altered fluids & electrolytes

285-295 mOsm/L

• 1) Na (has biggest effect on osmolarity) 135-145
• 2) glucose (= a big molecule, has a lot of pull) 70-100
• 3) BUN 10-20

Na lab values and I&O

Proportionately = loss of water and Na. There is no osmotic pull from ICF to ECF. The plasma voulume is greatly reduced.

"water conserving hormone" manufactured in the hypothalamus and stored in the posterior pituitary

hormone instrumental in F&E homeostasis, mainly Na and K balance. Secreted from adrenal cortex.

1) The decr. in intravascular pressure leads to an incr. in colloidal osmotic pressure which moves fluid from the intersititial to intravascular spaces.

• Hormones secreted:
• 2) The decr. in kidney flow (isotonic dehydration= reduced plasma volume) causes aldosterone release which causes Na retention and K loss. ADH is also released causing renal retention of water (helps bc you're dehydrated)

• 1) hemorrhage
• 2) profuse diaphoresis (sweating)
• 3) GI fluid loss

• -postural tachycardia (when HR incr. from laying flat to sitting or standing)
• -postural hypotension (when BP drops >20 mmHg systolic and >10 mmHg diastolic over a 2-3 min period)

• -weak pulse
• -tachypnea (pt. breathing quickly bc FVD causs less plsma volume = less circulating O2)
• -flat neck veins supine
• -slow vein filing in hands

• - Urine <20-40 ml/hr
• - incr. BUN (dehydration causes incr. BUN bc it's reabsorbed
• - incr. Hct (if no hemorrhage, due to heme concentration)

• -thirst at 1-2% loss
• - eyes sunken
• -soft eyeballs
• -dry mucous membranes
• -weight loss

• Replace both fluids and electrolytes.
• 1) oral intake of salty foods (e.g. Bullion)
• 2) Fluid expanders: IV fluids which stay in the vascular space and therefore incr. blood volume and restore circulation there

• 1) Normal Saline- NS (0.9% NaCl)
• 2) Ringers Lactate- RL (has buffers like K, HCO3, Ca...like gatoratde of IV fluids)
• 3) Albumin (used for oncotic pull properties to help pull fluid back into vascular space, incr. colloid osmotic pressure in edematous cases)

• Water loss greater than Na loss. Na greater than 145 mEq/L.
• ECF and ICF volumes are both decr.
• Incr. ECF osmolarity (soulutes) results in a shift of fluid from the ICF to the ECF causing severe cellular dehydration.

• 1) soulte taken in w/o adequate water (tube feedings of high concentration) Kidney wants to remove high solutes via osmotic diuresis. (pt. on tube feedings may need a H2O bolus to make up for high concentration feedings)
• 2) Pts w/ decr. LOC and are unaware they are thirsty.
• 3) Diabetics w/ high blood sugar having osmotic diuresis.

• Skin and membrane dehydration:
• -dry skin (tenting skin)
• -tongue furrows
• -dysphagia
• -wt. loss
• -thirst

• Nervous system dehydration:
• -mental status changes (with incr. or decr. IC space)
• -muscle weakness

• 1) water taken in orally if possible
• 2) IV D5W or D5 w/ 0.2% NaCl (it's not standard to hang D5W, suspect that pt. is in hypernatremic state, check labs)
• 3) additional water w/ tube feedings

• -aka hypervolemia
• -excessive fluid in the ECF compartment (plasma)
• -serum osmolarity remains normal despite overhydration
• -no shifting of fluids between ECF and ICF compartments
• -isotonic circulatory overload can lead to edema

• PUSH:
• 1) incr. in capillary fluid hydrostatic pressure (and oncotic pull can't compensate)
• 2) decr. in interstitial fluid hydrostatic pressure

• PULL:
• 1) decr. in capillary oncotic pressure
• 2) incr. in interstitial oncotic pressure

• 1) heart failure- leads to decr. excretion of H2O and Na (heart can't pump correctly, fluid backs up, can't excrete)
• 2) renal failure- leads to decr. excretion of H20 and Na
• 3) longterm cortiocosteroid therapy results in H20 and Na retention (i.e. prednisone is cousins w/ aldosterone and causes Na retention therefore H20 retention and pt. will gain wt.)
• 4) poorly controlled IV therapy
• 5) High aldosterone levels (stress response, adrenal dysfunction)

weights

• - wt. gain over 2.2 lbs/24 hr = 1Kg = 1L gain
• -diuresis (attempting to remove excess fluid, if kidneys are normal)
• -jugular vein distention (JVD)
• -tachycardia (bounding) to push more fluid
• -lung sounds = fine crackles (bc capillaries in lungs are overhydrated)
• late signs:
• -s/s of pulmonary edema
• -peripheral edema: pitting edema, approx. 8lbs wt. gain

• -elevation of dependant part
• -tx. of underlying condition
• -diuretics
• -daily weights
• -strict I&O
• -fluid restriction
• -reduced salt intake (PMS foods)
• Processed
• Moo (dairy)
• Salty

• -the excess fluid is hypotonic to normal body fluids (usually accompanied by hyponatremia, Na less than 135)
• -osmolarity of the ECF decr., and hydrostatic pressure incr. Fluid moves into the intracellular space bc of decr. vascular osmotic pressure, and all body fluid compartments expand

• 1) incr. water w/o incr. Na or other electrolytes leads to cellular swelling:
• -tap water enemas given repeatedly (pulls out Na)
• -Contiunous bladder irrigation w/ sterile water (careful w/ men w/ prostate cancer to flush blood clots)
• -high intake of Na free fluids IV or PO (if pt. is treated w/ D5 w/ water for hypernatremia and then bag keeps hung eventhough pt. is hyponatremic
• 2) syndrome of inappropriate antidiuretic hormone (SIADH)= excess release of ADH (water conserving hormone)
• 3) replacement of isotonic fluid loss with hypotonic fluids

• -weight gain
• -GI dysfunction
• -anorexia, cramping, N/V
• -neurological (brain swelling): cerebral cells absorb free water more readily that other cells, thus are very sensitive to hpotonic ECF state
• -HA/depression/confusion
• -lethargy and stupor
• -convulsions/coma

• -treat underlying condition
• -diuretics (pt. will void H20 but be careful bc pt also voiding Na, we need to give Na supplements)
• -fluid restriction
• -Na supplements (IV)
• -daily wt/strict I&O