Evidence on nutritional therapy practice guidelines and implementation in adult critically ill patients: a scoping review protocol

Modern medicine has increased the chances of survival for many patients, which has increased the rate of critical illness [1]. Critical illness can be defined as a life-threatening multisystem process preceded by a period of increased catabolism and physiological deterioration [2]. Increased catabolism and drug-induced adverse effects, which accompany critical illness, reduce appetite, or increase nausea and vomiting making patients unable to achieve nutritional requirements by oral intake [3]. In addition, the intensive care unit (ICU) routine may also interrupt patient feeding, which warrants consideration of other methods to deliver nutritional requirements including enteral nutritional therapy (EN), parenteral nutritional therapy (PN), or a combination of both [3]. Failure to provide adequate nutritional therapy leads to malnutrition characterized by loss of lean body mass; lack of adequate physical activity and, ultimately, weakness and inability to mobilize; long periods of stay in the ICU; infectious complications; and high morbidity and mortality [4]. Therefore, means to monitor the prevalence and the indicators of critical illness-related malnutrition, emphasizing the role of nutritional therapy and the effects of nutritional therapy practice guidelines, are warranted.

This study will follow the methodological framework for scoping reviews proposed by Arksey and O’Malley and adapted by Levac et al. [26‐28]. The framework has five stages that include (1) identifying the review question, (2) searching for relevant studies, (3) selecting eligible studies, (4) extracting data, and (5) collating, summarizing, and reporting of the results. However, in our review, we will identify both the research question and the eligibility criteria for the selection of studies in stage 1, as technically, the same framework that is used to identify the research question is conceived for guiding and reporting inclusion and exclusion criteria.

Previously, scoping reviews did not include an assessment of the methodological quality of included studies, however, that has changed; current recommendations state that the absence of quality assessment makes the results of scoping studies more difficult to interpret and limit the translation of scoping study findings into policy and practice [33, 34]. For this study, the review team will use the Mixed Method Appraisal Tool (MMAT) 2018 to determine the quality of included studies. The quality of qualitative studies will be assessed using section one of the MMAT tool. For quantitative studies, sections two, three, and four will be used for randomized controlled, non-randomized, and descriptive studies, respectively. For mixed methods studies, section one we will be used for assessing the qualitative component, while sections two, three, or four will be used for the appropriate quantitative component of a study. Section five will be used to assess quality of the mixed methods components of the included studies. Studies will be assessed for appropriateness of the study aim, study design, data collection, data analysis, relevant results, significant results, and authors’ conclusions. Further, studies will be rated as low, moderate, and high [34]. Assessment of the methodological quality of the included studies will help to determine the overall quality of the resultant review.

The high incidence of critical illness, advances in critical care, and improvements in patient selection have led to an increased survival of critically ill patients with high nutritional demands and resultant malnutrition [35]. Combating this double burden of malnutrition (DBM) has become a significant global health challenge in many healthcare settings [36]. DBM is characterized by the coexistence of undernutrition along with obesity or diet-related noncommunicable disease and is associated with poor outcomes and increased cost of hospitalization [20, 36]. Literature has shown that nutritional therapy, both enteral and parenteral, is the most cost-effective intervention in managing malnutrition in critical illness before ICU admission and after discharge, including the rehabilitation period [37‐39]. However, nutritional practices in critically ill patients remain widely varied. This has become an indication of the need for the development and implementation of nutritional therapy practice guidelines in the form of feeding protocols as a strategy to optimize adequate delivery of nutritional therapy [40]. Societies from different countries have played a major role in the development of these guidelines for use by professionals providing nutritional therapy to pediatric and adult in/out-patients in ambulatory, home, and specialized care settings [41]. Guidelines provide basic recommendations that are supported by reviews and analyses of the current literature, to standardize and improve nutritional practices [17]. The implementation of guidelines in clinical care practice can improve patients’ nutritional status and thus contribute to achieving the Sustainable Development Goals of ending malnutrition and ensuring healthy lives and well-being for all and at all ages [42].

In a study by Barr et al. [43], 78% of patients received nutrition therapy post-guideline implementation, compared with 68% pre-implementation; however, the study does not look at the extent of availability and implementation of guidelines. Other studies emphasize monitoring of nutrition therapy, however, do not state how this can be achieved [6, 44]. Sharada and Vadivelan and Seoung-Hyun et al. believe that the implementation of nutrition guidelines can enable monitoring, standardization, and improvement of nutritional practices and thus decrease complications in critically ill patients [6, 44]. Notwithstanding the volumes of research on nutrition guidelines development, evidence on nutritional therapy guidelines in critically ill adults is lacking, hence the need for this study.

The proposed scoping review will include studies that were published from 2002 to 2018 based on the trends in nutrition therapy guidelines in critically ill adults. Nutrition therapy guidelines of most countries were developed and published around the year 2002 [18, 45, 46]. Additionally, the focus has been on maternal and child nutrition, with less attention being paid to critically ill adults, which justifies the current choice of study population [47]. The results of this study may inform the development of innovative strategies to implement these guidelines, leading to reductions of the duration of critical illness and of healthcare care costs and improvement in the socioeconomic status of both patients and the state. The results of this review will be disseminated through presentation in research seminars, conferences, and congresses and will also be available electronically and in print.