Doubly labelled water for determining total energy expenditure in adult critically ill and acute care hospitalized inpatients: A scoping review.

BACKGROUND & AIMS: Doubly labelled water (DLW) is considered the reference standard method of measuring total energy expenditure (TEE), but there is limited information on its use in the Intensive Care Unit (ICU) and acute care setting. This scoping review aims to systematically summarize the available literature on TEE measured using DLW in these contexts. METHODS: Four online databases (MEDLINE, Embase, Emcare and CINAHL) were searched up to Dec 12, 2020. Studies in English were included if they measured TEE using DLW in adults in the ICU and/or acute care setting. Key considerations, concerns and practical recommendations were identified and qualitatively synthesized. RESULTS: The search retrieved 7582 studies and nine studies were included; one in the ICU and eight in the acute care setting. TEE was measured over 7-15-days, in predominantly clinically stable patients. DLW measurements were not commenced until four days post admission or surgery in one study and following a 10-14-day stabilization period on parenteral nutrition (PN) in three studies. Variable dosages of isotopes were administered, and several equations used to calculate TEE. Four main considerations were identified with the use of DLW in these settings: variation in background isotopic abundance; excess isotopes leaving body water as carbon dioxide or water; fluctuations in rates of isotope elimination and costs. CONCLUSION: A stabilization period on intravenous fluid and PN regimens is recommended prior to DLW measurement. The DLW technique can be utilized in medically stable ICU and acute care patients, with careful considerations given to protocol design.

The effect of high-polyphenol extra virgin olive oil on cardiovascular risk factors: A systematic review and meta-analysis.

The polyphenol fraction of extra-virgin olive oil may be partly responsible for its cardioprotective effects. The aim of this systematic review and meta-analysis was to evaluate the effect of high versus low polyphenol olive oil on cardiovascular disease (CVD) risk factors in clinical trials. In accordance with PRISMA guidelines, CINAHL, PubMed, Embase and Cochrane databases were systematically searched for relevant studies. Randomized controlled trials that investigated markers of CVD risk (e.g. outcomes related to cholesterol, inflammation, oxidative stress) were included. Risk of bias was assessed using the Jadad scale. A meta-analysis was conducted using clinical trial data with available CVD risk outcomes. Twenty-six studies were included. Compared to low polyphenol olive oil, high polyphenol olive oil significantly improved measures of malondialdehyde (MD: -0.07µmol/L [95%CI: -0.12, -0.02µmol/L]; I2: 88%; p = 0.004), oxidized LDL (SMD: -0.44 [95%CI: -0.78, -0.10µmol/L]; I2: 41%; P = 0.01), total cholesterol (MD 4.5 mg/dL [95%CI: -6.54, -2.39 mg/dL]; p<0.0001) and HDL cholesterol (MD 2.37 mg/dL [95%CI: 0.41, 5.04 mg/dL]; p = 0.02). Subgroup analyses and individual studies reported additional improvements in inflammatory markers and blood pressure. Most studies were rated as having low-to-moderate risk of bias. High polyphenol oils confer some CVD-risk reduction benefits; however, further studies with longer duration and in non-Mediterranean populations are required.

Malnutrition screening in outpatients receiving hyperbaric oxygen therapy: an opportunity for improvement?

Outpatients who receive hyperbaric oxygen treatment (HBOT) may represent a group at significant risk of malnutrition owing to the underlying conditions that are often treated with HBOT (e.g., non-healing diabetic wounds and radiation-induced skin injury). In this issue, See and colleagues provide new, preliminary evidence of the prevalence of malnutrition in a small group of HBOT outpatients treated in an Australian hospital, reporting that approximately one-third of patients receiving HBOT were at risk of malnutrition. To our knowledge, routine malnutrition screening is not available in HBOT centres providing outpatient treatment, which may be a key gap in the nutrition care of these patients. Malnutrition screening was developed to identify those at risk of malnutrition across the healthcare continuum. In the outpatient setting, it is recommended that patients are screened at their first clinic appointment and that screening is repeated when there is clinical concern. Malnutrition screening tools are designed to be quick and simple to complete by trained healthcare staff and include questions relating to appetite, oral intake and recent weight loss. The early identification of patients at risk of malnutrition using validated screening tools enables the appropriate and timely referral of patients to dietetic services for assessment and treatment. Why might malnutrition screening in HBOT services be important? It is well documented that the consequences of malnutrition are systemic, with increased morbidity and mortality attributed to malnutrition. Beyond the detrimental impact of malnutrition to the individual, malnutrition also has significant economic ramifications, with medical costs significantly higher in severely malnourished compared to well-nourished patients. Of particular relevance, malnutrition is associated with impaired and prolonged wound healing. This may influence the effectiveness and success of HBOT treatment, although studies in the area of HBOT and concurrent nutrition therapy are lacking. Furthermore, there are no reliable markers of nutrition status that are easily obtainable in the healthcare setting. In the past, prealbumin (transthyretin) and albumin have been used as surrogate markers of nutritional status. However, these serum proteins are acute-phase proteins and, therefore, are reduced during acute inflammation and infection, making them unreliable indicators of nutrition status. Transferrin, retinol binding protein and C-reactive protein are similarly not recommended as markers of nutrition status and malnutrition. Therefore, the implementation of malnutrition screening may be the most practical and validated method of identifying patients who would benefit from a comprehensive assessment of their nutrition status and provision of nutrition support in the HBOT setting. The assessment of nutrition status involves the collective evaluation of anthropometric data, biochemical markers, clinical symptoms impacting on nutrition (e.g., nausea) and oral intake. Tools such as the subjective global assessment have been developed and validated to assess nutrition status and diagnose malnutrition by trained staff. In contrast to other outpatient services, HBOT presents a unique opportunity to complete both malnutrition screening and engage a relevant dietetic service for nutrition assessment early in the course of treatment. The frequent contact with outpatients would also lend itself well to group nutrition education sessions to address important nutrition information related to wound healing. Although there is a paucity of data to support the use of malnutrition screening and dietetic assessments in HBOT, current best practice guidelines recommend these services in outpatient settings. The implementation of routine malnutrition screening and referral processes to dietetic services warrants consideration in the HBOT outpatient setting. If going down this path, careful consideration of available resources, how referral systems can be incorporated into current procedures as well as partnership with dietetic departments is integral. In the interim, the referral of patients to dietetic departments who are suspected to be at risk of poor wound healing due to nutrition factors and those failing treatment should be considered by treating hyperbaric physicians. Although further research is required to assess the effectiveness of malnutrition screening and nutrition intervention in the HBOT outpatient population, the data by See and colleagues provides an important starting point in unpacking malnutrition risk in this population.