Cardiogenic shock and nutrition: safe?

The medical treatment of cardiogenic shock

Cardiogenic shock is characterized by tissue hypoperfusion due to the inadequate cardiac output to maintain the tissue oxygen demand. Despite some advances in cardiogenic shock management, extremely high mortality is still associated with this clinical syndrome. Its management is based on the immediate stabilization of hemodynamic parameters through medical care and the use of mechanical circulatory supports in specialized centers. This review aims to understand the cardiogenic shock current medical treatment, consisting mainly of inotropic drugs, vasopressors and coronary revascularization. In addition, we highlight the relevance of applying measures to other organ levels based on the optimization of mechanical ventilation and the appropriate initiation of renal replacement therapy.

Extra-cardiac management of cardiogenic shock in the intensive care unit

Cardiogenic shock (CS) is a heterogeneous clinical syndrome characterized by low cardiac output leading to end-organ hypoperfusion. Organ dysoxia ranging from transient organ injury to irreversible organ failure and death occurs across all CS etiologies but differing by incidence and type. Herein, we review the recognition and management of respiratory, renal and hepatic failure complicating CS. We also discuss unmet needs in the CS care pathway and future research priorities for generating evidence-based best practices for the management of extra-cardiac sequelae. The complexity of CS admitted to the contemporary cardiac intensive care unit demands a workforce skilled to care for these extra-cardiac critical illness complications with an appreciation for how cardio-systemic interactions influence critical illness outcomes in afflicted patients.

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 management of heart failure

Nutrition in the cardiovascular field to date has focused on improving lifestyle-related diseases such as hypertension and diabetes from the viewpoint of secondary prevention. For these conditions, "nutrition for weight loss" is recommended, and nutritional guidance that restricts calories is provided. On the other hand, in symptomatic Stage C and D heart failure, it is known that underweight patients who manifest poor nutrition, sarcopenia, and cardiac cachexia have a poor prognosis. This is referred to as the "Obesity paradox". In order to "avoid weight loss" in patients with heart failure, a paradigm shift to nutritional management to prevent weight loss is needed. Rather than prescribing uniform recommendation for salt reduction of 6 g/day or less, awareness of the behavior change stage model is attracting attention. In this setting, the value of salt restriction will need to be determined to determine the priority level of intervention for undernutrition versus the need to prevent congestive signs and symptoms. In the Intensive Care Unit (ICU)/Cardiac Care Unit (CCU) for acute heart failure, nutritional intervention should be considered within 48 h of admission. Key points are selection of access route, timing of intervention, and monitoring of side effects. In nutritional management at home and in end-of-life care, food is a reflection of an individual's values, as well as a source of joy and encouragement. The importance of digestive tract should also be recognized in heart failure from oral flail to intestinal edema, constipation, and the intestinal bacteria called the heart-gut axis. Finally, we would like to propose a new term "heart nutrition" for nutritional management in patients with heart failure in this review. Compared to the evidence for exercise therapy in heart failure, studies assessing nutritional management remain scarce and there is a need for research in this area in the future.

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.

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.

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.

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.

Journal of Clinical Monitoring and Computing 2016 end of year summary: cardiovascular and hemodynamic monitoring

The assessment and optimization of cardiovascular and hemodynamic variables is a mainstay of patient management in the care for critically ill patients in the intensive care unit (ICU) or the operating room (OR). It is, therefore, of outstanding importance to meticulously validate technologies for hemodynamic monitoring and to study their applicability in clinical practice and, finally, their impact on treatment decisions and on patient outcome. In this regard, the Journal of Clinical Monitoring and Computing (JCMC) is an ideal platform for publishing research in the field of cardiovascular and hemodynamic monitoring. In this review, we highlight papers published last year in the JCMC in order to summarize and discuss recent developments in this research area.

Peri-operative nutrition

Patients are frequently malnourished or are at risk of malnutrition before surgery. Peri-operative nutritional support can improve their outcomes. This review focuses on new developments in peri-operative nutrition, including: patient preparation and pre-operative fasting; the role of nutritional supplementation; the optimal route and timing of nutrient delivery; and the nutritional management of specific groups including critically ill, obese and elderly patients.

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.

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)

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.

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.

Mesenteric blood flow, glucose absorption and blood pressure responses to small intestinal glucose in critically ill patients older than 65 years

PURPOSE

To compare nutrient-stimulated changes in superior mesenteric artery (SMA) blood flow, glucose absorption and glycaemia in individuals older than 65 years with, and without, critical illness.

METHODS

Following a 1-h 'observation' period (t (0)-t (60)), 0.9 % saline and glucose (1 kcal/ml) were infused directly into the small intestine at 2 ml/min between t (60)-t (120), and t (120)-t (180), respectively. SMA blood flow was measured using Doppler ultrasonography at t (60) (fasting), t (90) and t (150) and is presented as raw values and nutrient-stimulated increment from baseline (Δ). Glucose absorption was evaluated using serum 3-O-methylglucose (3-OMG) concentrations during, and for 1 h after, the glucose infusion (i.e. t (120)-t (180) and t (120)-t (240)). Mean arterial pressure was recorded between t (60)-t (240). Data are presented as median (25th, 75th percentile).

RESULTS

Eleven mechanically ventilated critically ill patients [age 75 (69, 79) years] and nine healthy volunteers [70 (68, 77) years] were studied. The magnitude of the nutrient-stimulated increase in SMA flow was markedly less in the critically ill when compared with healthy subjects [Δt (150): patients 115 (-138, 367) versus health 836 (618, 1,054) ml/min; P = 0.001]. In patients, glucose absorption was reduced during, and for 1 h after, the glucose infusion when compared with health [AUC(120-180): 4.571 (2.591, 6.551) versus 11.307 (8.447, 14.167) mmol/l min; P < 0.001 and AUC(120-240): 26.5 (17.7, 35.3) versus 40.6 (31.7, 49.4) mmol/l min; P = 0.031]. A close relationship between the nutrient-stimulated increment in SMA flow and glucose absorption was evident (3-OMG AUC(120-180) and ∆SMA flow at t (150): r (2) = 0.29; P < 0.05).

CONCLUSIONS

In critically ill patients aged >65 years, stimulation of SMA flow by small intestinal glucose infusion may be attenuated, which could account for the reduction in glucose absorption.

Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: a prospective observational pilot study

INTRODUCTION

Malabsorption, which is frequently underdiagnosed in critically ill patients, is clinically relevant with regard to nutritional balance and nutritional management. We aimed to validate the diagnostic accuracy of fecal weight as a biomarker for fecal loss and additionally to assess fecal macronutrient contents and intestinal absorption capacity in ICU patients.

METHODS

This was an observational pilot study in a tertiary mixed medical-surgical ICU in hemodynamically stable adult ICU patients, without clinically evident gastrointestinal malfunction. Fecal weight (grams/day), fecal energy (by bomb calorimetry in kcal/day), and macronutrient content (fat, protein, and carbohydrate in grams/day) were measured. Diagnostic accuracy expressed in terms of test sensitivity, specificity, positive (PPV) and negative predictive value (NPV), and receiver operator curves (ROCs) were calculated for fecal weight as a marker for energy malabsorption. Malabsorption was a priori defined as < 85% intestinal absorption capacity.

RESULTS

Forty-eight patients (63 ± 15 years; 58% men) receiving full enteral feeding were included. A cut-off fecal production of > 350 g/day (that is, diarrhea) was linked to the optimal ROC (0.879), showing a sensitivity and PPV of 80%, respectively. Specificity and NPV were both 96%. Fecal weight (grams/day) and intestinal energy-absorption capacity were inversely correlated (r = -0.69; P < 0.001). Patients with > 350 g feces/day had a significantly more-negative energy balance compared with patients with < 350 g feces/day (loss of 627 kcal/day versus neutral balance; P = 0.012).

CONCLUSIONS

A fecal weight > 350 g/day in ICU patients is a biomarker applicable in daily practice, which can act as a surrogate for fecal energy loss and intestinal energy absorption. Daily measurement of fecal weight is a feasible means of monitoring the nutritional status of critically ill patients and, in those identified as having malabsorption, can monitor responses to changes in dietary management.