Nutrition intervention in the critically ill cardiothoracic patient

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.

Vitamin C to Improve Organ Dysfunction in Cardiac Surgery Patients-Review and Pragmatic Approach

The pleiotropic biochemical and antioxidant functions of vitamin C have sparked recent interest in its application in intensive care. Vitamin C protects important organ systems (cardiovascular, neurologic and renal systems) during inflammation and oxidative stress. It also influences coagulation and inflammation; its application might prevent organ damage. The current evidence of vitamin C's effect on pathophysiological reactions during various acute stress events (such as sepsis, shock, trauma, burn and ischemia-reperfusion injury) questions whether the application of vitamin C might be especially beneficial for cardiac surgery patients who are routinely exposed to ischemia/reperfusion and subsequent inflammation, systematically affecting different organ systems. This review covers current knowledge about the role of vitamin C in cardiac surgery patients with focus on its influence on organ dysfunctions. The relationships between vitamin C and clinical health outcomes are reviewed with special emphasis on its application in cardiac surgery. Additionally, this review pragmatically discusses evidence on the administration of vitamin C in every day clinical practice, tackling the issues of safety, monitoring, dosage, and appropriate application strategy.

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.

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

Background

Infants undergoing cardiac surgery are at risk of a negative protein balance, due to increased proteolysis in response to surgery and the cardiopulmonary bypass circuit, and limited intake. The aim of the study was to quantify the effect on protein kinetics of a short-term high-protein (HP) diet in infants following cardiac surgery.

Methods

In a prospective, double-blinded, randomized trial we compared the effects of a HP (5 g · kg⁻¹ · d⁻¹) versus normal protein (NP, 2 g · kg⁻¹ · d⁻¹) enteral diet on protein kinetics in children <24 months, on day 2 following surgical repair of congenital heart disease. Valine kinetics and fractional albumin synthesis rate (FSR_alb) were measured with mass spectrometry using [1-¹³C]valine infusion. The Mann–Whitney U test was used to investigate differences between group medians. Additionally, the Hodges-Lehmann procedure was used to create a confidence interval with a point estimate of median differences between groups.

Results

Twenty-eight children (median age 9 months, median weight 7 kg) participated in the study, of whom in only 20 subjects isotopic data could be used for final calculations. Due to underpowering of our study, we could not draw conclusions on the primary outcome parameters. We observed valine synthesis rate of 2.73 (range: 0.94 to 3.36) and 2.26 (1.85 to 2.73) μmol · kg⁻¹ · min⁻¹ in the HP and NP diet, respectively. The net valine balance was 0.54 (−0.73 to 1.75) and 0.24 (−0.20 to 0.63) μmol · kg⁻¹ · min⁻¹ in the HP and NP group. Between groups, there was no difference in FSR_alb. We observed increased oxidation and BUN in the HP diet, compared to the NP diet, as a plausible explanation of the metabolic fate of surplus protein.

Conclusions

It is plausible that the surplus protein in the HP group has caused the increase of valine oxidation and ureagenesis, compared to the NP group. Because too few patients had completed the study, we were unable to draw conclusions on the effect of a HP diet on protein synthesis and balance. We present our results as new hypothesis generating data.

Trial registration

Dutch Trial Register NTR2334.

Is stroke rehabilitation a metabolic problem?

BACKGROUND

This study looks at the impact of inflammation during the rehabilitation stage of strokes and its effect on neuro-functional recovery.

METHODS

This study investigated 94 patients suffering from strokes and admitted to rehabilitation. Anthropometric characteristics, serum proteins and inflammatory markers, plasma amino acids and neurofunction were all assessed.

RESULTS

55.3% patients had an inflammatory status (Interleukin-6 = 19.24 ± 23.01 pg ml⁻¹ vs. 4.1 ± 1.6 pg ml⁻¹ for non-inflamed subjects (p < 0.001). Inflammation was positively linked to positive proteins (alpha-1 globulin, p < 0.02) and negatively linked to negative proteins (albumin, p < 0.02; prealbumin, p < 0.01; transferrin, p < 0.05) of the acute-phase response. Inflammation was associated with low plasma concentrations of total amino acids. For the multiple logistic regression analysis, albumin (p < 0.001) and body weight maintenance (p < 0.001) were independent predictors of patient functional independence. Inflammation in dysphagic stroke (31.9%) patients was associated with more accentuated disability compared to non-inflamed dysphagics. The serum positive reactant alpha 1 globulin was the most powerful predictor of dysphagia severity (p < 0.001). At discharge, dysphagia improvement was associated with improved acute-phase negative proteins.

CONCLUSIONS

An inflammatory status may persist for most patients with strokes during the rehabiliation stage of the disease, its prevalence being higher in dysphagic compared to non-dysphagic subjects. The improvement in circulating albumin and body weight maintenance are predictors of neuro-function, even in dysphagic subjects.