Refeeding syndrome can be defined as the potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving artificial refeeding
(whether enterally or parenterally).

Hypophosphataemia is the biochemical hallmark of RS, though hypomagnesaemia and hypokalaemia are commonly present as well.

What are the clinical consequences of RS?
In RS, whole body depletion of phosphate occurs. Insulin surge cause by refeeding causes a greatly increased uptake and use of phosphate in the cells. These changes lead to a deficit in intracellular as well as extracellular phosphate. In this environment, even small decreases in serum phosphate can lead to widespread dysfunction of cellular processes affecting almost every physiological system.
Phosphate depletion leads to reduced levels adenosine triphosphate (ATP), causing failure of cell functions dependent upon energy rich phosphate compounds. Low phosphate also lead to reduced levels of red cell 2,3- DPG (diphosphoglycerate), thereby increasing the affinity of hemoglobin for oxygen and reducing oxygen release at the tissue level.
These processes cause impaired tissue functioning leading to;

• Cardiac failure and cardiac arrhythmias (thiamine deficiency can compound failure)
• Convulsions and coma
• Respiratory failure
• Muscle weakness and pain

Serum phosphate concentrations of less than 0.50 mmol/l (normal range 0.85-1.40 mmol/l) can produce the clinical features of refeeding syndrome. Low potassium and magnesium also affects membrane potential and can lead to cardiac arrhythmias and neuromuscular complications

What is the pathogenesis of RS?

• During undernutrition, the body down regulates membrane pumping to conserve energy. This causes leakage of intracellular potassium (K), magnesium (Mg), calcium (Ca) and phosphate (PO4), with subsequent whole body depletion.
• In starvation the secretion of insulin is decreased in response to a reduced intake of carbohydrates.   This results in further intracellular loss of electrolytes, in particular phosphate.
• Refeeding leads to reversal of the above processes and leads to movements of electrolytes into cells. This can lead to precipitous falls in circulating levels of K, Mg, Ca and PO4. This phenomenon usually occurs within four days of starting to feed again.

How to identify patients at high risk of developing refeeding problems?
The National Institute for Health and Clinical Excellence (NICE) in England and Wales identifies the following groups at high risk of RS: 7

A.  Patient has one or more of the following:

• BMI less than 16 kg/m2
• unintentional weight loss greater than 15% within the last 3–6 months
• little or no nutritional intake for more than 10 days
• low levels of potassium, phosphate or magnesium prior to feeding

B.  Or patient has two or more of the following:

• BMI less than 18.5 kg/m2
• unintentional weight loss greater than 10% within the last 3–6 months
• little or no nutritional intake for more than 5 days
• a history of alcohol abuse or drugs including insulin, chemotherapy, antacids(binds phosphate) or diuretics (loss of electrolytes)

How to prevent development of RS?

• Identification of high risk patients is crucial. Any patient who is malnourished or had negligible food intake for more than 5-10 days is at risk of developing refeeding problems.
• Check baseline potassium, calcium, phosphate and magnesium. However, correction of electrolyte deficiencies before feeding is not necessary. It should be done alongside feeding. Electrolyte replacement prior to refeeding may provide a false sense of security as improvement in plasma levels could occur with no significant change in overall electrolyte status. A severely malnourished individual would be unable to correct intracellular electrolyte deficits unless simultaneous feeding is given to encourage transmembrane transfer.   It therefore seems logical to provide generous supplements of oral, enteral or intravenous supplements of potassium (likely requirement 2–4 mmol/kg/day), phosphate (likely requirement 0.3–0.6 mmol/kg/day) and magnesium (likely requirement 0.2 mmol/kg/day intravenous, 0.4 mmol/kg/day oral) with feeding unless pre-feeding plasma levels are high.
• The electrolytes should be monitored daily for 7 days and at least three times in the following week.
• Specific micronutrient deficiencies can compound the problems of RS. Although all vitamin deficiencies may occur at variable rates with inadequate intake, thiamine is of most importance in complications of refeeding. Thiamine is an essential coenzyme in carbohydrate metabolism. NICE recommends vitamin and mineral supplementation immediately before and during the first 10 days of feeding: oral thiamine 200–300 mg daily, vitamin B co strong 1 or 2 tablets, three times a day (or full dose daily intravenous vitamin B preparation, if necessary) and a balanced multivitamin/trace element supplement once daily.
• Refeeding should be started at a maximum of10 kcal/kg/day (no more than 50% of energy requirements). The rate can be increased slowly to meet full needs by 4–7 days, if no refeeding problems are detected on clinical or biochemical monitoring.
• Refeeding should be started using only 5 kcal/kg/day in extreme cases (for example, BMI less than 14 kg/m2 or negligible intake for more than 15 days) and monitoring cardiac rhythm continually in these people and any others who already have or develop any cardiac arrhythmias

How can refeeding syndrome be detected and treated?

Refeeding syndrome is detected by considering the possibility of its existence and by measuring serum electrolytes described above. If the syndrome is detected, the rate of feeding should be slowed down and essential electrolytes should be replenished.

Discuss phosphate replacement treatment?
The best method for electrolyte repletion has not yet been determined. Hypophosphatemia is ideally treated with intravenous supplementation in hospitalized patients, but this is not without risks.  Intravenous phosphate can precipitate with calcium and produce a variety of adverse effects including hypocalcaemia, renal failure, and potentially fatal arrhythmias.
We use intravenous phosphate at phosphate levels less than 0.5 mmol/l. The maximum intravenous dose used is 18mmol in 24 hours.

Ref

1. NICE guidance: Nutrition support in adults
2. British Society of Gastroenterology Guidelines for enteral feeding in adult hospital patients
3. Mehanna HM et al. Refeeding syndrome: what it is, and how to prevent and treat it.  BMJ. 2008 Jun 28; 336(7659):1495-8.

NICE 2006

• Unconscious patient
• Neuromuscular swallowing disorder- Post CVA, MS, MND, Parkinson’s disease
• Upper GI obstruction- oesophageal stricture or tumour
• GI dysfunction or Malabsorption- dysmotility, IBD, short bowel (PN may be needed)
• Physiological anorexia- cancer, sepsis, liver disease, HIV
• Increased nutritional requirements- cystic fibrosis, burns
• Psychological problems- severe depression or anorexia nervosa
• Mental health- patients with dementia

What are the routes of access for enteral tube feeding?

• Nasogastric tubes are used most commonly for short term feeding (< 4 weeks)
• Consider gastrostomy or jejunostomy feeding if the patient is likely to need long term (4 weeks or more) ETF.
• Post pyloric feeding can be achieved by endoscopically placed NJ tube or surgical jejunostomy (by laparoscopy or mini lap)

Discuss post pyloric feeding?

Post pyloric feeding is indicated when the digestive tract functions normally, but the patients cannot meet their nutritional requirements due to a passage problem at the gastric level. It also has the advantage of reducing the risk of pulmonary aspiration of the gastric contents.  The indications for post pyloric feeding are:

• Gastric outlet obstruction
• Gastroparesis or gastric food intolerance- National guidelines by Society of Critical Care Medicine and the ASPEN do not recommend holding gastric tube feeding unless the gastric residual volume is greater than 500 ml.  This rule has markedly reduced the number of patients diagnosed with gastric feeding intolerance. Prokinetic agents should be prescribed to patients who exhibit gastric feeding intolerance prior to consideration of an alternative feeding route (jejunal or parenteral nutrition).
• Known severe reflux and aspiration of gastric contents- It is important to define whether episodes of aspiration are truly caused by GORD or are the result of disorders in swallowing. It is important to understand that post pyloric feeding does not completely abolish the risk of aspiration. (risk is 2.4% Gutierrez GD et al. Radiology 1991;178:759-762)
• Intolerance of oral feeding due to passage disorder due to swelling or outside pressure onto the duodenum (pancreatitis or tumour).  Gastric feeding should be tried first in pancreatitis and if not tolerated, jejunal feeding should be considered. Jejunal feeding has the advantage of not only bypassing the passage problem but also avoids pancreatic stimulation (and thus provides rest to pancreas).
• Proximal (duodenum and first part jejunum) enteric fistula.

Discuss post pyloric feeding in critical care settings?

Many intensivists worry that gastric feeding predisposes to aspiration and pneumonia and thus prefer to feed critically ill patients via the post-pyloric route, believing that it reduces the incidence of pneumonia. However, post-pyloric feeding has no clinical advantages over gastric feeding in most critically ill medical, neurosurgical and trauma patients unless gastric feeding intolerance is present.
A meta-analysis showed no difference between gastric and small intestinal feedings with regard to the incidence of pneumonia, length of stay or mortality in a mixed group of critically ill medical, neurosurgical, and trauma patients (Marik PE et al. Gastric versus post-pyloric feeding: a systematic review. Critical Care 2003, 7:R46-R51doi:10.1186/cc2190)

If jejunal feeding is needed, are there any real clinical outcome differences between placing a PEG with J tube extension or placing a direct-PEJ (DPEJ)?

PEG/J tubes are easier to place than DPEJ tubes, however, the J-tube extension of the PEG/J system has a significantly higher rate of dysfunction (clogging, kinking, migration), leading to a higher rate of endoscopic re-interventions and interruptions in feeding.

When do you initiate feeding after placement of an enteral access device?

Traditional surgery dogma was that post-operative feedings should wait until there was evidence that bowel function had returned as evidenced by flatus or a bowel movement. This has been challenged in recent literature. So ASPEN 2009 recommends;

• Enteral feedings should be started postoperatively in surgical patients without waiting for flatus or a bowel movement. The current literature indicates that these feedings can be initiated within 24-48 hours.
• A PEG tube may be utilized for feedings within several hours of placement: current literature supports within 2 hours in adults and 6 hours in infants and children.

How much feeds need to be given?
See the module “Estimating calorie requirements”
If no advice is available 25ml/kg/day of standard 1 Kcal/ml feed is often appropriate.

Discuss initiation and advancement of an enteral nutrition regimen?
There are limit data to form strong recommendations for the best starting administration rate for initiation of enteral feeding. Stable patients tolerate a fairly rapid progression of EN, generally reaching the established goal within 24-48 hours of initiation.
In practice, formulas are frequently initiated at full strength at 10-40 mL/h and advanced to the goal rate in increments of 10-20 mL/h every 8-12 hours as tolerated.

What are the modes of ETF?

What are the types of enteral feed formulae?

The choice of feed to be given via ETF is influenced by a patient’s nutritional requirements, any abnormality of gastrointestinal absorption, motility, or diarrhoeal loss, and the presence of other system abnormality, such as renal or liver failure.

Most commercial feeds contain 1.0 kcal/ml, with higher energy versions containing 1.5 kcal/ml. They are generally available in fibre free and fibre enriched forms.
They are nutritionally complete. The following feeds are generally used.

• Whole protein (polymeric) feeds- These contain nitrogen as whole protein.
• The carbohydrate source is partially hydrolysed starch and the fat contains long chain triglycerides (LCTs).
• Elemental/peptide feeds- These feeds contain nitrogen as either short peptides or, in the case of elemental diets, as free amino acids. The aim of ‘‘predigested diets’’ is to improve nutrient absorption in the presence of significant malabsorption. Their importance is probably greater in maldigestive (for example, pancreatic disease) rather than malabsorptive states, and in patients with a short gut and no colon their high osmolality can cause excess movement of water into the gut and hence higher stomal losses
• Disease specific and pharmaco nutrient feeds- Renal feeds- Contain reduced amounts of sodium, potassium and phosphate.   Liver patients need low sodium low volume feeds.

Which formula should be used in non stressed diabetic patients?

American Diabetes Association and European Association for the Study of Diabetes recommend that 60–70% of energy be divided between carbohydrates and monounsaturated fat (MUFA), with less than 10% from polyunsaturated fat, less than 10% from saturated fat and less than 15% from protein. Simple carbohydrates can be included but should constitute less than 10% of total energy. Most diabetes-specific enteral formulae comply with this rule.

Which formula should be used for blood glucose control in ICU-patients?

In the ICU setting where strict glycaemic control with the use of exogenous insulin is achieved relatively easily when standard or ICU-specific formulae are used, there is no reason to believe that any specific formulae would be required.

How to monitor enteral feeding?

• Early monitoring requires blood glucose to be checked at 4–6 hour intervals and plasma sodium, potassium, magnesium, and phosphate to be checked daily especially those at risk of refeeding syndrome
• LFTs and full blood counts must be repeated weekly until the patient is stable.
• Body weight should be measured weekly
• Trace element (Zn, copper, selenium) and vitamin levels (B12, folate, Vit D) should be measured on commencing ETF if possible. Patients on long term feeding should have periodic checks of vitamin and trace element status.

What are the complications of ETF?

Complications are diarrhoea and aspiration.

• Diarrhoea-
  • ETF related diarrhoea occurs in 30% of enterally fed patients on the ward and 60% of patients on ICU.
  • Parenteral nutrition may be required if elimination of all other causes of GI upset and/or administration of simple symptomatic treatments fails to resolve the problem.
  • Likely causes of ETF diarrhoea
    • Feed related
      • Bolus feeding
      • Continuous feeding at high rate
      • Feed temperature (cold)
      • The evidence for any of these leading to diarrhoea is minimal. It is unlikely that enteral feeds causes ETF related diarrhoea but a lack of cephalic response in ETF feeding is significant in the pathogenesis of ETF diarrhoea.
    • Non Feed related
      • Drugs- Antibiotics (commonest cause), laxatives, Mg antacids, Drugs containing active fillers like sorbitol
      • Infections- C diff and other
      • Lactase deficiency (primary or secondary) – limit milk if the pt is also taking food orally
      • Fat malabsorption in those with pancreatic deficiency, biliary obstruction or extensive ileal resection
      • Hypoalbuminaemia- considerable debate whether it can cause diarrhoea through intestinal edema. Unlikely as pts with nephrotic syndrome or cirrhosis do not have diarrhoea.

Discuss the treatment of ETF diarrhoea?

• Treat any predisposing conditions as above.
• Standard feeds contain little or no fibre. Use fibre enriched forms of enteral feed. Ingestion of fibre slow intestinal transit time plus fermentable polysaccharides stimulates colonic bacterial population and hence stool mass. However fibre rich diet does not often help ETF diarrhoea
• Use loperamide/codeine on a symptomatic basis
• Anecdotal reports of usefulness of probiotics

What are the precautions needed during enteral feeding to reduce the risk of aspiration?

• Patient positioning- ASPEN 2009 recommends
  • Elevate the backrest to a minimum of 30º, and preferably to 45º, for all patients receiving EN unless a medical contraindication exists.
  • Use the reverse Trendelenberg position to elevate the head of bed (HOB), unless contraindicated, when the patient cannot tolerate a backrest elevated position.
  • Feeding can be continued during short periods of time when it is necessary to lower the HOB for a procedure or a medical contraindication.
• Monitor gastric residue volume (GRV) – Measurement of GRV is one technique used to prevent aspiration. ASPEN 2009 recommends
  • Check gastric residuals every 4 hours during the first 48 hours for gastrically fed patients. After enteral feeding goal rate is achieved, GRV monitoring may be decreased to every 6-8 hours in noncritically ill patients. However, every-4- hour measurements are prudent in critically ill patients.
  • If the GRV is > 250 mL after a second gastric residual check, a promotility agent should be considered in adult patients.
  • A GRV >500 mL should result in holding EN and reassessing patient tolerance by use of an established algorithm including physical assessment, GI assessment, evaluation of glycemic control, minimization of sedation, and consideration of promotility agent use, if not already prescribed.
  • Consideration of a feeding tube placed below the ligament of Treitz when GRVs are consistently measured at > 500 mL.

Ref

1. Bankhead R et al. Enteral Nutrition Practice Recommendations. JPEN J Parenter Enteral Nutr. 2009 Jan 27.

• Explain the procedure to the patient.
• Mark the tube at a distance equal to that from the xiphisternum to the nose via the earlobe (50–60 cm). Fine bore 5-8 French NG tubes are used for feeding.
• Lubricate the tube externally with gel/water and internally with water if a guidewire is present. Check the guidewire moves freely.
• Check nasal patency by ‘‘sniff’’ with each nostril occluded in turn. The clearer nostril can be sprayed with lignocaine to minimise discomfort.
• Sit the patient upright with the head level. Slide the tube gently backwards along the floor of the clearer nostril until visible at the back of the pharynx (10–15 cm).
• If the patient is cooperative, ask them to take a mouthful of water and then advance the tube 5–10 cm as they swallow.
• Repeat the water swallow/advance until the preset mark on the tube reaches the nostril.
• Withdraw the tube at any stage if the patient is distressed, coughing, or cyanosed.
• If there is difficulty passing the tube, ask the patients to tilt their head forwards or turn it to one side.
• Once in place, remove any guidewire and secure carefully.
• Check position of the tube before use (this does not usually require an x ray).

If the tube aspirate has a pH < 5, it confirms proper placement of NG tube. X-ray confirmation is only needed if there is any doubt over the position of the tube or difficulty in obtaining aspirate.  The pH test is valueless if patients are on acid suppression, and if there is any doubt, or any other reason, an x ray is needed. Checking the position of a tube by injecting air through it and listening for bubbles with a stethoscope is unreliable.

Ref

1. British Society of Gastroenterology Guidelines for enteral feeding in adult hospital patients

• Multinutrient liquid supplements that are energy dense and contain both macronutrients (protein, carbohydrate and fat) and micronutrients (vitamins, minerals and trace elements).
• ONS could be nutritionally complete, nutritionally incomplete (e.g. fat free or lacking some essential micronutrients) and modular (e.g. usually containing one or two energy sources only) varieties.
• A range of specialized ‘disease- specific’ supplements is also available (e.g. for patients with malabsorption, diabetes, renal and hepatic disease).

How much should be prescribed?
The number of supplements required will vary according to the patient’s nutritional needs and food intake.

What products can be prescribed on NHS?
Not all supplements are available on the NHS. Those that can be prescribed on FP10 are listed in the BNF (Appendix 7)

What are the different types of ONS available?

• Polymeric or elemental
• With or without fibre
• Nutritionally complete or disease specific
• Energy dense or standard

How do you select ONS?

Enteral formulas should be selected according the clinical needs of the patient. Most standard formulae contain whole protein, lipid in the form of long-chain triglycerides
(LCT) and fiber. Most standard formulae contain neither gluten nor lactose in clinically relevant amounts.

• Normal Gut function- Select nutritionally complete polymeric ONS (intact carbohydrates, protein and fat) like ensure (250ml, 1Kcal/ml) or ensure plus (220ml, 1.5Kcal/ml).
• Volume restriction (calorie dense) – scandishake mix (1 satchet powder- 240ml/588Kcal), calogen (4.5Kcal/ml, usual dose 30ml tds).
• Increased protein needs- fortisip extra. High protein formulae contain 20% or more of total energy from protein.
• Impaired gut function- Elemental ONS like Elemental O28Xtra, peptamen.
• Liver failure/ CRF on HD or CAPD- high energy, low fluid, low electrolyte ONS like nepro (2kcal/ml), Ensure plus, Enrich plus

NB

• hyperosmolar feeds should be avoided if the short bowel ends in a stoma or the short bowel is anastomosed to the colon
• Nutilis- for thickening of foods in pts at risk of aspiration

Ref

1. Stratton RJ, Elia M. Who benefits from nutritional support: what is the evidence? Eur J Gastroenterol Hepatol. 2007 May; 19(5):353-8. Review.

Estimating calorie requirement is an essential component of nutrition support to avoid under or over feeding. Energy requirements can be calculated;

• Using doubly labelled water technique or indirect calorimetry. However these methods are not practical in the day to day clinical practice.
• Arbitrary estimates of energy requirements per kilogram body weight. This is an imprecise method. Adult energy requirements tend to be between 25-35Kcal/kg (NICE 2006)
• Using predictive equations like Schofield or Harris Benedict equations

Discuss the calculations for estimating calorie requirement?

Total energy requirement is calculated by adding

• Basal metabolic rate (BMR) or REE (resting energy expenditure) using predictive equations
• Dietary induced thermogenesis (DIT) – energy used during digestion and absorption (usually 10%). However considerations are different when using artificial nutrition. Continuous NG feeding appear to have little effect on energy expenditure; however those receiving bolus feeding DIT may account for 5% of the total energy expenditure and this figure should be added to the estimates of the energy needs.
• Activity level- Clinically, the following factors combining activity level plus DIT can be used
  • Bed bound immobile                               BMR + 10%
  • Sitting/bed bound immobile                    BMR +15-20%
  • Mobile around ward                                BMR +25%
• Stress level- use with caution due to the risk of overfeeding. The period during which stress factor is applied depends on clinical judgement Elia’s nomogram can be used to guide stress level adjustments Sepsis/abscess-20%, surgery- uncomplicated- 5-20%, complicated surgery- 25-40%, ICU- ventilated- 0-10%, ICU-sepsis-20-60%, COPD- 15-20%, CVA- 5%, Cerebral he-30%, Acute Pancreatitis-10% (Todorovic and Micklewright 2004)

Schofield equation is commonly used to calculate energy requirements in UK.

Schofield equation (based on DoH 1991)

Total Energy requirements- BMR +activity level (+DIT) +stress levels
Harris-Benedict Equation (BEE):
Females: 655.1 + [(9.56 x W) + (1.85 x H) - (4.68 x A)]
Males:      66.47+ [(13.75 x W) + (5 x H) - (6.76 x A)]
W = weight in kg; H = height in cm; A = age in years
NB- Pregnant women in second or third trimester: Add an additional 300 kcal/day

Discuss calculating energy requirements is specific clinical conditions?

Obesity-
In obese pts (BMI>30kg/m2), predictive equations tend to overestimate energy requirements. Ideally energy requirements should be assessed using indirect calorimetry (ASPEN 2002), however this is not feasible in clinical practice.
Feeding to actual body weight (ABW) sustains obesity and may precipitate metabolic effects of overfeeding such as hyperglycemia and respiratory distress (NICE 2006). Conversely feeding to an ideal body weight (IBW) will promote weight loss but may compromise glucose tolerance and wound healing. A balance is thus needed.

Todorovic and Micklewright 2004 suggest the following

• For non stressed pts- calculate requirements using Schonfield equations and then subtract 400-1000Kcal/day to encourage a decrease in energy stores
• Mild-Mod stress- use BMR calculated using ABW. In order to prevent adverse effects of overfeeding, do not add the activity or stress factor
• Severely stressed- calculate BMR using ABW and add a stress factor
• Monitoring is essential and should include nutritional parameters, blood glucose and RQ (should be 0.8-0.9)

The following can be useful to double check if concerns regarding over or underfeeding

• Use 19-21 Kcal/kg actual body weight
• BMR using Schonfield equation and adjusted body weight (ABW+IBW/2), then add activity and stress factor as usual
• Ireton-Jones energy equation for obesity

Liver disease
Calculations should use dry body weight and adjustments made for fluid overload and ascites

Discuss the nutritional needs of an individual?

NICE 2006 guidance suggest that nutrition support prescriptions should consider individual needs for energy, protein/nitrogen, fluid, electrolytes (Na/K), minerals (Mg, Po4), other micronutrients (vitamins and trace elements) and fibre
For example, NICE 2006 suggest
For people who are not severely ill or injured, nor at risk of refeeding syndrome, the suggested nutritional prescription for total intake should provide all of the following:

• 25–35 kcal/kg/day total energy (including that derived from protein)
• 0.8–1.5 g protein (0.13–0.24 g nitrogen)/kg/day
• 30–35 ml fluid/kg (with allowance for extra losses from drains and fistulae, for example, and extra input from other sources – for example, intravenous drugs). In general fluid input should be 500-750 mls more than the output.
• Adequate electrolytes, minerals, micronutrients (allowing for any pre-existing deficits, excessive losses or increased demands) and fibre if appropriate.

Protein/ nitrogen requirements

Protein is the only macronutrient that contains nitrogen. Approximately 16% of protein is nitrogen, so 1 gm of nitrogen is equivalent to 6.25 gm of protein. In practice nitrogen is often calculated when estimating requirements for parenteral nutrition while protein is used at all other times. Nitrogen support should aim to keep the body in nitrogen balance i.e. N2 intake is equal to N2 loss (in urine, stool, fistula output etc). N2 balance may not always be achievable (in such cases aim to minimise N2 losses)

Protein needs-

• Maintenance- 0.75gm/kg/day (DoH 1991) – This overestimates protein needs in obese- so 75% of the estimated protein requirements should be use if BMI is > 30 and 655 if BMI>40
• Stress
  • Mild stress level: 1-1.2 g/kg/day
  • Moderate stress level: 1.2-1.5 g/kg/day
  • Severe stress level: 1.5-2 g/kg/day

  A more precise estimate of the N2 needs can be obtained by measuring 24 hr urinary urea. gm protein lost/24hr= mmoles urinary urea excreted in 24 hrs/5 (not reliable in liver or renal failure)

Carbohydrate (dextrose):   5 g/kg/day
Fat- 20-40% of the calorie requirements

Ref

1. Manual of Dietetic Practice.  By Briony Thomas, Jacki Bishop, British Dietetic Association. Blackwell Publishing, 2007 ISBN 1405135255, 9781405135252

Malnutrition Universal Screening Tool (‘MUST’) is an evidence based tool designed to identify adults, who are malnourished, at risk of malnutrition (undernutrition), or obese. NICE 2006 recommends the use of MUST

MUST has been developed for use in

• All adults (sick and healthy)
• Hospital inpatients
• Outpatients
• In the community

MUST is a five step screening tool;

Step 1

Measure height and weight to get a BMI score. If unable to measure height and/or weight, use alternative procedures;

If height cannot be measured
Use recently documented or self-reported height (if reliable and realistic).
If the subject does not know or is unable to report their height, use one of the alternative measurements to estimate height (ulna, knee height or demispan).
If height & weight cannot be obtained
Use mid upper arm circumference (MUAC) measurement to estimate BMI category.

Step 2
Note percentage unplanned weight loss and score using tables provided.
If recent weight loss cannot be calculated, use self-reported weight loss (if reliable and realistic).

Step 3
Establish acute disease effect and score.

Step 4
Add scores from steps 1, 2 and 3 together to obtain overall risk of malnutrition.

Step 5
Use management guidelines and/or local policy to develop care plan.

Ref

1. http://www.bapen.org.uk/musttoolkit.html

• Nutrition support should be considered in people who are malnourished, as defined by any of the following:
  • A body mass index (BMI) of less than 18.5 kg/m2
  • Unintentional weight loss > 10% within the last 3–6 months
  • A BMI of less than 20 kg/m2 and unintentional weight loss greater than 5% within the last 3–6 months.
• Nutrition support should be considered in people at risk of malnutrition, defined as those who have:
  • Anticipated or actual inadequate food intake by mouth for > 5 days.
  • A poor absorptive capacity  and/or high nutrient losses and/or increased nutritional needs from causes such as catabolism.

NB- Malnutrition Universal Screening Tool (MUST) is an evidence-based and easy-to-use tool for identifying malnutrition (see www.bapen.org.uk for more information)

What are the methods to provide artificial nutrition support?

• Oral nutrition support – for example, fortified food, additional snacks and/or sip feeds
• Enteral tube feeding (ETF) – the delivery of a nutritionally complete feed directly into the gut via a tube like NG/NJ tube, PEG or jejunostomy
• Parenteral nutrition – the delivery of nutrition intravenously.

How to select the most appropriate route of feeding?

The adage ‘if the gut works, use it’ is still valid. It is also cheaper, more physiological, less invasive and associated with less serious complications than parenteral feeding.

• Food fortification and supplementation represent the cheapest and safest methods of artificial nutritional support and are normally the most acceptable for the patient.
• ETF is indicated in patients who have inadequate or unsafe oral intake and a functional gastrointestinal tract.
• Consider gastrostomy or jejunostomy feeding if the patient is likely to need long term (4 weeks or more) ETF.
• Post-pyloric feeding by NJ tube may be advantageous in some patients.  The main advantage of post-pyloric feeding is a reduced risk of pulmonary aspiration of the gastric contents.
• Parenteral nutrition- indicated in the presence of a non-functional, inaccessible (like oesophageal obstruction) or perforated gastrointestinal tract.

Ref

1. NICE guidance: Nutrition support in adults
2. British Society of Gastroenterology Guidelines for enteral feeding in adult hospital patients
3. MUST toolkit

What supports nutritional support?

There is no doubt that a patient on complete starvation will die eventually. Similarly it is obvious that the alternative to tube feeding in complete dysphagia or to parenteral nutrition in intestinal failure is death within a finite time.

It is almost impossible to perform blinded studies of nutritional support versus no nutritional support due to obvious reasons.

It is therefore not a scientific question if nutritional support is necessary in starvation but rather to which degree may a patient be starved without increasing his risk or what is an adequate balance between the risks of artificial nutrition and the risks of starvation.

Although nutritional support therapy is exactly what it says—supportive rather than specific treatment of the underlying disease. It prevents the harmful effects of starvation while the underlying condition resolves. It is thus, only one facet of overall management and needs to be integrated properly into it. Shortcomings in other aspects of care may negate any benefits of nutritional support.

There is excellent evidence that undernutrition is an independent risk factor for higher morbidity, increased length of hospital stay, higher readmission rates, delayed recovery, lower quality of life as well as higher hospital costs and higher mortality.

How does the law regard enteral nutrition? Is it basic care or a medical treatment?

The law differentiates between oral intake and enteral tube feeding. While tube feeding is clearly considered therapy, oral nutritional supplements can be basic care as well as therapy.

What should be done in case of doubt whether enteral tube feeding will be beneficial
or when the prognosis of the underlying condition is uncertain?

If in doubt give a trial of treatment. This should be for a defined period agreed among all
members of the team and with the patient’s family and/or representative. Goals and criteria for continuing or discontinuing the feed should be agreed in advance.

Persistent vegetative state

In cases of severe brain damage where the prospect of recovery is extremely unlikely, how does the law regard withdrawal of food and fluid administration by tube?

The law was clarified by the Cuzan case in the US and by the Tony Bland case in the UK. The courts will not entertain an application to withdraw treatment within 12 months of the onset of the condition, by which time it becomes possible to determine whether the patient has lost all features of personhood although brain stem function persists
i.e. a persistent vegetative state. The court may then give permission for doctors to stop treatment, ‘if it is in the best interests of the patient’.

Ref-

1. ESPEN guidelines: