Enteral nutrition in critically ill patients with severe hemodynamic failure after cardiopulmonary bypass

Early Enteral Nutrition May Improve Survival in Patients With Cardiogenic Shock

Background and Aim: International guidelines recommend early enteral nutrition (EEN) for critically ill patients. However, evidence supporting the optimal timing of EN in patients diagnosed with cardiogenic shock (CS) is lacking. As such, this study aimed to compare the clinical outcomes and safety of EEN versus delayed EN in patients diagnosed with CS. Methods: This retrospective cohort study was conducted using data from the Medical Information Mart for Intensive Care IV version 2.2 database. Patients who received EN within 2 days of admission were assigned to the EEN group. A 1:1 propensity score-matched (PSM) analysis was performed to control for bias in baseline characteristics and ensure the reliability of the results. To exclude the impact of confounders, an adjusted proportional hazards regression model was used to verify the independence between EEN and survival outcomes. Results: Of 1846 potentially eligible patients, 1398 received EEN and 448 received delayed EN. After 1:1 PSM, 818 patients were assigned to the EEN (n = 409) and delayed EN (n = 409) groups. Regarding cumulative survival, patients with CS receiving EEN experienced better 30-, 90-, and 180-day survival outcomes than the delayed EN group (hazard ratio [HR] 0.803 [95% confidence interval [CI] 0.647-0.998], p=0.045; HR 0.729 [95% CI 0.599-0.889], p=0.001; and HR 0.778 [95% CI 0.644-0.938], p=0.008, respectively). After adjusting for confounders, EEN was found to be independently associated with survival outcomes. Moreover, EEN did not increase the risk(s) for ileus, aspiration pneumonia, or gastrointestinal bleeding. Patients who received delayed EN experienced longer hospital stays than those receiving EEN (17 days [interquartile range [IQR] 10-25] versus 12 days [IQR 7-19 days], respectively; p < 0.001). Conclusion: EEN was not associated with harm, but rather with improved survival outcomes in patients diagnosed with CS. Further studies are required to verify these findings.

When can we start early enteral nutrition safely in patients with shock on vasopressors?

Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability generally require vasopressors to maintain the target mean arterial pressure. Enteral nutrition (EN) is an important therapeutic intervention in critically ill patients and has unique benefits for intestinal recovery. However, the initiation of early EN in patients with shock receiving vasopressors remains controversial. Current guidelines make conservative and vague recommendations regarding early EN support in patients with shock. Increasing studies demonstrates that early EN delivery is safe and feasible in patients with shock receiving vasopressors; however, this evidence is based on observational studies. Changes in gastrointestinal blood flow vary by vasopressor and inotrope and are complex. The risk of gastrointestinal complications, especially the life-threatening complications of non-occlusive mesenteric ischemia and non-occlusive bowel necrosis, cannot be ignored in patients with shock during early EN support. It remains a therapeutic challenge in critical care nutrition therapy to determine the initiation time of EN in patients with shock receiving vasopressors and the safe threshold region for initiating EN with vasopressors. Therefore, the current review aimed to summarize the evidence on the optimal and safe timing of early EN initiation in patients with shock receiving vasopressors to improve clinical practice.

Nutritional support in the cardiac intensive care unit

Optimal care of critically ill patients in the cardiac intensive care unit includes adequate nutritional support. This review highlights the high prevalence of malnutrition in acute heart failure, acute coronary syndrome, cardiogenic shock, and post-cardiac arrest and its adverse impact on prognosis. There is a lack of robust evidence regarding appropriate nutritional support in this patient population. Initiation of nutritional support with a comprehensive assessment of the patient's nutritional status is critical. High-risk cardiac patients who are not critically ill can receive oral nutrition adapted to individual risk factors or deficiencies, although overfeeding should be avoided in the acute phase. For critically ill patients at risk of or with malnutrition on admission, general principles include initiation of nutritional support within 48 h of admission, preference for enteral over parenteral nutrition, preference for hypocaloric nutrition in the first week of intensive care unit admission, and adequate micronutrient supplementation. Enteral nutrition in haemodynamically unstable patients carries a risk, albeit low, of intestinal ischaemia. In the case of malnutrition, the risk of refeeding syndrome should always be considered.

Effect of early enteral nutrition on short-term outcomes and survival in patients in the cardiothoracic intensive care unit: An inverse probability weighted retrospective study

OBJECTIVES

The merits of early enteral nutrition (EEN) in patients in the cardiothoracic intensive care unit (CTICU) remain unclear. This retrospective study aimed to address this issue.

METHODS

We analyzed data from the MIMIC IV v2.0 database, including patients with a CTICU stay of ≥4 d. Patients were divided into early and delayed enteral nutrition (EN) groups. Differences in baseline data were corrected using an inverse probability weighting (IPW) approach. Generalized linear models (GLMs) were used to compare trends over time between groups, and survival effects were evaluated with weighted logistic and Cox regression, supplemented by weighted Kaplan-Meier curves. Subgroup analysis facilitated the exploration of potential interactions.

RESULTS

The study included 720 CTICU patients. Following IPW, all baseline variables were balanced. EEN led to shorter hospital and CTICU stays, lower incidence of respiratory and blood infections, and reduced total insulin usage in the first week of CTICU admission, albeit with an increased total gastric residual volume. Mortality risk between the groups did not significantly differ at 28 d or at 1 y. Excessive early energy and protein intake elevated the risk of 28-d mortality, but the relationship may not be linear. Overweight patients or those with fewer comorbidities had a higher mortality risk with EEN.

CONCLUSIONS

EEN may improve short-term outcomes in CTICU patients without a clear survival benefit. Early high caloric and protein intake could lead to adverse outcomes, suggesting a careful evaluation for initiating EN in specific patients.

When is enteral nutrition indicated?

Enteral nutrition (EN) is a vital component of nutrition around the world. EN allows for delivery of nutrients to those who cannot maintain adequate nutrition by oral intake alone. Common questions regarding EN are when to initiate and in what scenarios it is safe. The answers to these questions are often complex and require an evidence-based approach. The Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) established an Enteral Nutrition Committtee to address the important questions surrounding the indications for EN. Consensus recommendations were established based on eight extremely clinically relevant questions regarding EN indications as deemed by the Enteral Nutrition Committee. These consensus recommendations may act as a guide for clinicians and stakeholders on difficult questions pertaining to indications for EN. This paper was approved by the ASPEN Board of Directors.

A Narrative Review of Nutrition Therapy in Patients Receiving Extracorporeal Membrane Oxygenation

The use of extracorporeal membrane oxygenation (ECMO) in patients with severe cardiorespiratory failure has seen significant growth in the last decade. Despite this, there is paucity of data surrounding the optimum nutritional management for ECMO patients. This review aimed to describe current nutrition practices in patients receiving ECMO, critically appraise available studies and identify areas for future research. A literature search was conducted in PubMed, MEDLINE, and CINAHL Plus to identify all randomized trials and observational studies published between July 2000 and July 2020 investigating nutrition practices in critically ill adults receiving ECMO. The primary outcomes were nutritional adequacy, gastrointestinal complications, and physical function. Secondary outcomes included mortality, length of stay, and duration on ECMO support. From a total of 31 studies identified, 12 met the inclusion criteria. Nine observational studies were reviewed following eligibility assessment. Early enteral nutrition was deemed safe and feasible for ECMO patients; however, meeting nutritional targets was challenging. Utilizing alternative nutrition routes is an option, although risks and benefits should be taken into consideration. Data on gastrointestinal complications and other clinical outcomes were inconsistent, and no data were identified investigating the effects of nutrition on the physical and functional recovery of ECMO patients. Nutrition therapy in ECMO patients should be provided in line with current guidelines for nutrition in critical illness until further data are available. Further prospective, randomized studies investigating optimum nutrition practices and effects on clinical and functional outcomes are urgently required.

Improving nutrition practices for postoperative high-risk heart transplant and ventricular assist device implant patients in circulatory compromise: A quality improvement pre- and post-protocol intervention outcome study

BACKGROUND

Patients undergoing heart transplant (HT) and ventricular assist device (VAD) implant may experience intra- and postoperative complications requiring high-dose vasopressor agents and/or mechanical circulatory support. These complications increase the risk of nonocclusive bowel ischemia (NOBI) and inadequate enteral nutrition (EN) delivery, and guidance for this high-risk patient population is limited. To optimize nutrition support practices in this patient population at our institution, we created the High-Risk Nutrition Support Protocol (HRNSP) to improve nutrient delivery and promote safer EN practices in the setting of NOBI risk factors after HT and VAD implant.

METHODS

We developed and implemented a nutrition support protocol as a quality improvement (QI) initiative. Data were obtained before (n = 62) and after (n = 52) protocol initiation. We compared nutrition and clinical outcomes between the pre- and post-intervention groups.

RESULTS

Fewer calorie deficits (P < 0.001), fewer protein deficits (P < 0.001), a greater proportion of calorie/protein needs met (P < 0.001), zero NOBI cases (0%), and decreased intensive care unit (ICU) length of stay (LOS) (P = 0.005) were observed with 100% (n = 52 of 54) HRNSP implementation success. Increased use of parenteral nutrition did not increase central line-associated bloodstream infections (P = 0.46). There was no difference in hospital LOS (P = 0.44) or 90-day and 1-year mortality (P = 0.56, P = 0.35).

CONCLUSION

This single-center, QI pre- and post-protocol intervention outcome study suggests that implementing and adhering to a nutrition support protocol for VAD implant/HT patients with hemodynamic complications increases nutrient delivery and is associated with reduced ICU LOS and NOBI.

Enteral Nutrition in Critically Ill Patients Under Vasoactive Drug Therapy. The NUTRIVAD Study

BACKGROUND

Enteral nutrition (EN) in critically ill patients requiring vasoactive drug (VAD) support is controversial. This study assesses the tolerability and safety of EN in such patients.

METHODS

This prospective observational study was conducted in 23 ICUs over 30 months. Inclusion criteria were a need for VAD and/or mechanic circulatory support (MCS) over a minimum of 48 h, a need for at least 48 h of mechanical ventilation, an estimated life expectancy longer than 72 h, and at least 72 h of ICU stay. Patients with refractory shock were excluded. EN was performed according to established protocols during which descriptive, daily hemodynamic and efficacy and safety data were collected. An independent research group conducted the statistical analysis.

RESULTS

Of 200 patients included, 30 (15%) required MCS and 145 (73%) met early multiorgan dysfunction criteria. Mortality was 24%. Patients needed a mean dose of norepinephrine in the first 48 h of 0.71 μg/kg/min (95%CI: 0.63-0.8) targeting a mean arterial pressure of 68 mmHg (95%CI: 67-70) during the first 48 h. EN was started 34 h (95%CI: 31-37) after ICU admission. Mean energy and protein delivered by EN/patient/day were 1159 Kcal (95%CI: 1098-1220) and 55.6 g (52.4-58.7) respectively. Daily energy balance during EN/patient/day was -432 (95%CI: -496 to -368). 154 (77%) patients experienced EN-related complications. However, severe complications such as mesenteric ischemia were recorded in only 1 patient (0.5%).

CONCLUSIONS

EN in these patients seems feasible, safe and unrelated to serious complications. Reaching the energy target only through EN is difficult.

CLINICAL RELEVANCY STATEMENT

Enteral nutrition (EN) in critically ill patients requiring vasoactive drugs (VAD) is currently a subject of controversy. Factors such as when to start EN, dosing, monitoring, or whether to avoid EN altogether are a real challenge because of its link to a risk of bowel ischemia. We describe our experience with EN in 200 critically ill patients on mechanical ventilation and requiring VAD. Under adequate supervision, EN proved feasible and safe. Our findings require confirmation in clinical intervention trials. This article is protected by copyright. All rights reserved.

Heart Failure-Related Cardiogenic Shock: Pathophysiology, Evaluation and Management Considerations: Review of Heart Failure-Related Cardiogenic Shock

Despite increasing prevalence in critical care units, cardiogenic shock related to HF (HF-CS) is incompletely understood and distinct from acute myocardial infarction related CS. This review highlights the pathophysiology, evaluation, and contemporary management of HF-CS.

Nutrition in the Intensive Care Unit-A Narrative Review

Background: While consent exists, that nutritional status has prognostic impact in the critically ill, the optimal feeding strategy has been a matter of debate. Methods: Narrative review of the recent evidence and international guideline recommendations focusing on basic principles of nutrition in the ICU and the treatment of specific patient groups. Covered topics are: the importance and diagnosis of malnutrition in the ICU, the optimal timing and route of nutrition, energy and protein requirements, the supplementation of specific nutrients, as well as monitoring and complications of a Medical Nutrition Therapy (MNT). Furthermore, this review summarizes the available evidence to optimize the MNT of patients grouped by primarily affected organ system. Results: Due to the considerable heterogeneity of the critically ill, MNT should be carefully adapted to the individual patient with special focus on phase of critical illness, metabolic tolerance, leading symptoms, and comorbidities. Conclusion: MNT in the ICU is complex and requiring an interdisciplinary approach and frequent reevaluation. The impact of personalized and disease-specific MNT on patient-centered clinical outcomes remains to be elucidated.

Impact of early nutrition route in patients receiving extracorporeal membrane oxygenation: A retrospective cohort study

BACKGROUND

Early nutrition management in patients receiving extracorporeal membrane oxygenation (ECMO) remains controversial. Despite its potentially beneficial effect, enteral nutrition (EN) could be associated with gastrointestinal (GI) complications. Total daily energy requirements remain difficult to achieve with ECMO support. Analysis of nutrition practices could improve nutrition management of this particular population.

METHODS

A monocentric retrospective study of patients requiring ECMO in a cardiac surgery intensive care unit (ICU) between 2010 and 2014 with follow-up ≥6 days. Nutrition support was monitored daily until ECMO weaning. We compared patients exposed (EN group, n = 49) and unexposed (No EN group (NEN), n = 63) with EN, as well as the energy and protein intakes within 4 days after initiation of ECMO. Vital status and nosocomial infections were followed up until ICU discharge. Primary outcome was the incidence of GI intolerance and risk-factor identification. Secondary outcomes included impact of nutrition inadequacy and clinical outcome.

RESULTS

A total 112 patients were analyzed, representing 969 nutrition days. Median ratio of energy and protein prescribed/required daily was 81% (58-113) and 56% (36-86), respectively. GI intolerance was experienced by 53% (26 of 49) of patients in the EN group and was only associated with ECMO duration (odds ratio, 1.14: 95% CI, 1.00-1.31; P = .05). Low-energy and protein days were not associated with clinical outcomes such as nosocomial infections.

CONCLUSION

EN is associated with almost 50% GI intolerance without clinical benefit for patients receiving ECMO. Adequacy in energy and protein amounts did not affect clinical outcome.

Combination of enteral and parenteral nutrition in the acute phase of critical illness: An updated systematic review and meta-analysis

BACKGROUND

Uncertainty remains about the best route and timing of medical nutrition therapy in the acute phase of critical illness. Early combined enteral nutrition (EN) and parenteral nutrition (PN) may represent an attractive option to achieve recommended energy and protein goals in select patient groups. This meta-analysis aims to update and summarize the current evidence.

METHODS

This systematic review and meta-analysis includes randomized controlled trials (RCTs) targeting the effect of EN alone vs a combination of EN with PN in the acute phase of critical illness in adult patients. Assessed outcomes include mortality, intensive care unit (ICU) and hospital length of stay (LOS), ventilation days, infectious complications, physical recovery, and quality-of-life outcomes.

RESULTS

Twelve RCTs with 5543 patients were included. Treatment with a combination of EN with PN led to increased delivery of macronutrients. No statistically significant effect of a combination of EN with PN vs EN alone on any of the parameters was observed: mortality (risk ratio = 1.0; 95% CI, 0.79-1.28; P = .99), hospital LOS (mean difference, -1.44; CI, -5.59 to 2.71; P = .50), ICU LOS, and ventilation days. Trends toward improved physical outcomes were observed in two of four trials.

CONCLUSION

A combination of EN with PN improved nutrition intake in the acute phase of critical illness in adults and was not inferior regarding the patients' outcomes. Large, adequately designed trials in select patient groups are needed to answer the question of whether this nutrition strategy has a clinically relevant treatment effect.

Association between early enteral nutrition and clinical outcome in patients with severe acute heart failure who require invasive mechanical ventilation

BACKGROUND

This study aimed to examine the association between early enteral nutrition (EEN) and clinical outcome in patients with severe acute heart failure (AHF).

METHODS

This retrospective observational study enrolled consecutive patients with AHF who required continuous invasive mechanical ventilation (IMV) for >48 h and were admitted to a single-center cardiac care unit (CCU). The primary outcome was CCU length of stay (LoS). We compared patients who were initiated on EN within 48 h of intubation (EEN group) with those who were initiated on EN after 49 h of intubation (delayed EN [DEN] group). Multivariate logistic regression analysis was performed to determine independent factors for primary and secondary outcomes. CCU LoS and IMV time were categorized using the median.

RESULTS

We included 86 patients with AHF (EEN group, n = 56; DEN group, n = 30) who met the inclusion criteria. The median CCU LoS was significantly shorter in the EEN group (10 [8-15] days) than in the DEN group (15 [12-26] days, P = .007). Multivariate analysis indicated that time to EN initiation was an independent factor for CCU LoS (odds ratio [OR], 8.39; 95% confidence interval [CI], 2.18-32.20; P = .002), IMV time (OR, 4.84; 95% CI, 1.37-17.20; P = .015), and incidence of infection (OR, 2.73; 95％ CI, 1.04-7.18; P = .042).

CONCLUSION

EEN (within 48 h of intubation) for patients with severe AHF who require continuous IMV might be associated with reduced CCU LoS, IMV time, and incidence of infection.

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.

Meeting nutritional targets of critically ill patients by combined enteral and parenteral nutrition: review and rationale for the EFFORTcombo trial

While medical nutrition therapy is an essential part of the care for critically ill patients, uncertainty exists about the right form, dosage, timing and route in relation to the phases of critical illness. As enteral nutrition (EN) is often withheld or interrupted during the intensive care unit (ICU) stay, combined EN and parenteral nutrition (PN) may represent an effective and safe option to achieve energy and protein goals as recommended by international guidelines. We hypothesise that critically ill patients at high nutritional risk may benefit from such a combined approach during their stay on the ICU. Therefore, we aim to test if an early combination of EN and high-protein PN (EN+PN) is effective in reaching energy and protein goals in patients at high nutritional risk, while avoiding overfeeding. This approach will be tested in the here-presented EFFORTcombo trial. Nutritionally high-risk ICU patients will be randomised to either high (≥2·2 g/kg per d) or low protein (≤1·2 g/kg per d). In the high protein group, the patients will receive EN+PN; in the low protein group, patients will be given EN alone. EN will be started in accordance with international guidelines in both groups. Efforts will be made to reach nutrition goals within 48-96 h. The efficacy of the proposed nutritional strategy will be tested as an innovative approach by functional outcomes at ICU and hospital discharge, as well as at a 6-month follow-up.

Safety and Outcomes of Early Enteral Nutrition in Circulatory Shock

Circulatory shock is one of the most common reasons for an intensive care unit admission, has been shown to impair gut barrier and immune functions, and promotes dysbiosis. The exact timing and dose of enteral nutrition (EN) in circulatory shock remains unclear. In fact, because of fear of complications such as nonocclusive mesenteric ischemia and bowel necrosis and splanchnic steal phenomenon, clinicians may hesitate to start EN in critically ill patients with circulatory shock. In this narrative review, we identify and appraise contemporary evidence evaluating the safety and outcomes of EN in circulatory shock.

Differences in effect of early enteral nutrition on mortality among ventilated adults with shock requiring low-, medium-, and high-dose noradrenaline: A propensity-matched analysis

BACKGROUND & AIMS

Despite extensive research on early enteral nutrition (EEN), it remains unclear whether EEN is effective for patients with shock requiring vasopressors. This study aimed to compare outcomes between EEN and late enteral nutrition (LEN) in ventilated patients with shock requiring low-, medium-, or high-dose noradrenaline.

METHODS

Using a national inpatient database in Japan, we identified ventilated patients admitted to intensive care units who had shock requiring catecholamines (noradrenaline or dobutamine) from July 2010 to March 2016. We defined patients who started enteral nutrition within 2 days after starting mechanical ventilation as EEN group and the others as LEN group. Propensity score matching was performed between patients undergoing EEN and LEN in each of the low- (<0.1 μg/kg/min), medium- (0.1-0.3 μg/kg/min), and high-dose (≥0.3 μg/kg/min) noradrenaline groups.

RESULTS

We identified 52,563 eligible patients during the 69-month study period, including 38,488, 11,042, and 3033 patients in the low-, medium-, and high-dose noradrenaline groups, respectively. One-to-two propensity score matching created 5,969, 2,162, and 477 one-to-two matched pairs in the low-, medium-, and high-dose noradrenaline groups, respectively. The 28-day mortality rate was significantly lower in the EEN than LEN group in the low-dose noradrenaline group (risk difference, -2.9%; 95% confidence interval [CI], -4.5% to -1.3%) and in the medium-dose noradrenaline group (risk difference, -6.8%; 95% CI, -9.6% to -4.0%). In the high-dose noradrenaline group, 28-day mortality did not differ significantly between the EEN and LEN groups (absolute risk difference, -1.4%; 95% CI, -7.4%-4.7%).

CONCLUSIONS

Although the size of the subgroup requiring high-dose noradrenaline may have been too small to demonstrate a significant difference, the results suggest that EEN was associated with a reduction in mortality in ventilated adults treated with low- or medium-dose noradrenaline but not in those requiring high-dose noradrenaline.

Perioperative Enteral Nutrition After Left Ventricular Assist Device Implantation

Objective:

We assessed what predicts nutritional adequacy at day 14 following implantation of left ventricular assist device (LVAD).

Method:

We retrospectively reviewed the cases of 97 adult patients who underwent LVAD implantation at our institution from June 2011 to June 2016. We divided the patients into two groups based on the administered enteral nutrition (EN) calories on post-operative day (POD) 14: the EN calories of group SEN (sufficient enteral nutrition) were >80% of their total target calories, or the EN calories of group IEN (insufficient enteral nutrition) were <80% of their total target calories. We compared the two groups in terms of the perioperative factors within 1 week after surgery.

Results:

Groups SEN and IEN consisted of 53 and 44 patients, respectively. The mean doses of adrenaline and noradrenaline, mean central venous pressure (CVP), duration of nitric oxide administration, and mean residual gastric volume during 1 week after surgery in group SEN were significantly lower than those in group IEN (P < .05). In multivariate analysis, higher CVP during 1 week after surgery was identified as an independent risk factor for delayed EN on POD14 (odds ratio, 1.40; 95% confidence interval, 1.11-1.66; P = .0037). Total bilirubin, occurrence of acute kidney injury, and mixed venous blood saturation during 1 week after surgery were not significant predictors for EN on POD14.

Conclusions:

Increased CVP within 1 week after LVAD implantation was an independent factor for reduced EN feeding.

Current Evidence about Nutrition Support in Cardiac Surgery Patients-What Do We Know?

Nutrition support is increasingly recognized as a clinically relevant aspect of the intensive care treatment of cardiac surgery patients. However, evidence from adequate large-scale studies evaluating its clinical significance for patients&rsquo; mid- to long-term outcome remains sparse. Considering nutrition support as a key component in the perioperative treatment of these critically ill patients led us to review and discuss our understanding of the metabolic response to the inflammatory burst induced by cardiac surgery. In addition, we discuss how to identify patients who may benefit from nutrition therapy, when to start nutritional interventions, present evidence about the use of enteral and parenteral nutrition and the potential role of pharmaconutrition in cardiac surgery patients. Although the clinical setting of cardiac surgery provides advantages due to its scheduled insult and predictable inflammatory response, researchers and clinicians face lack of evidence and several limitations in the clinical routine, which are critically considered and discussed in this paper.

Association of Oral Intake and Transient Mixed Venous Oxygen Desaturation in Patients Undergoing Fast-Track Postoperative Care After Open-Heart Surgery

OBJECTIVE

The impact of early resumption of oral intake after cardiac surgery on hemodynamics has not been characterized. The authors examined the effects of early oral intake on the oxygen supply-demand relationship in patients undergoing on-pump cardiac surgery in an early recovery after surgery program.

DESIGN

Prospective data were collected in postcardiac surgical patients in a multidisciplinary intensive care unit (ICU) during an 18-month period.

SETTING

Single institution study.

PARTICIPANTS

Forty-three patients who underwent either mitral or aortic valve repair and were successfully liberated from ventilatory support within 10 hours after surgery.

INTERVENTIONS

Patients were either allowed to resume oral intake on the morning of the first postoperative day or not at the discretion of the surgical team after extubation.

MEASUREMENTS AND MAIN RESULTS

The oxygen supply-demand relationship was assessed continuously with cardiac index and mixed venous oxygen saturation (SvO₂). Among the subjects, 22 patients were allowed to eat, and transient SvO₂ decrease was noted in 13 patients. All transient SvO₂ decreases occurred in the patients with early oral intake. The hemodynamic status and oxygen supply-demand relationship did not differ between the patients with and without transient SvO₂ decrease. All the subjects were discharged successfully from the ICU on the first postoperative day, and the length of hospital stay was similar irrespective of SvO₂ decrease after early oral intake.

CONCLUSIONS

Early oral intake shortly after extubation was associated with transient but significant SvO₂ decrease in patients who underwent fast-track recovery after open-heart surgery. Because this phenomenon did not negatively affect the postoperative outcome, early oral intake may not be harmful.

Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2)

BACKGROUND

Whether the route of early feeding affects outcomes of patients with severe critical illnesses is controversial. We hypothesised that outcomes were better with early first-line enteral nutrition than with early first-line parenteral nutrition.

METHODS

In this randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2 trial) done at 44 French intensive-care units (ICUs), adults (18 years or older) receiving invasive mechanical ventilation and vasopressor support for shock were randomly assigned (1:1) to either parenteral nutrition or enteral nutrition, both targeting normocaloric goals (20-25 kcal/kg per day), within 24 h after intubation. Randomisation was stratified by centre using permutation blocks of variable sizes. Given that route of nutrition cannot be masked, blinding of the physicians and nurses was not feasible. Patients receiving parenteral nutrition could be switched to enteral nutrition after at least 72 h in the event of shock resolution (no vasopressor support for 24 consecutive hours and arterial lactate <2 mmol/L). The primary endpoint was mortality on day 28 after randomisation in the intention-to-treat-population. This study is registered with ClinicalTrials.gov, number NCT01802099.

FINDINGS

After the second interim analysis, the independent Data Safety and Monitoring Board deemed that completing patient enrolment was unlikely to significantly change the results of the trial and recommended stopping patient recruitment. Between March 22, 2013, and June 30, 2015, 2410 patients were enrolled and randomly assigned; 1202 to the enteral group and 1208 to the parenteral group. By day 28, 443 (37%) of 1202 patients in the enteral group and 422 (35%) of 1208 patients in the parenteral group had died (absolute difference estimate 2·0%; [95% CI -1·9 to 5·8]; p=0·33). Cumulative incidence of patients with ICU-acquired infections did not differ between the enteral group (173 [14%]) and the parenteral group (194 [16%]; hazard ratio [HR] 0·89 [95% CI 0·72-1·09]; p=0·25). Compared with the parenteral group, the enteral group had higher cumulative incidences of patients with vomiting (406 [34%] vs 246 [20%]; HR 1·89 [1·62-2·20]; p<0·0001), diarrhoea (432 [36%] vs 393 [33%]; 1·20 [1·05-1·37]; p=0·009), bowel ischaemia (19 [2%] vs five [<1%]; 3·84 [1·43-10·3]; p=0·007), and acute colonic pseudo-obstruction (11 [1%] vs three [<1%]; 3·7 [1·03-13·2; p=0·04).

INTERPRETATION

In critically ill adults with shock, early isocaloric enteral nutrition did not reduce mortality or the risk of secondary infections but was associated with a greater risk of digestive complications compared with early isocaloric parenteral nutrition.

FUNDING

La Roche-sur-Yon Departmental Hospital and French Ministry of Health.

Standard vs. Calorie-Dense Immune Nutrition in Haemodynamically Compromised Cardiac Patients: A Prospective Randomized Controlled Pilot Study

Background. The aim of study was to test the hypothesis that early enteral nutrition (EN) with calorie-dense and protein rich enteral formula improves enteral energy and protein delivery in critically ill cardiac patients. Methods. Prospective randomized pilot study of 40 ventilated adult patients undergoing elective cardiac surgery with use of cardiopulmonary bypass receiving inotropic support postoperatively. Patients were to receive either standard isocaloric (1000 Kcal/L and 38 g/L protein) early EN (n = 20) or calorie-dense and protein-rich (1300 Kcal/L and 66.7 g/L protein) early EN (n = 20). Results. The mean time to EN initiation was 27 ± 11 h. Early EN with the calorie-dense formula provided significantly more energy and protein enteral delivery on the 2nd, (p < 0.0001), 5th (p = 0.036), and 7th days (p = 0.024), and was associated with higher levels of prealbumin concentration on the 14th day (0.13 ± 0.01 g/L and 0.21 ± 0.1 g/L; p = 0.04) and significantly increased levels of transferrin on the 3rd, 5th, and 7th day (p < 0.05) after surgery. Conclusion. Present findings support hypothesis that early EN using a calorie-dense and protein rich formula leads to better enteral energy and protein delivery and higher levels of short-lived serum proteins.

Critical Care Nutrition: Where's the Evidence?

The surgical critically ill patient is subject to a variable and complex metabolic response, which has detrimental effects on immunity, wound healing, and preservation of lean body muscle. The concept of nutrition support has evolved into nutrition therapy, whereby the primary objectives are to prevent oxidative cell injury, modulate the immune response, and attenuate the metabolic response. This review outlines the metabolic response to critical illness, describes nutritional risk; reviews the evidence for the role, dose, and timing of enteral and parenteral nutrition, and reviews the evidence for immunonutrition in the surgical intensive care unit.

Cardiothoracic Critical Care

High-value CCC is rapidly evolving to meet the demands of increased patient acuity and to incorporate advances in technology. The high-performing CCC system and culture should aim to learn quickly and continuously improve. CCC demands a proactive, interactive, precise, an expert team, and continuity.

Role of nutrition support in adult cardiac surgery: a consensus statement from an International Multidisciplinary Expert Group on Nutrition in Cardiac Surgery

Nutrition support is a necessary therapy for critically ill cardiac surgery patients. However, conclusive evidence for this population, consisting of well-conducted clinical trials is lacking. To clarify optimal strategies to improve outcomes, an international multidisciplinary group of 25 experts from different clinical specialties from Germany, Canada, Greece, USA and Russia discussed potential approaches to identify patients who may benefit from nutrition support, when best to initiate nutrition support, and the potential use of pharmaco-nutrition to modulate the inflammatory response to cardiopulmonary bypass. Despite conspicuous knowledge and evidence gaps, a rational nutritional support therapy is presented to benefit patients undergoing cardiac surgery.

Gastric Versus Small Bowel Feeding in Critically Ill Adults

Critically ill patients often require enteral feedings as a primary supply of nutrition. Whether enteral nutrition (EN) should be delivered as a gastric versus small bowel feeding in the critically ill patient population remains a contentious topic. The Society of Critical Care Medicine (SCCM)/American Society for Parenteral and Enteral Nutrition (ASPEN), the European Society for Parenteral and Enteral Nutrition (ESPEN), and the Canadian Clinical Practice Guidelines (CCPG) are not in consensus on this topic. No research to date demonstrates a significant difference between the two feeding routes in terms of patient mortality, ventilator days, or length of stay in the intensive care unit (ICU); however, studies provide some evidence that there may be other benefits to using a small bowel feeding route in critically ill patients. The purpose of this paper is to examine both sides of this debate and review advantages and disadvantages of both small bowel and gastric routes of EN. Practical issues and challenges to small bowel feeding tube placement are also addressed. Finally, recommendations are provided to help guide the clinician when selecting a feeding route, and suggestions are made for future research.

Impact of early nutrition and feeding route on outcomes of mechanically ventilated patients with shock: a post hoc marginal structural model study

PURPOSE

Few data are available about optimal nutrition modalities in mechanically ventilated patients with shock. Our objective was to assess associations linking early nutrition (<48 h after intubation), feeding route and calorie intake to mortality and risk of ventilator-associated pneumonia (VAP) in patients with invasive mechanical ventilation (IMV) and shock.

METHODS

In the prospective OutcomeRea database, we identified adults with IMV >72 h and shock (arterial systolic pressure <90 mmHg) within 48 h after intubation. A marginal structural Cox model was used to create a pseudo-population in which treatment was unconfounded by subject-specific characteristics.

RESULTS

We included 3,032 patients. Early nutrition was associated with lower day-28 mortality [HR 0.89, 95 % confidence interval (CI) 0.81-0.98, P = 0.01] and day-7 mortality (HR 0.76, CI 0.66-0.87, P < 0.001) but not with lower day-7 to day-28 mortality (HR 1.00, CI 0.89-1.12, P = 0.98). Early nutrition increased VAP risk over the 28 days (HR 1.08, CI 1.00-1.17, P = 0.046) and until day 7 (HR 7.17, CI 6.27-8.19, P < 0.001) but decreased VAP risk from days 7 to 28 (HR 0.85, CI 0.78-0.92, P < 0.001). Compared to parenteral feeding, enteral feeding was associated with a slightly increased VAP risk (HR 1.11, CI 1.00-1.22, P = 0.04) but not with mortality. Neither mortality nor VAP risk differed between early calorie intakes of ≥20 and <20 kcal/kg/day.

CONCLUSION

In mechanically ventilated patients with shock, early nutrition was associated with reduced mortality. Neither feeding route nor early calorie intake was associated with mortality. Early nutrition and enteral feeding were associated with increased VAP risk.

Early Trophic Enteral Nutrition Is Associated With Improved Outcomes in Mechanically Ventilated Patients With Septic Shock: A Retrospective Review

PURPOSE

Current guidelines provide weak recommendations for starting enteral nutrition (EN) in patients with septic shock (on vasopressor support). Outcomes of patients receiving EN in septic shock on vasopressor support have not been well studied. We hypothesize that early trophic EN in mechanically ventilated patients with septic shock is associated with improved outcomes.

METHODS

Single-center retrospective study of mechanically ventilated patients admitted with septic shock to identify patients receiving (1) no EN, (2) <600 kcal/d within 48 hours, and (3) ≥600 kcal/d within 48 hours. Outcomes studied included in-hospital mortality, length of intensive care unit stay (LOS), duration of mechanical ventilation (DOMV), and complications of feeding intolerance.

RESULTS

Sixty-six patients were identified. In all, 15 received no EN, 37 received <600 kcal/d, and 14 received ≥600 kcal/d EN daily. Median LOS was 12, 5, and 13 days, respectively. The LOS was lower in patients receiving <600 kcal/d when compared to either no EN (P < .001) or those receiving ≥600 kcal/d (P < .001). Median DOMV was lower in patients receiving <600 kcal/d (median 3, P < .001) as compared to no EN (median 7, P < .001) or those receiving ≥600 kcal/d (median 7.5, P < .001). Mortality was not different. There were no significant complications among groups.

CONCLUSION

In patients with septic shock, those receiving <600 kcal/d EN within 48 hours had lower DOMV and LOS when compared to those who did not receive EN or those who received ≥600 kcal/d. These observations provide strong justification for prospective evaluation of the effect of early trophic EN in patients with septic shock.

Methicillin-resistant Staphylococcus aureus bloodstream infections are associated with a higher energy deficit than other ICU-acquired bacteremia

PURPOSE

Caloric insufficiency during the first week of intensive care unit (ICU) stay was reported to be associated with increased infection rates, especially ICU-acquired bloodstream infection (ICU-BSI). However, the predisposition to ICU-BSI by a given pathogen remains not well known. We aimed to determine the impact of early energy-calorie deficit on the pathogens responsible for ICU-BSI.

DESIGN

Prospective, observational, cohort study in a 18-bed medical ICU of a tertiary care hospital.

METHODS

Daily energy balance (energy-calorie intakes minus calculated energy-calorie expenditure) was compared according to the microbiological results of the blood cultures of 92 consecutive prolonged (at least 96 h) acute mechanically ventilated patients who developed a first episode of ICU-BSI.

RESULTS

Among the 92 ICU-BSI, nine were due to methicillin-resistant Staphylococcus aureus (MRSA). The cumulated energy deficit of patients with MRSA ICU-BSI was greater than those with ICU-BSI caused by other pathogens (-1,348 ± 260 vs -1,000 ± 401 kcal/day from ICU admission to day of ICU-BSI, p = 0.008). ICU admission, risk factors for nosocomial infections, nutritional status, and conditions potentially limiting feeding did not differ significantly between the two groups. Patients with MRSA ICU-BSI had lower delivered energy and similar energy expenditure, causing higher energy deficits. More severe energy deficit and higher rate of MRSA blood cultures (p = 0.01 comparing quartiles) were observed.

CONCLUSIONS

Early in-ICU energy deficit was associated with MRSA ICU-BSI in prolonged acute mechanically ventilated patients. Results suggest that limiting the early energy deficit could be a way to optimize MRSA ICU-BSI prevention.

Early enteral nutrition in critically ill patients with hemodynamic instability: an evidence-based review and practical advice

Early enteral nutrition (EEN) in critically ill patients is associated with significant benefit as well as elevated risk of complications. Concomitant use of EEN with vasopressors has been associated with nonocclusive bowel necrosis in critically ill patients with hemodynamic instability. The decision when to initiate enteral nutrition in hemodynamically unstable patients that require vasoactive substances remains a clinical dilemma. This review summarizes the effect of EEN and vasoactive agents on gastrointestinal blood flow and perfusion in critically ill patients, based on current evidence. Animal and clinical data involving simultaneous administration of EEN and vasoactive agents for hemodynamic instability are reviewed, and the factors related to the safety and effectiveness of EEN support in this patient population are analyzed. Moreover, practical recommendations are provided. Additional randomized clinical trials are warranted to provide cutting-edge evidence-based guidance about this issue for practitioners of critical care.

Enteral nutrition in the hemodynamically unstable critically ill patient

The benefit of enteral nutrition in critically ill patients has been demonstrated by several studies, especially when it is started early, in the first 24-48h of stay in the Intensive Care Unit, and this practice is currently advised by the main clinical guidelines. The start of enteral nutrition is controversial in patients with hemodynamic failure, since it may trigger intestinal ischemia. However, there are data from experimental studies in animals, as well as from observational studies in humans that allow for hypotheses regarding its beneficial effect and safety. Interventional clinical trials are needed to confirm these findings.

Nutrition support protocols and their influence on the delivery of enteral nutrition: a systematic review

BACKGROUND

Malnutrition remains prevalent in critically ill adults and is associated with poor outcomes and increased cost of hospitalization.

AIM

To (a) determine whether implementation of a nutrition support protocol improves delivery of nutrients in critically ill patients, and (b) evaluate whether patients receiving nutrition support based on a protocol have better outcomes than those who do not.

METHODS

CINHAL and PUBMED databases were searched utilizing keywords "model," "nutrition," intensive care," "algorithm," "critical care," "protocol," and "feeding guidelines." Selection criteria included original studies published in English with publication date between January 1, 2005, and December 31, 2010; a critically ill adult population; and level 1 or 2 studies. Studies were collected and reviewed by a single reviewer. Data extraction and quality assessment were assured utilizing a standardized form. A narrative description of results was provided due to variability in methods and outcome measures of included studies.

RESULTS

Ninety-nine studies emerged and 22 studies were considered for inclusion. Four studies were selected. Use of a nutrition support protocol was found to lead to increased efficacy in the delivery of nutrients via the enteral route.

LINKING EVIDENCE TO ACTION

The use of a nutrition support protocol appears to increase the efficacy of enteral nutrition delivery. Further research is needed to determine the effect of increased enteral nutrition adequacy on patient outcomes. The use of an evidenced-based protocol is recommended to improve protein and energy delivery in the critically ill.

Early enteral nutrition in patients with hemodynamic failure following cardiac surgery

BACKGROUND

Enteral nutrition (EN) is controversial in patients with circulatory compromise. This study assesses the feasibility and safety of EN given early after cardiac surgery in patients with hemodynamic failure.

METHODS

Prospective observational study conducted in a surgical intensive care unit (ICU) of a tertiary hospital over 17 months.

INCLUSION CRITERIA

Cardiac surgery patients with hemodynamic failure (dependence on 2 or more vasoactive drugs and/or mechanical circulatory support) requiring more than 24 hours of mechanical ventilation. Variables Examined: Descriptive data, daily hemodynamic data, and variables related to the efficacy and safety of EN. EN was performed according to our EN protocol.

RESULTS

Of 642 patients admitted to the ICU, 37 (5.8%) met the inclusion criteria. Of these, 11 (29.7%) required mechanical circulatory support, and 25 (68.0%) met the criteria for early multiorgan dysfunction. Mortality was 13.5%. Mean EN duration was 12.3 days (95% confidence interval [CI], 9.6-15.0). The mean EN diet volume delivered/patient/d was 1199 mL (95% CI, 1118.7-1278.8), and mean EN energy delivered/patient/d was 1228.4 kcal (95% CI, 1145.8-1311). The set energy target was achieved in 15 patients (40.4%). The most common EN-related complication was constipation. No case of mesenteric ischemia was detected.

CONCLUSIONS

Our findings indicate that early EN is feasible in this type of patients and not associated with serious complications. However, it is difficult to attain an appropriate energy target by EN alone. These observations point to a need for monitoring of daily energy delivery and balance, as well as careful monitoring of warning signs of intestinal ischemia.

A pilot study to explore the safety of perioperative postpyloric enteral nutrition

BACKGROUND

The practice of holding enteral nutrition (EN) 8 hours prior to surgery is common. We hypothesized that it was safe to continue postpyloric EN, and we developed an institutional practice pattern to investigate our hypothesis.

METHODS

Our pilot study included intubated patients in the surgical intensive care unit at Froedtert Memorial Lutheran Hospital who received EN via a nasojejunal (NJ) feeding tube and underwent 1 or more surgical procedures. Demographic, illness, and injury information were collected as well as length of time to NJ placement, time to initiation of EN, EN interruptions, and complications. Additional hours of EN were calculated by totaling the number of hours a patient received EN past midnight on the day of surgery.

RESULTS

A total of 14 patients with mean (SD) age 44.3 (19.9) were included. Patients had a mean (SD) Injury Severity Score (ISS) of 26.1 (9.2) on admission and underwent a total of 38 operations following placement of a feeding tube. The most frequent operation performed was an orthopedic procedure (n = 17; 46.1%). The mean (SD) length of EN interruptions for a single procedure was 222.4 (206.9) minutes. Patients received an additional 11.9 (4.7) hours of EN over the course of their hospitalization and an additional 1064.9 (490) kcal/d per operation. There were no adverse events.

CONCLUSION

Perioperative continuation of postpyloric EN is feasible in some critically ill surgical patients and can result in additional calories provided. A multidisciplinary approach and an institutional policy can increase the likelihood of meeting nutrition goals in these patients.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): cardiac patient]

Patients with cardiac disease can develop two types of malnutrition: cardiac cachexia, which appears in chronic congestive heart failure, and malnutrition due to the complications of cardiac surgery or any other type of surgery in patients with heart disease. Early enteral nutrition should be attempted if the oral route cannot be used. When cardiac function is severely compromised, enteral nutrition is feasible, but supplementation with parenteral nutrition is sometimes required. Sustained hyperglycemia in the first 24 hours in patients admitted for acute coronary syndrome, whether diabetic or not, is a poor prognostic factor for 30-day mortality. In critically-ill cardiac patients with stable hemodynamic failure, nutritional support of 20-25 kcal/kg/day is effective in maintaining adequate nutritional status. Protein intake should be 1.2*-1.5 g/kg/day. Routine polymeric or high protein formulae should be used, according to the patient's prior nutritional status, with sodium and volume restriction according to the patient's clinical situation. The major energy source for myocytes is glutamine, through conversion to glutamate, which also protects the myocardial cell from ischemia in critical situations. Administration of 1 g/ day of omega-3 (EPA+DHA) in the form of fish oil can prevent sudden death in the treatment of acute coronary syndrome and can also help to reduce hospital admission for cardiovascular events in patients with chronic heart failure.