Nutritional therapy is important for critically ill patients in the ICU. Patients experience metabolic disturbances like hypermetabolism and loss of lean body mass. Nutritional requirements should be calculated using methods like indirect calorimetry or formulas, with a focus on adequate protein, calories, and adjustments for fever. Enteral nutrition is preferred over parenteral nutrition when possible due to benefits and lower risk of complications, though parenteral may be needed if enteral is not feasible or sufficient. Monitoring is important to watch for complications from each type of nutrition support.

2. NUTRITION THERAPY
FOR THE CRITICALLY ILL
PATIENTS
AHMED ELMENSHAWY
MD, ALEXANDRIA

3. OVERVIEW
• Importance of Nutritional therapy
• Stress-Related Metabolic Disturbances
• Nutritional Assessment and Requirements
• Enteral And Parenteral Nutrition
• Monitoring And Complications

4. ICU CARE MAY PROFOUNDLY INFLUENCE THE
METABOLIC RESPONSE

5. PHASES OF CRITICAL CARE

6. METABOLIC ALTERATIONS IN ICU PATIENTS
• moderate to severe hypermetabolism,
• increased gluconeogenesis with insulin
resistance,
• a large increase in endogenous lipolysis
• net loss of the lean body mass
• Cytokines
• Stress hormones
• Opoids and neurotransmitors
• Others
• Fever,
• Increase in cardiac output
• Increase in energy demand

7. THE INCREASE IN ENERGY EXPENDITURE (EE), IS DIRECTLY
RELATED TO THE EXTENT AND TYPE OF INJURY/SEPSIS
EE increases
minor or localised infections 5-15%
severe infection or multiple trauma 10-15%
uncontrolled sepsis,
Acute Respiratory Distress Syndrome (ARDS),
burn patients
More than 20%

8. CALCULATING ENERGY EXPENDITURE
• Profound sedation
±muscular paralys
decrease EE
• EE increase by
10% /c° > 37

9. NUTRITION ASSESSMENT
• The clinical assessment,
• Signs: oedema, cachexia, muscle atrophy and mucosal lesions: glossitis
• Body weight
• Biological markers
• Plasma albumin,
• transthyretin,
• transferrin,
• Measurements of body composition
• skinfold thickness
• arm muscle circumference,
• by bioelectrical impedance
• Nitrogen (N) balance
• Electrolytes
• retinol-binding protein
• fibronectin
• insulin-like growth factor-1

10. PRACTICAL ASSESSMENT OF NUTRITIONAL STATUS
• Patient history and clinical setting
• Diseases associated with increased risk of malnutrition (e.g. chronic debilitating disease)
• History of chronic low food intake, drug abuse, alcoholism, chronic psychiatric disorders
• Diseases associated with hypermetabolism and prolonged catabolic activity (e.g. polytrauma, burns, persistent fever, sepsis, multiple organ
failure)
• Clinical and anthropometric assessment
• Signs of malnutrition on physical examination (e.g. cachexia, muscle atrophy, oedema)
• Recent severe body weight loss (≥5% of usual body weight in one month or ≥ 10% in three months)
• Body mass index (body weight in kg/(height in m2)) < 18.5 kg/m2
• Biochemical parameters
• Hypoalbuminemia < 35g/L
• Plasma electrolytes levels (K, Mg, P, Ca)
• Nitrogen balance (negative) values: ≤5 g (low stress) 5 to 15 g (moderate stress) ≥15 g (severe stress)

11. NUTRITIONAL REQUIREMENTS
• indirect calorimetry: Reference method or Gold standard
• Harris-Benedict formulae
• Men: EE (kcal/day) = 66 + (13.7 x W) + (5 x H) - (6.8 x A)
• Women: EE (kcal/day) = 655 + (9.6 x W) + (1.7 x H) - (4.7 x A)
• W = weight in kg, H = height in cm, A = age in years.
• Faisy equation: In ventilated critically ill patients
• In practice,
• 25-35 (20-30 non-protein) kcal/kg/
• 10% for every degree of body temperature >37˚ C.
• protein intake 1.2 and 1.5 g/kg/day,
• not exceed 2.0 g/kg/day
• except in losses (e.g.
• extensive burns,
• GI and/or urinary losses,

12. WHEN TO GIVE NUTRITIONAL THERAPY
• Any critically ill patient in whom oral intake is not expected to cover the full
energy needs in the first three days following ICU admission
Pragmatic indications
• Severe stress in patients unable to eat for 5-7
days or more
• Severe trauma and burns
• After small bowel resection
• Resumption of gastrointestinal tract activity
and preparation for oral feeding
Evidence-based indications
• Well-nourished patients including
patients with prolonged fasting or
insufficient oral intake.
• Pre-existing malnutrition,, in a patient
unable to cover their full energy needs
by oral intake.
•

13. ROUTE OF ENTERAL NUTRITION
ENTERAL NUTRITION (EN)
• first-line nutritional support
• nasogastric or nasojejunal tube,
• or through percutaneous
• gastrostomy
• jejunostomy
PARENTERAL NUTRITION (PN)
• if EN is not feasible
• Total PN: in CVC (>900 mosm/l)
• Peripheral PN: in peripheral line (≤900 mosm/l)
COMBINED EN AND PN
• If EN is difficult to fully optimise in the first three days following ICU admission in
malnourished patients

14. ADVANTAGES OF EN AND PN
ENTERAL NUTRITION (EN)
• Favours intestinal villous integrity and function,
• Promotes gut motility,
• Maintains GI tract immune functions
• Reduces bacterial translocation from the gut
• Avoids infectious complications associated with parenteral
nutrition
• Reduces the risk of metabolic complications with PN:
hyperglycaemia, insulin resistance, hypertriglyceridemia, fatty
liver
• Less costly
PARENTERAL NUTRITION (PN)
• Easy to perform
• Ensures full delivery of specific nutritional needs
• Avoids risks of
• gastrooesophageal reflux,
• aspiration pneumonia,
• enteral-feeding associated diarrhoea and GI intolerance
(vomiting,...)

15. CONTRAINDICATION FOR EN
ABSOLUTE
• Adequate oral intakes (>80% of the energy
target)
•• Generalised peritonitis
Non-functional gut: anastomotic disruption,
lower GI obstruction, gut ischaemia/necrosis
• Uncontrolled severe shock states
RELATIVE
• Expected period of fast ≤5 days, except in severely injured
patients
• Abdominal distension/severe protracted diarrhoea
• Localised peritonitis, intra-abdominal abscess, active upper GI
tract haemorrhage
• Coma with risk of aspiration (especially gastric feeding)
• Very short bowel (less than 70 cm) or high output fistulae
• Electrolytes or fluid or substrate intolerance (kidney, heart, liver
failure)
• Terminal disease
• Dementia, agitation, confusion

16. CONTRAINDICATION FOR PN
ABSOLUTE
• Adequate oral intake
• Enteral nutrition feasible and
covering > 60% of the energy target
within 3 days
• Uncontrolled severe shock states
RELATIVE
• Absence of central venous access (
• Electrolyte or fluid or substrate intolerance (kidney,
heart, liver failure)
• Incompatibility between intravenous drugs and
parenteral nutrition solution in the absence of multiple
port catheters
• Dementia, agitation, confusion

19. MONITORING AND COMPLICATIONS
EN
• Tube misplacement and bronchial
aspiration
• Gastrointestinal dysfunction
• High residual volume
• Abdominal cramps, nausea, vomiting
and diarrhoea
PN
• Catheter-related sepsis (CRS)
• Non-septic complications:
• air embolism,
• injury to thoracic structures
• Metabolic complications
• Hyperglycaemia
• hypertyglcidemia
• Hypoglycaemia
• cardiac arrhythmias,
• Catheter thrombosis
• Liver abnormalities
• Pancreatic disorders