.282, R = 0.531, p < 0.001; Y = 0.008183*X - 0.9228, R2 = 0.194, R = 0.440, p < 0.001). Δ SMI/day (%) was positively correlated with daily caloric intake ≥80% of resting energy expenditure in weeks 2, 3, and 1-3 post-trauma and with protein intake >1.2 g/kg/d in weeks 3 and 1-3 post-trauma.

CONCLUSION

Loss of skeletal muscle mass is associated with poor prognosis and nutritional intake in patients admitted to hospital with abdominal trauma.

Association of nitrogen balance trajectories with clinical outcomes in critically ill COVID-19 patients: A retrospective cohort study

BACKGROUND & AIMS

The intensity and duration of the catabolic phase in COVID-19 patients can differ between survivors and non-survivors. The purpose of the study was to assess the determinants of, and association between, nitrogen balance trajectories and outcome in critically ill COVID-19 patients.

METHODS

This retrospective monocentric observational study involved patients admitted to the intensive care unit (ICU) of the University Hospital of Clermont Ferrand, France, from January 2020 to May 2021 for COVID-19 pneumonia. Patients were excluded if referred from another ICU, if their ICU length of stay was <72 h, or if they were treated with renal replacement therapy during the first seven days after ICU admission. Data were collected prospectively at admission and during ICU stay. Death was recorded at the end of ICU stay. Comparisons of the time course of nitrogen balance according to outcome were analyzed using two-way ANOVA. At days 3, 5, 7, 10 and 14, uni- and multivariate logistic regression analyses were performed to assess the impact of a non-negative nitrogen-balance on ICU death. To investigate the relationships between nitrogen balance, inflammatory markers and protein intake, linear and non-nonlinear models were run at days 3, 5 and 7, and the amount of protein intake necessary to reach a neutral nitrogen balance was calculated. Subgroup analyses were carried out according to BMI, age, and sex.

RESULTS

99 patients were included. At day 3, a similar negative nitrogen balance was observed in survivors and non-survivors: -16.4 g/d [-26.5, -3.3] and -17.3 g/d [-22.2, -3.8] (p = 0.54). The trajectories of nitrogen balance over time thus differed between survivors and non-survivors (p = 0.01). In survivors, nitrogen balance increased over time, but decreased from day 2 to day 6 in non-survivors, and thereafter increased slowly up to day 14. At days 5 and 7, a non-negative nitrogen-balance was protective from death. Administering higher protein amounts was associated with higher nitrogen balance.

CONCLUSION

We report a prolonged catabolic state in COVID patients that seemed more pronounced in non-survivors than in survivors. Our study underlines the need for monitoring urinary nitrogen excretion to guide the amount of protein intake required by COVID-19 patients.

How much underfeeding can the critically ill adult patient tolerate?

Critical illness leads to significant metabolic alterations that should be considered when providing nutritional support. Findings from key randomized controlled trials (RCTs) indicate that underfeeding (<70% of energy expenditure [EE]) during the acute phase of critical illness (first 7 days of intensive care unit [ICU] admission) may not be harmful and could instead promote autophagy and prevent overfeeding in light of endogenous energy production. However, the optimal energy target during this period is unclear and full starvation is unlikely to be beneficial. There are limited data regarding the effects of prolonged underfeeding on clinical outcomes in critically ill patients, but recent studies show that oral food intake is suboptimal both in the ICU and following discharge to the acute care setting. It is hypothesized that provision of full nutrition (70-100% of EE) may be important in the recovery phase of critical illness (>7 days of ICU admission) for promoting recovery and rehabilitation; however, studies on nutritional intervention delivered from ICU admission through hospital discharge are needed. The aim of this review is to provide a narrative synthesis of the existing literature on metabolic alterations experienced during critical illness and the impact of underfeeding on clinical outcomes in the critically ill adult patient.

Evaluation of energy intake compared with indirect calorimetry requirements in critically ill patients with acute brain injury

BACKGROUND

Nutrition support in critically ill patients with acute brain injury is vitally important because of known hypermetabolism. We aimed to describe energy and protein intake within the first 72 h in a broad neurocritical care population and compare energy intake with the indirect calorimetry (IC) resting energy expenditure (REE) target.

METHODS

IC data, daily energy, and protein intake were collected through chart review over the first 7 days of hospital admission. We evaluated the type and amount of tube-feed product received, volume of propofol (1.1 kcal/ml) and clevidipine (2 kcal/ml), and amount of supplemental protein received.

RESULTS

Ninety-one patients were included, with the majority presenting with either intracerebral hemorrhage (35.2%) or acute ischemic stroke (26.4%). The median day of admission on which IC was completed and enteral nutrition was initiated was day 3 (2-5) and day 1 (1-2), respectively. The difference in kilocalories received compared with IC REE target within the first 72 h was significantly different (2831 kcal [1663-4072] vs 4275 kcal [3450-5811]; Z = -6.469; P < .001). The median kilocalories received as tube feeds during the first 72 h was 88% (55%-99%), and the mean protein received in the first 72 h was 0.7 ± 0.5 g/kg/day.

CONCLUSION

In this population, patients had lower energy intake compared with their energy needs determined by IC during the first 72 h of admission but attained 7-day goals. Future studies should investigate barriers to improve energy delivery in this patient population.

The Outcomes of Tracheostomy in Pediatric Cardiac Surgical Patients

Objectives To describe the outcomes of postoperative tracheostomy and determine the predictors of survival.

Design Prospective, observational study.

Setting Cardiac surgical intensive care unit of a tertiary care hospital.

Participants All pediatric patients below 10 years of age who underwent tracheostomy after cardiac surgery from January 2019 to December 2019. Different variables were compared between survivors and nonsurvivors.

Intervention Tracheostomy.

Results Among 1084 pediatric patients who underwent cardiac surgery during the study period, 41 (3.7%) received tracheostomy. Survival rate was 71%.

Earlier, sternal closure (SC) (p = 0.04), acute kidney injury (AKI) (p = 0.001), serum C-reactive protein (CRP) (p = 0.007), duration of total parenteral nutrition (TPN) (p = 0.005) and days of feed interruption (FI) (p = 0.02), activated partial thromboplastin time (aPTT) before tracheostomy (p = 0.006), and bleeding from tracheostomy site (p = 0.02) were significantly low in the survivor group.

Among the peritracheostomy variables taken at different time points, the levels of pH on tracheostomy day 1 (p = 0.03), serum lactate on tracheostomy day 2 (p = 0.01) and day 3 (p = 0.01), and random blood sugar (RBS) on tracheostomy day 3 (p = 0.04) were significantly lower in the survivor group.

The arterial oxygen saturation (SaO2) on tracheostomy day 1 (p = 0.04) and the platelet count before tracheostomy (p = 0.02) were significantly higher in the survivor group.

Conclusions Our study demonstrated a survival of 71% among the study cohort. Lesser duration of open sternum, lower incidence of AKI, less number of days on TPN and FI, lower posttracheostomy aPTT, bleeding, RBS, lactate, and higher pretracheostomy platelet count and posttracheostomy SaO2 were found to be the predictors of survival.

Feasibility of achieving different protein targets using a hypocaloric high-protein enteral formula in critically ill patients

Background and aims

Combining energy and protein targets during the acute phase of critical illness is challenging. Energy should be provided progressively to reach targets while avoiding overfeeding and ensuring sufficient protein provision. This prospective observational study evaluated the feasibility of achieving protein targets guided by 24-h urinary nitrogen excretion while avoiding overfeeding when administering a high protein-to-energy ratio enteral nutrition (EN) formula.

Methods

Critically ill adult mechanically ventilated patients with an APACHE II score > 15, SOFA > 4 and without gastrointestinal dysfunction received EN with hypocaloric content for 7 days. Protein need was determined by 24-h urinary nitrogen excretion, up to 1.2 g/kg (Group A, N = 10) or up to 1.5 g/kg (Group B, N = 22). Variables assessed included nitrogen intake, excretion, balance; resting energy expenditure (REE); phase angle (PhA); gastrointestinal tolerance of EN.

Results

Demographic characteristics of groups were similar. Protein target was achieved using urinary nitrogen excretion measurements. Nitrogen balance worsened in Group A but improved in Group B. Daily protein and calorie intake and balance were significantly increased in Group B compared to Group A. REE was correlated to PhA measurements. Gastric tolerance of EN was good.

Conclusions

Achieving the protein target using urinary nitrogen loss up to 1.5 g/kg/day was feasible in this hypercatabolic population. Reaching a higher protein and calorie target did not induce higher nitrogen excretion and was associated with improved nitrogen balance and a better energy intake without overfeeding. PhA appears to be related to REE and may reflect metabolism level, suggestive of a new phenotype for nutritional status.

Trial registration 0795-18-RMC.

Validation of the modified NUTrition Risk Score (mNUTRIC) in mechanically ventilated, severe burn patients: A prospective multinational cohort study

BACKGROUND

Whether nutrition therapy benefits all burn victims equally is unknown. To identify patients who will benefit the most from optimal nutrition, the modified Nutrition Risk in Critically Ill (mNUTRIC) Score has been validated in the Intensive Care Unit. However, the utility of mNUTRIC in severe burn victims is unknown. We hypothesized that a higher mNUTRIC (≥5) will be associated with worse clinical outcomes, but that greater nutritional adequacy will be associated with better clinical outcomes in patients with higher mNUTRIC score.

METHODS

This prospective study included data from mechanically ventilated, severe burn patients (n = 359) from 51 Burn Units worldwide included in a randomized trial. Our primary and secondary outcomes were hospital mortality and the time to discharge alive (TTDA) from hospital. We described the association between nutrition performance and clinical outcomes.

RESULTS

Compared to low mNUTRIC (n = 313), the high mNUTRIC group (n = 46) had higher mortality (61% vs. 19%, p = 0.001), and longer TTDA (>90 [87->90] vs. 64 [38-90] days, p = <0.0001). Only in the high mNUTRIC group, increased calorie intake (per 20% increase) was associated with lower mortality and a faster TTDA.

CONCLUSIONS

The mNUTRIC score identifies those with poor clinical outcomes and may identifies those mechanically ventilated, severe burn patients in whom optimal nutrition therapy may be more advantageous.

Audit of the provision of nutritional support to mechanically ventilated dogs and cats

OBJECTIVES

To evaluate the use of enteral and parenteral nutrition in a population of mechanically ventilated cats and dogs, identify factors associated with implementation of nutrition, and assess the frequency of nutritional support within 72 hours of absent caloric intake.

DESIGN

Retrospective, single-center audit from June 2013 to June 2016.

SETTING

ICU of a veterinary university teaching hospital.

ANIMALS

Fifty-eight animals (50 dogs, 8 cats) that underwent mechanical ventilation for ≥6 hours with complete medical records.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data collected included nutritional provision, time to initiation of nutrition, period of absent caloric intake, percentage of caloric intake obtained, and possible factors contributing to the delay or failure to implement nutrition. Thirty-one percent of patients (dogs 16/50, 32%; cats 2/8, 25%) received nutritional support during mechanical ventilation with all but 2 dogs receiving parenteral nutrition. Of those patients that did not receive nutrition (dogs 34/50, 68%; cats 6/8, 75%), documented contraindications or notations within the medical record for its omission were present in 16 of 34 dogs (47%) and 4 of 6 cats (66.7%). Thirteen animals (11 dogs, 2 cats) had >72 hours of absent caloric intake with only a small number of these receiving nutrition (dogs 4/11, 36.4%; cats 0/2, 0%).

CONCLUSIONS

Only 18 of 58 (31%) mechanically ventilated dogs and cats at our institution received nutritional support, and the majority of these were fed parenterally (16/18, 88.9%). For animals that did not receive nutrition, there was no clear reason for its absence in many cases. Animals with absent caloric intake >72 hours had poor implementation of nutritional support in contrast to current guidelines. A repeat audit after implementing changes to institutional protocols for nutritional provision is warranted to assess the impact on morbidity and mortality.

Effect of high-protein nutrition in critically ill patients: A retrospective cohort study

BACKGROUND & AIMS

Early provision of a high-protein nutrition improves the prognosis of patients in intensive care units (ICUs). However, high protein intake increases blood urea nitrogen (BUN). No study has compared outcomes according to protein intake, and the clinical significance of changes in BUN (ΔBUN) in ICU patients is unclear. Here, we investigated the association of high protein intake with outcomes and BUN and assessed the clinical significance of ΔBUN.

METHODS

This was a single-center retrospective cohort study. Between 1 January 2016 and 30 September 2019, 295 ICU patients received enteral nutrition for at least 3 days while undergoing mechanical ventilation. After applying the exclusion criteria of an age of <18 years, gastrointestinal disease, maintenance dialysis, renal replacement therapy after admission, kidney transplantation, and death within 7 days of commencing enteral nutrition, 206 patients remained.

INTERVENTIONS

Participants were divided into those receiving >1.2 g/kg/day of protein (high-protein group; n = 111) and those receiving ≤1.2 g/kg/day of protein (non-high-protein group; n = 95). The groups were balanced by propensity score matching. The primary endpoint was 28-day mortality, and the secondary endpoints were 90-day mortality, length of ICU stay, number of ventilator-free days in the first 28 days, and ΔBUN.

RESULTS

The high-protein group had significantly lower 28- and 90-day mortality and significantly greater ΔBUN, including after propensity score matching. ΔBUN might not be associated with outcomes.

CONCLUSIONS

Provision of >1.2 g/kg/day of protein may be associated with lower mortality of tube-fed and mechanically ventilated patients. Furthermore, while high protein intake may be associated with higher BUN, these changes may not be adversely associated with outcomes.

Nutrition Adherence in Critically Ill Patients; How is nutritional intake within the 1st week of hospitalization affecting the patient's Outcome?

Nutritional requirements vary during a patient's stay in the Intensive Care Unit (ICU) and their calculation can be relatively complex. During ICU stay nutrition requirements are rarely met, especially during the initial days of the hospitalization. Studies have shown that poor nutrition is associated with adverse patient outcome. This study examines for correlation between poor nutrition (calories, proteins, lipids and micronutrients) during the 1^st week of ICU stay and adverse patient outcome. Nutritional adherence effect is examined on groups of patients, such as patients with high BMI that receive low nutrition and critically ill males. Regarding the latter analysis, an accuracy rate of 76.4% was achieved when classifying the critically ill males towards their outcome. The results of this work could contribute to the development of smart alarms in the ICU.

Assessment of Metabolic and Nutritional Imbalance in Mechanically Ventilated Multiple Trauma Patients: From Molecular to Clinical Outcomes

The critically ill polytrauma patient is characterized by a series of metabolic changes induced by inflammation, oxidative stress, sepsis, and primary trauma, as well as associated secondary injuries associated. Metabolic and nutritional dysfunction in the critically ill patient is a complex series of imbalances of biochemical and genetic pathways, as well as the interconnection between them. Therefore, the equation changes in comparison to other critical patients or to healthy individuals, in which cases, mathematical equations can be successfully used to predict the energy requirements. Recent studies have shown that indirect calorimetry is one of the most accurate methods for determining the energy requirements in intubated and mechanically ventilated patients. Current research is oriented towards an individualized therapy depending on the energy consumption (kcal/day) of each patient that also takes into account the clinical dynamics. By using indirect calorimetry, one can measure, in real time, both oxygen consumption and carbon dioxide production. Energy requirements (kcal/day) and the respiratory quotient (RQ) can be determined in real time by integrating these dynamic parameters into electronic algorithms. In this manner, nutritional therapy becomes personalized and caters to the patients’ individual needs, helping patients receive the energy substrates they need at each clinically specific time of treatment.

Effect of Protein-Fortified Diet on Nitrogen Balance in Critically Ill Patients: Results from the OPINiB Trial

Nitrogen balance (NB) is considered a good marker of adequate protein intake and it has been suggested to be a good predictor of patients' health outcomes. However, in literature, there is a lack of large randomized trials examining NB-guided protein intake in patients in intensive care units (ICUs). A randomized controlled trial enrolling patients admitted to ICU was done to compare changes in NB. Participants were randomized to a standard or protein-fortified diet (protein intake of 1.8 g/kg/day according to the guidelines of the Society of Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition). The primary endpoint was represented by the NB on Day 1, 3, and study exit. Forty patients were enrolled in the study (19 in the protein-fortified group). The longitudinal analysis showed that, on Day 3, patients randomized to the protein-fortified diet were more likely (p < 0.001) to present better NB (at 3 days, patients in the protein-fortified diet were estimated to have a nitrate value of 5.22 g more than patients in the standard diet, 95% CI 3.86-6.58). The protein-fortified diet was found to be significantly and directly associated with changes in NB in critically ill patients admitted to ICU.

Reliability of, and Agreement Between, two Breath-by-Breath Indirect Calorimeters at Varying Levels of Inspiratory Oxygen

BACKGROUND

Indirect calorimetry (IC) is considered the accurate way of measuring energy expenditure (EE). IC devices often apply the Haldane transformation, introducing errors at inspiratory oxygen fraction (FiO₂ ) >60%. The aim was to assess measurement reliability and agreement between an unevaluated IC (device 2) (Beacon Caresystem, Mermaid Care A/S, Noerresundby, Denmark) not using Haldane transformation and an IC that does (device 1) (Ecovx, GE, Helsinki, Finland) at varying FiO₂ .

METHODS

Twenty healthy male subjects participated, with 16 completing the study (33 ± 9 years, 83.3 ± 16 kg, 1.83 ± 0.08 m). Subjects were mechanically ventilated in pressure support (3cmH₂ O; positive end-expiratory pressure: 3cmH₂ O) at FiO₂ of 21%, 50%, 85%, and 21% for 15 minutes at each FiO₂ . Mean EE, oxygen consumption (VO₂ ), and CO₂ production (VCO₂ ) were compared within and between devices across FiO₂ levels.

RESULTS

Device 2 showed within-device EE significant differences at 21% vs 50% FiO₂ and device 1 for VCO₂ at 50% vs. 85% FiO₂ . For all variables, both devices showed reliable measurements at 21% and 50% FiO₂ , but at 85%, FiO₂ bias and limits of agreement increased. Between devices, there were significant differences for EE at both 21% and 85% FiO₂ for VO₂ and for VCO₂ at 85% FiO₂ .

CONCLUSION

Both systems measured EE, VO₂ , and VCO₂ at 21%-85% FiO₂ reliably but with bias at 85% FiO₂ . The devices were in agreement at 21% and 50% FiO₂ , but further studies need to confirm accuracy at high FiO₂ .

Protein Provision in Critically Ill Adults Requiring Enteral Nutrition: Are Guidelines Being Met?

BACKGROUND

In a previous audit, 81% of enteral protein prescriptions failed to meet protein guidelines. To address this, a very high-protein enteral formula and protein supplements were introduced, and protein prescriptions were adjusted to account for nonnutrition energy sources displacing enteral formula. This follow-up audit compared protein provision in critically ill adults requiring exclusive enteral nutrition (EN), first, with local and international guidelines, and second, after changes to practice, with the previous audit in the same intensive care unit (ICU).

METHODS

Data were collected from 106 adults consecutively admitted to the ICU of a U.K. tertiary hospital and requiring exclusive EN ≥3 days. Protein targets based on local guidelines (1.25, 1.5, or 2.0 g/kg/d), nutrition prescription, and delivery were recorded for 24 hours between days 1-3, 5-7, 8-10, and 18-20 post-ICU admission.

RESULTS

The proportion of day 1-3 protein prescriptions meeting protein targets increased from 19% in 2015 to 69% in 2017 (P < .0005, φ = 0.50). The median percentage of protein target delivered was lower than prescribed (79% vs 103%; (P < .0005; r = 0.53) and EN delivery only met the target of 22% of patients. The proportion of protein prescriptions meeting protein targets was similar for days 1-3 (69%), 5-7 (71%), and 8-10 (68%), but increased slightly by days 18-20 (74%). The proportion of patients for which EN delivery met protein targets increased with the number of days post-ICU admission (22%, 26%, 37%, and 53% for days 1-3, 5-7, 8-10, and 18-20, respectively).

CONCLUSION

The proportion of protein prescriptions meeting guideline targets was higher after changes to practice.

Optimization of Nutrition Therapy with the Use of Calorimetry to Determine and Control Energy Needs in Mechanically Ventilated Critically Ill Patients: The ONCA Study, a Randomized, Prospective Pilot Study

BACKGROUND

Adequate nutrition therapy in critically ill patients poses a challenge because of the variable energy and substrate needs. The objective was to investigate whether nutrition therapy involving indirect calorimetry (IC), instead of equations for assessment of energy needs, could improve the nutrition status of critically ill patients.

METHODS

Forty mechanically ventilated patients were randomized into a group in which energy needs were controlled by calorimetry (IC group) and a group treated with a formula-based approach reflecting standard care (SC group). The primary outcome was change in the phase angle (PhA), a bioelectrical impedance parameter related to nutrition status and prognosis.

RESULTS

The mean IC-based energy requirement was lower than the formula-based estimate (21.1 ± 6.4 versus [vs] 25 kcal/kg/d, P < .01). The IC group reached 98% ± 8% of the energy goal, whereas the SC group reached only 79% ± 29% (P < 0.05), although mean intake was similar in both groups. The protein intake goal was better met in the IC group (91% ± 24%) than the SC group (73% ± 33%). The PhA of the IC group did not change during treatment, whereas that of the SC group tended to decrease by 0.36° ± 0.86° (P = .077). A shorter length of stay in intensive care was observed in the IC than in the SC group (13 ± 8 vs 24 ± 20 days, P < .05).

CONCLUSION

Intensified individual nutrition therapy involving IC appears to be useful for improving nutrition status in critically ill patients.

Current perspective for tube feeding in the elderly: from identifying malnutrition to providing of enteral nutrition

With the number of individuals older than 65 years expected to rise significantly over the next few decades, dramatic changes to our society and health care system will need to take place to meet their needs. Age-related changes in muscle mass and body composition along with medical comorbidities including stroke, dementia, and depression place elderly adults at high risk for developing malnutrition and frailty. This loss of function and decline in muscle mass (ie, sarcopenia) can be associated with reduced mobility and ability to perform the task of daily living, placing the elderly at an increased risk for falls, fractures, and subsequent institutionalization, leading to a decline in the quality of life and increased mortality. There are a number of modifiable factors that can mitigate some of the muscle loss elderly experience especially when hospitalized. Due to this, it is paramount for providers to understand the pathophysiology behind malnutrition and sarcopenia, be able to assess risk factors for malnutrition, and provide appropriate nutrition support. The present review describes the pathophysiology of malnutrition, identifies contributing factors to this condition, discusses tools to assess nutritional status, and proposes key strategies for optimizing enteral nutrition therapy for the elderly.

The CoCoS trial: Caloric Control in Cardiac Surgery patients promotes survival, an interventional trial with retrospective control

BACKGROUND & AIMS

Malnutrition is widespread among cardiac surgery patients and is independently related to an adverse postoperative evolution or outcome. We aimed to assess whether nutrition therapy (NT) could alter caloric deficit, morbidity, and mortality in patients scheduled for non-emergency coronary artery bypass graft (CABG) or aortic valve surgery.

METHODS

351 patients undergoing either elective CABG or aortic valve surgery were studied. Patients receiving NT were enrolled from January 2013 until December 2014. A retrospective control group (CT) consisted of 142 matched patients. The primary endpoint was to evaluate whether NT could limit caloric deficit (Intake to Need Deviation). Secondary endpoints addressed the potential effect of NT on morbidity and mortality. Patients were followed for one year after surgery.

RESULTS

There was no significant difference in patient, laboratory or mortality profile between the groups. Caloric deficit could be limited in the intervention group, essentially by providing oral feeding and oral supplements. A minority of patients required enteral or parenteral nutrition during their hospital stay. Caloric deficit increased after the second postoperative day because more patients were switched to oral feeding and intravenous infusions were omitted. Combining CABG and aortic valve surgery, male patients in the NT group had significantly less arrhythmia than in the CT group (7% versus 31%; P = 0.0056), while females in the NT group had significantly less pneumonia than in the CT group (7% versus 22%; P = 0.0183). Survival was significantly higher in female NT patients compared to CT patients, both for CABG (100% versus 83%; P = 0.0015) and aortic valve surgery (97% versus 78%; P = 0.0337).

CONCLUSION

The results suggest that NT beneficially affects morbidity and mortality in elective cardiac surgery patients. The impact of NT seems more pronounced in women than in men. Registration: Clinicaltrials.gov: NCT02902341.

High-Protein Hypocaloric Nutrition for Non-Obese Critically Ill Patients

High-protein hypocaloric nutrition, tailored to each patient's muscle mass, protein-catabolic severity, and exogenous energy tolerance, is the most plausible nutrition therapy in protein-catabolic critical illness. Sufficient protein provision could mitigate the rapid muscle atrophy characteristic of this disease while providing urgently needed amino acids to the central protein compartment and sites of tissue injury. The protein dose may range from 1.5 to 2.5 g protein (1.8-3.0 g free amino acids)/kg dry body weight per day. Nutrition should be low in energy (≈70% of energy expenditure or ≈15 kcal/kg dry body weight per day) because efforts to match energy provision to energy expenditure are physiologically irrational, risk toxic energy overfeeding, and have repeatedly failed in large clinical trials to demonstrate clinical benefit. The American Society for Parenteral and Enteral Nutrition currently suggests high-protein hypocaloric nutrition for obese critically ill patients. Short-term high-protein hypocaloric nutrition is physiologically and clinically sensible for most protein-catabolic critically ill patients, whether obese or not.

Energy Requirements in Critically Ill Patients

During the management of critical illness, optimal nutritional support is an important key for achieving positive clinical outcomes. Compared to healthy people, critically ill patients have higher energy expenditure, thereby their energy requirements and risk of malnutrition being increased. Assessing individual nutritional requirement is essential for a successful nutritional support, including the adequate energy supply. Methods to assess energy requirements include indirect calorimetry (IC) which is considered as a reference method, and the predictive equations which are commonly used due to the difficulty of using IC in certain conditions. In this study, a literature review was conducted on the energy metabolic changes in critically ill patients, and the implications for the estimation of energy requirements in this population. In addition, the issue of optimal caloric goal during nutrition support is discussed, as well as the accuracy of selected resting energy expenditure predictive equations, commonly used in critically ill patients.

Alterations in energy substrate metabolism in mice with different degrees of sepsis

BACKGROUND

Nutritional management is crucial during the acute phase of severe illnesses. However, the appropriate nutritional requirements for patients with sepsis are poorly understood. We investigated alterations in carbohydrate, fat, and protein metabolism in mice with different degrees of sepsis.

MATERIALS AND METHODS

C57BL/6 mice were divided into three groups: control mice group, administered with saline, and low- and high-dose lipopolysaccharide (LPS) groups, intraperitoneally administered with 1 and 5 mg of LPS/kg, respectively. Rectal temperature, food intake, body weight, and spontaneous motor activity were measured. Indirect calorimetry was performed using a respiratory gas analysis for 120 h, after which carbohydrate oxidation and fatty acid oxidation were calculated. Urinary nitrogen excretion was measured to evaluate protein metabolism. The substrate utilization ratio was recalculated. Plasma and liver carbohydrate and lipid levels were evaluated at 24, 72, and 120 h after LPS administration.

RESULTS

Biological reactions decreased significantly in the low- and high-LPS groups. Fatty acid oxidation and protein oxidation increased significantly 24 h after LPS administration, whereas carbohydrate oxidation decreased significantly. Energy substrate metabolism changed from glucose to predominantly lipid metabolism depending on the degree of sepsis, and protein metabolism was low. Plasma lipid levels decreased, whereas liver lipid levels increased at 24 h, suggesting that lipids were transported to the liver as the energy source.

CONCLUSIONS

Our findings revealed that energy substrate metabolism changed depending on the degree of sepsis. Therefore, in nutritional management, such metabolic alterations must be considered, and further studies on the optimum nutritional intervention during severe sepsis are necessary.

Timing of PROTein INtake and clinical outcomes of adult critically ill patients on prolonged mechanical VENTilation: The PROTINVENT retrospective study

BACKGROUND & AIMS

Optimal protein intake during critical illness is unknown. Conflicting results on nutritional support during the first week of ICU stay have been published. We addressed timing of protein intake and outcomes in ICU patients requiring prolonged mechanical ventilation.

METHODS

We retrospectively collected nutritional and clinical data on the first 7 days of ICU admission of adult critically ill patients, who were mechanically ventilated in our ICU for at least 7 days and admitted between January 1st 2011 and December 31st 2015. Based on recent literature, patients were divided into 3 protein intake categories, <0.8 g/kg/day, 0.8-1.2 g/kg/day and >1.2 g/kg/day. Our primary aim was to identify the optimum protein dose and timing related to the lowest 6 month mortality. Secondary endpoints were ventilation duration, need for renal replacement therapy (RRT), ICU length of stay (LOS) and mortality and hospital LOS and mortality.

RESULTS

In total 455 patients met the inclusion criteria. We found a time-dependent association of protein intake and mortality; low protein intake (<0.8 g/kg/day) before day 3 and high protein intake (>0.8 g/kg/day) after day 3 was associated with lower 6-month mortality, adjusted HR 0.609; 95% CI 0.480-0.772, p < 0.001) compared to patients with overall high protein intake. Lowest 6-month mortality was found when increasing protein intake from <0.8 g/kg/day on day 1-2 to 0.8-1.2 g/kg/day on day 3-5 and >1.2 g/kg/day after day 5. Moreover, overall low protein intake was associated with the highest ICU, in-hospital and 6-month mortality. No differences in ICU LOS, need for RRT or ventilation duration were found.

CONCLUSIONS

Our data suggest that although overall low protein intake is associated with the highest mortality risk, high protein intake during the first 3-5 days of ICU stay is also associated with increased long-term mortality. Therefore, timing of high protein intake may be relevant for optimizing ICU, in-hospital and long-term mortality outcomes.

Adequacy of nutrition support during extracorporeal membrane oxygenation

BACKGROUND

The use of veno-venous extracorporeal membrane oxygenation (vv-ECMO) is increasing in adults with severe respiratory failure. Observational data suggest that there are significant challenges to providing adequate nutrition support for patients on vv-ECMO. We aimed to describe firstly the nutrition support practices in a large single-centre providing vv-ECMO to adults and secondly any association with clinical outcome.

METHODS

We conducted a retrospective review of patients receiving vv-ECMO on the Intensive Care Unit (ICU) of a large London teaching hospital. Adult patients admitted to the ICU with severe respiratory failure between December 2010 and December 2015 were included. Daily energy and protein delivery were compared with estimated targets and reasons for feeding interruptions were collected from electronic medical records. Adequate feeding was defined as 80-110% of estimated targets.

RESULTS

We analysed 203 eligible patients. Median duration of ICU stay was 21.0 (IQR, 15.0-33.0) days and vv-ECMO 10.0 (IQR, 7.0-16.0) days. Although median energy (89.8% (IQR, 80.5-96.0%)) and protein (84.7% (IQR, 74.0-96.7%)) delivery was adequate, underfeeding of either energy or protein occurred on nearly one third (28.3%) of nutrition support days. A higher admission severity of illness score was associated with inadequate protein delivery (p = 0.040). Patients with more severe organ dysfunction on the first day of vv-ECMO received inadequate energy (p = 0.026). The most common reasons for interrupted feeding were medical procedures (39.1%) followed by poor gastric motility (22.8%).

CONCLUSION

Adequate energy and protein delivery during vv-ECMO is possible but underfeeding is still common, especially in those who are more severely ill or who have more severe organ dysfunction. Patients with inadequate energy or protein delivery did not differ in ICU and 6-month survival. Prospective studies investigating optimal feeding in this patient cohort are required.

Factors affecting the caloric and protein intake over time in critically ill trauma patients

BACKGROUND

Major trauma leads to increased nutritional requirements. However, little is known about the actual amount of calories and protein administered and the factors affecting the intake over time in critically ill trauma patients.

METHODS

Prospective study including 100 trauma patients admitted to the Los Angeles County + University of Southern California Medical Center intensive care unit between March 2014 and October 2014. Inclusion criteria were age > 16 y, surgery at admission, and no oral nutrition. The caloric and protein intake was recorded, and requirements were calculated daily for 28 d. The nutritional intake and the impact of clinical factors on the intake over time were assessed using mixed model analysis.

RESULTS

The caloric and protein intake significantly increased over time, but the median intake did not meet the median calculated requirements at any time. Multivariable analysis revealed a smaller increase of the nutritional intake over time in patients with an injury severity score > 45, whereas penetrating injury and laparotomy were associated with a higher increase of the intake. Body mass index scores ≥ 30 kg/m², traumatic brain injury, and gastrointestinal tract injuries were associated with a smaller increase of the caloric intake over time.

CONCLUSIONS

The median nutritional intake did not meet the median calculated requirements over time. A smaller increase of the nutritional intake over time was found in patients with a higher injury burden, whereas penetrating injury and laparotomy were associated with a higher increase of the intake. Higher body mass index scores, traumatic brain injury, and gastrointestinal tract injuries were associated with a smaller increase of the caloric intake over time. These clinical factors can help to adjust the nutritional support in critically ill trauma patients.

Energy and Protein in Critically Ill Patients with AKI: A Prospective, Multicenter Observational Study Using Indirect Calorimetry and Protein Catabolic Rate

The optimal nutritional support in Acute Kidney Injury (AKI) still remains an open issue. The present study was aimed at evaluating the validity of conventional predictive formulas for the calculation of both energy expenditure and protein needs in critically ill patients with AKI. A prospective, multicenter, observational study was conducted on adult patients hospitalized with AKI in three different intensive care units (ICU). Nutrient needs were estimated by different methods: the Guidelines of the European Society of Parenteral and Enteral Nutrition (ESPEN) for both calories and proteins, the Harris-Benedict equation, the Penn-State and Faisy-Fagon equations for energy. Actual energy and protein needs were repeatedly measured by indirect calorimetry (IC) and protein catabolic rate (PCR) until oral nutrition start, hospital discharge or renal function recovery. Forty-two patients with AKI were enrolled, with 130 IC and 123 PCR measurements obtained over 654 days of artificial nutrition. No predictive formula was precise enough, and Bland-Altman plots wide limits of agreement for all equations highlight the potential to under- or overfeed individual patients. Conventional predictive formulas may frequently lead to incorrect energy and protein need estimation. In critically ill patients with AKI an increased risk for under- or overfeeding is likely when nutrient needs are estimated instead of measured.

High protein intake without concerns?

The high fashion in nutrition for the critically ill is to recommend a high protein intake. Several opinion leaders are surfing on this wave, expanding the suggested protein allowance upwards. At the same time, there is no new evidence supporting this change in recommendations. Observational data show that in clinical practice protein intake is most often far below current ESPEN recommendations of 1.2–1.5 g/kg/day. Therefore, it may be in the best interests of our patients just to adhere to that guideline, and not to stretch them upwards for protein intake? Here we give arguments to stay conservative.

Intravenous citrulline generation test to assess intestinal function in intensive care unit patients

Background

Assessment of a quantifiable small intestinal function test is cumbersome. Fasting citrulline concentrations have been proposed as a measure of enterocyte function and elaborated into a citrulline generation test (CGT), which is applicable only when glutamine is administered orally. CGT is an oral test, limiting its use, for example, in critically ill patients.

Objective

Assessment of normative values and feasibility of an intravenously performed CGT in intensive care unit (ICU) patients with presumed gastrointestinal motility disturbances, especially when performed intravenously.

Design

CGT reference values were determined in 16 stable ICU patients using two different CGT methods, namely following either enteral or intravenous glutamine administration and both with simultaneous arterial and venous plasma citrulline sampling at six time-points. Plasma amino acid analysis was performed using reverse-phase high-performance liquid chromatography.

Results

The median total generation of citrulline in 90 min (CGT iAUCT90) was markedly higher with arterial citrulline sampling compared with venous citrulline sampling, being 724±585 and 556±418 µmol/L/min for enteral glutamine, respectively (p=0.02) and 977±283 and 769±231 µmol/L/min for intravenous glutamine, respectively (p=0.0004). The median slope (time-dependent increase) for plasma arterial and venous citrulline during the CGT was 0.20±0.16 and 0.18±0.12 µmol/L/min for enteral glutamine, respectively (p=0.004) and 0.22±0.16 and 0.19±0.05 µmol/L/min for intravenous glutamine, respectively (p=0.02).

Conclusion

Intravenous glutamine administration combined with arterial plasma citrulline sampling yielded the least variation in CGT characteristics in stable ICU patients. A 2-point measurement test had comparable test characteristics as a 6-point measurement CGT and seems promising.

Experimental and Outcome-Based Approaches to Protein Requirements in the Intensive Care Unit

Insight into protein requirements of intensive care unit (ICU) patients is urgently needed, but at present, it is unrealistic to define protein requirements for different diagnostic groups of critical illness or at different stages of illness. No large randomized controlled trials have randomized protein delivery, adequately addressed energy intake, and evaluated relevant clinical outcomes. As a pragmatic approach, experimental studies have focused on protein requirements of heterogeneous ICU patients. Data are scarce and the absolute value of protein requirements therefore is an approximation. Experimental studies indicate a protein requirement of >1.2 g/kg protein, which is supported by several outcome-based observational studies. Protein intake levels of up to 2.0-2.5 g/kg appear to be safe. A higher level of personalized treatment, within 1.2 and 2.5 g/kg, must involve identification of patients with low muscle protein mass that might benefit most from adequate protein nutrition in the ICU.

Benefits of early specialized nutritional support in malnourished patients

INTRODUCTION AND OBJECTIVE

Disease related malnutrition (DRM) is highly prevalent in Spain, affecting 23% of in-hospital patients, and is associated with clinical complications. Specialized nutritional support (SNS) can reduce these complications.

MATERIAL AND METHODS

Prospective study carried out in standard clinical practice conditions to test if SNS during the first 5 days of hospitalization, or subsequently, was associated to a lower length of stay or reduced complications in patients with a NRS-2002 score≥3 points.

RESULTS

In the group of patients who initiated early SNS, the length of stay was 8.83 days shorter than in the group with a later introduction (95% CI 3.55-14.10); nevertheless, the higher prevalence of male and oncological patients in this group could have impacted the results. A tendency towards a statistically significant lower mortality rate and a reduced amount of total complications was described.

CONCLUSION

The early introduction of SNS (within the first 5 days of hospitalization) in patients with DRM was associated with a 32.4% reduction in the length of stay.

Nutritional Assessment in Critically Ill Patients

BACKGROUND

Malnutrition is an important factor in the survival of critically ill patients. The purpose of the present study was to assess the nutritional status of patients in the intensive care unit (ICU) on the days of admission and discharge via a detailed nutritional assessment.

METHODS

Totally, 125 patients were followed up from admission to discharge at 8ICUs in Shiraz, Iran. The patients' nutritional status was assessed using subjective global assessment (SGA), anthropometric measurements, biochemical indices, and body composition indicators. Diet prescription and intake was also evaluated.

RESULTS

Malnutrition prevalence significantly increased on the day of discharge (58.62%) compared to the day of admission (28.8%) according to SGA (P<0.001). The patients' weight, mid-upper-arm circumference, mid-arm muscle circumference, triceps skinfold thickness, and calf circumference decreased significantly as well (P<0.001). Lean mass weight and body cell mass also decreased significantly (P<0.001). Biochemical indices showed no notable changes except for magnesium, which decreased significantly (P=0.013). A negative significant correlation was observed between malnutrition on discharge day and anthropometric measurements. Positive and significant correlations were observed between the number of days without enteral feeding, days delayed from ICU admission to the commencement of enteral feeding, and the length of ICU stay and malnutrition on discharge day. Energy and protein intakes were significantly less than the prescribed diet (26.26% and 26.48%, respectively).

CONCLUSION

Malnutrition on discharge day increased in the patients in the ICU according to SGA. Anthropometric measurements were better predictors of the nutritional outcome of our critically ill patients than were biochemical tests.

Clinical Guide for the Use of Metabolic Carts: Indirect Calorimetry--No Longer the Orphan of Energy Estimation

Critically ill patients often require nutrition support, but accurately determining energy needs in these patients is difficult. Energy expenditure is affected by patient characteristics such as weight, height, age, and sex but is also influenced by factors such as body temperature, nutrition support, sepsis, sedation, and therapies. Using predictive equations to estimate energy needs is known to be inaccurate. Therefore, indirect calorimetry measurement is considered the gold standard to evaluate energy needs in clinical practice. This review defines the indications, limitations, and pitfalls of this technique and gives practice suggestions in various clinical situations.

Vitamin and Trace Element Loss from Negative-Pressure Wound Therapy

OBJECTIVE

This study investigated select vitamin and trace element loss from wound exudates in burn and trauma patients treated with negative-pressure wound therapy (NPWT).

DESIGN

A prospective observational study was performed using wound exudate samples.

SETTING

A level I trauma center acute care hospital.

PARTICIPANTS

The study was composed of 8 patients with open abdomens and 9 patients with 12 soft-tissue wounds.

MAIN OUTCOME MEASURES

The goal was to collect wound exudate samples daily for 3 days, then every other day to day 9 or until NPWT was discontinued, and to analyze for vitamins A (retinol), C, and E and zinc (Zn), iron (Fe), and copper (Cu). Daily loss of each micronutrient was calculated from their concentration and 24-hour volumes of the exudates.

MAIN RESULTS

Exudate loss in the open-abdomen group was significantly higher than in the patients with soft-tissue wounds (900 ± 547 vs 359 ± 246 mL/d). The mean 24-hour loss of vitamins A, C, and E were 0.3, 2.8, and 11 mg, respectively, in the open-abdomen group. Over the same period, the losses of Zn, Fe, and Cu were 0.5, 0.4, and 0.25 mg, respectively, in these patients. Micronutrient 24-hour loss was significantly lower in the soft-tissue wound patients than in the open-abdomen group.

CONCLUSIONS

The data support the concept that significant amounts of micronutrients can be lost from NPWT wound exudates, particularly in open abdomens. These losses should be considered in the nutritional support of these patients who typically are in a hypermetabolic and catabolic state.

Protein Requirements in the Critically Ill: A Randomized Controlled Trial Using Parenteral Nutrition

BACKGROUND

Current recommendations for higher protein/amino acid provision in the critically ill are based on weak evidence. This double-blinded randomized controlled trial aimed to compare standard amino acid intake with the higher level recommended as the minimum for critically ill patients.

METHODS

In total, 119 patients requiring parenteral nutrition (PN) in an intensive care unit (ICU) were randomized to receive blinded PN solutions containing amino acids at either 0.8 g/kg or 1.2 g/kg. Primary outcome was handgrip strength at ICU discharge. Secondary outcomes measured at study day 7 included handgrip strength, fatigue score (using the Chalder scale), and ultrasound measurements of muscle thickness at defined body sites. Analysis of covariance was used to control for age, sex, nutrition status (Subjective Global Assessment), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and baseline measurement.

RESULTS

Actual amino acid delivery to the 2 groups was 0.9 and 1.1 g/kg respectively, averaged over the first 7 days. Grip strength at ICU discharge was not significantly different between groups (P =054) despite being improved at study day 7 in the group receiving the higher level of amino acids (mean [SD], 22.1 [10.1] vs 18.5 [11.8] kg, P =025). These patients also had less fatigue (Chalder score, mean [SD], 5.4 [2.2] vs 6.2 [2.2], P = .045) and greater forearm muscle thickness on ultrasound (mean [SD], 3.2 [0.4] vs 2.8 [0.4] cm, P < .0001). Nitrogen balance was significantly better at study day 3 but not at day 7. There was no difference between groups in mortality or length-of-stay measures.

CONCLUSION

The higher level of amino acids was associated with small improvements in a number of different measures, supporting guideline recommendations for ICU patients. This trial was registered at Australian New Zealand Clinical Trials Registry (www.anzctr.org.au) as ACTRN12609000366257.

Measuring resting energy expenditure during extracorporeal membrane oxygenation: preliminary clinical experience with a proposed theoretical model

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in patients with severe respiratory failure. Indirect calorimetry (IC) is a safe and non-invasive method for measuring resting energy expenditure (REE). No data exist on the use of IC in ECMO-treated patients as oxygen uptake and carbon dioxide elimination are divided between mechanical ventilation and the artificial lung. We report our preliminary clinical experience with a theoretical model that derives REE from IC measurements obtained separately on the ventilator and on the artificial lung.

METHODS

A patient undergoing veno-venous ECMO for acute respiratory failure due to bilateral pneumonia was studied. The calorimeter was first connected to the ventilator and oxygen consumption (VO2 ) and carbon dioxide transport (VCO2 ) were measured until steady state was reached. Subsequently, the IC was connected to the membrane oxygenator and similar gas analysis was performed. VO2 and VCO2 values at the native and artificial lung were summed and incorporated in the Weir equation to obtain a REEcomposite .

RESULTS

At the ventilator level, VO2 and VCO2 were 29.5 ml/min and 16 ml/min. VO2 and VCO2 at the artificial lung level were 213 ml/min and 187 ml/min. Based on these values, a REEcomposite of 1703 kcal/day was obtained. The Faisy-Fagon and Harris-Benedict equations calculated a REE of 1373 and 1563 kcal/day.

CONCLUSION

We present IC-acquired gas analysis in ECMO patients. We propose to insert individually obtained IC measurements at the native and the artificial lung in the Weir equation for retrieving a measured REEcomposite .

Protein requirements, morbidity and mortality in critically ill patients: fundamentals and applications

Recent evidence suggests that a negative protein balance secondary to severe disease is associated with increased morbidity. A loss of total body protein is inevitable in this scenario, even with an aggressive nutritional approach, primarily due to the catabolism of skeletal muscle fibers. The ubiquitin-proteasome system is the primary metabolic and biochemical mechanism involved in this process; paradoxically, this system consumes adenosine triphosphate as its energy source. It is possible that a neutral protein balance in these clinical situations is important for improving outcomes and achieving the caloric goals estimated or measured by indirect calorimetry. Recent studies have suggested that the use of higher protein concentrations in nutritional therapy for critically ill patients may help to reduce mortality. The purpose of this study was to review some of the nutrition therapy principles related to protein metabolism, evaluate the main assertions of the guidelines of specialty societies and review the recent studies that address these issues using critical insights from the authors' clinical experience.

Neuromuscular electrical stimulation prevents muscle wasting in critically ill comatose patients

Fully sedated patients, being treated in the intensive care unit (ICU), experience substantial skeletal muscle loss. Consequently, survival rate is reduced and full recovery after awakening is compromised. Neuromuscular electrical stimulation (NMES) represents an effective method to stimulate muscle protein synthesis and alleviate muscle disuse atrophy in healthy subjects. We investigated the efficacy of twice-daily NMES to alleviate muscle loss in six fully sedated ICU patients admitted for acute critical illness [n=3 males, n=3 females; age 63 ± 6 y; APACHE II (Acute Physiology and Chronic Health Evaluation II) disease-severity-score: 29 ± 2]. One leg was subjected to twice-daily NMES of the quadriceps muscle for a period of 7 ± 1 day whereas the other leg acted as a non-stimulated control (CON). Directly before the first and on the morning after the final NMES session, quadriceps muscle biopsies were collected from both legs to assess muscle fibre-type-specific cross-sectional area (CSA). Furthermore, phosphorylation status of the key proteins involved in the regulation of muscle protein synthesis was assessed and mRNA expression of selected genes was measured. In the CON leg, type 1 and type 2 muscle-fibre-CSA decreased by 16 ± 9% and 24 ± 7% respectively (P<0.05). No muscle atrophy was observed in the stimulated leg. NMES increased mammalian target of rapamycin (mTOR) phosphorylation by 19 ± 5% when compared with baseline (P<0.05), with no changes in the CON leg. Furthermore, mRNA expression of key genes involved in muscle protein breakdown either declined [forkhead box protein O1 (FOXO1); P<0.05] or remained unchanged [muscle atrophy F-box (MAFBx) and muscle RING-finger protein-1 (MuRF1)], with no differences between the legs. In conclusion, NMES represents an effective and feasible interventional strategy to prevent skeletal muscle atrophy in critically ill comatose patients.

Optimising enteral nutrition in critically ill patients by reducing fasting times

BACKGROUND

Enteral nutrition is currently the route of choice for feeding critically ill patients with a functioning gut but delivery is commonly associated with disruptions. Common reasons for interruptions to enteral nutrition are fasting for diagnostic procedures, surgery and airway management. These interruptions result in significant calorie deficits that are associated with increased complications. We aimed to describe the specific interruptions in our patient group and the impact they have on nutrition delivery before and after implementation of a fasting guideline.

METHODS

A service improvement project was undertaken over two different time points, 1 year apart, to evaluate the effectiveness of a fasting guideline in a general/trauma ICU in a London teaching hospital.

RESULTS

There were 62 interruptions to enteral nutrition delivery with the first data collection and 64 in the second. Prolonged fasting before and after surgery and airway procedures were initially identified as the two most important causes of delays. Implementation of the fasting guideline resulted in statistical and clinical improvements in reducing fasting for airways procedures. The calorie deficit also statistically and clinically decreased as a result of the guideline.

CONCLUSIONS

We conclude that the introduction of a simple guideline stipulating reduced fasting times before ICU procedures can result in less time lost in feed interruptions and improved enteral nutrition delivery.

Prevalence of Underprescription or Overprescription of Energy Needs in Critically Ill Mechanically Ventilated Adults as Determined by Indirect Calorimetry: A Systematic Literature Review

BACKGROUND

Underfeeding and overfeeding has been associated with adverse patient outcomes. Resting energy expenditure can be measured using indirect calorimetry. In its absence, predictive equations are used. A systematic literature review was conducted to determine the prevalence of underprescription and overprescription of energy needs in adult mechanically ventilated critically ill patients by comparing predictive equations to indirect calorimetry measurements.

METHODS

Ovid MEDLINE, CINAHL Plus, Scopus, and EMBASE databases were searched in May 2013 to identify studies that used both predictive equations and indirect calorimetry to determine energy expenditure. Reference lists of included publications were also searched. The number of predictive equations that underestimated or overestimated energy expenditure by ±10% when compared to indirect calorimetry measurements were noted at both an individual and group level.

RESULTS

In total, 2349 publications were retrieved, with 18 studies included. Of the 160 variations of 13 predictive equations reviewed at a group level, 38% underestimated and 12% overestimated energy expenditure by more than 10%. The remaining 50% of equations estimated energy expenditure to within ±10 of indirect calorimetry measurements. On an individual patient level, predictive equations underestimated and overestimated energy expenditure in 13-90% and 0-88% of patients, respectively. Differences of up to 43% below and 66% above indirect calorimetry values were observed.

CONCLUSIONS

Large discrepancies exist between predictive equation estimates and indirect calorimetry measurements in individuals and groups. Further research is needed to determine the influence of indirect calorimetry and predictive equation limitations in contributing to these observed differences.

Sarcopenia and critical illness: a deadly combination in the elderly

Sarcopenia is the age-associated loss of lean skeletal muscle mass. It is the result of multiple physiologic derangements, ultimately resulting in an insidious functional decline. Frailty, the clinical manifestation of sarcopenia and physical infirmity, is associated with significant morbidity and mortality in the elderly population. The underlying pathology results in a disruption of the individual's ability to tolerate internal and external stressors such as injury or illness. This infirmity results in a markedly increased risk of falls and subsequent morbidity and mortality from the resulting traumatic injury, as well as an inability to recover from medical insults, resulting in critical illness. The increasing prevalence of sarcopenia and critical illness in the elderly has resulted in a deadly intersection of disease processes. The lethality of this combination appears to be the result of altered muscle metabolism, decreased mitochondrial energetics needed to survive critical illness, and a chronically activated catabolic state likely mediated by tumor necrosis factor-α. Furthermore, these underlying derangements are independently associated with an increased incidence of critical illness, resulting in a progressive downward spiral. Considerable evidence has been gathered supporting the role of aggressive nutrition support and physical therapy in improving outcomes. Critical care practitioners must consider sarcopenia and the resulting frailty phenotype a comorbid condition so that the targeted interventions can be instituted and research efforts focused.

Impact of early enteral versus parenteral nutrition on mortality in patients requiring mechanical ventilation and catecholamines: study protocol for a randomized controlled trial (NUTRIREA-2)

Background

Nutritional support is crucial to the management of patients receiving invasive mechanical ventilation (IMV) and the most commonly prescribed treatment in intensive care units (ICUs). International guidelines consistently indicate that enteral nutrition (EN) should be preferred over parenteral nutrition (PN) whenever possible and started as early as possible. However, no adequately designed study has evaluated whether a specific nutritional modality is associated with decreased mortality. The primary goal of this trial is to assess the hypothesis that early first-line EN, as compared to early first-line PN, decreases day 28 all-cause mortality in patients receiving IMV and vasoactive drugs for shock.

Methods/Design

The NUTRIREA-2 study is a multicenter, open-label, parallel-group, randomized controlled trial comparing early PN versus early EN in critically ill patients requiring IMV for an expected duration of at least 48 hours, combined with vasoactive drugs, for shock. Patients will be allocated at random to first-line PN for at least 72 hours or to first-line EN. In both groups, nutritional support will be started within 24 hours after IMV initiation. Calorie targets will be 20 to 25 kcal/kg/day during the first week, then 25 to 30 kcal/kg/day thereafter. Patients receiving PN may be switched to EN after at least 72 hours in the event of shock resolution (no vasoactive drugs for 24 consecutive hours and arterial lactic acid level below 2 mmol/L). On day 7, all patients receiving PN and having no contraindications to EN will be switched to EN. In both groups, supplemental PN may be added to EN after day 7 in patients with persistent intolerance to EN and inadequate calorie intake. We plan to recruit 2,854 patients at 44 participating ICUs.

Discussion

The NUTRIREA-2 study is the first large randomized controlled trial designed to assess the hypothesis that early EN improves survival compared to early PN in ICU patients. Enrollment started on 22 March 2013 and is expected to end in November 2015.

Trial registration

ClinicalTrials.gov Identifier: NCT01802099 (registered 27 February 2013)

Early high protein intake is associated with low mortality and energy overfeeding with high mortality in non-septic mechanically ventilated critically ill patients

Introduction

Early protein and energy feeding in critically ill patients is heavily debated and early protein feeding hardly studied.

Methods

A prospective database with mixed medical-surgical critically ill patients with prolonged mechanical ventilation (>72 hours) and measured energy expenditure was used in this study. Logistic regression analysis was used to analyse the relation between admission day-4 protein intake group (with cutoffs 0.8, 1.0, and 1.2 g/kg), energy overfeeding (ratio energy intake/measured energy expenditure > 1.1), and admission diagnosis of sepsis with hospital mortality after adjustment for APACHE II (Acute Physiology and Chronic Health Evaluation II) score.

Results

A total of 843 patients were included. Of these, 117 had sepsis. Of the 736 non-septic patients 307 were overfed. Mean day-4 protein intake was 1.0 g/kg pre-admission weight per day and hospital mortality was 36%. In the total cohort, day-4 protein intake group (odds ratio (OR) 0.85; 95% confidence interval (CI) 0.73 to 0.99; P = 0.047), energy overfeeding (OR 1.62; 95%CI 1.07 to 2.44; P = 0.022), and sepsis (OR 1.77; 95%CI 1.18 to 2.65; P = 0.005) were independent risk factors for mortality besides APACHE II score. In patients with sepsis or energy overfeeding, day-4 protein intake was not associated with mortality. For non-septic, non-overfed patients (n = 419), mortality decreased with higher protein intake group: 37% for <0.8 g/kg, 35% for 0.8 to 1.0 g/kg, 27% for 1.0 to 1.2 g/kg, and 19% for ≥1.2 g/kg (P = 0.033). For these, a protein intake level of ≥1.2 g/kg was significantly associated with lower mortality (OR 0.42, 95%CI 0.21 to 0.83, P = 0.013).

Conclusions

In non-septic critically ill patients, early high protein intake was associated with lower mortality and early energy overfeeding with higher mortality. In septic patients early high protein intake had no beneficial effect on mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0701-z) contains supplementary material, which is available to authorized users.

Proteins and amino acids are fundamental to optimal nutrition support in critically ill patients

Proteins and amino acids are widely considered to be subcomponents in nutritional support. However, proteins and amino acids are fundamental to recovery and survival, not only for their ability to preserve active tissue (protein) mass but also for a variety of other functions. Understanding the optimal amount of protein intake during nutritional support is therefore fundamental to appropriate clinical care. Although the body adapts in some ways to starvation, metabolic stress in patients causes increased protein turnover and loss of lean body mass. In this review, we present the growing scientific evidence showing the importance of protein and amino acid provision in nutritional support and their impact on preservation of muscle mass and patient outcomes. Studies identifying optimal dosing for proteins and amino acids are not currently available. We discuss the challenges physicians face in administering the optimal amount of protein and amino acids. We present protein-related nutrition concepts, including adaptation to starvation and stress, anabolic resistance, and potential adverse effects of amino acid provision. We describe the methods for assessment of protein status, and outcomes related to protein nutritional support for critically ill patients. The identification of a protein target for individual critically ill patients is crucial for outcomes, particularly for specific subpopulations, such as obese and older patients. Additional research is urgently needed to address these issues.

Fundamental determinants of protein requirements in the ICU

PURPOSE OF REVIEW

Currently, feeding the ICU patient is highly discussed. Energy feeding has been the topic of randomized studies, but protein feeding has not. Study results are contradictory on early feeding; however, little is known about early protein requirement. What is this protein requirement based on, therefore what are the fundamental determinants?

RECENT FINDINGS

Recent studies have addressed the importance of protein feeding and/or muscle (protein) wasting in critically ill patients. Targeted feeding has been shown to improve protein balance in one study, and infection rate in one study. Low muscle mass that is already present during ICU admission has been shown to be related to higher mortality, in two studies. Four studies have related muscle wasting to (protein) feeding strategies with very diverse results: Two small studies have reported no advantage [n = 15, computed tomography] or negative impact (n = 62, ultrasound, 50% sepsis patients) of protein on muscle wasting. Two studies, one small (n = 33, computed tomography) and one very large (n = 1372, Subjective Global Assessment), have reported a positive impact of (early) feeding on muscle wasting.

SUMMARY

Fundamental to adequate protein feeding in critically ill patients, at least 1.2 g protein/kg per day, is targeted energy feeding using indirect calorimetry. The level of protein requirement is related to fat free mass or muscle mass, which makes sex and BMI also relevant. Targeted early protein feeding is found to improve short-term outcome, reduction of muscle wasting and hospital mortality. Long-term outcome of protein feeding has not been studied. However, targeted protein feeding may be harmful in sepsis patients. Up to now, we lack biomarkers that provide caregivers with an instrument to increase protein feeding up to the individual protein requirement of the critically ill patient.