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Definitions. Food : - is defined as any solid or liquid which when ingested will enable the body to carry out any of its life function. Most foods are made up of several simple substances, which we call nutrients . There are six nutrients each of which has specific function - PowerPoint PPT PresentationTRANSCRIPT
DefinitionsDefinitionsFoodFood: - is defined as any solid or liquid which when ingested will
enable the body to carry out any of its life function.Most foods are made up of several simple substances, which we
call
nutrientsnutrients. There are six nutrients each of which has specific function
in the body. Those that supply energy are the carbohydrates and fats.
Those responsible for growth and repair of tissues cells are proteins.
Those, which regulate chemical process in the body, are the vitamins
and minerals. Water is present in most foods and is an indispensable
component of our bodies. It is the means of transportation for mostnutrients and is needed for all cellular activities.
Why human beings need Why human beings need food?food?
Human beings need food to provide energy for the essentialphysiological functions like:-.. Respiration.. Circulation.. Digestion.. Metabolism.. Maintaining body temperature... Growth and repair body Tissues
CarbohydratesCarbohydrates
• Ready fuel for energy, less expensive and Nitrogen sparing effect.
• RBCs, WBCs and renal medulla require glucose and brain prefers glucose as fuel.
• Disadvantages: excess carbohydrates inc. , Glucagon secretion and Insulin resistance
• Severe hyperglycemia in sepsis (impaired utilization).• Excessive glucose -› fat -› Hepatic Steatosis• Excess glucose inc. CO₂ production -› pulmonary work load.
Fats Fats • Provide energy• Regulation of Cardiovascular tone ( PGs)• Components of cell membranes ( Phospholipids)• Cellular messengers (Phosphoinositides)• Immune function• Linoleic acid: essential fatty acid
should provide 4% of total calorie intake
Fats continued…Fats continued…
• Diets high in linoleic acid - immunosuppressive Low intake – improves immune function• Deficiency of linoleic acid: eczema like rash, neutropenia
and thrombocytopenia.• ω-6 and ω-3 PUFA are essential fatty acids.• ω-6 PUFA – ω-3 PUFA ratio should be 1:1.
Proteins Proteins • Minimum intake: 0.5g/kg/day• Intact digestion : intact protein diet• Impaired digestion: peptides (< 10 amino acids) based diet
advantageous (dec. diarrhoea, improved wound healing and inc. protein synthesis).
• Restrict proteins if BUN > 100mg/dl and rising or elevated NH₃ assoc. with encephalopathy.
Water and Water and electrolyteselectrolytes
• 25ml/kg dry body weight of fluids to avoid dehydration.• Adults : 1ml/kcal consumed; Infants: 1.5ml/kcal consumed• K, Mg, PO₄ and Zn in amounts to maintain normal serum
levels.• RDA for all vitamins and minerals usually provided in 1000 –
1500 ml of most enteral formulas.
Intravenous Vitamins: RDI Intravenous Vitamins: RDI Vitamin• Thiamine (B1) 6 mg• Riboflavin (B2) 3.6 mg• Pyridoxine (B6) 6 mg• Cyanocobalamin (B12) 5 mcg• Niacin 40 mg• Folic acid 600 mcg• Pantothenic acid 15 mg• Biotin 60 mcg• Ascorbic acid (C) 200 mg• Vitamin A 3300 IU• Vitamin D 5 mg• Vitamin E 10 IU• Vitamin K 150 mcg
Mineral requirementsMineral requirementsMineral Recommended
Daily Intake: Enteral
Recommended Daily Intake: Parenteral
Sodium 90 – 150 mEq 90 -150 mEq
Potassium 60 – 90 mEq 60 -90 mEq
Magnesium 350mg 10 -30 mEq
Calcium 1000mg 10 – 20 mEq
Phosphorus 1000mg 10 – 35 mmol
The energy requirementsThe energy requirementsThe energy requirements of individuals depend on
♦ Physical activities♦ Body size and composition
♦ Age may affect requirements in two main ways– During childhood, the infant needs more energy
because it is growing– During old age, the energy need is less because aged
people are engaged with activities that requires lessenergy.
♦ Climate: Both very cold and very hot climate restrict outdooractivities.
In general feeding is dependent on the controlling centres, appetiteand satiety in the brain. There are a variety of stimuli, nervous,
chemical and thermal, which may affect the centres and so alterfeeding behaviour.
Calculation of daily Calculation of daily requirementrequirement
• Sample calculation for 60 kg, stable, euvolemic pt. with good urine output and moderate stress
• Fluid requirement: 35ml/kg = 2100 ml/day• Calories: 25kcal/kg = 1500 kcal/day• Proteins: 1g/kg = 60 g/day = 240 kcal/day (4kcal/g)• Fats: 30% of total calories = 450 kcal/day = 50g fat(9kcal/g)• Carbohydrates: 1500 – (240+450) = 810kcal = 202.5g of
dextrose (4kcal/g)
Convert requirements Convert requirements into prescriptioninto prescription
• Determine volume of lipid emulsion: 10% lipid emulsionFluid volume reqd. = Amt. of substance(gm) X 100
Conc. Of substance(%) Volume of lipid
emulsion = 50/10 x 100 = 500 ml
• Determine volume of amino acid infusion: 10 % solutionVolume of amino acids = 60/10 X 100 = 600 ml
• Selection of dextrose infusion: in remaining 1000 ml volume, 202.5g dextrose needs to be infused.1000 = 202.5 X 100 Conc. of subst.
• Concentration of substance = 202.5/1000 X 100 = 20.25% = 20% approx.
• Prescription: Pt. needs 500ml of 10% lipid emulsion600ml of 10% amino acid and1000 ml of 20% dextrose
StarvationStarvation• Adult volunteers
o Fasted for 30-40 days: 25% weight loss
o More prolonged fasting: 50% weight loss
• Weakness
• Apathy
• Reduced work capacity; cardiorespiratory failure
• Total starvation is fatal in 8 to 12 weeks
Assessing Nutritional StatusAssessing Nutritional Status• Focused nutrition history• Assess current weight and weight-loss
history• Physical examination• Assess malabsorption
− Fecal fat test− Schilling test − Hydrogen breath test− D-xylose
Assessing Nutritional Status:Assessing Nutritional Status:SGA – Subjective Global SGA – Subjective Global
AssessmentAssessmentA. History• Weight change
<5% = “small”5–10% = “potentially significant” >10% = “definitely significant”
• Change in dietary intake• Gastrointestinal symptoms
(nausea, vomiting, diarrhea, anorexia)
• Functional capacity• Disease and its relation to nutritional
requirements
B. Physical
Anthropometric measurements Loss of subcutaneous fat
Muscle wasting
Ankle edema
Sacral edema
Ascites
C. SGA Rating A = Well nourished
B = Moderately malnourished
C = Severely malnourished
Nutritional assessment….Nutritional assessment….• Body Mass Index: Height, Body weight etc. Unreliable• Biochemical Data: • S.Proteins and S. Albumin: index of visceral and somatic
protein stores. Hypoalbuminemia: Overhydration, inc. catabolism Decreased synthesis ( liver ds.) Increased loss ( burns, large wounds,
etc)• Note: S. Albumin level serve as a marker for initial nutritional
state. It does not serve as marker for improved nutritional state following nutritional support.
• S. Transferrin, TBPA, RBP and Fibronectin Transferrin- Half life 8 days TBPA Half life 2 days RBP Half life 12 hrs Fibronectin Half life 12 hrs
Can be used as markers of improved nutritional status. Limitation : Costly
• S.Electrolytes, Renal and Hepatic function tests, Pulmonary function tests.
Timing of nutritional supportTiming of nutritional support• Nutritional support should be started before effects of
starvation appear.• Note : In acute hypercatabolic critical illness, stabilization of
hemodynamics and correction of fluid, electrolytes and acid base status takes precedence over nutrition.
Routes of feedingRoutes of feeding
Enteral nutritionEnteral nutrition• If the bowel works, use it.• More physiologic, safe and less expensive.• Preserves gut integrity, barrier and immune function.• Supplies gut preferred fuels (glutamine, glutamate and short
chain fatty acids), unlike standard PN.• Prevents cholelithiasis by stimulating GB motility.• Recommendation :Initiation within 24-48 hrs of ICU
admission in hemodynamically stable pts.
Indications of Enteral Indications of Enteral nutritionnutrition
• Malnourished patients whose oral intake is poor for 3 – 5 days.
• Well nourished patients with poor oral intake for 7 – 10 days.• Inability to eat adequately ( oropharyngeal lesions,
oesophageal lesions etc.)• Following massive small bowel resection.• Enterocutaneous fistulae with output < 500ml/day.
Indications continued… Indications continued… • Severe full thickness burns (early enteral feeds limit
sepsis and reduce protein loss from bowel)• Following major upper GI surgery ( Total gastrectomy,
Total oesophagectomy, feeds through jejunostomy tubes).
• Following surgery for necrotizing suppurative pancreatitis ( initial TPN is followed by jejunostomy or nasojejunal feeds following recovery of bowel function).
Contraindications of Contraindications of Enteral nutritionEnteral nutrition
• GI causes: severe diarrhoea, paralytic ileus, intestinal obstruction, severe GI bleeding, acute pancreatitis and high output external fistula.
• Cardiac causes: haemodynamic instability, low cardiac output, circulatory shock. Potential risk of GI ischemia.
• Lack of access: unobtainable safe access to GIT.• Complications of enteral feeding: aspiration, severe diarrhoea
and intestinal ischemia or infarct.
Routes of enteral Routes of enteral nutritionnutrition
Jejunal feeding is likely to be the best
Starting tube feedsStarting tube feeds
Gastric feedingGastric feedingAdvantages:
•Stomach initiates digestion
•Gastric acid secretion sterilizes gastric contents
( risk of bacterial contamination reduced)
•Stomach protects gut from osmotic load (motility reduced in presence of hyperosmolar
fluid and diluted till isoosmolar )
Disadvantages:•Development of
gastric atony
•Risk of aspiration of gastric contents
Monitoring of gastric residual volume
every 2-4 hrs:
mandatory
Monitoring of gastric residual volume
every 2-4 hrs:
mandatory
Complications of Complications of enteral feedingenteral feeding
Tube Related•Malposition•Displacement•Blockage•Breakage/leakage•Local complications (eg. Erosion of skin/mucose)Gastrointestinal•Diarrhoea•Bloating, nausea, vomiting•Abdominal cramps•Aspiration•Constipation
Complications of Complications of enteral feedingenteral feeding
Metabolic/bio-chemical•Electrolyte disorder•Vitamin, minirals, trace elements deficiencies•Drug interactionsInfetive•Exogenous (handling contamination)•Endogenous (patient)
Parenteral nutritionParenteral nutrition
• Definition : Total parental nutrition (TPN) is defined as
the provision of all nutritional requirement by means of the intravenous route and without the use of the gastrointestinal tract.
Indications of parenteral Indications of parenteral nutritionnutrition
• General indicationso Inadequate oral or enteral nutrition for atleast 7-10 days
(ASPEN and CCPG). ESPEN: initiate within 24-48 hrs of ICU pts who can’t be fed
enterallyo Pre existing severe malnutrition with inadequate oral or
enteral nutrition.• Anticipated or actual inadequate oral or enteral intakeo Conditions that impair absorption of nutrients: Enterocutaneous fistula
Common Indications for Common Indications for PNPN
• Inability to absorb adequate nutrients via the GI tract :o Massive small-bowel resection / short bowel syndromeo Severe, untreatable steatorrhea / diarrhoea / malabsorptiono Complete bowel obstruction, or intestinal pseudo-obstructiono Prolonged acute abdomen or ileus
• Severe catabolism & GI tract unusable within 5–7 days• Enteral access not feasible, not adequate or not tolerated• Pancreatitis with intolerance (eg pain) of jejunal nutrition• High output EC fistula (>500 mL) & no distal enteral
access
Short bowel syndrome Small bowel obstruction Effects of radiation or chemotherapyo Need for bowel rest: Severe pancreatitis Inflammatory bowel disease Ischemic bowel Peritonitis Pre and post op statuso Motility disorders: Prolonged ileus
o Inability to achieve or maintain enteral access:
Haemodynamic instability Massive GI bleeding Unacceptable aspiration risk Hyperemesis gravidarum, eating disorders• Significant multiorgan system disease Significant renal, hepatic or pulmonary disease Multiorgan failure, severe head injury, burns etc.
Parenteral Nutrition TeamParenteral Nutrition TeamPossible MembersPossible Members
• Nutritionist – expertise across PN, EN, short bowel• Pharmacist – with nutritional / PN expertise• Physician – with nutritional expertise• Specialist Nutrition Support Nurse• Support groups
o Vascular access team – PICC lineso Diagnostic imaging – Central lines / portso Infectious diseaseso Enterostomal therapyo Surgery
St. Bartholomew’s Hospital/Science Photo Library
Delivering parenteral Delivering parenteral nutritionnutrition
Peripheral IV: short-linePeripheral IV: short-linePROS• Least expensive• Easily placed and
removed• Lowest risk for CRI• Beneficial for short-term
support (< 1 week)
CONS• Need to change often
o Every 48-72h
• Phlebitis and vein injury• Only one lumen• Limits energy delivery
o Volumeo Osmolality (600-900 mOsm/l) o pH restriction (pH 5-9)
Central parenteral Central parenteral nutritionnutrition
• Most efficient way to deliver all the nutrients by central venous catheter inserted in SVC or IVC.
• Composition: varied compositionConc. forms of dextrose(50-70%) and amino acids (8.5-10%). Osmolarity 1000-1900 mosm/l
• Selection of catheter for CPN: Polyurethane(for short term use) or silicon rubber(mths to yrs)
Peripherally Inserted Central Peripherally Inserted Central Catheter (P.I.C.C.) LineCatheter (P.I.C.C.) Line
Tip in SVC
O
• More expensive than peripheral lines
• More difficult to place
• Last up to 6 - 12 months
• Restrict arm movement
• Allow higher osmolarity “Central” TPN solutions
Systems for delivering Systems for delivering PNPN
Multiple bottle systemMultiple bottle system
•Flexible and easy to adjust.
•Needs proper monitoring to avoid Hyperglycemia and
hypertriglyceridemia•Higher risk of
incompatibility due to improper mixing of
nutrients.
Multiple bottle systemMultiple bottle system
•Flexible and easy to adjust.
•Needs proper monitoring to avoid Hyperglycemia and
hypertriglyceridemia•Higher risk of
incompatibility due to improper mixing of
nutrients.
3 in1 system3 in1 system
•Most efficient method of PN
•Convenient, cost effective•Less chances of infection
•Less metabolic complications
•Less flexibility in changing contents.
•Lesser stability d/t lipids.
3 in1 system3 in1 system
•Most efficient method of PN
•Convenient, cost effective•Less chances of infection
•Less metabolic complications
•Less flexibility in changing contents.
•Lesser stability d/t lipids.
• Continuous parenteral nutrition:• Recommended in acute, critical and hospitalized pts.• Advantages: slow continuous infusion avoids volume
overload, hyperglycemia and hypertriglyceridemia.
• Cyclic parenteral nutrition: • PN delivered over 8-12 hrs. • Effective for stable, chronically ill pts. needing nutrition
support. Eg. Home PN.• Avoid in: Glucose intolerance and fluid overload
Clinical data monitored Clinical data monitored dailydaily
• History: fever, h/s/o fluid overload or glucose and electrolyte imbalance.
• Vital signs: Temp., HR, BP, RR• Fluid balance: input/output chart, weight• Local care: inspection and dressing of site of vascular
access.• Delivery system: inspection of solution for contamination
and functioning of infusion pump.
Laboratory dataLaboratory dataFingerstick glucose test 3 times daily until pt. stable
Blood glucose, Na, K, Cl, HCO₃, BUN
Daily until glucose infusion load and pt. stable, then twice
weekly
LFT, S.Creatinine, albumin, PO₄, Ca, Mg, Hb/Hct, WBC
Baseline, then twice weekly
Clotting, INR Baseline, then weekly
Micronutrient test As indicated
Monitoring response to nutritional therapy:Improvement in clinical status, Protein concentrations
(Albumin, prealbumin, transferrin)
Complications of parenteral Complications of parenteral nutritionnutrition
Mechanical Metabolic/ GI Infectious
First 48 hrs.
Malposition, Haemothorax,
Pneumothorax, Air embolism, Blood loss,
Puncture of Subclavian/ Carotid
Art.
Fluid overload, Hypoglycemia,
Hypophosphatemia, Hypokalemia,
Hypomagnesemia, Refeeding syndrome
_ _
First 2 weeks
Catheter displacement, Thrombosis,
occlusion, Air embolism
Hypoglycemic coma, Acid base and
Electrolyte imbalance
Catheter induced sepsis, Exit site
infection
3 months onwards
Tear of catheter, catheter thrombosis, Air embolism, blood
loss
Ess. FA def., Vitamins or trace
element def, Metabolic bone ds.,
Liver ds.
Tunnel infection, Catheter induced sepsis, Exit site
infection
Metabolic Complications of Metabolic Complications of
Parenteral Nutrition – 1Parenteral Nutrition – 1
• Electrolyte imbalanceoNa, K, Mg, PO4, Ca
• Hyperglycemia / hypoglycemia
• Dehydration
• Fluid Overload
• Metabolic Acidosis
Metabolic Complications of Metabolic Complications of
Parenteral Nutrition - 2Parenteral Nutrition - 2
• Hyperlipidemia
• Hypercapnea
• Vitamin/trace element deficiencies
• Essential fatty acid deficiency
• Liver dysfunction
Hepatic DiseaseHepatic Disease• Cholestasis (incl “sludge) + Hepatocellular disease
• Impaired hepatic transulfurationo Transulfuration products facilitate:
• Fat mobilisation
• Lipid membrane stability
• Bile secretion
• May progress to liver failure / transplantation• Treatment: - do not overfeed
- ursodeoxycholic acid- enteral supplements- carnitine
Metabolic Bone DiseaseMetabolic Bone Disease• Pre-existing disease & malabsorption• Aluminium contamination• Inadequate calcium provision• Excess Vitamin D in TPN
- measure both 25-OH & 1,25 DHCC• Monitor DEXA, Ca++, Vit D, PTH,
Albumin
Possible ComplicationsPossible Complications
Associated with Long-Term TPNAssociated with Long-Term TPN
• Gastrointestinal dysfunction
• Trace element deficiencies
• Hepatic steatosis/cholestasis
• Metabolic bone disease
• Psychosocial difficulties
• Financial difficulties