In this study, we developed an early nutritional support management system by deploying dedicated dietitians in the EICU and implementing an early nutritional initiation flowchart, along with an early enteral nutrition protocol. Consequently, the time from EICU admission to the commencement of enteral nutrition was reduced, and the rate of enteral nutrition initiation within 48 h post-admission increased. Additionally, energy and protein sufficiency rates improved and the incidence of diarrhea during enteral nutrition management decreased.
Previous study has emphasized the importance of dedicated dietitians in ICU settings, and their focus on nutritional management has been associated with a reduced time from ICU admission to the initiation of enteral nutrition [17]. A study involving 81 facilities worldwide also reported higher rates of early enteral nutrition initiation in ICUs with dietitians [18]. Furthermore, authorizing dietitians to create nutrition-related orders in acute care hospitals can reduce the time to implement oral nutritional supplementation [19]. In this study, similar results were obtained by implementing an early nutrition support immediately after admission to the EICU using a locally developed early nutrition initiation flowchart and enteral feeding protocol under the guidance of a full-time dietitian, although no dedicated dietitian was authorized to write orders. Therefore, it is critical for dietitians to collaborate with multiple healthcare professionals to establish a common understanding of the enteral nutrition initiation process, which will play an important role in achieving these outcomes.
Regarding nutritional sufficiency rate, Kim et al. demonstrated that the use of enteral nutrition protocols leads to improved nutritional sufficiency rate [20]. In our study, we evaluated enteral nutritional intake through both oral and tube feeding. Nutritional sufficiency rate improved even when non-compulsory nutritional administration methods were used. Our analysis using a general linear model revealed that increases in energy and protein sufficiency rates remained significant after adjusting for covariates such as age, sex, BMI, APACHE II score, and SOFA score. This suggests that continued nutritional support results in an enhanced nutritional sufficiency rate, which is attributed to the visualization of daily target feeding quantities through the early enteral nutrition protocol, the establishment of a shared goal within the multidisciplinary medical team, and increased frequency of dietary adjustments for oral intake by dietitians. These findings underscore the significant role of dietitians as nutrition specialists in improving the nutritional sufficiency rate through gastrointestinal nutritional support in critical care environments.
In a study on nutritional dosage in the ICU, patients were recommended to receive 70% of their estimated energy requirement and minimum intake of 1.3 g/kg/day of protein by the fourth day of ICU admission [21]. Our early support group did not meet these criteria, which is a challenge to overcome in future study. Although standardized nutritional management can be achieved through enteral nutrition protocols, these protocols need to be refined to accommodate variations in clinical characteristics, such as age, body size, and severity of illness.
Regarding complications related to enteral nutritional management, Shimoni et al. reported a reduction in the incidence of diarrhea upon adding soluble fiber to enteral nutritional supplements in well-nourished elderly patients [22]. Likewise, Yagmurdur and Leblebici reported that the administration of enteral nutrition fortified with soluble fiber to critically ill patients in the ICU decreases the frequency of diarrhea [23]. Furthermore, Qu et al. compared the effects of intermittent versus continuous enteral feeding in critically ill patients through a meta-analysis and reported that intermittent enteral feeding is associated with a higher incidence of diarrhea [24]. In this study, we found a significant decrease in the frequency of diarrhea in the early support group. In contrast, Heffernan et al. compared intermittent versus continuous administration of enteral nutrition in a systematic review and found no significant differences in the incidence of diarrhea, vomiting, aspiration, or increased gastric residual volume [25].
In our study, patients on enteral nutrition management received enteral nutrition through a nasogastric tube. Prior to the introduction of the early nutrition support system, the standard method of administration at the start of enteral nutrition in our EICU was intermittent administration, which was changed to continuous administration at slower rates after the system was introduced. The change to continuous administration and slower rate of administration were thought to be two of the reasons for the lower incidence of diarrhea. In addition, the type of enteral nutrition (digestible or semi-digestible), dosage, primary medical condition, severity, nutritional status, and medications also appeared to affect the incidence of complications. Thus, guided by established guidelines, the unique enteral nutrition protocol at our institution allowed us to enhance the nutritional sufficiency rate without increasing complication rates. Standardizing nutritional management and consistently sharing information improve the efficiency and safety of nutritional care, which is beneficial for patients.
Regarding outcomes, lower in-hospital mortality was observed in the early support group than in the control group. Doig et al. reported a reduction in mortality with early enteral nutrition in trauma patients requiring intensive care [13], whereas Ortiz-Reyes et al. reported improvements in outcomes during a multicenter study, including decreases in 28-day mortality rate, number of days spent in the ICU, and duration of ventilator use associated with early enteral nutrition [11]. However, when these aspects were subjected to multivariate analysis adjusted for the severity of the patients’ conditions and other factors, no significant differences were observed. In the present study, no significant differences were observed in inpatient mortality. This lack of difference might be because the study did not specify conditions related to the duration of ventilator use or administration of vasoactive agents. Additionally, patients in our study exhibited less severe organ damage than those in the study by Ortiz-Reyes et al. Early enteral nutrition in critically ill patients has the potential to improve outcomes; however, further study is warranted.
This study has several limitations. First, it was a single-center retrospective observational study, and its results cannot be generalized for all EICU patients because it only included patients who spent a minimum of 5 days in the EICU. Additionally, assessment of the nutritional management status was limited to the first 7 days after EICU admission, leaving the influence of nutritional therapy beyond the eighth day unaccounted for. Furthermore, the potential impact of unmeasured confounding factors could not be ruled out. Considering these limitations, future studies should expand the study cohort and use propensity scores to account for the confounding variables.
In Japan, the effects of early nutritional support in the ICU have been investigated using univariate analysis, focusing on the time from ICU admission to the initiation of enteral nutrition and presence or absence of early nutritional support. In this study, it became evident that the time from EICU admission to commencement of enteral nutrition was reduced, and the nutritional sufficiency rate improved even after adjusting for patient severity, organ damage, and nutritional impairment. This underscores the significance of dedicating a dietitian exclusively to the EICU and fortifying the nutritional management system with a dietitian at its core.