Samantha Cook is the lead Dietitian in Critical Care at University Hospitals of North Midlands NHS Trust.
"Leaving school I had little idea of what I wanted to be “when I grow up,” so I pursued my interests and choose to study BSc Biochemistry at the University of Birmingham. Fast forward to my final year of study and I was little the wiser as to where I wanted my career to take me. During finals my father underwent a Coronary Artery Bypass Graft and as part of his rehabilitation saw a dietitian – cue light-bulb moment…
I went on to study Nutrition and Dietetics gaining a MSc from the University of Chester. Now 10 years into my NHS career and I’m working as the lead dietitian for Critical Care at the University Hospitals of North Midlands NHS Trust.
My position was created around 5 years ago following significant investment into allied health professionals to support the rehabilitation of critically ill patients. As a new role it has continually evolved since its inception, not least due to the COVID-19 pandemic and with inspiration from Critical Care Dietitians across the UK, I am excited to see what we can achieve! I say “we” because dietitians work as part of the wider multi-professional team to help provide the best outcomes for our patients. So if you don’t yet have a dietitian as part of your team, please read on…
No Two Patients Are The Same
Critically ill patients are likely to require enteral, parenteral or oral nutritional support (or a combination of these) to meet their nutritional needs and as is the case across healthcare, no two patients are the same and not all patients will receive the same benefit from nutrition support. Although enteral feeding protocols may be useful to ensure initiation of nutrition support, they are unable to account for this variability. The dietitian is uniquely positioned to complete clinical assessment of nutritional risk and provide evidence based individualised care to manage this. As part of this assessment the dietitian will consider; age, comorbidities, stage of critical illness and projected length of stay, number of organ failures, potential for increased losses, GI function, degree of inflammation and baseline nutritional status. Those identified as being at nutritional risk are more likely to suffer harm if underfed.
What Is Our Target?
Current evidence suggests that both under and overfeeding is associated with negative outcomes for the critically ill but what is our target? The gold standard for calculating energy requirements is indirect calorimetry; however, until recently the equipment has been impractical and inaccessible for use in the clinical setting. As more cost and time effective calorimeters become available dietitians are perfectly placed to introduce this technology and interpret the results. Where indirect calorimetry isn’t available the dietitian may use a variety of validated equations, most suited to the patient, to estimate nutritional requirements.
Once target requirements for calories and protein have been identified (either through measurement or estimation) the next challenge is to ensure that at least 80% of target energy has been provided. On average critically ill patients only receive around 60% of the prescribed energy and protein. Feed interruptions can be numerous and may include fasting for theatre, extubation, rehabilitation or high gastric residual volumes. A professional focus on nutrition provides dietitians with the incentive to audit adequacy of nutrition delivery and support strategies to achieve the 80% target. These strategies are likely to draw on their knowledge of refeeding syndrome, prokinetics, bowel management and route of delivery. There are also times when a dietitian will reduce provision of enteral or parenteral nutrition due to the risk of overfeeding in the presence of non-nutritional energy, usually in the form of propofol or dextrose.
The Importance of Dietitians
There is accumulating evidence supporting the importance of dietitians on the intensive care unit; with research demonstrating a significantly shorter length of stay when patients received enteral nutrition according to the advice of a critical care dietitian, reduced inappropriate use of parenteral nutrition and meeting the standard of 80% energy targets. The benefits of a dietitian on the intensive care unit also expand past the bedside, promoting the benefits of good nutritional care via teaching and education for clinicians, nurses and allied health professionals and the development and implementation of evidence-based guidelines and local protocols.
The future of the profession looks towards extended scope of practice including (but not limited to) supplementary prescribing, indirect calorimetry and bedside post-pyloric tube placements. Indeed, all of these are already being undertaken by dietitians in intensive care units within the UK, with supplementary prescribing allowing advanced practice dietitians to be accountable for their own parenteral nutrition prescribing.
Ask yourself, would you be confident to decide when and how much to feed a critically ill patient in order to provide the best clinical outcome? Would you be confident that appropriate nutrition goals have been set and supported post discharge to support rehabilitation after critical illness? The dietitian is the best placed member of the critical care multi-professional team to provide advice on the optimal nutritional management of all critically ill patients, working to tailor care to the individual. So if you don’t yet have a dietitian as part of your team… perhaps you should."