Nutritional support and Fluid& electrolyte imbalance Flashcards
Nutrition labs
albumin levels of < 3.35 indicate protein malnutrition: edema can be expected if albumin level is < 2.7
hgb < 12 for women and < 13 for men can indicate lack of iron or protein resulting in inadequate oxygen profusion
earliest indication of malnutrition
prealbumin
when do you transfuse?
8 and 24
when a person gets 2 units how does it affect hgb and htc
1:3 is the ration of hgb to htc
1 unit of pRBC: hgb goe sup 1 then hematocrit goes up 3
IF cannot use the GI tract
diverticulitis, perf diverticula etc
Parenteral Nutrition
support greater than 2 weeks or using dextrose solution > 10% then need central vein
otherwise can use peripheral
IF can use GI tract and need support greater than 6 weeks (brain injury, closed head injury)
Enterostomal tube (PEG tube)
If cannot use GI tract and need support less than 6 weeks then use:
nasoenteric tube (ND- duotube)
risk for aspiration: duodenal tube
not risk for aspiration: NG tube
Complications of enteral nutrtional support
enteral is the solution
Aspiration diarrhea emesis gi bleeding mechanical obstruction of tube hypernatremia** dehydration**
complications of parenteral nutritional support
parenteral is mode of delivery
pneumothorax hemothorax arterial laceration air emboli catheter thrombosis catheter sepsis hyperglycemia** HHNK**
evaluation of hyponatremia
- urine Na (10-20)
- serum osmolality (usually 2x Na)
- clinical status
what does measuring urine Na help distinguish?
renal from non-renal causes.
what does a urine Na > 20 suggest?
renal salt waisting (problem with the kidneys)
what does a urine Na < 10 suggest?
renal retention of Na to compensate for extrarenal fluid loss (problem other than the kidneys)
Isotonic hyponatremia
- occurs with extreme hyperlipidemia or hyperproteinemia
- body water is normal and the patients are asymptomatic
- tx: cut down fat (no fluid restriction***)
pseudeohyponatremia: serum osmo 284-292
what does isotonic mean
- of equal tension
- having the same tonicity as another solution
- a solution that causes no change in cell volume (don’t swell or shrink)
hypotonic
a fluid in which cells would swell
- having a lesser osmotic pressure than a reference solution
- low tonicity
hypotonic Hyponatremia
-serum osmo < 280: state of body water excess diluting all body fluids; clinical signs rise from water excess
what do you need to do in a patient with hypotonic hyponatremia?
need to assess if the patients is hypovolemic or hypervolemic
-if hypovolemic, assess whether hyponatremia is due to extrarenal salt losses or renal salt wasting
how does someone end up hypovolemic with urine Na < 10
- dehydration
- diarrhea
- vomiting (NG tube suctioning-prolonged)
what are causes of hypovolmia with urine Na > 20
- low volume and kidneys cannot conserve Na
- diuretics**
- ace inhibitors
- mineralcorticoid deficiency (adrenal insuficiency)
What are causes of hypervolemic, hypotonic hyponatremia
-edematous states
chf
liver dz
advanced renal failure
what do you do with Hypervolemic, hypotonic (serum osmo < 280) hyponatremia
restrict water
Hypertonic solution examples
D10 saline 3%-5% NS or NaCl D5 D5 0.9% D5 0.45% 5% dextrose in lactated Ringer's
Isotonic solutions
D5W
0.9%NS
D5 1/4 NS
Lactated Ringer’s
Hypotonic solutions
- 45% NS
0. 33% NS
how do hypertonic solutions work
How do isotonic solutions work
used to replace fluid losses, usually extracellular lossses and to expand the intravascular volume. Most isotonic solutions do not provide calories or free water
0.9% NS and lactated ringers
how do hypotonic solutions work
administered to expand intracellular space
- commonly used to infused to dilute extracellular fluid and rehydrate cells of pts who have hypertonic fluid imbalances and to tx gastric fluid loss and dehydration from excessive diuresis.
- provides free water, Na, Cl
0. 45% NS or 1/2 NS
when are hypertonic solutions used?
tx pts who have severe hyponatremia
Hypertonic hyponatremia
(serum osmo > 290)
- hyperglycemia: usually fron HHNK***
- Osmolality is high and the Na is low
Management of hyponatremia
tx based on cause
- if hypovolemic give NS IV
- if urine Na > 20, treat cause
- if hypervolemic implement water restriction
- if symptomatic give NS with a loop diuretic
- if CNS symptoms consider 3% NS with loop diuretics
Hypernatremia
usually d/t excess water loss; always indicates hyperosmolality (ie., deficit of water)
Management of Hypernatremia
with hypovolemia
-severe hypermatremia with hypovolemia should be treated with NS followed by 1/2 NS
Management of hypernatremia with euvolemia
free water (D5W-isotonic)
Management of hypernatremia with hypervolemia
- free water and loop diuretics
- may need dialysis
Hypokalemia causes
-diuretics*** GI loss excess renal loss alkalosis laxative abuse trauma (via epi) insulin excess hyperaldosteronism Cushing's renin-producing tumor
S&S Hypokalmeia
- muscular weakness, fatigue and -muscle cramps***
- constipation or ileus due to smooth muscle involvement
- if severe (< 2.5) flaccid paralysis, tetany, hyporeflexia and rhabdo
Labs and diagnostics hypokalemia
- decreased amplitude on ecg
- broad T waves
- prominent U waves
- PVCs, V-tach, V-fib
management of hypokalemia
oral replacement if > 2.5 and no ecg abnormalities
- IV replacement at 10 if cannot take PO
- if < 2.5 or severe S/S may give 40 meq/hr IV- check 3 hours and institute continuous ecg monitoring
Hyperkalemia
-excess intake
-renal failure
-drugs (NSAIDS)
hypoaldosteronism
-shifts of intracellular K to extracellular space occur with acidosis. K increases 0.7 meq/L with each 0.1 drop in pH
Hyperkalemia S/S
- weakness, flaccid paralysis
- abd distention
- diarrhea
Hyperkalemia mngt
exchange resins (kayexelate) - if> 6.5 or cardiac toxicity or muscle paralysis consider: insulin 10 u with 1 amp D50
Calcium
a major cellular ion and impt as a mediator of neuromuscular and cardiac function.
normal total calcium of 2.2-2.6mmol/L (8.5-10.5 mg/dl)
normal ionized calcium of 1.1-1.4 mmol/L
what is calcium maintained by?
Vitamin D, parathyroid hormone and calcitonin
what increases and decreases ionized calcium
acidemia increases
alkalemia decreases
what is the role of albumin in calcium levels?
-50% of calcium is bound to albumin, a normal caclium level in presence of low albumin suggests that the patient is hypercalcemic
how to calculate corrected calcium?
corrected calcium = measured total Ca _ 0.8 or 4- serum albumin where 4 represents the average albumin level
Causes of hypocalcemia
hypothyroid hypomagnesemia pancreatitis renal failure severe trauma multiple blood transfusions
S/S of hypocalcemia
increased DTRs muscle/abd cramps trousseau's sign convulsions chvostek's sign prolonged QT
Management of hypocalcemia
- check blood pH (alkalosis)
- if acute, IV calcium gluconate
chronic: oral supplements, vit d, aluminum hydroxide
hypercalcemia causes
- hyperparathyroidism
- hyperthyroid
- vit d toxicity
- prolonged immobilization**
- thiazide diuretics**
S/S hyperkalemia
- fatigue
- muscle weakness
- depression
- anorexia
- N/V
- constipation
- severe hypercalcemia can cause coma and death
- serum ca > 12 considered emergency
Management of hypercalcemia
- may need calcitonin if impaired cardiovascular or renal function
- dialysis
- if > 12 begin NS infusion with loop diuretics
Hypocalcemia
S/S high
Hypercalcemia
S/S low
