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Flashcards in Fluids- electrolytes Deck (60)
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Components of body fluid?

- ICF: 2/3 of total body fluid
-ECF: 1/3
ISF, plasma, and lymphatic fluid


Electrolytes in ECF and ICF?

- ECF: Na+ (142 mEq/L), Cl- (103 mEq/L), HCO3-
- ICF: K+ (140 mEq/L), Mg, phosphates


Water movement regulation?

- starling forces: hydrostatic pressures and osmotic pressures:
Capillary hydrostatic pressure: pressure in capillary pushing fluid out
Interstial fluid hydrostatic pressure: pushing fluid in from ISF
- Osmotic force due to plasma concentration (drawing fluid into capillaries)
- Osmotic force due to ISF protein concentration (drawing fluid out)


What is osmolality? What is most important factor?

- concentration of an osmotic soln when measured in osmols of solvent
plasma: 280-295 mOsm/kg
- Na+ is most impt plasma osmolality factor (water follows Na+)


Process of fluid and electrolyte replacement? IV solutions?

- assess ins and outs
- oral replacement preferred when tx dehydration
- IV:
saline equivalents: crystalloids - normal saline or LR
water equivalents: D5W
if 3% NS - have to do central line (will destroy peripheral veins)


What are the components of LRs?

- 250-273 mOsm/L
- Na+, Cl-, lactate, Ca+, K+


Parenteral colloids?

- albumin: 290-31- mOsm/L
- blood products:
packed RBCs, fresh frozen plasma


Saline: 3%, 5%, D5W1/2NS adverse effects?

- ICF depletion
- fluid overload
- hypernatremia
- hyperchloremia


Albumin adverse effects?

- allergic reactions
- possible infection transmission (hepatitis)


Impt steps in assessing types of fluid loss?

- pt hx
- sxs
- vital signs and PE


What is hypervolemia?

- too much Na+
- expansion of effective arterial blood volume
- CHF, cirrhosis, aldosterone, renal disease


WHat is hypovolemia?

- too little Na+
- volume contraction
- dehydration: V/D, exercise, not drinking enough water


What is hyponatremia? Hypernatremia? Edema?

- too much water
- not enough Na+

- too little water (dehydration)
- excess Na+

edema: too much Na+ with water retention in the ISF (abdomen, lungs) - alcoholics, cirrhosis, metastatic cancers


Severity of edema?

- 1+ = 2 mm
- 2+ = 4 mm
- 3+ = 6 mm
- 4+ = 8 mm


How to tx mild dehydration?

- oral replacement:
fluids with electrolytes are preferred
- avoid fluids with high sugar concentration
- water and sports drink or in children pediolyte
- stop activities that create ongoing losses


Assessing degree of fluid loss for moderate hypovolemia?

- hx: any GI losses (V/D), excessive exercise, renal losses
- sx: easy fatiguability, thirst, muscle cramps, postural dizziness, abdominal pain, CP, lethargy, confusion, decreased urination
- clinical manifestations: decreased skin turgor, tachycardia, dry mucus membranes


How do electrolyte imbalances present? How do these imbalances occur?

- sxs: precipitate as CV, neuro, and neuromuscular abnormalities
- disruptions occur: via drugs, disease states, diarrhea, vomiting, infection, hormone imbalances, malignancies
- to tx these: need results of lab tests then start IV fluids


Etiologies of hyponatremia?

- hypovolemia: GI losses: vomiting, and diarrhea, dehydratioon
renal losses: (thiazide diuretics), ACEIs, mineralocorticoid deficiency
- normovolemia: SIADH, primary polydipsia/marathon runners, low dietary solute intake, psychogenic polydipsia
- hypervolemia: CHF, cirrhosis, nephrotic syndrome, advanced syndrome (rare)
- others: hypothyroidism, primary adrenal insufficiency, drugs


What lab values do you want to know for hyponatremia? lab value indications?

hyponatremia is less than 135 meq/L
- serum osmolality impt
- urine Na+
- assess severity:
less or equal to 120 meq/L panic value***
- 120-130: depends on sxs and situations
- greater than 130 is generally not tx


Clinical manifestations of chronic hyponatremia?

- cerebral adaption:
going to have fatigue, nausea, dizziness, confusion, lethargy, muscle cramps, gait disturbances and forgetfulness


Clinical manifestations of acute hyponatremia?

- acute hyponatremic encephalopathy: cerebral over hydration related to degree of hyponatremia
fatigue an malaise are usually the first sxs
- HA, lethargy, coma, seizures and eventually respiratory arrest
- acute hyponatremic encephalopathy may cause permanent neuro damage or death
- can be hyponatremic classified by ECF status: hypovolemic: GI losses, renal losses (thiazides), normovolemic: SIADH, low Na+ intake, hypervolemic: CHF, cirrhosis


How does osmotic demyelination happen?

- try to correct hyponatremia and then you overcorrect making ECF hypernatremic so H2O leaves brain too quickly and it shrinks


How can acute hypotonic hyponatremia occur? WHat are the sxs?

- can result in sxs of neuronal cell expansion and cerebral edema
- Nausea/HA, seizure, coma and death


Hyponatremia etiologies with inability to suppress ADH problem?

- true volume depletion (GI or renal losses - thiazide diuretics), decreased tissue perfusion (reduced CO or systemic vasodilation in cirrhosis for instance)
syndrome of inappropriate ADH secretion (SIADH)


Causes of hyponatremia with appropriate suppression of ADH secretion?

- primary polydipsia
- low dietary solute intake
- advanced renal failure


Causes of hypovolemic hyponatremia?

- GI or renal losses
- if serum Na+ hasn't dropped critically low quickly
- usually just volume replacement orally or IV if more severe


Tx for hypovolemic hyponatremia?

- NS/isotonic saline
- depending on pt status may do slow bolus
- then maintenance depending on ongoing losses


Causes of hypervolemic hyponatremia?

- CHF, cirrhosis, renal failure


Tx of hypervolemic hyponatremia?

- restrict fluids: 1000-1200 ml/day
- restrict sodium: 1000-1200 mg/day
- utilize loop diuretics to remove excess fluid, K+ replacement


What is SIADH? Causes? Tx?

- too much ADH. Either Eu/hypervolemic hypotonic hyponatremic presentation

can be:
drug induced: carbamazepine, SSRIs, haloperidol, and thorazine

disease induced: malignancies, CNS disorders, post-surgery, pulmonary infections

Tx: tx underlying cause, fluid restriction is mainstay!!!!! May use oral salt tablets, loop diuretics