PPT2 Exam 2

sodium, chloride, potassium, calcium, phosphate, magnesium

~ 3 L

SODIUM, chloride, proteins, glucose, meds

POTASSIUM, proteins

to ICF (higher concentration because less water there)

main determination of tonicity and osmolality! regulates total body water.
disorders in sodium are related to total body water disturbances.

Regulating ECF volume and distribution
Maintaining blood volume (by increasing tonicity in ECF)
Transmitting nerve impulses and contractions
Sodium-Potassium pump action

Kidney, aldosterone, natriuretic hormones, vasopressin

> 145
common in patients with inability to retain water (output greater than input)
assoc with increased hospital mortality
state of: hyperosmolality and intracellular dehydration

<136 with osmolality < 280
mainly a sign of relative excess of water
total body sodium may be increased, decreased, or normal

2/3 tbw
1/3tbw
3/4 of ecf
1/4 of ecf (5 l)

sodium and chloride

isotonic hypertonic hypotonic

isovolemia
hypervolemia
hypovolemia

excessive isotonic fluid intake
hyperaldosteronism
increases sodium/water reabsorption
weight gain
HYPERtension
edema
distended neck veins
DECREASED hgb/hct count (dilutional effect)

ECF losses
decreased fluid intake
hemorrhage
wound drainage
weight loss
dry skin
decreased urine output
hypotension
tachycardia (body senses low volume so INCREASES heart beat)

sodium

ICF (K, prots)
ECF (Na/Cl, prots, glucose, medications)

in the serum, sodium and prots
hydrostatic pressures (cardiac contraction) (increased cardiac output moves from ecf to icf)

INC hydrostatic pressure
INC membrane permeability (inflammation disease states)
DEC serum oncotic pressure

localized: trauma, brain, lungs, pericardial, ascites
general: feet, legs, pitting edema

weight gain
swelling/puffiness
dehydration
INC risk of infection
pressure sores
SOB
chest pain/tightness

1. Inc/Dec INTAKE
2. Inc/Dec UTILIZATION
3. Inc/Dec EXCRETION

main determiner of tonicity and osmolality
disorders in sodium related to TBW therefore must consider volume status
very common in hospitalized patients

regulating ECF vol and distrib
maintain blood volume (increase tonicity)
transmit nerve impulses and contractions
Sodium/Potassium pump action

kidney
aldosterone
natriuretic
vasopressin, avp (STRONG stimulus to dec vol/bp -- increases reabsorp)

common when unable to obtain water
hyperosmalility
intracellular dehydration
iatrogenic can cause this
hypovolemic is most common

diuretics, gi loss, skin loss
renal failure, glycosuria
increased total body solute

skin loss, di
PURE WATER LOSS
renal loss
insensible loss

mineralcorticoid excess
uncommon
PURE SODIUM EXCESS

mainly CNS
if you treat too fast, increased edema in brain
Common sympts: thirst, irritability, lethargy, convulsions, coma (weight gain, edema, restlessness, muscle twitching)
can have HYPOVOL signs (tachy, orthostatic hypotension, dry mucous membranes)

< 136
OSMOLALITY <280
common in hospitalized
a sign of excess water... retention or dec elim

TOTAL BODY SODIUM MAY BE INCREASED, DECREASED, OR NORMAL

therefore, first look at tonicity then volume status

not true cause
isotonic infusions
pseudohypernatremia
280-290

not true cause
hyperglycemia
hypertonic infusions
INCREASE IN BLOOD GLUCOSE IS MAIN CAUSE

MUST CORRECT SODIUM
>295

must do for hypertonic hyponatremia

measured sodium + .016(serum glucose-100)

true cause
3 types: hypovolemic, isovolemic, hypervolemic
<280

ECF volume depletion
GI loss
Diuretics
adrenal insufficiency

Pure water loss

CONGESTIVE HEART FAILURE
hepatic cirrhosis
D5W admin

CNS
110-125
apathy, lethargy, nausea, vomitting, HA, confusion
<110
stupor, seizures, coma, brain, edema

muscle cramps with rapid change