Flashcards in Fluids- electrolytes Deck (60)
Components of body fluid?
- ICF: 2/3 of total body fluid
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
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+
- albumin: 290-31- mOsm/L
- blood products:
packed RBCs, fresh frozen plasma
Saline: 3%, 5%, D5W1/2NS adverse effects?
- ICF depletion
- fluid overload
Albumin adverse effects?
- allergic reactions
- possible infection transmission (hepatitis)
Impt steps in assessing types of fluid loss?
- pt hx
- 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