Electrolyte Range Magic 4
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Transcript Electrolyte Range Magic 4
Megan McClintock
Winter 2012
FLUID & ELECTROLYTES
ACID BASE IMBALANCES
CHAPTER 17
HOMEOSTASIS
Maintained by the intake and output of water and
electrolytes and regulation by the renal and
pulmonary systems
Acid-base balance is necessary for many
physiologic processes (respiration, metabolism,
function of the CNS)
Many disease and treatments
affect this balance
WATER
More important to life than any other nutrient
60% of an adult’s body weight, more in a child,
less in the elderly
Found in foods (but not in alcohol)
Daily need is about 2000 mL
1 liter of water weighs 1 kg
URINE SPECIFIC GRAVITY
Measures the kidney’s ability to concentrate or
dilute urine
1.002 – 1.028
High
is dehydrated
Low is overhydrated (or unable to concentrate)
Kidney failure often causes a fixed specific gravity
ELECTROLYTES
Cations (positively charged)
K+,
Na+, Ca+, Mg+
Transmit nerve impulses to muscles and contract
skeletal and smooth muscles
Anions (negatively charged)
Attached
to cations
Cl-, HCO3-, PO4-, SO4
Are always kept in
balance
DISTRIBUTION OF BODY FLUIDS &
ELECTROLYTES
Intracellular (2/3) – K+, PO4 Extracellular (1/3) – Na+, Cl
Interstitial
(lymph)
Intravascular (blood plasma)
Transcellular (cerebrospinal, pleural, peritoneal,
synovial fluids)
REGULATION OF FLUID & ELECTROLYTE
MOVEMENT
OSMOLALITY
Indicates the water balance of the body
Serum osmolality (275 - 295)
High
is water deficit
Low is water excess
Urine osmolality (100-1300)
High
is concentrated
Low is dilute
FLUID SPACING
First spacing
Normal
Second spacing
Edema
Third spacing
Ascites
Burn
edema
REGULATION OF WATER BALANCE
Hypothalmic Regulation
Thirst is stimulated
ADH (vasopressin) release is stimulated
Pituitary Regulation
Adrenal Cortical Regulation
ADH (vasopressin) is released
Glucocorticoids & mineralocorticoids are released
Renal Regulation
Adjust urine volume and electrolyte excretion
Normal is 1.5 Liters of urine/day
REGULATION OF WATER BALANCE (CONT.)
Cardiac Regulation
ANP
& BNP will stop the action of the adrenal
cortex and the kidney
GI Regulation
Intake
and output are reabsorbed here
Diarrhea and vomiting can lead to significant losses
Insensible Water Loss
600-900
mL/day from the lungs and skin
Increases with fever, exercise
GERONTOLOGIC CONSIDERATIONS
Structural changes in the kidney and decreased renal
blood flow
Decreased GFR
Decreased creatinine clearance
Loss of ability to concentrate urine and thus conserve water
Decrease in renin and aldosterone
Increase in ADH and ANP
Loss of subcutaneous tissue
Decrease in thirst mechanism
Musculoskeletal changes
Mental status changes
Incontinence
FLUID VOLUME DEFICIT
What
causes
it?
What
can you
do?
FLUID VOLUME EXCESS
What
causes
it?
What
can you
do?
NURSING INTERVENTIONS
Strict I/O
Intake – oral, IV, tube feedings, retained irrigants
Output – urine, excess sweating, wound/tube drainage,
vomitus, diarrhea
Urine specific gravity
Assessment of CV, Resp, Neuro, Skin status
Daily weight under standardized conditions
Don’t “catch up” IV fluids
No water with NG suction, use isotonic saline
Keep fluids accessible and within reach
Give warm or cold fluids (not room temperature)
SERUM ELECTROLYTES
Sodium (Na) 135 - 145
Primarily
responsible for maintaining osmotic pressure
(intracellular and extracellular fluids)
Increased with fluid deficit
Decreased with fluid excess
Potassium (K) 3.5 – 5.0
Chloride (Cl) 96 – 106
Works with Na to maintain osmotic pressure
Increased with poor kidney function
Decreased with excessive vomiting or diarrhea
Calcium (Ca) 8.6 – 10.2
Major component of cardiac function
Increased with poor kidney function
Decreased with excessive urination, diarrhea or vomiting
Transmission of nerve impulses, heart and muscle contractions,
blood clotting, formation of teeth and bone
Phosphate (PO4) 2.4 – 4.4
Function of muscle, RBCs, and the nervous system
THE MAGIC FOURS
Electrolyte
Potassium
Chloride
Sodium
pH
CO2
HCO3
Range
3.5 - 5.0
96 - 106
135 - 145
7.35 - 7.45
35 - 45
22 - 26
Magic 4
4
104
140
7.4
40
24
Hematocrit normal is 3 times the hemoglobin
SODIUM (135 - 145)
Major cation of ECF
Primary determinant of osmolality
GI tract absorbs sodium from food
Regulated by kidneys, ADH, aldosterone
Sodium level reflects the ratio of sodium to
water
Imbalances are typically associated with fluid
volume problems
HYPERNATREMIA (HIGH SODIUM)
What
causes
it?
What can you
do?
HYPONATREMIA (LOW SODIUM)
What
causes
it?
What
can you
do?
POTASSIUM (3.5 - 5.0)
Major cation of ICF
Sodium-potassium pump requires magnesium
Moves into cells during formation of new
tissues and leaves the cell during tissue
breakdown
Diet is the source of potassium
Kidneys are primary route of loss
HYPERKALEMIA (HIGH POTASSIUM)
What
causes
it?
What
can you
do?
HYPOKALEMIA (LOW POTASSIUM)
What
causes
it?
What
can you
do?
CALCIUM (8.6 – 10.2)
Primary source is bones
Regulated by parathyroid hormone, calcitonin,
and vitamin D
Affects transmission of nerve impulses, heart
and muscle contractions, blood clotting, and
forming of teeth and bone
HYPERCALCEMIA (HIGH CALCIUM)
What
causes
it?
What
are the
symptoms?
What
can you
do?
HYP0CALCEMIA (LOW CALCIUM)
PHOSPHATE IMBALANCES
Hyperphosphatemia
Cause - renal failure
S/S – calcium deposits in joints, skin, kidneys, eyes;
hypocalcemia, tetany, neuromuscular irritability
Tx – decrease intake of dairy products, good hydration, fix
hypocalcemia
Hypophosphatemia
Cause – malnutrition, malabsorption syndrome, alcohol
withdrawal
S/S – CNS depression, confusion, muscle weakness,
dysrhythmias
Tx – oral supplements (Neutra-Phos), lots of dairy products,
IV phosphate (but this can cause sudden hypocalcemia)
MAGNESIUM IMBALANCES
Hypermagnesemia
Cause – increased intake (ie. MOM, Maalox) with chronic kidney
disease
S/S – lethargy, n/v, loss of DTRs, can have respiratory and
cardiac arrest
Tx – avoid magnesium-containing drugs, IV calcium, increased
fluid intake, may need dialysis
Hypomagnesemia
Cause – prolonged fasting or starvation, chronic alcoholism,
diuretics
S/S – confusion, hyperactive DTRs, tremors, seizures, cardiac
dysrhythmias
Tx – oral supplements, increase green veggies, nuts, bananas,
oranges, peanut butter, chocolate; IV or IM magnesium (if given
too rapidly can cause cardiac or respiratory arrest)
MEDICATIONS
Loop diuretics
Thiazide diuretics
Potassium sparing diuretics
Electrolytes
Kayexolate
ACID BASE BALANCE
REGULATION OF ACID-BASE BALANCE
Buffer system (immediate)
Primary
regulator
Won’t work without good functioning respiratory
and renal symptoms
Respiratory system (minutes, max in hours)
Excretes
CO2 and water
Renal system (2-3 days to max respond)
Reabsorbs
HCO3
ARTERIAL BLOOD GAS
pH (7.35 – 7.45)
CO2 (35 – 45)
HCO3 (22 – 26)
Base excess (+2 to -2)
If high, metabolic alkalosis
If low, metabolic acidosis
DETERMINING
ACID–BASE BALANCE
1.
2.
3.
4.
5.
Is pH acid, base or normal?
Is CO2 acid, base or normal?
Is HCO3 acid, base or normal?
Which of the components match?
Is there compensation?
Is non-matching reading abnormal? – partial compensation
Is non-matching reading normal? – no compensation
RESPIRATORY ALKALOSIS
RESPIRATORY ALKALOSIS
Causes
Hyperventilation
Pulmonary disease
High altitudes
Signs/symptoms
Hyperventilation
Feels “light-headed”
Arrhythmias
Anxiety
Treatment
Breathe into paper bag
Rebreather mask
Anti-anxiety medicine
Relaxation techniques
Reduce stimulation
Treat pain/fever
Assess:
Resp rate/depth
HR & BP
Serum K levels
Hydration status
Check for digitalis toxicity
RESPIRATORY ACIDOSIS
RESPIRATORY ACIDOSIS
Causes
CNS depression
Loss of lung surface
Neuromuscular disease
Immobility
Mechanical ventilation
Treatment
Signs/symptoms
Dyspnea
Hypoxia
Drowsiness
Tachycardia
Seizures
Diaphoresis
Turn, cough, deep breathe
Semi-Fowler’s position
Suction
Incentive spirometer
Seizure precautions
Decrease use of sedatives
Bronchodilators
May need ventilator
Assess:
Resp rate/depth
HR & BP
Patiency of airway
METABOLIC ALKALOSIS
METABOLIC ALKALOSIS
Causes
NG suctioning
Prolonged vomiting
Diuretic use
Multiple blood transfusions
CPR (given bicarb)
Signs/symptoms
Dizziness
Dysrhythmias
Convulsions
Confusion
Muscle cramps (late sign)
Treatment
Identify and treat the cause!
IV fluids
Stop giving bicarbonate
Give antiemetics
Give Diamox
Assess:
Resp rate/depth
HR & BP
Serum K levels (usually low)
Hydration status (tend to be
dehydrated)
Check for digitalis toxicity
Parasthesias
METABOLIC ACIDOSIS
METABOLIC ACIDOSIS
Causes
Diabetic ketoacidosis
Renal or liver failure
Severe diarrhea
Vomiting
Starvation
Signs/symptoms
Kussmaul respirations
Hypotension
Arrythmias
Warm to hot ,flushed skin
Confusion
Treatment
Identify and treat the cause!
Administer insulin (if due to
ketoacidosis)
Give antiemetics
IV fluids
IV bicarbonate
Assess:
Renal function (BUN,
creatinine)
Serum K levels (tends to go
up but down once insulin
given)
Hydration status
IV FLUIDS
Isotonic
Hypertonic
3% NS
D51/2NS
D10W
Hypotonic
NS
D5W
LR
1/2NS
Plasma Expanders
CENTRAL VENOUS ACCESS DEVICES
Centrally
inserted
catheters (CVCs)
Peripherally
inserted central
catheters (PICCs)
Implanted
infusion ports
NURSING CARE OF CVADS
Inspect site for redness, edema, warmth, drainage, pain
Dressing change/cleaning with sterile technique using
chlorhexidine (back and forth scrub to generate friction)
Maintain transparent dressing c/d/I
Change injection caps using sterile technique
Teach pt to turn head away from insertion site during
cleaning and cap change
Have patient Valsalva during cap change if unable to
clamp
Use push-pause method to flush (creates turbulence)
Removal of non-tunneled CVCs and PICCs may be done
by a trained nurse (have pt Valsalva as last of catheter is
withdrawn, apply pressure immediately, inspect catheter
tip)