Explainers

Nutritional Status Assessment of the Critically Ill Patient


Malnutrition, including erosion of lean body mass and depletion of essential nutrients, is very common in critically ill patients as their nutrition status declines (Ziegler 2009).

Malnutrition is associated with an impaired immunologic function, and malnourished patients have poorer outcomes after medical treatment or surgery (Leonard 2009).

Early nutritional support should, therefore, be assessed as soon as possible, preferably upon admission, with ongoing monitoring for all critically ill patients to ensure individual needs are identified and catered for to improve outcomes (Singer & Webb 2005).

Importance of Assessing Nutritional Status

The aim of assessing a patient’s nutritional status is to:

  • Evaluate pre-existing hydration and nutritional conditions;
  • Identify any hydration and nutrition-related complications that could affect the outcome;
  • Determine the patient’s nutritional requirements;
  • Maintain the optimum level of intake and promote adequate utilisation of hydration and food to promote growth, healing and recovery.

(Cresci 2005)

Factors that Affect Nutritional Status in Critically Ill Patients

The most common factors that can affect nutritional status in critically ill patients include:

  • The patient may be unable to drink and eat;
  • Vomiting and diarrhoea;
  • Constipation;
  • Glucose intolerance;
  • Renal dysfunction;
  • Pain;
  • Physical disability;
  • Restricted fluid intake;
  • Reduced gut motility;
  • Fasting before procedures/investigations.

(Jevon 2012)

Assessing a Critically Ill Patient’s Nutritional Status

All patients should undergo nutritional screening on admission to hospital or healthcare settings (NICE 2006). You should follow your local policies and protocols to identify patients at risk of malnutrition and dehydration.

Steps for appropriate management include:

1. Screening:

The screening process categorises patients into groups and those at ‘risk patients’.

A nutritional care plan should be developed, and referral for nutritional support made to an expert/dietitian for more detailed assessment (Kondrup et al. 2003a).

The most widely used screening tool is the malnutrition universal screening tool (MUST)(Russell and Elia 2011). ‘MUST’ is a screening tool used in hospitals, communities and other healthcare settings. It’s a tool used to identify adults who are malnourished, at risk of malnutrition, or obese and it includes management guidelines that can be used to develop a care plan. (Malnutrition Advisory Group 2004).

2. Assessment:

A full examination of nutritional, metabolic and functional variables should be conducted, and consideration paid to patient history, current medication, laboratory results and patients’ ability to swallow and bowel function.

The assessment should provide information leading to an appropriate care plan (Mallet 2013).

3. Monitoring and Outcome:

The effectiveness of the nutritional intervention should regularly be monitored, leading to adjustments in treatment as necessary throughout the patient’s stay.

4. Communication:

Screening and assessment results and the developed nutritional care plan should be communicated to other health professionals when the patient is transferred somewhere else.

Modes of Feeding in Critically Ill Patients

Oral nutrition is generally considered the first line method, but patients who cannot tolerate oral feeding can be fed enterally or parenterally. The route used will depend on:

  • If the patient has a functioning GI tract system;
  • Which route is appropriate;
  • How long feeding will be required.

(Mallet 2013)

Enteral feeding:

Enteral feeding is feeding patients liquid feed via a tube placed in the stomach or post-pyloric and is a route of choice for critically ill patients where oral feeding is not possible. This method is used if a patient has a functional and accessible GI tract (NICE 2006).

Routes of Enteral Feeding

  • Nasogastric: a tube through the nose into the stomach.
  • Nasoduodenal: a tube through the nose into the duodenum.
  • Nasojejunal: a tube through the nose into the jejunum (Marshall & Boyle 2007).
  • Percutaneous endoscopic gastrostomy (PEG): PEG tubes should be considered when enteral feeding is necessary for four weeks or more (NICE 2006).

Best Practice for Enteral Feeding

  • Adhere to best practice feeding protocols.
  • Always confirm tube position before the commencement of feed.
  • Always flush tubes before and after administration of medications.
  • Monitor tube position during feeding regularly.
  • Monitor the patient’s vital signs, particularly the airway.
  • Keep the head of the bed elevated to 30-45 degree while administrating feed to reduce the risk of aspiration.
  • Increase feed to meet nutritional requirements following local guidelines.
  • Ensure feed is in date and administered following manufacturer’s recommendations.
  • Monitor absorption of feed and follow the prescribed feeding regime.
  • Maintain fluid balance.
  • Monitor bowel function.
  • Monitor patient’s blood chemistry.

(Jevon 2012)

Parenteral Nutrition:

Parenteral nutrition involves the intravenous infusion of nutrients. It is administrated via a single dedicated lumen either peripherally, via a PICC line, or centrally, via a CVP line.

This route is used when oral and or enteral nutrition is unable to fully meet the patient’s nutritional requirements or when enteral nutrition is contraindicated (Ziegler 2009).

Best Practice for Parenteral Feeding

  • Only use when enteral route is not possible.
  • Do not use feed bag if there are signs of contamination.
  • Administer feed following local protocols.
  • Ensure that entire infusion line is dedicated to the parental nutritional use.
  • Ensure that feed and tubing are regularly changed.
  • Never add anything to a bag of TPN.
  • Monitor patient’s blood chemistry.
  • Monitor blood sugar 2-hourly when first initiated.
  • Avoid breaks in the circuit.
  • Monitor patient for complications of parental nutrition, particularly infection.
  • Regularly flush line when not in use to maintain patency.

(Jevon 2012)

Conclusion

Nutritional status should be assessed and regularly monitored in all critically ill patients. The method of nutritional support should also be closely monitored, in particular, the patients’ tolerance of it.

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Reference

  • Cresci, GA 2005, Nutrition Support for the critically ill Patient, Boca Raton: Taylor & Francis.
  • Jevon, P, Ewens, B & Pooni, JS 2012, Monitoring the Critically Ill Patient, 3rd edn, John Wiley & Sons Ltd. Chichester.
  • Kondrup, J, Allison, SP, Alia, M, Vellas, B & Plauth, M 2003, ‘ESPEN Guidelines For Nutrition Screening’, Clinical Nutrition, vol. 22, no. 4, pp. 415-21, viewed 20 June 2018, http://espen.info/documents/screening.pdf
  • Kondrup, J, Rasmussen, HH, Hamberg, O, Stangam Z & Ad Hoc ESPEN Working Group 2003b, ‘Nutritional risk screening (NRS 2002): A new method based on an analysis of controlled clinical trials’, Clinical Nutrition, vol. 22, no. 3, pp. 321-36, viewed 20 June 2018, https://www.ncbi.nlm.nih.gov/pubmed/12765673
  • Leonard, R 2009, ‘Enteral and Parenteral nutrition’, in: Bersten, AD & Sons, N (eds), Oh’s Critical Care Manual, 6th edn, Philadelphia, PA: Butterworth Heinemann Elsevier.
  • Mallet, J, Albarran, J & Richardson, R 2013, Critical care Manual of Clinical Procedures and competencies, Oxford: Wiley-Blackwell.
  • Malnutrition Advisory Group 2004, Malnutrition Universal Screening Tool, Redditch: BAPEN.
  • Marshall, A & Boyle, M 2007, ‘Support of metabolic function’, in: Elliot, R, Aitken, LM & Chaboyer, W (eds), ACCCN’s Critical Care Nursing, Marrickville, NSW: Mosby Elsevier.
  • National Institute for Health and Care Excellence 2012, Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition, NICE, viewed 20 June 2018, https://www.nice.org.uk/guidance/cg32
  • Russell, CA & Elia, M 2011, Nutrition screening survey in the UK and Republic of Ireland in 2010, Redditch: BAPEN.
  • Scott, A, Skerrat, S & Adam, S 1998, Nutrition for the critically ill: A practical handbook, London: Arnold.
  • Singer, M & Webb, A 2005, Oxford Handbook of Critical Care, 2nd edn, Oxford: Oxford University Press.
  • Ziegler, TR 2009, ‘Parenteral nutrition in the critically ill patient’, New England Journal of Medicine, vol. 361, pp. 1088-97.

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