nutricion en uci

1. Nutrition in ICU
Hani Sammour, MD, PB
Anesthesia and IC, Shifa hospital
Critical Care

2. • Diets are composed of nutrients: macronutrients (protein, fats and
carbohydrates) and micronutrients (vitamins, minerals and trace
elements).
• Malnutrition is caused by an imbalance (deficiency or excess) of
energy, protein and other nutrients.
• Malnutrition leads to adverse effects on tissue/body form, function
and clinical outcome.

3.  Preserving tissue mass.
 Decreasing catabolism and usage of endogenous nutrient stores.
 Maintaining or improving organ function (immune, renal, hepatic
systems; muscle, maintaining gut barrier.
 Improve wound healing & decrease infection rate.
 Decreasing morbidity and mortality & overall outcome and LOS.
Goals of nutritional support for critically ill patients

4. Consequences of malnutrition
 Underfeeding :
- Loss of muscle mass
- Reduced respiratory function
- Reduced immune function
- Poor wound healing
- Gut mucosal atrophy
- Reduced protein synthesis

5. Consequences of malnutrition
 Overfeeding:
- Increased oxygen consumption (VO2)
- Increased CO2 production (VCO2)
- Hyperglycemia
- Fatty infiltration of liver

6. Starvation
• ++ Glycogenolysis ( stores depleted within 24 hrs)
• ++ Lipolysis (Glycerol “glycolysis”& F. A. “ketosis”)
• ++ Gluconeogenesis
(a.a “glutamine , alanine,” F.A, )
• Neurons, RBCs, renal medulla utilize glucose normally
• Glucose administration decreases protein catabolism & ketosis

7. Nutritional Assessment Tools
• No single standard way of assessing nutritional status.
• Various validated assessment tools developed:
– Some disease specific
– Some age specific
• Example:
Subjective Global Assessment (SGA)
Mini Nutritional Assessment (MNA)

8. DIAGNOSIS OF MALNUTRITION
o Anthropometric measurements:
(e.g. skin fold thickness, mid-arm circumference). These are unreliable
due to weight gain/loss, fluid shifts and edema.
o Biochemical tests:
- Albumin falls as part of the acute phase response,
- Hemoglobin may be affected by disease process, hemorrhage,
transfusion, hemolysis, bone marrow suppression,
o Body Mass Index:
BMI = mass (kg) / height (m)2
Although low BMI is a predictor of higher mortality in ICU, acute
changes do not accurately reflect nutritional status.

9. Timing of Nutritional Support
• Data suggest that outcome can be improved with early and
optimal nutritional support.
• Current recommendations include initiation of nutritional
support within the first 24 to 48 hours after admission to the
ICU.

10. • The average REE is approximately 25 kcal/kg IBW/day
• IBW male = 50 + 2.3 × (Ht Inch - 60)
• IBW female = 45.5 + 2.3 × (Ht Inch - 60)
• Caloric requirement of the critically ill patient is higher as they are hypercatbolic
according to the stress factor:
• Trauma: REE ×1.3
• Sepsis: REE ×1.5
• Burn: REE ×2 (especially if extensive and deep)
Caloric requirement and composition

11. • Mixture in which total daily kilocalories are split into 20% protein,
30% lipids, and 50% carbohydrates
• Most patients require 1 to 1.5 g/kg of protein daily or 7-14 g of
nitrogen daily (6.25g of protein contains 1g of nitrogen).
• Patients with organ failure or disease may have increased or
decreased needs and should be considered individually.
Caloric requirement and composition

12. Quantity of nutrient
 Calories
- Lipids provide 9 kcal/g
- Carbohydrates provide 4 kcal/g
- Proteins provide 4 kcal/g.

15. Daily requirement of water and electrolytes

16. Working example
Calculate the caloric requirement and composition for an 80 kg
patient who is having sepsis in ICU.
• REE = 80 × 25 = 2000 Kcal/day
• Requirement in sepsis = 1.5 × 2000 = 3000 Kcal/day
• Composition: 50% carbohydrates (1500 Kcal) “1500 ml D25%”
30% lipids (900 Kcal) “500 ml Intralipid 20%”
20% protein (600 Kcal) “750 ml Aminosol 20”

18. What is the preferred feeding method
• Oral feeding is the optimal route of nutritional support.
• However most ICU patients are incapable or intolerant of oral diet and
are therefore fed enterally or parentrally
• Enteral nutrition is required for optimal gut function & maintenance of
gut barrier .
• Enteral nutrition is less expensive than parenteral nutrition.
• Enteral nutrition is the preferred route of nutritional support in both
pediatric and adult patients.

19. • Parenteral nutrition is indicated when enteral nutrition is not
possible, for example :
• Intestinal obstruction/perforation.
• Non-functioning gut, prolonged ileus
• High output gastrointestinal fistula.
• Esophageal/gastric surgery.
• TPN is not superior to enteral nutrition in patients with
inflammatory bowel disease or pancreatitis.
Enteral vs Parenteral nutrition

20. Enteral nutrition
- Enteral nutrition should be started within the first 24-48 hours of
admission (unless contraindicated).
- Routes include naso-gastric, naso-duodenal/jejunal, gastrostomy and
jejunostomy.
- Enteral feeding provides a more complete diet than parenteral
nutrition, maintains structural integrity of the gut, improves bowel
adaptation after resection and reduces infection risk.

22.  Feed composition
- Most patients tolerate iso-osmolar, non-lactose feed.
- Carbohydrates are provided as sucrose or glucose polymers.
- Protein as whole protein or oligopeptides
- Fats as medium chain (better absorbed) or long chain triglycerides.

23. - Feed is formulated at 1 Cal/ml .
- Special feeds are available, e.g. high fiber, high protein-calorie,
restricted salt, high fat or concentrated (1.5 or 2Cal/ml) for fluid
restriction.

24. - Confirm tube position
- Secure tube well and check site regularly for potential tube
dislodgment.
- Start feeding early.
- Aspirate regularly (4 hourly) and accept gastric residual volumes
of 200ml.
Important steps to ensure adequate enteral nutrition

25. • Patient should be head-up tilt at least 30°.
• Avoid bolus feeds.
• Use prokinetics early: metoclopramide 10mg IV 8 hourly +/-
erythromycin 75mg IV 6 hourly.
• Consider switch to post-pyloric tube feed.
Development of diarrhea associated with tube feeding needs further
evaluation.
Minimize aspiration risk

26. - Once a decision is made to start enteral nutrition, 30ml/h full strength
standard feed may be started immediately.
- After 4h at 30ml/h the feed should be stopped for 30min prior to aspiration
of the stomach.
- It is reasonable to accept an aspirate of <200 mL as evidence of gastric
emptying, and therefore to increase the infusion rate to 60mL/h.
- If the gastric aspirate volume is >200ml the infusion rate is not increased
but the feed is continued
Management of enteral nutrition

27. • Bolus: 300 to 400 ml rapid delivery via syringe several times
daily
• Intermittent: 300 to 400 ml, 20 to 30 minutes, several times/day
via gravity drip or syringe
• Cyclic: via pump usually at night
• Continuous: via gravity drip or infusion pump
Methods of Enteral Nutrition Administration

28. • Tube placement: tracheobronchial intubation, nasopharyngeal
perforation, intracranial penetration (basal skull fracture), oesophageal
perforation.
• Reflux
• Pulmonary aspiration
• Nausea and vomiting
• Abdominal distension
Complications of Enteral feeding

29. • Diarrhea: large volume, bolus feeding, high osmolality, infection,
lactose intolerance, antibiotic therapy, high fat content.
• Constipation
• Metabolic: dehydration, hyperglycaemia, electrolyte imbalance.
Cont.

30. Feed composition
- Carbohydrate is normally provided as concentrated glucose.
- 30–40% of total calories are usually given as lipid (e.g. soya bean
emulsion).
- The nitrogen source is synthetic, crystalline L-amino acids which
should contain appropriate quantities of all essential and most non-
essential amino acids.
Parenteral nutrition

31. • Carbohydrate, lipid and nitrogen sources are
usually mixed into a large bag in a sterile
pharmacy unit.
• Vitamins, trace elements and appropriate
electrolyte concentrations can be achieved in a
single infusion, thus avoiding multiple
connections.

32. Formulation of TPN

33. • Central venous
- A dedicated catheter (or multilumen catheter) is placed under
sterile conditions
- For long-term feeding, a subcutaneous tunnel is often used .
- This may reduce the risk of infection and clearly identifies the
special purpose of the catheter.
Choice of parenteral feeding route

34. - Ideally, blood samples should not be taken nor other injections or
infusions given via the feeding lumen.
- The central venous route allows infusion of hyperosmolar
solutions, providing adequate energy intake in reduced volume.

35. Peripheral venous
• Parenteral nutrition via the peripheral route requires a solution with
osmolality <800 mOsmol/kg.
• Either the volume must be increased or the energy content
(particularly from carbohydrate) reduced.
• Peripheral cannula sites must be changed frequently.
Peripheral PN

36. Peripheral PN
• 5 -10 % Glucose
• 3 - 4 % A.A.
• 1 % Lipids
• Osmolarity :not exceeding 800 mOsm/Litre
Unfortunately, volume restriction usually limits caloric
intake to only 1500-1800 Kcal/day . Thus, given for short
period

37. • Catheter related: misplacement, infection, thromboembolism
• Metabolic:-- / ++ CHO, Fat, Protein, electrolytes, vitamin
• Fluid excess
• Hyperosmolar, hyperglycemic state
• Rebound hypoglycemia: (abrupt TPN withdrawal)
• Hypophosphatemia
• Pancreatitis, Cholestasis & Fat embolism
• Hypercarbia
• Metabolic acidosis: hyperchloremia, metabolism of cationic amino
acids
Complications of TPN

38. Monitoring TPN
• S. Glucose/4 hrs
• S. Triglycerides 6 hrs after end of infusion (normal)
• Nitrogen balance Alb (&LFTs) weekly
• Fluid balance & KFTs daily
• Electrolytes daily
• Complete & Differential blood count