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Question: Our department have been using the new equations from the new PENG Pocket Guide since the beginning of April and some of the dietitians have questioned the age ranges as a 60 year old fits into two categories.

Answer from Carole-Anne Fleming, Dietetic Clinical Team Lead - Oncology, Gartnavel General Hospital: With regard to the age ranges in the oxford equations, the original Henry 2005 paper gives the age ranges as follows Table 13 18-29, 30-60, >60 and table 14 further categorises > 60 as the ranges 60-70 and 70 + in what they describe as 'young elderly and older elderly'. For the Pocket Guide we have combined the two tables which explains why the age 60 is in two categories.

It is important to remember that this data relates to populations and should only be used as a guide for individuals therefore one should be using their own clinical judgement of a patients disease state and physiological status in congunction with actual age when deciding on an equation to use rather simply asigning to category for chronological age.

Question: Section 13.8 – Refeeding Syndrome: Table 13.3 Suggests that Pabrinex is required od for 10 days for high risk patients where the IV route is being utilised. Within my trust we would only give 1 day for those on TPN or 2 days for enteral feeds?

Answer from Pete Turner, Specialist Nutritional Support Dietitian: Table 13.3 recommends that you give thiamine for 10 days in high risk patients. This is based on the recommendations from NICE clinical guideline 32 Nutrition Support in Adults 2006. This was a GPP recommendation and therefore the opinion of the panel rather than being based on hard evidence.

The route depends on the clinical condition of the patient. If they are for TPN or have poor gut function Pabrinex should be given for 10 days. Poor gut function is very subjective but could include short bowel or malabsorption conditions. Patients with alcoholic enteropathy or severe malnutrition may have impaired thiamine absorption and would probably require i.v supplementation.

The recommendation is for Thiamine for 10 days (along with other vitamins) so it is possible that you may start with Pabrinex but decide that they are able to absorbl oral / enteral products and switch to an oral or enteral product.

We have a conversation with Liz Weekes, the main author of the Pocket Guide to Clinical Nutrition Chapter on Nutritional Requirements:

Why are Henry equations now recommended?

In the latest edition of the Pocket Guide the authors recommend the use of the Oxford equations to estimate BMR rather than the Schofield equations. The main reason for this change is that recent work has queried the universal validity and application of the Schofield equations, with several studies suggesting that the equations overestimate BMR in many populations. A recent assessment of the validity of different BMR prediction equations found the Oxford equations to be the most rigorously tested and applicable to modern populations. Furthermore, the recent SACN report on energy requirements recommends the use of the Oxford BMR prediction equations for estimating average requirements for energy in healthy populations.

Why have the recommended nitrogen requirements changed in the new Pocket Guide?

The recommendations have not changed, we have simply included recommendations by other organisations.
In the latest update of the adult requirements section of the pocket guide no changes were made to the recommendations for estimating protein requirements. The section does now, however, include recommendations made by other organisations. The nutritional requirements section includes details of the NICE and ESPEN guidelines for nitrogen requirements in the table numbered 3.6. This chapter also includes a sentence that explicitly states that clinicians should only aim to provide up to 0.3gN/kg (2g protein/kg) in “uncomplicated depletion or the anabolic phase post injury”. There is information on how to detect whether or not a patient is metabolically stressed (page 3.4 of Chapter 3) and goes on to state that a patient is likely to be moving into the recovery phase as the relevant parameters return to the normal range.

What reference is there to concerns relating to refeeding in this chapter?

The requirements chapter makes it very clear on pages 3.2 and 3.3 that, in sick individuals, energy requirements are likely to be similar to, or lower than those for a healthy individual of the same age and gender. All the relevant statements are referenced to the SACN draft report. The chapter also cautions against over-feeding in the third paragraph of the stress factors section on page 3.4.

Why are there no estimates of electrolyte requirements suggested in the ‘Fluid requirements in obesity’?

This section was included at the request of dietitians and other clinicians who regularly use the handbook. There are no estimates for electrolyte requirements in obese individuals because I was unable to locate any evidence-based recommendations on this. Dietitians are unlikely to be solely responsible for the management of fluid and electrolytes in sick, obese individuals and thus we felt it unnecessary to include more detail.