Nutrition for the Critically Ill Flashcards
1
Q
Consequences of Impaired Nutrition
in a
Non-critical Patient
A
- ↑ incidence nosocomial infections
- longer hospital stay
- ↑ mortality
2
Q
Malnutrition
Immune Effects
A
- ↓ production of complement and Ig
- ↓ cellular immunity
- impaired WBC function
- chemotaxis
- phagocytosis
- oxidative burst
3
Q
Malnutrition
Wound Healing Effects
A
-
Impaired inflammatory phase
- d/t WBC function
-
Impaired proliferative phase
- d/t collagen synthesis
-
Impaired remodeling phase
- d/t collagen turnover
4
Q
Malnutrition
Muscle Mass Effects
A
- progressive loss of muscle mass and tone
- loss of respiratory muscles ⟾ ventilator dependence
5
Q
Malnutrition
in
Hospitalized Patients
A
30% of hospitalized patients malnourished.
Causes:
-
Anorexia
- cancer
- radiation/chemo
- sepsis
- liver disease
- cancer
-
Poor intake due to GI problems
- obstruction
- ileus
-
Bowel pathology
- scleroderma
- inflammatory bowel disease
- s/p gastric resection
-
Excessive loss
- protein losing enteropathies
- GI fistulas
-
Iatrogenic causes
- hospital food served without assistance
- NPO status for tests
6
Q
Hypercatabolic State
A
Associated with stress from:
-
Injury
- burns
- trauma
- With a TBI → [norepi] x7 of normal
-
Sepsis
- infection
- inflammation
Due to neuroendocrine response & inflammatory cytokines:
-
Neuroendocrine response
- Epi
- Glucagon
- Steroids
-
Cytokines
- IL-1, IL-2, IL-6
- TNF
7
Q
Burn Injury
A
- BEE is 140% above baseline s/p injury
- Remains elevated at 110% for up to 1 year after injury
- Proportional to extent of burn
8
Q
Role of Cytokines
A
-
↑ in sepsis, burns, and tissue injury
- produced by inflammatory cells (e.g. macrophages)
- enterocytes may be a source
-
Results in:
- proteolysis in muscle
- sustained levels → multiple organ failure
- fever exacerbates proteolysis & muscle wasting
9
Q
Role of GI Tract
A
- Intestinal ischemia or disuse → release of inflammatory mediators
- Leads to SIRS
- fever, hypotension, increased CO
- Lethal immunosuppression
- Apoptosis of enterocytes
10
Q
Intestinal Sequelae from Injury
A
Trauma → hemorrhagic shock → intestinal injury
-
Damage to gut immune system
- decreased IgA
-
Enterocyte damage leads to systemic release of:
- CRP
- IL-6
- intestinal fatty acid binding protein
11
Q
Elevated Energy Requirements
A
Resting Energy Requirement:
25 kcal/kg/day + 1 gm protein/kg/day.
- Walking, minor surgery → 1.3x
- Major surgery → 1.5x
- Major trauma → 1.7x
- Sepsis → 2x
- Burns > 20% BSA → > 2x
12
Q
Nutritional Assessment
A
-
Dietary hx
- support system
-
Clinical exam
- muscle tone
- skin turgor
- neurologic assessment
-
Respiratory Quotient
- ratio of CO2:O2
- used to monitor feeding
- depressed in sepsis
- SOFA score → sepsis related organ failure assessment score
- APACHE score → acute physiology and chronic health score
13
Q
Biochemical Assessments
A
-
Serum albumin
- 1/2 life of 14-18 days
- < 3.0 gm/dL abnl
- may change d/t fluid shifts
- measure of severity of underlying infection
- prognostic indicator
-
Pre-albumin
- 1/2 life of 3-5 days
- 16-35 mg/dL nl
- may change d/t fluid shifts
- synthesis may ↓ in favor of CRP or fibrinogen
-
Transferrin
- 1/2 of 7 days
- < 200mg/dL abnl
14
Q
Carbohydrate
Nutritional Support
A
-
Benefits:
- protein/AA sparing
- hepatic gluconeogenesis suppressed
-
Toxicity:
- excess carbs → HLD → liver toxicity
- CO2 production
- hyperglycemia
15
Q
Lipid
Nutritional Support
A
-
Major source of calories
- ↑ lipolysis by steroids, catecholamines, glucagon, cytokines
- ↓ lipolysis by insulin
- Metabolism impaired in stress
- 1/3 of daily caloric replacement should be lipids
-
Toxicity:
- excess accumulation in liver → ⨂ reticuloendothelial system
- elevated TAG levels
- pancreatitis
- pulmonary failure
-
Max fat infusion
- 2 g/kg/day in adults
- 4 g/kg/day in infants
16
Q
Protein Requirements
A
Baseline daily requirement = 0.8 gm/kg/day
- Post-op → 1-1.5
- Sepsis → 1.5-2
- Multiple trauma on vent → 1.5-2
- Major burn → 2-3
17
Q
Electrolyte Replacement
A
- sodium 50 mEq
- potassium 20-40 mEq
- calcium 0.2-0.3 mEq/kg/day
- magnesium 0.35-0.45 mEq/kg/day
-
phosphate 30-40 mmol/day
- deficiency ⟾ refeeding syndrome
- weakness, encephalopathy
- deficiency ⟾ refeeding syndrome
-
chromium
- deficiency ⟾ hyperglycemia
18
Q
Enteral Feeding
A
- Preferred method
- Via NG, gastric, or jejunostomy tube
-
Preserves:
- mucosal integrity
- hepatic substrate supply
- gut immune function
- IgA
- ↓ infectious complications (e.g. C. diff)
- Benefits can be achieved by trophic feedings (10 ml/hr)
-
Complications:
- 30% fail to meet nutritional goals
- stopped for residual volume in stomach
- held for surgical or radiologic procedures
- aspiration risk
- diarrhea/fluid loss
-
Start within 48 hrs unless hemodynamically unstable
- Instability can lead to bowel necrosis
19
Q
Parenteral Feedings
(PPN)
A
- via peripheral line
- unable to meet all nutritional needs
- short-term use
20
Q
Total Parenteral Feedings
(TPN)
A
- requires a central line
- hyperosmolar
- contains dextrose > AA and lipids
- can provide all required nutrients long term
-
complications:
- hyperglycemia
- volume overload
- electrolyte abnl
- elevated CO2
- hepatic dysfunction
- cholestasis
- acalculous cholecystitis
- impaired intestinal immunity
- metabolic bone disease
- catheter complications
- hemothorax, pneumothorax, sepsis, thrombosis, DVT
21
Q
Guidelines for Nutritional Support
A
- Protein most important
-
Early enteric nutritional support beneficial
- start within 24-48 hrs in ICU patient
- start within 4-6 hrs for burn pt
- Glutamine supplement w/o benefits
- EN safer than PN if gut working
- EN to stomach as safe as to intestine
- EN should be held in unstable pt on pressors d/t inc. risk of bowel ischemia
- PN if EN not possible
- BGL 140-180
- monitor phosphate
22
Q
Adipose Tissue
A
-
Hormonal and endocrine mediators produced:
- Leptin
- TNF
- Resisten
- Adiponectin
↓ adipose ⟾ ↑ longevity & ↓ tumors
