Nutrition Flashcards
Components of clinical assessment of nutrition
- history
- examination
- what to measure
History
- Wt. loss
- Diet
Examination
- Skin fat
- Dry hair
- Pressure sores
- Cheilitis (inflammation of the lip) → B6 deficiency
Measure
- weight and BMI
- Skin-fold thickness
- Arm circumference
Calorie requirements per kg weight for 24hours
20-40 kcal/kg/24 hours
How many g of carb, fat, protein is required per kg of a body mass in 24 hours?
Requirements (/kg/24h)
- Calories: 20-40 Kcal
- Carb: 2g
- Fat: 3g
- Protein: 0.5-1g
Possible routes of delivery of enteral nutrition
- oral → is best
- Fine bore NGT
- Percutaneous Endoscopic Gastrostomy (PEG)
- Jejunostomy
*Build up feeds gradually to prevent diarrhoea
What type of diet should we consider if there is a risk of aspiration?
Semi-solid
Indications for supplemental feeds
- Catabolic: sepsis, burns, major surgery
- Coma/ITU
- Malnutrition
- Dysphagia: stricture, stroke
Indications for use of a feeding tube
- used for individuals who have a functioning gastrointestinal (GI) tract but cannot ingest enough nutrients orally to meet their current needs
- tube feedings can be used as the sole source of nutrition or in combination with oral intake
What’s meant by enteral nutrition?
Enteral nutrition (EN) is the use of the GI tract for feeding
Advantages of using enteral nutrition
- GI tract should be used if possible because it tends to atrophy when not used
- Gut bacteria can translocate to the circulatory system through an atrophied GI tract and increase the risk for infection
What’s Parenteral nutrition?
Parenteral nutrition (PN) is the use of a site outside the GI tract, specifically, the circulatory system, for feeding
The general rule for deciding whether to use enteral or parenteral feeding is, “If the gut works, use it”
Specific indications for tube feeding
- Protein-energy malnutrition with inadequate oral nutrient intake for 5 or more days
- Less than 50% of required nutrient intake orally for 5-7 days
- Severe dysphagia
- Coma
- Low output enterocutaneous fistulas
Contraindications for enteral nutrition
- Intestinal obstruction, ileus, or hypomotility of the intestine
- Severe diarrhea
- High output enterocutaneous fistulas
- Severe acute pancreatitis or shock
- When prognosis does not warrant aggressive nutritional support
(3) types of transnasal tube feeding
Most commonly, feeding tubes are inserted through the nose and positioned to deliver formula into:
- the stomach (a nasogastric)
- the duodenum (a nasoduodenal)
- jejunum (a nasojejunal)
When to use the ostomy as a feeding route?
- ostomy can be used if there is a blockage in the GI tract -the ostomy would be created below the site of the blockage
- an ostomy (opening) can be surgically created so that the tube can be directly placed into the: esophagus (esophogastomy), stomach (gastrostomy ), or jejunum (jejunostomy)
Alternatives to surgical ostomies (2)
Alternatives to the classic surgical ostomies includemthe placement of the tube via:
- a needle catheter jejunostomy
- via a percutaneous endoscopic gastrostomy
Complications of tube feeding (just name)
- dumping syndrome
- regurgitation
- aspiration pneumonia
- diarrhoea and dyhadration
- Feed intolerance → diarrhoea
- Electrolyte imbalance
- Aspiration
- Refeeding syndrome
Why the use of a feeding tube may lead to regurgitation?
- the formula may enter the stomach much faster than it is emptied
If fluids are regurgitated and enter the lungs, a fatal infection or aspiration penumonia
Complications of NG tube use
- Nasal trauma
- Malposition or tube blockage
Indications for parenteral nutrition use
- Prolonged obstruction or ileus (>7d)
- High output fistula
- Short bowel syndrome
- Severe Crohn’s
- Severe malnutrition
- Severe pancreatitis
- Unable to swallow: e.g. oesophageal Ca
How is parenteral nutrition delivered?
- location
- short-term
- long - term
- Delivered centrally as high osmolality is toxic to veins
- Short-term: CV catheter
- Long-term: Hickman or PICC line
What to monitor with parenteral nutrition route use?
- standard monitoring
- initial monitoring
- monitoring when patient is stable
Line-related complications of parenteral nutrition (4)
- Pneumothorax / haemothorax
- Cardiac arrhythmia
- Line sepsis
- Central venous thrombosis → PE or SVCO
Feed - related complications of parenteral nutrition (7)
- Villous atrophy of GIT
- Electrolyte disturbances
- Refeeding syndrome
- Hypercapnia from excessive CO2 production
- Hyperglycaemia and reactive hypoglycaemia
- Line sepsis
- Vitamin and mineral deficiencies
Refeeding syndrome
- definition
Refeeding syndrome
• Life-threatening metabolic complication of refeeding via any route after a prolonged period of starvation
Chemistry picture in Refeeding syndrome
↓K, ↓Mg, ↓PO4
Pathophysiology in Refeeding Syndrome
Pathophysiology
Before refeed:
- ↓ carbs → catabolic state c¯ ↓insulin, fat and protein
- catabolism and depletion of intracellular PO4
When refeeding
- ↑ insulin in response to carbs and ↑ cellular PO4 uptake → hypophosphataemia
Hypophosphataemia leads to:
- Rhabdomyolysis
- Respiratory insufficiency
- Arrhythmias
- Shock
- Seizures
Patients at risk of Refeeding syndrome (5)
- Malignancy
- Anorexia nervosa
- Alcoholism
- GI surgery
- Starvation
Prevention of Refeeding syndrome (2)
- Identify and monitor at-risk patients
- Liaise with dietician
Treatment of Refeeding syndrome
- Identify at-risk pts in advance and liaise with dietician
- Parenteral and oral PO4 supplementation
Pathophysiology of Dumping Syndrome
Dumping syndrome
- early: food of high osmotic potential moves into small intestine causing fluid shift
- late (rebound hypoglycaemia): surge of insulin following food of high glucose value in small intestine - 2-3 hours later the insulin ‘overshoots’ causing hypoglycaemia
Why diarrhoea and dehydration are more common in transpyloric feeding?
- Transpyloric feedings (delivered beyond the pyloric sphincter) to the duodenum and jejunum
- diarrhea and dehydration may occur if the formula enters the intestines too rapidly
- less likely to cause regurgitation
What materials (2) are most feeding tubes make of and why?
Silicon or polyurethane feeding tubes are commonly used:
- they are soft, flexible, and small in diameter
- they do not harden or corrode with exposure to gastric juice
What are (3) basic types of enteral formulas?
intact, hydrolyzed, and modular
Components and use of intact enteral formulas
Intact formulas
(aka polymeric formulas)
Components: unaltered molecules of proteins, carbohydrates, and fats
Use: best for people who can digest and absorb nutrients without difficulty
Components and use of hydrolyzed formula
(aka monomeric formulas)
Components: predigested proteins and simple carbohydrates, plus a small amount of oil or a blend of medium chain triglycerides (MCTs) and oil
Use:
- patients who lack the ability to digest or have a small absorptive area
- patients with feeding tubes in the lower GI tract
- patients that require bowel rest
Modular formula
- what is this
- disadvantage of use
Modular formula is:
- an incomplete liquid supplement
- contains specific nutrients, usually a single macronutrient (carbohydrate, protein or fat)
Disadvantage: Modular diets can be tailored to an individual’s needs but are generally complex to design, and may fail to meet all of the patient’s nutritional needs
What’s the calorie content of most ‘intact formulas’?
- Most intact formulas contain about 1 kcalorie per ml
- Some formulas are designed for those who need more kcalories and protein in a smaller volume of fluid and contain 1.5 to 2 kcals per ml
Can patients who have lactose intolerance take enteral formulas?
Most formulas are available as lactose free preparations
What types of protein do enteral formulas contain?
Enteral formulas contain:
- high biological value protein such as casein, lactalbumin, and soy protein isolate
What are Special Enteral Formulas?
Special formulas → to meet the needs of patients with specific medical problems
When to use Glutamine-Supplemented formula?
- The amino acid glutamine transports nitrogen throughout the body, including skeletal muscle nitrogen which is released during catabolism
- Glutamine concentrations in the blood and muscles fall during stress (trauma, burns, sepsis, surgery),
- Glutamine uptake is particulary high in the GI tract during stress → more glutamine required during stress-inducing conditions
- Glutamine is a source of fuel for the GI tract and controls glycogen synthesis and protein breakdown
- To keep the GI tract healthy during stress, glutamine supplementation may be beneficial.
- Special enteral formulas with added glutamine are available.
Contraindication (1) for glutamine supplementation formulas
- patients with liver disease → especially if blood ammonia concentrations are high
Methods of administration of tube feeding (3)
- Continuous Drip Feeding → administrated via gravity or a pump (usually better tolerated than bolus)
- Bolus Feeding → allow for more mobility than continuous drip feedings because there are breaks in the feedings, allowing the patient to be free from the TF apparatus for activities such as physical therapy
- Combination → continuous drip (at night) and bolus feedings (during the day)
Rate of administration of continuous drip vs bolus feeding
What should be checked before the next feed administration and why?
What rate the formula should be administrated at?
- Formulas should be administered slowly
- at first about 50 ml per hour → then increased by 25 ml per hour every 8-12 hours as tolerated until the required volume of formula is met
- A typical final rate is 100-125 ml /hr.
Signs of intolerance of the formula feed and what could be done?
- Signs of intolerance #: diarrhoea, nausea, vomiting, dehydration and cramping
- the rate should be slowed and/or concentration should be diluted until tolerance is achieved
What can increase the chances of intolerance to the formula-fed and development of e.g. diarrhoea? (2)
- hypoalbuminaemia
- antibiotic therapy
How to position the patient for formula feed?
Continuous drip and bolus feedings:
The patient’s head should be elevated at least 30 degrees during and after the feeding to prevent regurgitation.
Tube feeding into the intestine: positioning is not critical.
Why should we avoid giving medication via feeding tube?
- pill particles may clog the tube
What should we do before administering a liquid medication via a feeding tube?
The feeding tube should be flushed with 30 ml of water or saline before and after administration of a drug
Can medication be added to the feeding tube formulas?
- Some medications can be added to the TF formula
- drug-nutrient interactions may occur
- some drugs can cause the formula to clump and clog the feeding tube
The average daily kcal requirement for female and male in the UK is?
Female 1940 kcal
Male 2550 kcal
What’s the ideal % proportions of (carbs, fats, proteins) in the diet?
Carbs 50%
fats 35%
protein 15%
What’s the total energy expenditure?
Basal metabolic rate + physical activity
What vitamin(s) deficiency could be seen in:
- alcoholics
- small bowel disease
- liver and biliary tract disease
- Alcoholics: B1
- Small bowel: B12
- Liver and biliary: A D E K
Water requirement per day for an average female and male
- male 2.0L
- female 1.6 L
- severe malnutrition - BMI <15
- moderate malnutrition - BMI 15-19
BMI of :
- an overweight person
- obese
- overweight 25-30
- obese >30
What’s metabolic syndrome?
3 out of 5:
- central obesity
- diabetes type 2
- HTN
- low HDL (hyperlipidaemia)
- raised triglicerides
