The role of dietitians in critical care

Training path to becoming a critical care dietitian

To qualify as a dietitian in the United Kingdom (UK), a dietetic programme approved by the Health and Care Professions Council (HCPC) needs to be undertaken, either as an undergraduate BSc (Hons) or a postgraduate programme which either leads to a Postgraduate Diploma (PgDip) in dietetics or a Masters (MSc) in dietetics. Dietitians interested in specialising in critical care in the UK need a good grounding in nutrition support. There is no UK-based national training path to becoming a critical care dietitian, with training usually provided on the job via in-house training packages and through attendance at national and international conferences. In the UK, the Guidelines for the Provision of Intensive Care Services (GPICS V2) state that if the critical care dietitian is working alone, or leading a team, they must be at the level of advanced practice ¹ to ensure an appropriate range of expertise within the team and to have overall responsibility for the service provision. The UK Allied Health Professional (AHP) Career Development Framework for Critical Care (currently in production) is intended to facilitate AHP’s working in a critical care environment to develop their capabilities and career progression. It is expected that this will lead to the establishment of national multi-professional training courses and masters level education specifically for AHP’s. The Critical Care Specialist Group of the British Dietetic Association has over 300 members and provides specialist education and training. It has a strong social media presence (@BdaCare) and attracts high-profile international speakers to its annual study day.

History of the dietitian in ICU

Historically, nutrition support provision was managed by doctors and nurses via standard protocols. Evidence suggests that the provision of nutrition is complex, and not all patients will gain the same benefit. ² Given the lack of nutrition training and knowledge of healthcare professionals in the UK, ³ the dietitian is best placed to provide advice to the multi-professional team on the optimal way to manage the nutritional needs of all critically ill patients. Traditionally, dietitians internationally have not been adequately funded. In 2007, no UK ICU achieved the national guidance for funded dietitians or appropriate staffing bandings. ⁴ The UK National Critical Care Non-medical Workforce survey ⁵ in 2016 showed the number of UK units with a dietitian had increased to 86%, and 70% of these were of an advanced level. However, only 65% of units complied with UK GPICS staffing levels.

Current impact of the critical care dietitian

The provision of nutrition support (enteral or parenteral) to critically ill patients is vital, but achieving the optimum quantity and balance is a contentious topic. There are two major and contradictory perspectives with respect to how much to feed critically ill patients. The first maintains that overfeeding is potentially harmful in the early phase^6,7 and argues for permissive underfeeding. ⁸ The other argues that critically ill patients are underfed and that the resultant energy and protein deficit results in poor outcomes, such as an increase in infections, longer ICU and hospital stays.^2,9,10 Understanding the safety of different routes of feeding has been contentious, as historically it has been believed that utilising the gastrointestinal tract is safer than intravenous feeding. ¹¹ The CALORIES trial, ¹² the largest ICU feeding trial in the UK, demonstrated that, among adults with an unplanned ICU admission for whom early nutritional support could be provided through either the parenteral or the enteral route, there was no significant difference in mortality and infection rates at 30 days. This has a dramatic impact on patient care, as the focus can now be on how much nutrition support is optimal, with the knowledge that nutrition support can be safely delivered by either or both routes and thus achieve the target feeding rates. The problem of the optimum target for energy and protein intake still remains and needs to be urgently resolved. The nutritional status of every patient should be assessed with specific reference to the requirements for additional micronutrient supplementation and avoidance of refeeding syndrome.

Analysis from the International Nutrition Survey continually shows that there is a direct correlation between the total number of funded dietitians in Critical Care and improved patient care. There is better provision of nutrition support and earlier initiation of enteral feeding.^2,13,14 The combination of a dedicated dietitian on the ICU and a feeding protocol was required to increase energy provision to patients, increase the use of combined feeding methods to achieve targets and reduce inappropriate use of parenteral nutrition.^14,15 Braga et al. ¹⁶ showed that patients had a significantly shorter length of stay when they received enteral nutrition according to the advice of a critical care dietitian.

Up to 78% of patients present to ICU malnourished, ¹⁷ and this is associated with a significant increase in mortality, ¹⁸ ICU stay and ICU re-admissions. ¹⁹ The dietitian effectively identifies patients who are malnourished and at nutritional risk and implements appropriate nutritional treatment plans. They have the knowledge and skills to manage complex cases, in partnership with the clinicians, patients and carers, including advising on the most appropriate nutrition regimen, on-going monitoring to ensure patient safety and demonstrate outcome benefit. ²⁰ They will assess and take account of the many factors influencing the nutrition support treatment plan including age, degree of inflammation, number of organ failures, comorbidities and projected length of stay, gastrointestinal function and critical care treatment modalities.

On discharge from ICU, patients can experience malnutrition, changes in eating patterns, poor or excessive appetite and inability to eat. This impacts on recovery and rehabilitation which is not possible without an adequate nutrient delivery. ²¹ A structured handover on ICU discharge is required to ensure on-going dietetic provision and patient-focused nutrition goals are set in line with the National Institute for Health and Care Excellence (NICE) quality standard for rehabilitation after critical illness. ²²

In the UK, the dietitian leads the development, implementation and training of local nutrition support guidelines, as well as being central to the provision of on-going training and education for clinicians, nurses and allied health professionals. As a key member of the multidisciplinary team (MDT), they will work collaboratively contributing to consultant-led ward rounds, MDT meetings and have regular consultant communication where nutrition goals, risks and plans are discussed as per the NICE guideline on rehabilitation after critical illness in adults. ²² The UK dietitian also contributes to clinical governance activities including leading regular nutrition-related audit and acting on the results, plus undertaking quality improvement projects that demonstrate the impact of dietetics on service delivery, quality and effectiveness.

Suitably skilled and experienced ICU dietitians, in the UK and internationally, can safely and successfully insert post-pyloric feeding tubes in these patients along with performing indirect calorimetry to enhance the nutrition assessment of the patient.^23,24 Leading international critical care dietitians are helping shape the evidence base for critical care nutrition by contributing to large multicentre nutritional trials such as the CALORIES trial ¹² and international nutrition support guidelines.^11,25

Future for dietitians in critical care

Dietitians can significantly improve the ICU teams’ capacity to implement and deliver prompt and appropriate nutrition support, if adequate funding is provided to ensure consistent and established dietetic input. For dietitians to be influential, they need to be present on ICU and participate when important decisions are being made, such as during ward rounds, handovers, multidisciplinary team (MDT) meetings and clinical discussions with visiting teams. In addition, they need to have clinical privileges such as automatic referral, ability to order oral, enteral and parenteral nutrition and ordering of relevant laboratory tests. ²⁶

From 2017, in the UK, Health and Care Professions Council (HCPC)-registered advanced dietitians can now undertake non-medical supplementary prescribing training to allow them to prescribe interventions as parenteral nutrition (PN), vitamin and mineral supplementation and pancreatic enzyme therapy. It is envisaged that in the future, the majority of advanced practice critical care dietitians will be accountable for PN prescribing, rather than relying on junior doctors to sign off prescriptions for patients that they have not nutritionally assessed.

The future for critical care dietitians is exciting. Large, well-conducted nutrition trials are contributing to our understanding of what is and is not right for ICU patients, and dietitians are well placed to implement the evidence to improve nutrition delivery. The number of patients surviving critical illness is rising, but survival can be associated with reduced physical and functional abilities as well as reduction in the quality of life.^27,28 It is envisaged that in the future, dietitians will be contributing to research investigating how nutrition support during critical illness can improve physical recovery.

Growing evidence suggests that the dietitian is an essential member of the ICU team and helps improve patient outcomes. The ICU is a stimulating place to work for dietitians, offering many clinical and developmental opportunities. The extra effort required to gain the trust and respect from ICU team members will be rewarded with a fulfilling career.