Caring for critically ill patients requires expertise from healthcare professionals in various disciplines. This interprofessional team model is essential to enhance patient outcomes and team performance (1). The critical care dietitian is a key member of the interprofessional team with specialized expertise and complementary functions. The following discussion outlines the necessary, expansive, and evolving role of the dietitian for knowledge acquisition, dissemination, and translation within an evolving epoch in critical care nutrition (CCN), defined by the impact of emerging information on practice paradigms.
THE IMPACT OF NUTRITIONAL RISK ON CRITICAL CARE OUTCOMES
Malnutrition and critical illness have a bidirectional relationship, as both contribute to an increasing degree of nutritional risk (2–4). Nutritional risk is independently associated with more patient complications, increased mortality, greater length of hospital stay, and higher healthcare costs (5,6).
Since the 1974 seminal article by Butterworth (7) highlighting the iatrogenic and underrecognized protein-energy malnutrition among hospitalized patients, the past 5 decades have provided us with a better understanding of critical illness pathophysiology and how various nutritional interventions can play a salutary role. Critical illness–induced host inflammatory and immune responses impair gastrointestinal functions. These include impaired epithelial barrier function and gut dysbiosis, which incite gut-derived inflammation and multiple organ dysfunction syndrome (8). The provision of early enteral nutrition (EN) provides a distinct benefit, primarily by maintaining gut barrier functions (9). Additionally, survivorship from critical illness has increased in the past 3 decades (10). Unfortunately, survival is oftentimes accompanied by critical illness–related sarcopenia, protein-energy malnutrition, and impaired quality of life (11–17). These selected examples of the bidirectional relationship between deterioration of nutritional status and critical illness highlight the clear need for expertise in nutrition assessment, diagnosis, and monitoring, as well as implementation of nutritional strategies to modify and even redirect disease trajectory.
DIMINISHING PHYSICIAN, PHARMACIST, AND NURSING EDUCATION IN CLINICAL NUTRITION
Nutrition education in U.S. medical schools and postgraduate programs has remained poor despite a growing need to better understand nutrition-related factors contributing to health and disease (18,19). In 1985, the National Research Council established the Committee on Nutrition in Medical Education and conducted a survey of 45 medical schools to determine the depth and strategies of nutrition education (20). The survey found that medical students receive less than 20 hours of nutrition education, 20% of schools taught less than 10 hours of nutrition education, and only 20% required a dedicated nutrition course (20). The committee reviewed 6,000 questions from the National Board examinations and found that 3–4% were related to nutrition, and the distribution among specialties was uneven (20). The National Academy of Sciences recommended a minimum of 25 hours of nutrition education during medical school and Congress enacted the National Nutrition Monitoring and Research Act, which states medical schools were to provide students, residents, and fellows with appropriate training in nutrition and required the federal government to publish a report on dietary guidelines for Americans every 5 years (21). Nevertheless, the number of hours devoted to nutrition education remained stagnant and (22) by the turn of this past century, U.S. medical schools reported providing less than 20 hours of nutrition education with a downward trend, from 30% in 2004 to 25% in 2008, of schools reporting a required and separate course in nutrition (21,22). More recently, a survey of 933 Canadian medical students’ perceptions and satisfaction with nutrition education found they were uncomfortable in discussing the role of nutrition in the treatment of disease and nutrient requirements, and 87% believed their medical education should dedicate more time to nutrition education (23). In a survey of 72 postgraduate residency programs, program directors reported not having adequate knowledge of nutrition, only 26% reported having a formal nutrition curriculum, 16 lacked any identifiable experts in nutrition, and 77% indicated that required nutrition instruction was unmet at their program (19). A 2021 survey of members of the American Society of Parenteral and EN (ASPEN) found two thirds of physicians had a desire to pursue additional training in nutrition; however, the majority indicated that insufficient protected time from clinical duties or insufficient time and support for travel were barriers to pursuing training (1).
Even though students and physicians desire nutrition education, the diminishing emphasis on nutrition education within undergraduate and graduate medical education programs has delegated management of CCN to other members of the interdisciplinary ICU team. For example, the role of the critical care pharmacist has expanded to include determining and monitoring sterile procedures for compounding parenteral nutrition (PN), identifying drug-nutrient interactions, and monitoring nutrition support practices (21). Critical care nurses are being tasked to identify nutritional status, provide direct access for EN through placement of enteral tubes, care for EN/PN access devices, and monitor tolerance of nutrition support (24). Unfortunately, nutrition education within U.S. pharmacy and nursing programs has also been less than optimal (21). In a survey of two U.S. pharmacy schools, less than 14% of pharmacy students reported receiving a nutrition education, whereas more than 80% surveyed believe nutrition education should be incorporated into their curriculum (25). There are numerous consequences of limited nutrition education. The ASPEN PN Safety Consensus Recommendations highlighted that knowledge deficits and lack of training in nutrition support are linked to PN errors, and a survey of first-year pharmacy residents expressed having little to no training with compounding PN admixtures (26,27). Pervasive practices, such as withholding nutrition during nursing procedures and the utilization of unhelpful monitoring techniques, such as the presence or absence of bowel sounds and measurement of gastric residual volume in initiating and titrating EN, serve as barriers to meeting nutrition prescription targets (28–30). But what about critical care dietitians and their role in the ICU?
Models of care are important to guide clinical practice to achieve optimal performance metrics. Kleinpell et al (31) correctly highlight the complexities of critical care necessitating interprofessional team approaches to improve clinical outcomes: in this model, teams must communicate, collaborate, consult, and capitalize on the individual expertise each person can contribute. This model proffers an opportunity for consistency of practice. For example, if a member must be absent from patient rounds, then other members of the team (a critical care pharmacist or dietitian) could equally advocate for a patient-specific insulin regimen or PN prescription. Interprofessional team members practicing at the top of their license strengthen the team by sharing their unique experiences and expertise via establishment of practice protocols and day-to-day teaching. Therefore, a critical care dietitian would be considered an indispensable member of the ICU team (31).
VALUE-ADDED BY THE DIETITIAN IN CRITICAL CARE MEDICINE
The provision of nutrition therapy is complex. Critical care dietitians, by virtue of their dedicated training in dietetics, general clinical nutrition, and CCN, are well-suited to formulate and institute patient-specific comprehensive nutritional plans pre-, during, and post-ICU stays. Therefore, the question is not whether dietitians can provide necessary nutritional services in the ICU, but rather whether dietitians represent a necessary human resource on the ICU clinical team.
Standards of practice and professional performance for dietitians, as endorsed by the ASPEN, outline a four-step nutrition care process that align with the needs of critically ill patients (32). First, the critical care dietitian is trained and possesses skills to use accurate and relevant data (e.g., biochemical data and nutrition-focused physical examination) to conduct a nutrition assessment. Second, based on the nutrition assessment, dietitians are trained in establishing nutritional risk. Data obtained and interpreted by the dietitian to identify nutritional risk will prompt the physician to incorporate this aspect into an overall ICU care plan. Third, dietitians are able to tailor individualized EN/PN nutrition support plans (e.g., initiate appropriately and timely, formulate based on available resources, titrate to targets, and adapt to comorbidities). Fourth, dietitians monitor (e.g., drug-nutrient interaction, metabolic complications) and evaluate indicators and outcomes related to the nutrition diagnosis and intervention strategies (e.g., disease specific nutrition) to achieve the desired outcomes of nutrition care while maintaining patient safety (e.g., monitoring electrolytes for risk of refeeding syndrome and glycemic control impacted by carbohydrate provision/insulin resistance) (33–36). Additionally, critical care dietitians often have an expanded or specialist roles and possess advanced credential(s) such as Certified Nutrition Support Clinician or RD-AP (Advanced Practitioner Certification in Clinical Nutrition). Consequently, and in accordance with state regulations and organizational policies, many dietitians will have skills and privileges that represent “value added” to the ICU team. These include placement, confirmation of position, and management of postpyloric feeding tubes, interpretation of indirect calorimetry and other technologies, order-writing privileges, ordering of therapeutic diets and medical foods, detection of sarcopenia on CT scans, determination of strength using a hand grip dynamometer, and applicable to nearly all ICU survivors, ordering diets, and other nutritional interventions when transitioning to step-down or general medicine/surgery units (21,36–41). Dietitians bring these “value” and “value-added” skillsets to bear when developing ICU educational curriculum and training (for all team members), research, and administrative activities (e.g., continuous quality improvement) (Table 1).
Value and Value-Added by Critical Care Dietitians Based on Nutrition Service Domain
|Service||Value to the Patient||Value-Added by the Dietitian|
|Nutrition assessment||Nutrition focused physical examination to assess for nutritional risk||Identify impaired nutrition-related examination findings|
|Assess hand-grip strength|
|Interpret CT for sarcopenia|
|Nutritional risk diagnosis||Recognize nutritional risk to tailor and optimize nutrition prescription||Risk stratify nutritional risk|
|Identify micronutrient deficiencies|
|Detect protein-energy deficiency|
|Nutrition prescription||Identify optimal route, quantity, and composition of nutrition||Interpret indirect calorimetry|
|Formulate diet composition|
|Tailor disease-specific diet|
|Reduce inappropriate parenteral nutrition use|
|Nutrition monitoring||Identify barriers, complications, and methods to optimize nutrition delivery||Conduct calorie counts|
|Monitor for refeeding syndrome|
|Manage enteral access devices|
|Modify diet during transitions in care|
With value-added, nutrition care and by extension, the entirety of ICU care is optimized when a critical care dietitian is on the interprofessional team (40,42–44). The evidence supports this assertion. For example, Braga et al (42) found a critical care dietitian led EN prescription was associated with significantly shorter duration of ICU stay. Arney et al (39) found dietitian order-writing privileges improved EN order compliance and protein delivery. Soguel et al (44) found the presence of a critical care dietitian on the interprofessional ICU team improved energy balance by earlier introduction of EN. The International Nutrition Survey found a direct correlation between funded critical care dietitians and optimization of nutrition support and earlier initiation of EN (45). Since optimal interprofessional team performance is highly dependent on open communication, conflict resolution, cooperation, and coordination of care, the knowledge acquired and assessments made by the critical care dietitian are shared with other members of the interprofessional ICU team to ensure best practices are met toward optimizing patient- and family-centered outcomes (31,46).
AN EVOLVING UNDERSTANDING OF THE VALUE OF CCN THERAPY
A greater understanding of critical illness pathophysiology and increased ICU survivorship has led to a repurposing of CCN, beyond passive support to active engagement. As part of an implementation science imperative, this translates into logistical and infrastructural changes, particularly involving champions and teams (48). Specifically, this necessitates the inclusion of dieticians in the ICU interprofessional team due to their indispensable value-added to patient care. Numerous questions related to CCN remain unanswered, and the critical care dietitian plays an active role in answering questions within this evolving paradigm shift. For example, several randomized controlled trials conducted over the past 2 decades have challenged many long-held CCN concepts, including the assertion that energy expenditure must be met during the acute phase of critical illness (48,49), early exclusive PN should be avoided (50,51), and all critically ill patients must have gastric residual volume measured (52,53). Significantly, in the context of the COVID-19 pandemic, dietitians have stood on the forefront of establishing safe and novel nutrition delivery practices to critically ill COVID-19 patients placed in the prone patient or undergoing extracorporeal membrane oxygenation (54). In other words, many seemingly complicated ICU scenarios where the intuited equipoise (e.g., risk of EN or PN vs risk of prolonged underfeeding) leads to clinical inertia, or even wrong decisions, can be better interpreted, vetted, and resolved with dietitian input.
Advocating for the role of the dietitian in the ICU can be detailed even further. Survival from critical illness has increased but is marred by a durable loss of physical functioning and impaired quality of life for survivors (10,15,16). Discernably, protein supplementation in the patient with critical illness is warranted; however, optimal timing and protein dosing are unknown. In 2017, a panel of world experts in CCN identified numerous areas of uncertainty and suggested CCN research priorities for the next decade (17,55). The panel of experts prioritized research to evaluate optimal protein dose with and without standardized active and passive mobilization over the next decade and trials are underway (56–58). The critical care dietitian has become a key partner with clinical trialists and other members of the interprofessional team in successfully executing pragmatic and explanatory trials for knowledge generation (51,56,59). Additionally, dietitians appraise and disseminate updated knowledge of best CCN practices in a timely fashion to members of the interprofessional ICU team and the broader critical care community (51,52,60,61).
Due to their specialized training in clinical nutrition, the critical care dietitian is optimally positioned to lend their expertise in nutrition assessment, diagnosis, management, and monitoring and disseminate their knowledge to members of the interprofessional team to enhance patient care and interdisciplinary team communication. The role of the critical care dietitian is: 1) necessary due to value-added and evidence relating improved outcomes with dietitian involvement, 2) expanding due to the increased scope of activities, which include education and research, and 3) evolving due to introduction of novel nutritional interventions as pathophysiology is better understood, technology advanced, and infrastructure adapted. In short, the ICU dietitian applies skillsets to appraise evidence, generate knowledge, identify best practices, and provide direct patient care. If national and local funding allows, we would argue that the interprofessional model must include a dietitian (62,63). In conclusion, although ICU dietitian skills can be viewed as valuable but shared with other team members, the evidence clearly shows that many ICU dietitian skills can be viewed as value-added, evolving, and expanding—and therefore necessary.
MITRE Helps Deliver Lifesaving Innovation in Remote Critical Care
US Air Force’s (USAF) Air Mobility Command Saving lives with Critical Care Air Transport
Equum and CLEW join forces on telehealth services in acute critical care