Energy expenditure in COVID-19 mechanically ventilated patients: A comparison of three methods of energy estimation

Comparative characteristics of some methods for estimating energy expenditure in critically ill mechanically ventilated patients

AIM

To compare the energy expenditure (EE) assessed by ventilator-derived carbon dioxide production (EE-VCO2-ventilator) and the energy expenditure calculated from six predictive equations with the gold standard energy expenditure measured with indirect calorimetry (IC) in mechanically ventilated patients.

Metabolic Support in Acute Respiratory Distress Syndrome: A Narrative Review

Nutritional support for acute respiratory distress syndrome (ARDS) patients shares metabolic notions common to other critically ill conditions. Nevertheless, it generates specific concern regarding the primary limitation of oxygen supply and the complications of carbon dioxide elimination, as well as the significant metabolic alterations due to the body's response to illness. In the present narrative review, after briefly summarizing the pathophysiology of critical illness stress response and patients' metabolic requirements, we focus on describing the characteristics of metabolic and artificial nutrition in patients with acute respiratory failure. In patients with ARDS, several aspects of metabolism assume special importance. The physiological effects of substrate metabolism are described for this setting, particularly regarding energy consumption, diet-induced thermogenesis, and the price of their clearance, transformation, and storage. Moreover, we review the possible direct effects of macronutrients on lung tissue viability during ARDS. Finally, we summarize the noteworthy characteristics of metabolic control in critically ill patients with ARDS and offer a suggestion as to the ideal methods of metabolic support for this problem.

Nutrition support for critically ill patients during the COVID-19 pandemic: the Italian SIAARTI survey

BACKGROUND

Critically ill, COVID-19 patients are characterized by a hypermetabolic state and a reduced food intake and are at high risk of malnutrition and lean body mass loss. An appropriate metabolic-nutritional intervention aims to reduce complications and improve the clinical outcomes. We conducted a cross-sectional, multicenter, observational, nationwide online survey involving Italian Intensivists to assess the nutritional practices in critically ill patients with COVID-19.

RESULTS

A group of experts in nutrition of the Italian Society of Anaesthesia Analgesia Resuscitation and Intensive Care (SIAARTI) developed a 24-item questionnaire; the 9000 members of the Society were invited to participate through emails and social networks. Data was collected from June 1 to August 1, 2021. A total of 545 responses were collected: 56% in northern, 25% in central, and 20% in southern Italy. Artificial nutrition support is directly handled by intensivists in > 90 of the cases; the nutritional status is assessed as suggested by the guidelines in more than 70% of the cases, and a form of nutrition support is started within the first 48 h from ICU admission by > 90% of the respondents. Nutritional targets are reached in 4-7 days in > 75% of the cases, mainly by the enteral route. Indirect calorimetry, muscle ultrasound, and bioimpedance analysis are used by a limited part of the interviewees. Only about a half of the respondents reported the nutritional issues in the ICU discharge summary.

CONCLUSIONS

This survey among Italian Intensivists during the COVID-19 epidemic showed how the beginning, progression, and route of nutritional support adhere to international recommendations, while recommendations on the tools to set the target and monitor the efficacy of the metabolic support are less followed.