Artificial Feeding Flashcards
What percentage of patients are malnourished on acute admission to A and E?
40%
What percentage of patients are malnourished on discharge from hospital?
70%
The percentage increases from when the patient enters the hospital to when they leave
What happens if someone goes down to 30% of their normal body weight?
60% of people who reach this level will die
In a healthy person, how many days does it take for total starvation to occur?
between 60 and 70 days
if a small amount of food is allowed, the period of starvation is prolonged
In an ill person, how long would it take for 60% of patients to die from partial starvation?
between 30 and 40 days
What is the difference in the time it takes for a patient to die from complete starvation if they are healthy and if they have undergone trauma, infection or major surgery?
In a normal fit adult, complete starvation leads to death within 2 months
After trauma, infection or major surgery, starvation will lead to death in 1 month
what are the physical consequences of starvation?
- reduced muscle mass and function
- increased risk of chest infections
- difficulty in weaning from ventilator
- reduced cardiac output
- reduced motility which leads to bedsores and risk of DVT/PE
What are the immune consequences of starvation?
- impaired immune system leads to an increased risk of infection
- altered gut function leads to translocation of gut bacteria
What are the physiological consequences of starvation?
- depression
- apathetic tendencies
- irritability
- reduced mental concentration
How is malnutrition assessed in adults?
The malnutrition universal screening tool (MUST)
What does the malnutrition universal screening tool (MUST) assess?
Current malnutrition as well as malnutrition risk
This is whether someone is likely to become malnourished whilst in hospital
When is MUST carried out and how often is it repeated?
It is carried out within 24 hours of admission to hospital
It is then repeated weekly
What are the three trigger questions involved in MUST?
- has the patient lost weight recently?
- has the patient noticed a reduction in their appetite?
- will this admission have an impact on the patient’s nutritional uptake?
If the answer to any of the questions is yes, MUST should be carried out
What 3 measurements are involved in MUST?
- body mass index (BMI)
- recent weight loss as a percentage
- acute illness with, or likely to be, no nutritional intake for 5 days
How are the measurements taken in MUST scored?
BMI is scored between 0 and 2 points
Weight loss is scored between 0 and 2 points
No intake for the previous 5 days is scored either 0 or 2
What is considered a low, medium and high risk MUST score?
0 out of 6 is a low risk
1 out of 6 is a medium risk
greater than or equal to 2 is a high risk
What happens to patients who score 1 or more on MUST?
They are put on a food chart
What happens to patients who score 2 or more on MUST?
They are monitored as high risk patients
What are 4 common medical conditions that put patients at a high risk of malnutrition?
- swallowing problems
- poor absorption from the gut
- high nutrient losses
- increased nutritional needs
What is a common misconception about malnutrition?
Someone who is overweight or has a healthy BMI may still be malnourished
What are anthropometric assessments and what do they measure?
They measure fat
This involves measuring tricep skinfold thickness
or mid-arm circumference and mid-arm muscle circumference
What biochemical assessment is usually used in assessing malnutrition?
Blood test to measure serum albumin levels
Why are serum albumin levels measured in malnutrition?
It is not a marker of poor nutrition
albumin is a negative acute phase protein, so levels of albumin go down with sepsis
What else may be measured in the blood of a patient with malnutrition?
Levels of vitamins and trace elements
What does the amount of calories required depend on?
When calculating the amount of calories, what group equations are used?
amount of calories depends on physical stress and amount of physical activity
there are equations for each age group, gender and clinical condition
What do nutritional requirements ensure?
Patients get enough fat, protein and carbohydrate
They must also have sufficient levels of electrolytes, vitamins and minerals
What 3 categories of patients should have artificial nutrition?
- patients who cannot eat as they cannot swallow
- patients who cannot eat enough
- patients who shouldn’t eat
What type of patients cannot eat as they cannot swallow?
Stroke patients
Patients who have had head and neck surgery
What type of patients cannot eat enough?
usually patients who have sepsis or severe burns
what type of patients shouldn’t eat?
patients with a bowel obstruction, leaks after surgery and prolonger paralytic ileus
What is the preferred route for artificial feeding?
If the gut is functioning, it is always the preferred route for artificial feeding
What are 4 simple measures in place in hospital to prevent patients from becoming malnourished?
- encouragement to eat meals
- protected meal times
- red trays
- the consistency of food is changed to help patients with swallowing difficulties
What is meant by ‘protected meal times’ and ‘red trays’?
protected meal times mean that patients cannot be disturbed during the time they are eating, unless it is an urgent test
red trays are used to identify patients who cannot reach food placed at the end of their bed
What are oral nutrition supplements?
What is their nutritional value?
200ml bottles of fluid for patients struggling to consume food
each bottle has 340 kcal and 20 g of protein
it also contains 1/5 daily requirement for vitamins and minerals
What are the 2 types of artificial feeding?
Enteral and parenteral
What is enteral feeding?
Feeding into the gut
It requires a functioning gut
What types of patients will have enteral feeding?
- patients with persistent and poor oral intake
- patients with dysphagia (difficulty swallowing)
- patients who have had a head injury with prolonged recovery
What are the types of short-term enteral feeding?
how long are they used for?
Naso-gastric or a naso-jejunal feed
Nasal tubes are used for less than 4 weeks
What is involved in a naso-gastric feed?
A flexible, narrow tube enters the nose and sits in the stomach
When is a naso-jejunal feed used?
the tube sits in the jejunum, rather than the stomach
it is used if there is a gastric outlet obstruction or delayed emptying of the stomach
What are the two methods used in longer-term enteral feeding?
- percutaneous endoscopic gastrostomy (PEG)
2. Radiologically inserted gastrostomy (RIG)
What equipment is used in a PEG?
Why must this equipment be used?
It starts as a normal endoscopy, with a bright light at the end of the tube
If light can be seen from outside the stomach, then there is no part of the bowel that will be speared by the needle
What happens in a PEG?
A small opening through the skin of the upper abdomen, directly into the stomach, is made
A feeding tube can then placed and secured in the stomach
When is a RIG used?
Why is it used?
When patients have cancer in the upper GI tract
The pulling technique used in PEG has a risk of pulling cancer cells into the stomach
What is the basic procedure involved in a RIG?
Air is used to inflate the stomach, which is then pulled towards the abdominal wall
What is parenteral feeding?
Feeding through through a vein
What is the name of the type of nutrition used when the gut is not accessible?
Total parenteral nutrition
What is the difference in treatments if patients are having artificial feeding acutely and in the long-term?
Acutely - often solely parenteral nutrition
Long-term - may be a mixture of oral, parenteral and enteral feeding
What are the two requirements for parenteral nutrition?
In which patients is it normally used?
- there is an inability to establish any other route for nutrition
- there is an inability to meet nutritional requirements via the oral or enteral route
It is usually used when there is an obstruction in the GI tract
What 3 conditions usually lead to patients requiring parenteral nutrition?
- patients with short bowel syndrome
- fistulae, often between the bowel and skin
- patients who have had complications post-surgery
What are the 6 components of the parenteral nutrition feed?
- proteins
- glucose
- fats
- electrolytes
- vitamins
- trace elements
all components are made up to match an individual patient’s requirements
What electrolytes are included in a parenteral feed?
- sodium
- potassium
- calcium
- magnesium
- phosphate
What vitamins are included in a parenteral feed?
Both fat-soluble and water-soluble vitamins
What trace elements are included in parenteral feed?
- zinc
- selenium
- manganese
- copper
- iron
What types of veins are used as a route of insertion for intravenous feeding?
Either basilic or cephalic veins
What types of intravenous feeding techniques are used for short, medium and long-term feeding?
Short-term: peripheral feeding (midline)
Medium-term: central feeding (PICC)
Long-term: Tunnelled lines - Hickman
What is involved in peripheral feeding (midline)?
A long cannula is placed into a small arm vein
Feeding is done peripherally
what is involved in central feeding (PICC)?
A peripherally inserted central catheter enters the arm, but feeds into a large vein with fast-moving blood
What is involved in a tunnelled line (Hickman)?
A central line is inserted into the chest and tunnelled under the skin
Why is the Hickman line tunnelled under the skin?
To reduce the infection rate as it can stay in for up to 10 years once inserted
What lung condition can result from a Hickman line and why?
Pneumothorax
This occurs when the line damages the lung and causes it to rupture
What leads to a Hickman line infection and what do TPR charts show in this case?
If a line sits next to a stoma bag
TPR charts show fast pulse, high temperature and fast respiratory rate
Why is contrast fluid used when inserting an intravenous feeding line?
Putting in the line can puncture the outside of the vein
Contrast fluid can help to identify whether any of the contrast is outside of the vein
What is thrombophlebitis?
This occurs when the Hickman line irritates the vein and causes it to become inflamed
Why are patients on parenteral nutrition often given insulin?
Parenteral nutrition may result in high blood sugar levels as all of the daily blood sugar is given in a 12-hour period
Insulin prevents the risk of diabetes
What is refeeding syndrome (too much too soon) characterised by and who does it often affect?
characterised by fluid and electrolyte shifts
usually affects malnourished patients, those with no recent intake and alcoholics
In starvation, what does the absence of carbohydrates lead to?
Decreased insulin secretion and increased glucagon secretion
What is the main source of energy in starvation and why?
All of the glycogen stores are used up so the brain switches from using glucose to ketones
What are the consequences of ketones becoming the main source of energy?
- basal metabolic rate declines
- overall reduced lean body mass
- the brain adapts to using ketones, but there is atrophy (become smaller) of all other organs
What trace elements are most affected in starvation?
Potassium, magnesium and phosphate
They move out of the cells to try and protect the serum concentration
what happens to the movement of potassium, magnesium and phosphate as soon as feeding is recommenced?
The electrolytes go back into the cells causing the serum electrolyte levels to plummet
In refeeding, what is there an immediate increased uptake of?
What are the effects of this?
Increased uptake of glucose, potassium, phosphate and magnesium
It causes serum levels to plummet
What enzyme is re-activated when refeeding commences?
Sodium-potassium pump
This begins to move potassium back in to cells
It moves sodium and water out of cells
what happens in refeeding when carbohydrates begin to be consumed?
The body switches from catabolism to anabolic growth
What are the consequences of increased thiamine utilisation in refeeding?
Acute thiamine deficiency
Patients tend to act as if they are drunk
If this is not treated, it leads to irreversible loss of short-term memory
What are the consequences of re-feeding?
- low phosphate
- low potassium
- low magnesium +/- calcium
- low thiamine (Wernicke-Korsakoff’s)
- High glucose
- cardiac failure, pulmonary oedema and dysrhythmia
What drug is used to treat patients who are at risk of re-feeding syndrome?
What does it prevent?
Pabrinex
It is an IV version of vitamin B, vitamin C and thiamine
It prevents Wernike-Korsakoff’s syndrome
In what other ways is re-feeding syndrome avoided?
- patients are fed slowly, and this is built up over time
2. potassium, phosphate and magnesium levels are measured daily and abnormalities are corrected
What type of measurements are taken daily in long-term monitoring of parenteral nutrition?
- temperature
- pulse
- blood pressure
- weight measurements
- blood sugars are taken every 6 hours
What other tests are performed in long-term monitoring of parenteral nutrition?
- full blood count, U&E, magnesium and calcium readings taken daily at first
and then
- calcium, magnesium, phosphate and LFTs are performed 3 times a week
Which trace elements are given regularly in long-term monitoring of parenteral nutrition?
copper, zinc and selenium
