1. Critical Care
Metabolic demand for inflammation, sepsis, surgery, trauma, wounds, organ failure increase stress factor by 1.3
With intubation, sedation patients are at risk for acute malnutrition and catabolism
Body utilizes endogenous energy stores which deplete muscle mass, immune response, endocrine function
Glycogenolysis, breakdown of glycogen or stored hepatic glucose which provides energy for <3hrs
Gluconeogenesis, production of glucose by the liver by utilizing non-glucose substrates like TAGs and AAs

4. Critical Care
Lipolysis, breakdown of adipose tissue with FAs oxidation for slow steady energy demands
Ketosis, when glucose stores are depleted and FAs remain in circulation the liver produces ketone bodies for survival
Body utilizes endogenous energy stores which deplete muscle mass, immune response, endocrine function
The uses transporters specific for glucose, to triage vital organs for when energy stores are depleted
The brain NEEDS glucose as regulated by the brain-blood barrier, making it the priority for glycogen stores

9. Critical Care
The heart, liver, kidneys can function with FAs or ketone bodies but utilization of these requires increased energy
As starvation continues, organs begin to shut down to preserve energy, catabolism occurs, and output decreases
Hypermetabolism, when demand exceeds supply with increases BMR, negative nitrogen balance, and higher O2 demand
Catecholamines like glucagon and cortisol counter regulate starvation by increasing available energy stores
Aldosterone and ADH, increase to limit excretion of AAs or electrolytes and fluids

12. Critical Care
Markers for starvation ARE NOT albumin, pre-albumin, and CRP but rather indicators of clinical status
A patient can be adequately nourishes and have low lab values or be malnourished and have acceptable labs
C-reactive Protein is an inflammatory maker which typically indicates catabolic response
Critical care typically holds nutrition for 24-48hrs to stabilize a patient, BUT then >48hrs EARLY NUTRITION is vital
Heavy sedation, narcotics, and IVFs can complicate peristalsis, GI function, and electrolyte balance

14. Critical Care
Use of NGT/OGT is ideal, checking GRV every 4hrs with a decrease in rate at 250ml, or HOLD at 500ml
Early feeding, even 10ml/hr reduces risk for gut ischemia, paralytic Ileus, acidosis, tissue necrosis
NO EN with severe hypotension, perforated bowel, high dose pressors, esophageal strictures
Burns require the >energy and fluid, tissue damage and shock can utilize >5000 KCALS, 200gm PRO

16. Critical Care
PARKLAND formula for fluids is 4 x KG x %BS = mL/24hrs, then total mL/2/8hrs, with the remaining mL/16hrs
Man 85kg, with 20% burns, 4 x 85 x 20% = 6800ml, then 6800ml/2 = 3400ml, 3400ml/8hrs is 435ml/hr, 3400ml/16 = 213ml/hr
Specific EN formula for increased protein demand for burn patients typically providing 25% of total KCALS
Protein needs for ICU patients are 1.2-2gm/KG, or disease specific, with Obese at using IBW
OFTEN sedation or hydration can limit EN rate, causing chronic protein deficiency and need for elemental protein supplements

18. Critical Care
Sedation can affect EN rate given propofol is a lipid emulsion providing 1.1 KCALS/mL, or 40mL/hr = 1065 KCALS of total fat
Remember, IVFS D10W, D5W provide KCALS from CHO which need to be considered in total energy
In general, ICU patients have higher KCAL demand with stress factors at 1.3 or 130% of REE
That said, permissive under-feeding is often indicated depending on clinical status of the patient
Without nutrition ICU patients can lose 2% of total muscle mass in 24hrs, develop third spacing, and cardiac arrest

19. Critical Care
With intubated patients DO NOT over-feed, reduce respiratory function, risk for aspiration
Total KCALS are often less with intubation given ventilators fully support active breathing
In contrast COPD patients NOT INTUBATED have extreme KCAL demand at > 1.3 stress factor
Pulmonary specific EN formulas HAVE NOT been shown to reduce mortality or improve respiration

22. Critical Care
In COPD, high CHO intake increases CO2 output which MAY cause acidosis, SOB, and acute respiratory distress
Fiber containing EN formulas SHOULD NOT be used with ICU patients on pressors, ventilation, heavy sedation
LOW residue, KCAL dense formulas are ideal to prevent gastric distention, bloating, and high GRV
ICU patients should ALWAYS receive EN via continuous infusion, NOT BOLUS feeding

24. Critical Care
EN recommendations should advance to GOAL slowly to prevent refeeding syndrome, after starvation
Excessive metabolic activity in refeeding, causes electrolyte derangement with <labs for P, Mg, K
EN formulas should start at 25% of patients KCALS/KG, then advance by 25% every 12-24hrs
REMEMBER fluids are a vital nutrient that should always be considered in ANY nutrition assessment