Nutrition Flashcards
Basic daily energy requirement
25-35 kcal/kg/day
Daily protein requirement
0.8-1.5 g/kg/day (of which 0.13-0.24 g nitrogen/kg/day)
Daily free water requirement
30-35 mL/kg/day
Daily sodium requirement
1-2 mmol/kg/day
Daily potassium requirement
1 mmol/kg/day
Daily chloride requirement
1 mmol/kg/day
Magnesium and Calcium requirement
0.1 mmol/kg/day
Phosphate requirement
0.4 mmol/kg/day
List 7 advantages of commencing early feeding in the ITU
Reduction in:
- Overall complications
- Readmissions
- Length of stay
- Infections/sepsis/antibiotic use
- Pressure ulcers
- Ventilation days
- ?Mortality
Describe the advantages of post pyloric feeding
Reduction in ventilator associated pneumonia. Useful in gastric outlet obstruction.
At what point should you consider starting TPN
Day 8 of starvation as reduced mortality as compared with early TPN on day 3 (NEJM casear et al. 2011)
How can you combat the fatty acid deficiency inherent to TPN
Make up 3% of TPN calorie delivery with linoleic acid.
Which compounds are affected by refeeding syndrome
Reduction in:
- Phosphate
- Magnesium
- Potassium
- Glucose
- Thiamine
- Vitamins
What features should prompt for TPN use?
Non f(x) GI tract Ileus/poor absorption Proximal high output / enterocutaneous fistula Short gut syndrome Oral mucositis
What is “trophic enteral feed”
A slow feed used in conjunction with TPN designed to prevent gastric atrophy. Usually run at 10-30mL/hr
What percentage of nutrition should be supplied by EN before discontinuing TPN?
50%
What are the disadvantages of TPN
- High Cost
- No maintenance of GI Tract
- Risks inherent to CVC
- Specific risks of TPN:
- Large fluid load
- Liver function derangement
- Cholestasis
- Trace element deficiency (esp. copper, zinc, chromium)
- Fatty acid deficiency
- Hypovolaemia from osmotic diuresis
- Hypercarbia
- Hyperchloraemic metabolic acidosis
- HONK
- Hyperglycaemia (during infusion)
- Hypoglycaemia (during withdrawal)
- Hypernatraemia
- Hypophosphataemia
- Lipidaemia
What percentage of muscle mass is lost per day on the ICU
1-2%/day
List the names of some formulas used to estimate calorie requirement in the critically unwell
Pre-calculated: - ACCP - ESPEN Formulaic (all include age, gender and weight): - Schofield equation (includes stress factor) - Ireton Jones equation (trauma/burns) - Penn State equation (temp, MV) - Harris Benedict equation (IBW Heigh)
What factors increase your metabolic requirements in ITU?
Burns Trauma Surgery Fever Pain Physiotherapy
What factors decrease your metabolic requirements in ITU?
Hypothermia Ventilation Sedation Paralysis
What are the advantages of TPN?
- Can be used with EN contraindicated
- Can be patient specific
What are the advantages of EN?
- Cheap
- Maintenance of the GI tract
- Structure and function
- Maintenance of immune functions
- Decreased bacterial translocation
- Decreased stress ulceration
- Decreased hypoglycaemia
- No CVC required
- Generally safer
What are the disadvantages of EN?
- Often intollerent in ITU setting (e.g. burns, sepsis, trauma etc.)
- Results in undernutrition
- May require prokinetics
- Misplaced NG tube spells disaster
- Diarrhoea
- Nausea/Vomiting
What are the international guidelines of feeding in ITU?
- ESPEN - all patients to receive nutritional support within 24-48 hours, use PN if EN contraindicated
- ASPEN - Early EN is possible, if not, no nutritional support for 7 days, commense PN thereafter
What did the CALORIES trial show (NEJM 2014)
- Looked at early EN vs early PN (both initiated within 36 hours and continued for 5 days)
- No difference in 30 day mortality
- 50% of both groups failed to achieve nutritional goals
What are your calorie goals in critical illness
- Increased mortality in achieving < 25% or > 65% calorie goals
- Aim for 60-65% requirement
- Approx 16 kcal/kg/day
What are the disadvantages of post-pyloric feeding?
- Difficult to site line (needs endoscopy)
- Increased tube blockage
- Increased tube displacement
- Alters the gastric phase of digestion
- Increased diarrhoea
What are the sequelae of refeeding syndrome?
- Life threatening arrhythmias
- Increased O2 consumption
- Neuromuscular disturbance
How should you treat refeeding syndrome?
- Identification of at risk groups
- Slow initial feed (50% estimated requirement for 2 days)
- Slowly increase by 200-400 kcal/day
- Aggressive electrolyte correction
- Thiamine supplementation
