Malnutrition and Nutritional Assessment Flashcards
Why may malnutrition occur?
Starvation
Disease
Ageing
What is malnutrition?
A state resulting from lack of uptake or intake of nutrition
Leading to altered body composition and body cell mass
Leading to diminished physical and mental function and impaired clinical outcome from disease
In who is malnutrition most prevalent in?
Youngest and oldest adult age groups (over 65) - curvilinear (‘U’ shape) relationship as age increased
More common in women than men
Oncology and care of the elderly walls
Those with Gastrointestinal disease / dysfunction
Long term condtions e.g. diabetes
Chronic progressive conditions e.g. cancer or dementia
Those who abuse drugs or alcohol
What percentage of people admitted to hospital are malnourished at point of admission according to BAPEN?
1 in 3
33%
What percentage of people lose weight after discharge?
70%
Mainly fat-free (muscle) mass
Greatest weightloss seen in those undernourished upon admission
What factors exacerbate malnutrition (and consequently weight loss) during their stay at hospital?
Multi-factorial issue:
Disease related anorexia
Stress - increased demand of energy, proteins and micronutrients
What is disease related anorexia?
Loss of appetite as a result of pathophysiological mechanisms and modification of central regulation of feeding behaviour, which is observed in the presence of disease
Why is muscle broken down as a part of the weight loss from malnutrition in hospitals?
Metabolic response to stress = muscle breakdown to amino acids for gluconeogenesis and protein synthesis for the immune response and tissue repair
Why are patients with prior malnutrition more likely to experience significantly weight loss than others?
Patients with prior malnutrition who then develop acute illness have less reserve by which to face that illness
Why do people lose weight in hospital?
40% of food left on plate - less than 80% of the recommended protein and calorie intake by patients capable of eating
GI symptoms
Depression/Low mood
Quality of food
Lack of motivation
Food of secondary importance
Expectation / belief by patients of poor appetite during hospital stay, and appetite will return after discharge
What was the impact of malnutrition on recovery from surgery for duodenal cancer?
Post-op mortality 10x greater in those who had lost more than 20% of their body mass prior to surgery, than those who had lost less
Patients that are unable to mobilise adequate amounts of endogenous nitrogen in response to stress experience greater morbidity and mortality than those that are able to generate a catabolic response from adequate stores of muscle tissue
What did the ONS reveal about hospital deaths and malnutrition in 2016?
Direct cause 66 hospital deaths
Contributory factor 285 hospital deaths
How does malnutrition impact clinical outcomes?
Physical and function decline
Poorer clinical outcomes
Increased: Mortality Septic and post surgical complications Length of hospital-stay Pressure sores Re-admissions Dependency
Decreased: Wound healing Response to treatment Rehabilitation potential Quality of life
What is the cost of malnutrition in England per year?
£ 19.6 billion = 15% of total expenditure on health and social care
Mostly in secondary health care
How much more costly is it to treat a malnourished patient VS a well-nourished patient?
Health and social costs = 3x more in malnourished than well-nourished patients
What will happen to the costs of malnourishment in the future?
Rise - due to ageing population
How much can the NHS save yearly by identifying and treating malnutrition?
Up to 65 million
How is malnutrition diagnosed in acute settings?
Malnutrition universal screening tool (MUST) - most commonly used in the UK to screen for adult’s malnutrition
A simple tool to identify risk - based on BMI, unplanned weight loss and presence of acute disease
Carried out by any HCP
This is not assessment or diagnosis
Categorises individuals as low, medium and high risk of malnutrition
Provides immediate guidelines based on category
When is MUST used?
Malnutrition screening required within 6hrs of hospital admission and weekly thereafter
What are the limitations of MUST?
Can miss malnourished in clinical populations e,g. overhydration (ascites, oedema)
What happens when a patient triggers as a result of the MUST screening process?
Referred to dietitian for assessment of nutritional and functional status
What is nutrition assessment?
A comprehensive evaluation carried out by a registered dietitian for defining nutrition status
Uses anthropometric measurements, biochemical data, medical, social and nutritional histories, and physical examination
A systematic process of collecting & interpreting information to determine the nature and cause of the nutrient imbalance
Need to gather adequate info to make nutritional judgement
What is anthropometry?
Measurement of body
What is conducted in a anthropometry assessment?
Scale for weight - recent unplanned changes in weight reflect acute changes in protein energy status = associated with increased length of stay, morbidity and mortality
BMI is insignificant - due to influence of gender, ethnicity and age being ignored
Midarm muscle circumference - assessment of lean body mass = reduced length of hospital stay and improved functional ability
Multifrequency bioelectrical impedance analysis - renal and haematology patients
CT for muscle content and fat and their distribution - expensive and radiation
Hand grip strength - reflects upper extremity muscle strength, which responds earlier to malnutrition - muscle strength independent of muscle mass can predict morbidity and mortality
(reduction in mortality risk per 1kg increase in handgrip strength)
What biochemistry is used?
Forms part of nutritional assessment
Tests used to estimate nutrient availability in fluid and tissues = critical to assess clinical nutrient deficiencies
Measurements of micronutrients - expensive, therefore must have justified reason to request this
What can skew the results of the biochemistry tests used to determine micronutrient measurements?
Acute inflammatory response skews response
Therefore, not measured until CRP =< 10 micrograms /L
What is relevant from a medical history?
What is included in a nutritional / dietary history?
Alcohol and drug use Increased metabolic needs Increased nutritional losses Chronic disease Recent major surgery or illness Surgery of GI tract esp.
Anorexia Loss of sense of taste / smell Excessive alcohol intake Poor fitting dentures Allergies Fad dieting Usual patterns of food intake Chewing or swallowing problems Aversions Cultural, religious, ethical Dietary restrictions
Why might the social history of a patient also be relevant for a dietitian?
Socioeconomic status = ability to purchase food independently
Physical or mental disabilities
Eating alone
What is indirect calorimetry?
How is it carried out / measured?
Most reliable method to measure energy expenditure and guide energy prescription
Measurement of resting metabolic rate using a respirator gas exchange canopy
What are the limitations of indirect calorimetry?
What is used instead?
Restricting in clinical practice
Predictive equations estimating metabolic rate are used in clinical practice instead, to determine estimated energy requirement
What is the use of predictive equations clinically?
Predict (estimate) resting metabolic rate = used to calculate nutritional requirement based on patient’s gender, weight, height, and level of physical activity
What are limitations of the predictive equations?
So what are they used for actually in clinic?
Low to moderate performance = best reaching accuracy of 70%
Used as a baseline to determine first set of nutrition requirements - assessment of status determined nutritional diagnosis, outcomes, and intermediate goals
What is nutritional requirement?
Average dietary intake that is predicted to maintain energy balance in an adult of a defined age, gender, weight, height and physical activity
What is done once malnutrition has been diagnosed?
Plan
Implement
Monitor
Evaluate
When should nutrition support be considered according to NICE guidelines?
- Patients who are malnourished =
- A BMI of < 18.5 kg/m2 or
- Unintentional weight loss >10 % past 3 - 6 / 12 or
- BMI < 20 kg/m2 + unintentional weight loss > 5 % past 3 – 6 / 12.
- At risk of malnourishment =
- Have eaten little or nothing for > 5 days and / or are likely to eat little or nothing for the next 5 days or longer or
- Have a poor absorptive capacity, and / or have high nutrient losses and/or have increased nutritional needs from causes such as catabolism.
What is artificial nutrition support?
The provision of enteral or parenteral nutrients to treat or prevent malnutrition
What is used to decide how malnutrition is treated?
What is the first line of delivery of treatment?
Stratton and Elia flowchart is used
If oral route is safe and possible - always first and preferred approach
Cases where oral route is not possible - is GI tract function and accessible? If so, enteral (tube to gut) feeding needs to be considered. If GI tract = non functional or accessible, parenteral (drip into blood)nutrition is then considered
What implications does enteral nutrition have?
Ethical and Legal
ESBEN have guidelines on the ethical aspects of artificial nutrition and hydration
Why is enteral support superior to parental?
Enteral = uses the gut
Where parental nutrition is used, aim to return to enteral (oral feeding) as soon as clinically possible
How is access decided for enteral feeding?
Is gastric feeding possible?
Yes = Naso-gastric tube (NGT) No = Naso-duodenal (NDT) / naso-jejunal tube (NJT)
Long term (> 3 months) = Gastrostomy / jejunstomy tube can be inserted
Who determines the type of nutritional feed to put down the feeding tube?
Dietitian
Nutritional feed dependent on multiple factors –> renal, low sodium, respiratory, immune, elemental, peptide
What are the complications associated with enteral feeding?
Misplaced NGTs (21 deaths and 79 cases of harm between 2005-2011)
Mechanical - misplacement, bloackage, buried bumper
Metabolic - hyperglycaemia, deranged electrolytes
GI -aspiration, nasopharyngeal pain, laryngeal ulceration, vomiting, diarrhoea
What is done clinically when an NGT is placed?
When an NGT is placed, an aspirate needs to be obtained from the tube indicating a pH of 5.5 or less = reflects gastric contents (acidity) in the stomach
If pH >5.5, a chest x-ray is indicated
What is parenteral nutrition?
Parenteral nutrition (PN): The delivery of nutrients, electrolytes and fluid directly into venous blood
When is this used?
An inadequate or unsafe oral and/or enteral nutritional intake
OR
A non-functioning, inaccessible or perforated gastrointestinal tract
How is access for parenteral nutrition gained?
.
Central venous catheter (CVC): inserted into the subclavian, jugular or femoral veins, with tip at superior vena cava and right atrium
Or peripherally inserted CVCs at the antecubital dossea, with tip still at the superior vena cava
Different CVCs for short / long term use
Where can CVCs be inserted?
Subclavian
Jugular
Femoral
Antecubital fossa
What is the parenteral nutrition bag composed of?
Composed by dietitian
Ready made or prescribe a “scratch” bag
MDT and dietitian decide on fluid and electrolyte targets for that day
What are the complications associated with parenteral nutrition?
Mechanical = begins during insertion Pneumothorax Haemothorax Thrombosis Cardia arrhythmias Thrombus Catheter occlusion Thermophlebitis Extravasion
Metabolic = begins once starting the feed Deranged electrolytes Hyperglycaemia Abnormal liver enzymes Oedema Hypertriglycerideamia
Catheter-related =
Infections / septicemia
How does nutrition support benefit the malnourished patient?
Lowers mortality
Reduction in readmission
Weight increase
Significantly better outcomes - including all-cause mortality, intensive care unit admission, non-elective hospital readmissions, major complications, and functional status at day 30
What is albumin?
Most abundant circulating protein in the plasma of healthy individuals
Albumin synthesised in the liver - 10-15g produced daily
Low plasma albumin = poor prognosis
A negative acute phase protein = decreased plasma albumin when increased inflammation
What is albumin synthesis stimulated by?
Albumin synthesis is stimulated by hormones e.g. insulin, cortisol and GH (growth hormone)
What is albumin synthesis inhibited by?
Pro-inflammatory substances eg. IL-6, tumour necrosis factor (TNF)
What happens in acute inflammatory phase?
Inflammatory stimulus = activation of monocytes & macrophages = release cytokines
Cytokines act on liver to stimulate production of some proteins whilst downregulating production of others e.g. albumin
Albumin levels decrease - additionally from degradation and transcapillary loss
Is albumin a valid marker of malnutrition in the acute hospital setting?
No
Albumin synthesis reduces in response to inflammation - therefore not a valid marker of nutritional statur nor an indicator for nutritional intervention in the acute setting
Best evidence = hypoalbuminaemia in obese trauma patients
Dietitian focused on the aetiology / impact of the inflammatory state on nutritional status rather than albumin levels
What is refeeding syndrome?
A group of biochemical shifts & clinical symptoms that can occur in the malnourished or starved individual on the reintroduction of oral, enteral or parenteral nutrition
What happens in the body during starvation?
During starvation, body aims to utilise energy stores:
- Reduction in insulin secretion
- Increase in glucagon secretion to produce glucose
- Glycogen stores in the liver, amino acids in the skeletal muscle = metabolised into glucose
- There deplete within 24-72hrs, metabolism shifts to derive energy from ketone production due to free fatty acids being released from fat stores
Decrease in basal metabolic rate - brain adapts to using ketone bodies instead of glucose - results in loss of fat mass
Reduce energy expenditure by reducing action on cellular pumps - electrolytes are then able to leak across cell membrane = increase in extracellular water, total body water and Na+; but depletion in K+, Mg2+, and phosphate
Serum concentrations are maintained, but intracellular stores are depleted
Sodium and fluid leak into cells = leads to sodium and fluid intolerance
Micronutrient stores = depleted
Thiamine deficiency likely as it is water soluble and the body has limited stores
Why is the shift to using free fatty acids so important?
Shift spares skeletal muscle breakdown and fat free mass is preserved to an extent
What happens when carbohydrate is reintroduced after starvation?
Secretion of insulin - stimulates Na+/K+ ATPase pump activation - required Mg2+ as a co-factor
This drives potassium and phosphate into cells, and sodium and fluid out of cells into the ECF
Phosphate driven into cells = energy storage as ATP
ATP =
increased cellular uptake of glucose, magnesium, potassium and phosphate and subsequent reduction in extracellular concentrations
Thiamine = coenzyme in carbohydrate metabolism and deficiency can occur on refeeding in a vitamin B depleted patient
Increased uptake of solutes
Lower electrolytes in plasma - clinical manifestations
Carbohydrates = reduce sodium and fluid excretion = expansion of ECF resulting in refeeding oedema and fluid overload
What are the consequences of Refeeding syndrome?
Arrhythmia, tachycardia,
Congestive heart failure - lead to cardiac arrest, sudden death
Respiratory depression
Encephalopathy, coma, seizures, rhabdomyolysis
Wernicke’s encephalopy
According to NICE what are the criteria for defining the risk for refeeding syndrome (RFS)?
At risk: very little or no food intake for > 5 days
High risk: one or more of
- BMI less than 16 kg/m”2
- Unintentional weight loss greater than 15% within the last 3–6 months
- Very little or no nutritional intake for more than 10 days
- Low levels of potassium, phosphate or magnesium prior to feeding
OR high risk: two or more of
- BMI less than 18.5 kg/m”2
- Unintentional weight loss greater than 10% within the last 3–6 months
- Little or no nutritional intake for more than 5 days
- A (PMH) history of alcohol abuse or drugs including insulin, chemotherapy, antacids or diuretics
Extremely high risk:
- BMI less than 14 kg/m^2
- Negligible intake for more than 15 days
What is the management for RFS?
Start with 10-20 kcal/kg
Of that, 40-50% of the energy will be carbohydrates
Micronutrients given from onset of feeding
Monitor and replace electrolytes daily following Trust policy
Administer thiamine from the onset of feeding following Trust policy - first dose fiven 30 mins before onset of initial feeding
Monitor fluid shifts and minimise risk of fluid and Na+ overload
