cnsc all modules Flashcards
what is the first step in refeeding management?
correct deficiencies of potassium, phosphorus, magnesium
When a patient is at risk for refeeding syndrome, initiate dextrose at ____ or initiate kcal provision at ___ kcals/kg.
initiate with 100-150 grams dextrose or 10-20 kcals/kg
total body water females + elderly
50% of LBM
total body water males <70 years old
60% of LBM
ECF (extracellular fluid)
1/3 TBW
ICF (intracellular fluid)
2/3 TBW
water gain (sensible)
800-1500 ml from oral fluid, 500-700 ml from solid food
water gain (insensible)
250 ml from water oxidation
water loss (insensible)
600-900 ml via lungs/skin
weight/age based fluid requirement 18-55 years old
35 ml/kg
water loss (sensible)
800-1500 ml urine, 0-250 ml GI
weight/age based fluid requirement 56-75 years old
30 ml/kg
weight/age based fluid requirement >75 years old
25 ml/kg
holliday-segar method for fluid (adults)
1500 ml fluid for first 20 kg, then add:
</= 50 years: 20 ml/kg remaining
>50 years: 15 ml/kg remaining
factors that increase fluid needs
fever, vomiting, NGT output, ostomy/fistula output, hyperventilation (10-60%), excessive sweating, burns
***fluid needs increase by 12.5% for each 1 degree above normal (fever)
factors that decrease fluid needs
fluid overload, HF, renal failure, SIADH, ascites, anasarca
estimating minimal adult IV fluid needs
1000 ml urine output, add 500 ml for insensible loss, add net GI loss or subtract net GI gain
maintenance fluids
hypotonic (1/2 NS)
resuscitation fluids
isotonic (0.9% NS, LR, plasmalyte)
electrolyte losses in the stomach
Na: 60
Cl: 130
K: 15
HCO3: 0
electrolyte losses in the duodenum
Na: 140
Cl: 80
K: 5
HCO3: 0
electrolyte losses in the pancreas
Na: 140
Cl: 75
K: 5
HCO3: 115
electrolyte losses in the bile
Na: 145
Cl: 100
K: 5
HCO3: 35
electrolyte losses in the ileum
Na: 140
Cl: 104
K: 5
HCO3: 30
electrolyte losses in the colon
Na: 60
Cl: 40
K: 30
HCO3: 0
gastric fluid loss replacement
1/2 NS + 10-20 meq KCl/L
small bowel fluid loss replacement (duodenum, pancreas, bile, ileum)
balanced crystalloid (LR, plasmalyte), bicarb or acetate based customized fluid, 0.9% NS
normal serum sodium
135-145
normal serum potassium
3.5-5
normal serum chloride
98-108
normal serum CO2
23-30
normal serum calcium
9-10.5
normal serum phosphorus
2.5-4.5
normal serum magnesium
1.7-2.4
measure plasma osmolality
2 x (serum Na) + (glucose) / 18 + BUN / 2.8
<280 mOsm/kg = hypotonic
>280 mOsm/kg = isotonic
Na correction in hyperglycemia
((glucose -100) x 0.016) + Na
urine osmolality
> 100 mOsm/kg = inappropriate renal dilution
<100 mOsm/kg = appropriate renal dilution (excessive water intake, polydipsia, beer potomania, low solute intake)
anti-diuretic hormone (ADH)
increases water reabsorption in the kidneys
- pain, stress r/t surgery causes a sustained release of ADH in the first 1-2 days post op causing Na to drop
hypertonic hyponatremia treatment
insulin, dc mannitol
hypotonic hypovolemic hyponatremia treatment
isotonic fluids (0.9% NS, LR), dc diuretics, steroids
euvolemic hyponatremia treatment
fluid restrict +/- loop diuretics, isotonic fluids, NaCl tablets, urea, concentrate PN
hypervolemic hyponatremia treatment
Na and fluid restriction, diuretics, concentrate PN
free water deficit
TBW x ((current Na-140)/140)
what regulates entry of potassium into the cell?
Na-K-ATPase pump
what is responsible for an intracellular shift of potassium?
insulin, catecholamines, alkalosis
what is responsible for an extracellular shift of potassium?
glucagon, acidosis, aldosterone
*acidosis = high serum potassium
10 meq of IV potassium increases serum potassium by ___
0.1 meq/L
management of hyperkalemia
K cocktail if potassium is > 6 meg/L or ECG changes, cellular incorporation (insulin +/- D50, sodium bicarbonate, albuterol), increase elimination (furosemide, HD, Na polystyrene sulfonate)
what increases calcium levels?
vitamin d, PTH
what decreases calcium levels?
calcitonin, phosphorus, pH
peripheral calcium supplement
calcium gluconate
1 gram = 4.65 meq Ca
central calcium supplement
calcium chloride
1 gram = 13.6 meq Ca
hypercalcemia
acute: malignancy
chronic: hyperparathyroidism
treatment: hydration +/- loop diuretics, calcitonin (rapid onset), biphosphonates (slower onset), steroids
magnesium
absorbed in the jejunum and regulated by the kidney, enzyme cofactor, calcium channel blocker, neuromuscular transmission, CV tone, metabolism
long term PPI use (years) effects the active transport/absorption of ___ in the GI tract
magnesium
parenteral magnesium dosing
serum mg: 1-1.5 mg/dl = 8-32 meq, up to 1 meq/kg
serum mg: < 1 mg/dl = 32-64 meq, up to 1.5 meq/kg
parenteral magnesium infusion rate
</= 8 meq/hr - prevents renal wasting and infusion reactions
parenteral phosphorus dosing
serum P: 2.3-3.7 = 0.08-0.16 mmol/kg
serum P: 1.5-2.2 = 0.16-0.32 mmol/kg
serum P: <1.5 = 0.32-0.64 mmol/kg
parenteral phosphorus infusion rate
</= 7 mmol/hr
loss of night vision
vitamin a
angular stomatitis, cheilosis
riboflavin (vitamin b2), pyridoxine (vitamin b6), niacin, iron
glossitis (inflammation of the tongue/magenta color)
riboflavin, pyridoxine, niacin, folate, iron
poor nail blanching
vitamin a or c
PPN Osmolality calculations
AA (1 gram = 10 mOsm)
Dextrose (1 gram = 5 mOsm)
IV lipids (1 gram = 0.71 mOsm)
electrolytes (1 meq = 1 mOsm)
pinch off syndrome
CVC compressed between the clavicle and the first rib, catheter malposition
thrombotic occlusions
formation of thrombus within surrounding or at the tip of the catheter
push-pause flushing method helps prevent
fibrin sheath
tail extends from the catheter tip but is drawn inward blocking the opening of the catheter lumen on aspiration, resulting in an ability to infuse fluids but inability to withdraw blood
crohn’s disease key features
transmural, small bowel involvement, fistulas, granulomas, skip lesions, 25-30% have no bleeding
ulcerative colitis key features
mucosal disease, starts from rectum up, colonic involvement only, bleeding common
sites of absorption: duodenum
iron, folate, calcium, fat soluble vitamins
sites of absorption: lower jejunum
water soluble b vitamins
sites of absorption: terminal ileum
vitamin b12, bile salts
sites of absroption: ileum
magnesium
sites of absorption: colon
short chain fatty acids
autonomy
right of individuals to make their own decisions
beneficence
doing the right thing for the patient
nonmaleficence
doing no harm
justice
acting fairly, providing similar treatment to patients in similar situations
protein:nitrogen
6.25 grams protein = 1 gram nitrogen
manifestations of essential fatty acid deficiency
scaly dermatitis, alopecia, poor wound healing, thrombocytopenia, triene to tetraene ratio of more than 0.2
sodium maintenance dosage
1-2 meq/kg/day
potassium maintenance dosage
1-2 meq/kg/day
calcium maintenance dosage
10-15 meq/day
magnesium maintenance dosage
8-20 meq/day
phosphorus maintenance dosage
20-40 mmol/day
celsius to fahrenheit conversion
(C x 1.8) + 32
base component
HCO3
acid component
PCO2
arterial blood gas normal values
pH: 7.4 (7.35-7.45)
PCO2: 35-45
PO2: 80-100
HCO3: 22-26
respiratory acidosis
PCO2 is elevated (>40 mmHg)
respiratory alkalosis
PCO2 is reduced (<40 mmHg)
metabolic acidosis
HCO3 is <24
metabolic alkalosis
HCO3 is >24
medicare guidelines to cover home EN
> 3 months, non-function or disease of the structures that normally permit food to reach the small bowel, dysphagia, esophageal cancer, gastroparesis, disease of the small bowel which impairs digestion/absorption, sole source of nutrition
nutritionally at risk child
- weight for length, weight for height <10th percentile, -1.28 z score
- bmi for age/gender <5th percentile, -1.64 z score
- increased metabolic requirements
- impaired ability to ingest/tolerate oral feeding
- documented inadequate provision of or intolerance to nutrients
- inadequate weight gain or significant decrease in usual growth percentile
low birth weight
<2500 grams
very low birth weight
<1500 grams
extremely low birth weight
<1000 grams
micronate
<750 grams
pediatric bmi classifications
<5th percentile: underweight
5th-85th percentile: normal
85th-95th percentile: overweight
>95th percentile: obese
protein requirements 0-3 mos
1.5 grams/kg
protein requirements 4-12 mos
1.5 grams/kg
protein requirements 13-36 mos
1.1 grams/kg
protein requirements 4-13 yrs
0.95 g/kg
protein requirements 4-18 yrs
0.85 grams/kg
fluid requirements children (holliday-segar)
1-10 kg: 100 ml/kg
10-20 kg: 1000 ml + 50 ml/kg >10 kg
>20 kg: 1500 ml + 20 ml/kg >20 kg
EN initiation and advancement guidelines (infants)
bolus: initiate at 25% and divide by # of preferred feeds, increase volume by 25% daily
pump: initiate at 1-2 ml/kg/hr and advance by 0.5-1 ml/kg/hr every 6-24 hrs to goal
vitamin d in infants
supplement 400 IU/day in those exclusively breastfed
iron in infants
fortify in breastfed infants by 4-6 months
*formula contains iron
no cows milk before 1 year because
low in iron, low in vitamins c and e, low in essential fatty acids, high renal solute load
sodium needs in preterm neonates
2-5 meq/kg
sodium needs in infants/children
2-5 meq/kg
sodium needs in adolescents and children >50 kg
1-2 meq/kg
potassium needs preterm neonates
2-4 meq/kg
potassium needs infants/children
2-4 meq/kg
potassium needs adolescents + children >50 kg
1-2 meq/kg
calcium needs preterm neonates
2-4 meq/kg
calcium needs infants/children
0.5-4 meq/kg
calcium needs adolescents + children >50 kg
10-20 meq
phosphorus needs preterm neonates
1-2 mmol/kg
phosphorus needs infants/children
0.5-2 mmol/kg
adolescents + children >50 kg
10-40 mmol
magnesium needs preterm neonates
0.3-0.5 meq/kg
magnesium needs infants/children
0.3-0.5 meq/kg
magnesium needs adolescents + children >50 kg
10-30 meq
trace element deficiency associated with microcytic anemia and neutropenia
copper
trace element deficiency associated with growth failure and hair loss
zinc
neonate
first 28 days of life
neonate parenteral calorie goals
preterm: 85-111 kcals/kg, 3-4 grams pro/kg
late preterm: 100-110 kcals/kg, 3-3.5 grams pro/kg
term: 90-108 kcals/kg, 2.5-3 grams pro/kg
neonate enteral calorie goals
preterm: 110-130 kcals/kg, 3.5-4.5 g pro/kg
late preterm: 120-135 kcals/kg, 3-3.2 g pro/kg
term: 105-120 kcals/kg, 2-2.5 g pro/kg
cyclosporine commonly used after solid organ transplantation for immune suppression may cause
hyperkalemia, hypomagnesemia, hyperglycemia, hypercholesterolemia