Exam 3 Flashcards
What are the first 3 components of nutritional assessment?
- Risk Factors for Malnutrition - These pts need nutrition as EARLY as possible; Can use screening tools to determine risk
- Under body weight (20% below IBW), involuntary weight loss of > 10% within 6 months, alcohol/substance abuse, protracted nutrient losses
- ICU: if they are NPO for over 10 days (we use 7 days), gut malfunction, increased metabolic needs (trauma/burn, high dose steroids) and/or mechanical ventilation - History -
- Dietary: Previous diet, any problems, eating disorders, N/V/D?
- Medical: Surgical history (need to know if GI tract is still connected and working)
- Medications: Any that decrease nutrient absorption, alter taste, increase/decrease appetite, cause N/V? - Athropometrics - Look at trends
- Somatic (muscle) protein status: weight, triceps skin fold, physical appearance, arm muscle circumference
- Transthyretin (prealbumin): 2-3 day half life, normal serum conc. is 15-40mg/dL****we are especially worried if this is under 10. ***keep in mind ICU patients are in an inflammatory state, so this number may not tell you the whole story
- C-Reactive Protein (CRP): can help us see why prealbumin is decreasing. If prealbumin decreases as CRP increases, it’s due to inflammation. If prealbumin decreases as CRP is normal, it’s due to malnutrition.
What do the NUTRIC scores mean?
NUTRIC - High Risk of malnutrition (6-10, or 5-9 w/o IL-6), Low Risk of malnutrition (0-5 (0-4 w/o IL-6))
What are the last 2 components of nutritional assessment?
- Classifications of (chronic) Malnutrition -
- Marasmus (protein-calorie malnutrition): decrease in total intake and/or utilization of food. Pts have cachectic appearance. Experience wasting of skeletal muscle and SQ fat. Treated by providing a well-balanced substrate +/- vit B.
- Kwashiorkor (protein malnutrition): Adequate caloric intakes, but have relative protein malnutrition. Seen in catabolic trauma patients and burn patients. Present with large belly, diarrhea, decreased muscle mass, failure to gain weight, etc. Treated with carbs followed by high protein
- Could also be a mix of the two - Nitrogen Balance - Measurement of urinary excretion of nitrogen as urea nitrogen. It gives an indication of how we are using protein stores
- Nitrogen is released from protein catabolism, is converted to urea, then excreted in the urine. If stress goes up, protein catabolism increases, which increases UUN.
- Ideal goal is +3 to +5 grams
- Nitrogen balance = N(in)-N(out)
What is the process of calculating a patient’s nutritional requirements based on height, weight, and clinical situation? (caloric needs, NPC, and protein requirements)
- use NBW if pt’s actual body weight is 130% more than IBW. If it’s under 130% of IBW, use actual weight
Caloric needs:
Total energy expenditure = REE (resting) x stress/activity factor(s)
- TEE = REE x 1.2 (abbreviated Weir equation)
- Most patients will need 25-30kcal/kg/day (use NBW if obese)
- Non-stressed/depleted pts need 20-25kcal/kg/day
Protein needs:
- pts with mod to severe stress (ICU/trauma/surgery/burn): 1.5-2g/kg/day
- floor pts: 1-1.5h/kg/day
- maintenance: 0.8-1g/kg/day
- 1g protein = 4g kcal
NPC: non-protein calories
- Standard distribution is 70% dextrose & 30% fat
- Range is 70-85% dextrose, 15-30% fat
- Adjust due to blood sugars, triglycerides, RQ
- 100/0 can be used during sepsis or bloodstream infections
- 1g dextrose = 3.4 kcal
- 1g lipids = ~10 kcal
What are the indications for parenteral nutrition (PN - 6) and enteral nutrition (EN)?
*starting nutrition therapy early decreases ICU length of stay and increases patient outcomes
**all hospitalized patients should be started on some nutrition within 48 hours
Parenteral (IV) -
- anticipated prolonged NPO course (>7 days)
- inability to absorb nutrients via the gut (small bowel or colonic ileus, extensive small bowel resection, malabsorptive state, intractable V/D)
- enterocutaneous fistulas
- inflammatory bowel disease
- hyperemesis gravidum
- bone marrow transplantation
Enteral - if the gut works, use it
- oral consumption inadequate/contraindicated: esophageal obstruction, head and neck surgery, dysphagia, trauma, CVA, dementia
*provides GI stimulation, less risk of bacterial translocation (decreased infectious morbidity/mortality with EN), avoids risks associated with IVs, more physiologic than PN (esp bolus feeds), less stringent protocol, and less $$
What are the various routes and methods for the administration of PN and EN?
Parenteral -
- peripheral: dextrose and AA solutions are hypertonic, which are not well tolerated via peripheral vein. Requires large volumes of fluid, which may not be the best choice for HF or AKI/CKD pts. Calories are limited through this route and we can only do it for a short amount of time, so maybe we should not do peripheral access at all and just wait for central line, or don’t do PN at all.
- central: Allows administration of hypertonic solutions & more calories can be delivered. BUT more risk of infection & inserting central line can be risky. Can do central venous catheter (subclavian, internal jugular, or femoral vein), short term percutaneously inserted, or PICC, tunneled or implanted port for long term.
*there are single, double, and triple lumens (want at least 2-3 lumens for med administration)
Enteral -
- Nasogastric (NG)/Orogastric (OG), Nasojejunal (NJ)/Orojejunal (OJ), Gastrostomy (PEG), Jejunostomy; PEG/PEJ
- Administration: bolus (>200mL over 5-10 min, used primarily in pts with gastrostomy), intermittent (>200mL over 20-30 minutes, 4-8 feedings/day), continuous infusion (admin over 12-24 hours/day, need infusion pump, preferred with jejunum), trickle or trophic (slow infusion at 10-30mL/hr)
How do you choose a patient’s PN regimen (protein and carbs)?
Parenteral -
protein:
- want to choose most concentrated product (ex. Travasol 10%)
carbs:
- final dextrose conc. of over 10% in adults and 12.5% in peds shouldn’t be infused into peripheral vein (irritation); usually we do D5W
- max carbohydrate utilization: 4-5mg/kg/min
How do you choose a patient’s PN regimen (fat)?
Parenteral -
fat:
- IV fat emulsion provides concentrated source of calories
- check for allergies (glycerin & egg) with intralipid
- do not exceed 60% of caloric intake as lipid
- lipid rate for adults generally 1-1.5g/kg/day (max of 2.5g/kg/day if tolerating)
*propofol is a 10% lipid solution (1.1 kcal/mL)
- can only hang IV fat emulsion by itself for 12 hours due to stability (if in 3-in-1, can do 24 hours)
How do you choose a patient’s EN regimen (formula)? What should we not supplement with impact peptide? What types of proteins and fats are best for absorption?
Impact 1.5 - (immune modulating - arginine, glutamine, omega-3s, antioxidants) inc. protein content
- target pt population: major elective surgery, trauma, burn, head or neck cancer, mechanically ventilated
- use with caution in severe sepsis pts
*since this already have glutamine, DO NOT supplement glutamine
jevity - standard
glucerna - low carb (diabetic patients)
nepro - kidney patients (less volume)
- partially digested proteins are better for absorption, medium chain fatty acids better for absorption, glucose polymers usually used for tube feeding
What is clinimix and how does the pt’s renal function impact if we give Clinimix vs. Clinimix E?
Clinimix = standard TPN w/o lipid +/- electrolytes
CrCl < 50 = no electrolytes
CrCl ≥ 50 = with electrolytes
*most pts get 83.3mL/hr
**this is usually a short term thing until we can get a custom TPN
What does SMOFlipid contain and how is that different from Intralipid?
Intralipid:
Soybean oil 10% (linoleic acid (omega-6))
Glycerin 2.25%
Egg yolk phospholipid 1.2%
Water for injection
- Intralipid contains glycerin and egg (allergies)
SMOFlipid: better combo of fat
S - Soybean oil 30%(omega-6)
M - Medium chain triglycerides (longer chains are harder to break down)
O - Olive oil (omega 9)
F - Fish oil (omega 3)
- SMOF shows improved liver function & lower increase in TG levels from baseline compared to intralipid.
- Less pro-inflammatory, less neg impact on liver function, reduced risk of infection, and decreased length of stay compared to non-omega-3 PN
- SMOFlipid is superior to intralipid!!!
What electrolytes are we worried about in renal disease? What precipitation do we try to avoid? What should we put in TPNs to avoid deficiencies? Can we put iron in the TPN? What trace elements should we add in liver dysfunction and renal disease?
- Caution in renal disease: potassium, phosphate, magnesium
- Want to avoid calcium + phosphorous precipitation (Ca x Phos > 150)
- Can add multivitamins
- Must put trace elements in TPN or else they will become deficient (zinc, copper, chromium, selenium, manganese, iron)
- Do not put iron in a TPN, if giving iron, do it in a separate bag
In liver dysfunction: d/c trace elements, supplement only zinc and selenium
In renal disease (CKD/ESRD on HD): use selenium and chromium w/ caution.
What are the normal daily ranges for calcium, magnesium, phosphorus (mMol -> mEq conversion), sodium, potassium, and chloride/acetate? What’s the balancing equation?
calcium: 10-20 mEq (given as calcium gluconate)
magnesium: 8-24 mEq
phosphorus: 15-45 mMol (or 0.3mMol/kg to start); 1mMol of Phos = 1.4mEq Phos
*do not put in bag if renal failure
sodium: 1-2 mEq/kg (or 1/2 NS = 77mEq/L)
potassium: 0.5-1mEq/kg to start (up to 2 mEq/kg)
chloride: (acid) PRN for 2/3 acid-base balance
acetate: (base) PRN for 1/3 acid-base balance
positives (Na+ and K+) - negatives (phos) = remaining to balance
- then do 2/3 as chloride, 1/3 acetate
How do we determine the rate of initiation and discontinuation of PN?
Start at 25% of goal and achieve the final rate within 24 hours (titrate). Max rate of infusion is 200mL/hr
Initiation:
- check blood glucose q4-6 hours before each increase the rate
- if BG is >200, contiue same rate x4 hours and recheck, if repeat BG is >200, consider treating
Cessation: Titrate down
- Decrease rate by q2hrs until rate is <50mL/hr, then d/c
Can do PN cycling (infusion over 12-18 hours per day). There’s no specific guidelines for this, but generally cut back during first and last hour of infusion
How do we initiate enteral tube feeding?
- initiate at full strength at 25mL/hr
- advance 25mL/hr q4-6hr as tolerated up to goal rate
- check residuals q4-6hr
- don’t dilute formula
*can do cyclic over 8-20hrs/day to increase independence for the patient
**if we can’t achieve >50-60% goal calories in the first week, we should consider PN
How do you design a protocol for monitoring a patient receiving PN or EN?
- monitor ionized calcium (don’t want to mess with albumin)
Parenteral -
- Baseline: CMP, Mg, Phos, Ca; Hepatic function panel, prealbumin/CRP, and PT/INR
- q4-6h: finger sticks for glucose, residuals, distention, vomiting, aspiration
- Daily: vitals, I/Os, CMP, electrolytes (ICU setting)
- Twice weekly: prealbumin/CRP (1/2 life 2-3 days)
- Weekly: triglycerides, RQ
Enteral -
- GI: q4-6h check gastric residuals & emesis, check stools daily, bloating/distention, bronchial/tracheal aspirate
- Metabolic: I/Os, bowel movements, weight (2-3x/week), electrolytes, glucose, BUN/SCr daily if unstable, Mg/Phos/Ca/triglycerides/LFTs weekly, albumin/prealbumin/CRP/nitrogen balance weekly
- Mechanical: feeding tube placement, feeding tube patency
How do you calculate a patient’s nitrogen balance? What factors may affect nitrogen loss?
Non-urinary sources of nitrogen loss can include: sweat, feces, respirations, GI fistula, would drainage, skin exfoliation, burns (accounts for 10-15% of nitrogen excretion, the other 85-90% is excreted in urine)
Nitrogen balance = (N in) - (N out)
N in = [24 hour protein intake (g)]/6.25
N out = 24hr UUN(g) + factor(3-5g, usually use 4g)
*goal is +3 to +5, so if the nitrogen balance is low, we need to add protein to the nutrition.
What are the results of indirect calorimetry? What adjustments may need to be made to the patient’s nutrition regimen?
Indirect calorimetry is more specific for critically ill patients, since it looks at what is actually happening in their body.
We use the abbreviated Weir equation: TEE = REE x 1.2
For all energy production, oxygen is consumed and carbon dioxide is produced. We can look at the respiratory quotient to get an idea of if we are over or underfeeding the patient.
- RQ > 1 = over-feeding (lipogenesis)
- RQ <1 = under-feeding (starting to use protein for calories)
- The goal RQ is 0.85-0.95!!! (monitor once weekly)
Based on the RQ, we know whether or not to give more or less food.
What are the potential gastrointestinal, metabolic, and mechanical complications associated with PN?
PN -
- Mechanical (catheter-related): clotting of line, displacement
- Infectious: catheter-related sepsis, solution contamination, bacterial translocation (bacteria that relocates from other sites in GI due to not having gastric acid from enteral feeding)
- Metabolic: electrolyte imbalances, fluid imbalances, hyper and hypoglycemia, liver function abnormalities
What are the potential gastrointestinal, metabolic, and mechanical complications associated with EN?
EN -
- GI: High gastric residuals (only hold if >500mL), aspiration (elevate head of bed 30-45º, do post-pyloric, do continuous infusion), N/V or decreased motility, abdominal distention, diarrhea, constipation
*can give prokinetics to help with N/V, aspiration
*evaluate meds (diarrhea: hyperosmolar meds, sorbitol, antibiotics)
- Metabolic: hyper/hypoglycemia (check meds & insulin regimen), overhydration/dehydration, electrolyte imbalance (hyponatremia most common)
- Mechanical: clogging of feeding tube, tube malposition, rhinitis, sinusitis
- Medication-related: clogged feeding tubes, drug-tube feed interactions
Which drugs (antibiotics (4), anti-retrovirals (3), other (4)) have drug/tube feed interactions? How should we administer these meds?
Antibiotics: fluroquinolones, intraconazole solution, tetracyclines, penicillin V
Antiretrovirals: didanosine, dolutegravir, indinavir
Other: levothyroxine, phenytoin, theophylline, warfarin
Administration:
- Hold tube feed
- 1 hour later, give medication
- wait 2 hours, resume tube feed
What are the doses of these prokinetic drugs: metoclopramide, erythromycin, naloxone, methylnaltrexone
metoclopramide: 10mg IV/PO/feeding tube QID; PRN for N/V
erythromycin: base is 250-500mg PO/feeding tube TID or 3mg/kg IV Q8hr
naloxone: 8mg via feeding tube QID
methylnaltrexoneL weight based dosing IV x1
What are the signs and symptoms of refeeding syndrome and essential fatty acid deficiency? What are strategies that we can do to prevent these disorders from occuring?
Refeeding syndrome: Fluid, micronutrient, electrolyte, vitamin imbalances. Usually occurs w/in first few days of feeding a starved patient. This is potentially life threatening!!
- Hypophosphatemia, hypomagnesemia, hypokalema
- Replace the electrolytes as early as we can to avoid this (before initiating feeds). Then start low and titrate up. also give thiamine.
- limit fluid to 800mL/day, less than 150g/day of carbs
- only give 50% of calorie needs
Essential fatty acid deficiency: Giving continuous infusion of dextrose inhibits movement of fatty acid, which can lead to EFAD. Usually happens around 10-14 days on fat-free PN regimen
- Dry scaly skin, brittle hair, lack of luster
- Give twice weekly fat emulsion (500mL 10% or 250mL 20%)
What are the strategies for delivering medications via feeding tubes and managing medication-related complications with EN?
- Liquid meds are preferred whenever possible
- Crush the tablet into a fine powder (or empty capsule contents) and mix in water, but do not crush sustained-release or enteric coated formulations
- Administer each medication separately
- Ensure adequate flushing with water between each med
- Dilute hypertonic medications or those irritating to the gastric mucosa in at least 30mL of water before administrating
Unclogging tube: 1 sodium bicarb tab, 1 pancreatic enzyme cap, & 10mL of warm sterile water
- Clamp this in the tube for 15-30 mins, then flush when complete
What is important to note with EN for these special populations: Acute renal failure, hepatic failure, pulmonary failure, acute pancreatitis, burn
Acute renal failure: CRRT will need increased protein, HD will need less, prealbumin may be falsely high due to accumulation
Hepatic failure: standard enteral formulations usually good
Pulmonary failure: these pts can’t get a lot of volume, so we need to use calorically dense formulations (ex. impact peptide), refeeding is really bad in these pts (monitor phosphate carefully)
Acute pancreatitis: increased protein requirements, yes you can still use enteral feeding, PN does not affect pancreatic secretion and function
Burn: high protein and calorie requirements, start feeding early
What is are the MOA, adverse effects (5), indications (1), contraindications (3) of the depolarizing neuromuscular blocking agents?
Succinylcholine -
- MOA: binds and activates Ach receptors, resulting in a sustained depolarizing of neuromuscular junction, so the muscle contraction can’t occur (paralytic)
- pretty quick onset at ~1min, duration quick ~3-5mins
- used for rapid sequence intubation (RSI), NOT used for a sustained neuromuscular blockade
- AEs: APNEA (be ready to intubate), muscle fasciculations (deep muscle pain), hyperkalemia, prolonged apnea, intracranial pressure elevation
- CIs: major burns, crash injury, upper motor neuron disease (all due to hyperkalemia)
