Download Nutritional Support

Department of Biochemistry
Faculty of Pharmacy
Suez Canal University
Nutritional Support
 Oral, enteral or parenteral nutrition support, alone or
in combination, should be considered for all people
who are either malnourished or at risk of malnutrition.
Nutritional support
 Nutritional support should be considered in people
who are malnourished, as defined by any of the
following:
1. A body mass index (BMI) of less than 18.5 kg/m2.
2. Unintentional weight loss greater than 10% within
the last 3-6 months.
3. A BMI of less than 20 kg/m2 and unintentional
weight loss greater than 5% within the last 3-6
months.
Nutritional support
 Nutritional support should be considered in people at
risk of malnutrition, defined as those who have:
1. Eaten little or nothing for more than 5 days and/or
are likely to eat little or nothing for 5 days or longer.
2. A poor absorptive capacity.
3. High nutrient losses.
4. Increased nutritional needs from causes such as
catabolism.
Nutritional requirements
1) Water
 For most patients, allow 1,500 ml for the first 20 kg of
body weight plus 20 ml for every kg after this, and
replace additional losses as they occur.
Nutritional requirements
2) Energy
 This can be estimated by multiplying body weight in
kg by 30-35 kcal.
 In obese patients, use ideal body weights.
Nutritional requirements
3) Protein
 Most patients need 0.8-1.2 g of protein/kg/day.
 In moderate-to-severe stress, up to 1.5 g/kg/day are
required.
 Use ideal weight for patients with significant obesity.
Nutritional requirements
4) Electrolytes and minerals
 There is a large number of essential electrolytes and
daily requirements will need to be given to the patient.
 There is also a need for adequate vitamins and trace
minerals, usually supplied by premixed enteral
solutions (lower quantities are needed in parenteral
nutrition).
Nutritional requirements
5) Essential fatty acids
 2.4% of total calories should be given as linoleic acid.
 In parenteral nutrition, give at least 250 ml 20%
intravenous fat 2-3 times weekly.
Nutritional support
 Enteral or parenteral nutrition may be required for
patients with prolonged unconsciousness, inability to
swallow, intestinal failure, following major
gastrointestinal (GI) surgery or in aggressive
chemotherapy with severe inflammation of the mouth.
 Where possible, Enteral nutrition is preferred because
it is less invasive, has a lower risk for infection, and is
safer than the parenteral method.
Routes of Nutritional Support
 The nutritional needs of patients are met through a variety
of delivery routes and with an array of nutritional
formulation components and administration equipment.
1) Enteral nutrition (EN)
 Long-term nutrition: (Gastrostomy, Jejunostomy)
 Short-term
nutrition:
(Nasogastric
feeding,
Nasoduodenal feeding, Nasojejunal feeding)
2) Parenteral nutrition (PN)
 Peripheral Parenteral Nutrition (PPN)
 Total Parenteral Nutrition (TPN)
Parenteral nutrition
Specific indications for parenteral
nutrition
1.
2.
3.
4.
5.
6.
Complete mechanical intestinal obstruction.
Ileus or intestinal hypomotility.
Severe uncontrollable diarrhoea.
Severe acute pancreatitis.
High-output fistulae.
Shock.
 In patients who require immediate support but are
expected to improve within 1-2 weeks, peripheral
vein nutritional support can be given via standard
intravenous (IV) lines.
Parenteral nutritional support systems
 Basic solution comprises dextrose, amino acids and
water.
 Typical solution contains 25-35% dextrose and 2.756% amino acids, together with minerals, vitamins and
trace elements and fat emulsion (20%).
 Usually given at 30 ml/hour on day one and 60
ml/hour on day two.
Parenteral nutritional support systems
 Provides adequate protein but usually inadequate
energy that must be supplemented with intravenous
lipids, as described earlier.
 IV fat is increasingly used in patients with large
energy requirements, to prevent excess administration
of dextrose.
Complications of parenteral nutrition
 Malposition of central
possible pneumothorax.
venous
catheter
and
 Catheter blockage from reflux of blood into the
catheter.
 Infections.
 Hyperglycaemia, especially if the rate of infusion is
not properly regulated.
Enteral nutrition
Enteral feeding
 Patients who are able to sit up in bed and can protect
their airways, can be fed into the stomach.
 Feeding tubes can be placed directly into the GI tract.
Enteral nutritional support systems
 A wide range of commercially prepared solutions is
available.
 In most cases, isotonic solutions containing no lactose
or fibre are preferred.
 They generally contain 1,000 kcal and 37-45 g of
protein/litre.
Enteral nutritional support systems
 Preparations also available with elemental solutions
containing hydrolysed proteins or crystalline amino
acids without significant fat content for patients
with
malabsorption,
especially
pancreatic
insufficiency. They are highly hypertonic and can
cause severe diarrhoea.
Complications of enteral nutrition
 The most common complications are nausea
or vomiting, abdominal bloating and cramps,
diarrhoea and constipation.
 Unconsciousness and impaired swallowing or
vomiting may cause aspiration pneumonia, also
caused by reflux.
 Metabolic disturbances can occur, e.g. rebound
hypoglycaemia after sudden withdrawal.
 Blocked tubes.
Nutritional support
 Hydration state and overall clinical status needs daily
assessment, with nutrition adjusted accordingly.
 There is also the need to measure electrolytes, serum
glucose, phosphorus, magnesium, calcium and creatinine
and urea daily until stabilised.