MED SURG (FLUID & ELECTROLYTE : BALANCE AND DISTURBANCE)
LUKE 1:37
Fluid Volume Excess : Hypervolemia
Isotonic expansion of ECF caused by abnormal retention of
H2O and Na; approx same proportions in w/c they normally
water in ECF.
Secondary to increase in the total body Na content =
Increase in total body water.
There is isotonic retention of body substances = normal Na
concentration
Pathophysiology:
Assessment and Diagnostic Findings:
Decreased BUN and hct level - because of plasma dilution,
low protein intake, and anemia.
Chronic Renal failure - decreased serum osmolality and Na
level owing to excessive retention of H2O
Urine sodium level is INCREASED IF kidneys are
attempting to excrete excess volume
X-ray - reveal pulmonary confestion
Hypervolemia - occurs when ALDOSTERONE is
chronically stimulated (Cirrhosis, HF, nephrotic
syndrome) = Urine Na level DOES NOT INCREASE
Medical Management:
FVE is directed at the causes; IF r/t excessive administration
of Na-containing fluids = discon’t infusion.
Symptomatic Tx - administering diuretics and restricting
fluids and Na
a. Pharmacologic Therapy
Duiretics - prescribed when dietary restriction of Na
alone is INSUFFICIENT to reduce edema by inhibiting
the reabsorption of Na and H2O by kidneys
Consider the FF before administration:
i. Severeity of Hypervolemic state
ii. Degree of impairment of Renal
function
iii. Potency of diuretic
1. Thiazide Duiretics; hydrochlorothiazide
(HydroDIURIL) or chlorthalidone (Thalitone) -
block Na reabsorption in distal tubule (5-10% of
filtered Na is reabsorbed)
- Prescribed for mild -moderate
hypervolemia
2. Loop Diuretics ;furosemide (Lasix), bumetanide
(Bumes), torsemide (Demadex) - cause greater
loss of both Na and H20; they block Na
reabsorption in ascending limb of henle’s loop
(20-30% of filtered Na is normally reabsorbed)
-Prescribed for severe hypervolemia
Side effects (Diuretics)
i. Electrolyte Imbalances
a) Hypokalemia - occur with all diuretics EXCEPT
those that work in last distal tubule of nephrons
(Thiazide D.)
b) Hyperkalemia - occur with diuretics that work in
distal tubule (spirronolactone - Aldactone
(potassium-sparring diureitcs), esp in px with
decreased renal function (Loop D.)
c) Hyponatremia - occurs with diuresis owing the
increased release of ADH secondary to reduction
of circulating volume
d) Hypomagnesemia - occur with administration of
loop and thiazide diuretic d/t decreased
reabsorption and increased excretion of Mg by
the kidney
ii. Azotemia - increased nitrogen levels in blood; urea
and creatinine are not excreted owing to decreased
perfusion by kidneys and decreased excretion of
wastes
iii. Hyperuricemia - High uric acid; occur from increased
reabsorption and decreased excretion of uric acid by
kidneys
b. Dialysis
Done IF renal function is severely impaired and
pharmacologic agents cannot act efficiently.
Contributing factors:
a. Heart failure
b. Renal Failure
c. Liver cirrhosis
Consumption of excessive amounts of table or other
Sodium Salts
Excessive administration of sodium-containing fluids
in px w/ impaired regulatory mechanism
Severe stress
Prolonged corticosteroid therapy
Hyperaldosteronism augment fluid volume excess
r/t simple fluid overload/diminished f(x) of
homeostatic mechanisms resp. For
regulating fluid balance
FVE
S/Sx:
Acute Weight gain
Peripheral edma & ascites
Distended Jugular Veins
Crackles
Elevated CVP
Shortness of Breath
↑BP, ↑Respiratory Rate.
↑urine output
Bounding pulse and
cough
Lab Findings:
↓Hgb & hct
↓Serum & urine
osmolality
↓Urine Na and
specific gravity
