Implementation of a multidisciplinary nutritional support team and clinical outcomes in critically ill patients with COVID-19

BACKGROUND & AIMS

The South Korean government established the multidisciplinary nutritional support teams (NST) system for enhancing the evaluation and adequate supply of nutritional support to patients at high risk of malnutrition. However, the impact of the NST on clinical outcomes in critically ill patients with coronavirus disease 2019 (COVID-19) remains unclear. We aimed to investigate whether NST implementation affects survival outcomes in patients with COVID-19 requiring intensive care unit (ICU) admission.

METHODS

Using data from the National Health Insurance Service and Korea Disease Control and Prevention Agency in South Korea, adult patients with COVID-19 admitted to the ICU between October 8, 2020, and December 31, 2021, were included. The NST comprised four professional personnel (physicians, full-time nurses, full-time pharmacists, and full-time clinical dietitians). Patients admitted to ICUs with and without the NST system were assigned to the NST and non-NST groups, respectively.

RESULTS

A total of 13,103 critically ill adult patients were included in the final analysis; among them, 10,103 (77.1 %) and 3,000 (22.9 %) patients were included in the NST and non-NST groups, respectively. In the NST group, 2,803 (27.7 %) critically ill patients with COVID-19 were prescribed enteral or parenteral nutrition by the NST. In a covariate-adjusted multivariable model, the NST group showed a 40 % lower in-hospital mortality rate than the non-NST group (odds ratio: 0.60, 95 % confidence interval: 0.51, 0.71; P < 0.001). In subgroup analyses, compared with the non-NST group, the NST group showed significantly lower in-hospital mortality rates at 2, 3, 4, and 5 points on the World Health Organization clinical progression scale among patients with acute respiratory distress and mechanical ventilatory support.

CONCLUSIONS

NST implementation was associated with improved survival outcomes in critically ill patients with COVID-19; accordingly, it may be recommended for improving adequate nutritional support and evaluation in critically ill patients.

The Use of Specialized Enteral Formulas in Pulmonary Disease

The relationship between pulmonary disease and nutrition is significant. Malnutrition and its associated adverse pulmonary effects can directly affect outcomes in the individual with pulmonary disease. The use of nutrition support is common for these patients as a supportive or therapeutic measure. Historical reports of adverse respiratory function associated with high parenteral carbohydrate intakes have led to the controversial use of high-fat enteral products in patients with chronic pulmonary dysfunction. The rationale for using this type of formula is that by providing less carbohydrates, carbon dioxide production will be reduced, respiratory quotient will therefore decrease, and a favorable respiratory outcome will result. In the patient with acute respiratory distress syndrome, an inflammatory state exists in which proinflammatory mediators are produced and affect the course of the disease. An enteral formula with modified lipids designed to modulate eicosanoid production and therefore influence the inflammatory cascade is available. This article reviews the rationale for use of modified enteral formulas in both chronic and acute pulmonary disease, reviews the available studies evaluating the efficacy of these formulas, and provides overall recommendations for the use of specialized enteral formulas in individuals with pulmonary disease.

The Acute Respiratory Distress Syndrome: Role of Nutritional Modulation of Inflammation Through Dietary Lipids

The acute respiratory distress syndrome (ARDS) is the most serious form of acute hypoxic respiratory failure. ARDS represents the expression of an acute, diffuse, inflammatory process in the lungs consequent to a variety of infectious and noninfectious conditions. It is characterized pathologically by damage to pulmonary epithelial and endothelial cells, with subsequent alveolar-capillary leak and exudative pulmonary edema. The main clinical features of ARDS include rapid onset of dyspnea, severe defects in gas exchange, and imaging studies demonstrating diffuse pulmonary infiltrates. The role of nutrition in the management of ARDS has traditionally been supportive. Recent research has demonstrated the potential of certain dietary oils (eg, fish oil, borage oil) to modulate pulmonary inflammation, thereby improving lung compliance and oxygenation, and reducing time on mechanical ventilation. This article reviews the alterations in the immune response that underlie ARDS, discusses the physiology of dietary oils as immunonutrients, summarizes animal and human studies that explore the therapeutic effects of dietary oils, and provides clinical recommendations for their use.

The Omega-3 Fatty Acid Docosahexaenoic Acid Modulates Inflammatory Mediator Release in Human Alveolar Cells Exposed to Bronchoalveolar Lavage Fluid of ARDS Patients

BACKGROUND

This study investigated whether the 1 : 2 ω-3/ω-6 ratio may reduce proinflammatory response in human alveolar cells (A549) exposed to an ex vivo inflammatory stimulus (bronchoalveolar lavage fluid (BALF) of acute respiratory distress syndrome (ARDS) patients). Methods. We exposed A549 cells to the BALF collected from 12 ARDS patients. After 18 hours, fatty acids (FA) were added as docosahexaenoic acid (DHA, ω-3) and arachidonic acid (AA, ω-6) in two ratios (1 : 2 or 1 : 7). 24 hours later, in culture supernatants were evaluated cytokines (TNF-α, IL-6, IL-8, and IL-10) and prostaglandins (PGE2 and PGE3) release. The FA percentage content in A549 membrane phospholipids, content of COX-2, level of PPARγ, and NF-κB binding activity were determined.

RESULTS

The 1 : 2 DHA/AA ratio reversed the baseline predominance of ω-6 over ω-3 in the cell membranes (P < 0.001). The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001) but was increased by the 1 : 7 ratio (P < 0.01). The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001) as well as NF-κB translocation into the nucleus (P < 0.01), while it increased activation of PPARγ and IL-10 release (P < 0.001). Conclusion. This study demonstrated that shifting the FA supply from ω-6 to ω-3 decreased proinflammatory mediator release in human alveolar cells exposed to BALF of ARDS patients.

Polyunsaturated Fatty Acids and Cytokines: Their Relationship in Acute Lung Injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are inflammatory diseases whose clinical severity depends on the grade of inflammatory response. Inflammatory cytokines are key elements in the pathogenesis of ALI/ARDS, and the occurrence of an imbalance between pro- and anti-inflammatory cytokines leads to additional non-pulmonary organ dysfunction which contributes to excess mortality rates.

Treatment of these patients includes nutrition support with lipids, usually soybean oil-based lipid emulsions, which are rich in omega (n)-6 polyunsaturated fatty acids (PUFAs) and deficient in n-3 PUFAs; however, too much n-6 PUFAs are detrimental due to their pro-inflammatory effects. Conversely, a large amount of experimental studies and some randomized clinical trials showed the benefits of the n-3 PUFA administration in the context of ALI because of their anti-inflammatory properties. Based on these data, several scientific societies recommended in their guidelines, with an A or B grade of recommendation, the use of n-3 PUFAs in ALI/ARDS patients. However, at present, the issue of lipid therapy in ALI/ARDS is still controversial due, at least in part, to inconclusive or contradicting results in several recent clinical trials using n-3 PUFAs.

Nutrition therapy for ALI and ARDS

The importance of nutrition support in critically ill patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) cannot be overstated. ALI and ARDS are characterized by a proinflammatory response associated with hypercatabolism that could lead to significant nutrition deficits. Nutrition support is necessary to prevent cumulative caloric deficits, malnutrition, loss of lean body mass, and deterioration of respiratory muscle strength. Furthermore, early delivery of enteral nutrition has been associated with the modulation of stress and the systemic immune response as well as the attenuation of disease severity.