-
Fluid & Electrolyte balance
- }Fluids,
- electrolytes, & acids & bases need to be balanced within the body to maintain health.
- }These
- balances are maintained by the intake & output of water & electrolytes
- & by the regulation of the kidneys & lungs
}Homeostatsis is the term we use when this balance exists
-
Distribution of body fluids
- 60% of body weight is water
- Higher % in infants & children
- Less % >60 years
- Less in women
- Intracellular (ICF)
- Extracellular (ECF)
- ◦Intravascular (Plasma)
- ◦Interstitial (Between cells)
- ◦Transcellular
- CSF, Synovial, Pericardial, Pleural, Digestive
-
Composition of Body Fluids
- }Oxygen
- }Nutrients
- }Products of metabolism
- }Charged particles (ions): electrolytes
- ◦Cations- positive charge (Ca+)
- ◦Anions- negative charge (Cl-)
- ◦Measured as:
- milliequivalents (mEq/L)
- mg/100 ml)
- ◦Although concentration of lytes differ in ICF vs. ECF the balance of cations & anions always exist
-
Movement of Body fluids and Electrolytes
F & E constantly shift from compartment to compartment
- Osmosis
- Diffusion
- Filtration
- Active Transport
-
Osmosis
Osmosis- Movement of water across semi-permeable membrane from less concentration to greater concentration
Solutes- substances dissolved in a liquid
- ◦Cystalloids- dissolve into solution
- ◦Colloids- do not dissolve easily in solution
-
Osmolality & Tonicity
- Concentration of solutes in the body= osmolality
- Osmolality of a solution (IV)= tonicity
- ◦Solutions such as IVs:
- Isotonic- same osmolality as body fluids (0.9%NS)
- Hypertonic- higher osmolality than body fluids
- (3% NaCl)
- Hypotonic-less osmolality than body fluids
- (0.45% NaCl)
-
How Body Regulates Fluids
Fluid Intake
- Primarily through drinking fluids
- Oral fluids- 1500 mL
- Water in foods- 1000 mL
- Food metabolism – 200 mL
- Fluid intake regulated by thirst
- •Change in plasma osmolality
- •Hypothalamus
-
How Body Regulates Fluids
Fluid Output
- Urine: 1500 mL/day
- Skin as sweat: 100 ml/day
- Feces: 100-200 ml/day
- Insensible water loss: not measurable
- ◦Skin: 350-450 mL/day (perspiration)
- ◦Lungs: 350-400 mL/day (exhalation)
-
How the Body Regulates Fluids
Other factors
- Kidneys- primary regulator
- ◦Regulates water by reabsorption
- ◦Regulates lytes by selective retentions & excretion
- Antidiuretic hormone(ADH)
- Renin-angiotensin system
- Aldosterone
- Atrial natriuretic factor
-
ADH
- Hormone made in pituitary
- Diuresis- secretion & passage of large amts of urine
- ADH- hormone against diuresis: fluids retained
- ADH acts on the kidneys
- ◦Serum osmolality rises- ADH produced
- ◦Serum osmolality falls- ADH suppressed
-
Renin-angiotension-aldosterone System
- Sequence:
- Blood flow to kidneys is decreased
- Renin is released
- Renin converts angiotensin I to angiotensin ll
- Angiotensin ll release aldosterone from the adrenal gland
- Result:
- Kidneys retain sodium & water to restore blood volume
-
ANF
- Atrial natriuretic factor
- Sequence:
- Excessive blood volume stretches atrial walls & ANF is released
- Causes sodium wasting & diuresis
- Result: Reduces vascular volume
- Thirst inhibited
-
How the Body Regulates Electrolytes
}Regulation needed for normal body fuction
}Concentration differs between fluid compartments but a balance always exists
- }Electrolytes mostly obtained through dietary intake
- }Some lytes not stored in body- Na & Cl
- }Some stored- K & Ca
-
Factors Affecting Fluid & Electrolyte balance
- }Age
- ◦Young & old have different % of fluid in body
- ◦Older people – Ca+ lose & osteoporosis
- }Gender- men have more water
- }Body size
- }Environmental temperature
- ◦Lost through sweating esp. Na & Cl
- }Life style
- ◦Diet
- ◦Exercise
- ◦Alcohol consumption
-
Disturbances in Fluid Volume
- }2 basic types:
- }Isotonic imbalances:
- ◦loss or gain of fluid & lytes are in equal proportion
- }Osmolar Imbalances:
- ◦loss or gain of water only
-
Fluid volume deficit (FVD)-
know this
- isotonic loss: water & lytes lost in same amount
- }Risk factors
- ◦Vomiting
- ◦Diarrhea
- ◦Sweating
- ◦Fever
- ◦Drainage- wound or NGT
- ◦Bleeding
- ◦Insufficient intake
- ◦Third spacing
- }Symptoms:
- }Weight loss
- }Decreased BP & T
- }Orthostatic hypotension
- }Flat veins
- }Hypovolemia
- }Dry skin & mucous membranes
- }Nonelastic skin turgor
- }Decreased urine output
- Sunken eyeballs
-
FVE Labs
- Decreased:
- }Hematocrit
- }Specific gravity in urine
- }BUN
-
FVD Labs
- }Increased:
- ◦Hematocrit
- Normal: Men- 40-54%
- Women- 37-47%
- ◦◦Urine specific gravity
- Normal: 1.005-1.030
- ◦Blood Urea nitrogen (BUN)
- Normal: 5-20 mg/dL
- 8-23 if >60 years old
-
Fluid volume excess (FVE)-
isotonic gain: water & lytes gained in same amount
- }Risk factors
- ◦Too much Na IV fluids
- ◦Excess ingestion of diet or meds with water & NA
- ◦Medical Dx: heart, kidney, or liver failure
- ◦Meds: steroids
- }Symptoms
- ◦Wt gain
- ◦Increased BP
- ◦Distended neck & peripheral veins
- ◦Hypervolemia
- ◦Fluid in lungs, short of breath
- ◦Mental confusion
- ◦Edema
- ◦Pitting edema
-
Osmolar Imbalances
- }Hyperosmolar
- }Water lost
- }Dehydration
- }Serum osmolality & serum Na increased
- }SX: cell dehydration
- }Cause:
- ◦Elders- decreased thirst
- ◦Enteral feeding without water
- }Hypoosmolar
- }Water gain
- }Overhydration
- }Serum osmolality & serum Na decreased
- }SX: cerebral edema
- }Cause:
- ◦Fluid replacement w/o lytes
- ◦ADH imbalances
-
Nsg Interventions for Fluid Volume Imbalances
- }Assess for sx of FVD or FVE
- }Daily weights
- }Assess VS
- }Monitor I & O
- }Assess skin turgor
- }Assess veins
- }Assess lung sounds
- }Assess for edema
- }Restrict or provide fluids
- }Provide mouth care
- }Assess labs
-
Electrolytes
- }Function:
- }Maintaining fluid balance
- }Acid-base balance
- }Enzyme reactions
- }Neurotransmission & muscle contraction
- }Sodium- most abundant cation in ECF
- •135-145 mEq/L
- }Potassium
- - most abundant cation in ICF
- 3.5-5 mEq/L
- }Calcium- Stored in bone mostly
- •8.5- 10.5 mg/dL
-
Hyponatremia
- Risk Factors:
- Loss of sodium
- GI fluids
- diuretics
- Sweating
- Gain of water:
- Hypotonic tube feedings, oral ingestion, IV-D5W
- Disease:
- SIADH: head injury, tumor
- Signs & Symptoms:
- Serum Na <135
- Serum osmolality <280
- Neuromuscular: Confusion, headache, muscle twitching, seizures, lehtargy
- GI: abdominal cramps, N/V, anorexia
-
Hyponatremia
Nursing Interventions
- }Monitor I/O
- }Monitor labs
- }Restrict water intake
- }Increase oral sodium intake
- }Assess closely if receiving hypertonic solutions
-
Hypokalemia
- Risk factors
- }Potassium loss:
- ◦GI- low K intake, vomiting, gastric suction, diarrhea
- Meds- K wasting diuretics
- Steroid Administration
- ◦Disease- Hyperaldosteronism
- Anorexia or bulemia
- Signs & Symptoms
- Serum K < 3.5
- ECG changes
- Neuromuscular: Muscle weakness
- leg cramps
- Fatigue
- GI: Anorexia, Nausea/vomiting
- Decreased bowel sound
- Cardiac: dysrhythmias
-
Hypokalemia
Nursing interventions
- }Administer prescribed K supplements
- }Monitor HR and rhythm
- }Assess digitalized clients for symptoms of digitalis toxicity (hypokalemia increases risk of digitalis toxicity)
- }Prevention: encourage K rich foods for at risk clients
-
Hyperkalemia
- Risk Factors
- }Decrease potassium excretion:
- ◦Renal failure
- ◦Potassium sparing diuretics
- ◦Hypoaldosteronism
- }High K intake:
- ◦ improper use of supplements
- ◦Salt subst. containing K
- }Shift of K out of cells: acidosis, burns, tissue trauma
- Signs & Symptoms
- Serum K >5
- Neuromuscular:First sign is vague muscle weakness
- Irritability, apathy, confusion, absent reflexes
- GI: Diarrhea, GI hyperactivity
- Cardiac: ECG changes, dysrhythmias
-
Hyperkalemia
Nursing interventions
- ◦Monitor K levels
- ◦Hold K supplements
- ◦Monitor EKG
- ◦Administer diuretics, glucose and insulin as ordered
- ◦Hyperkalemia is life threatening-it must be detected early
- ◦Teach at risk clients to avoid foods high in K
-
Hypocalcemia
- Risk factors
- }Neck surgery:
- ◦Hypoparathyroidism
- ◦Thyroid cancer
- }Acute pancreatitis
- }Vitamin D deficiency:
- ◦Malabsorption
- ◦Alcohol abuse
- Signs & Symptoms
- Total serum Ca <8.5
- Neuromuscular:
- Numbness
- Tingling of fingers and toes
- Muscle cramps
- Convulsion, seizures
- Laryngeal spasms
- ECG changes
- Positive signs
- Chvostek’s sign
- Trousseau’s sign
-
Hypocalcemia
Nursing interventions
- ◦Monitor serum calcium
- ◦Monitor airway
- ◦Seizure precautions
- ◦Administer parenteral calcium as ordered
- ◦Educate women about calcium supplements
-
Hypercalcemia
- Risk factors
- }Lost from bone:
- }Prolonged immobility
- }Bone cancer
- }Hyperparathyroidism
- }Excessive ingestion
- } Calcium
- }Supplements
- }Antacids
- }Vitamin D-megadoses
- Signs & Symptoms
- Serum Ca >10.5
- Neuromuscular:
- Muscle weakness
- Changes in behavior
- Cardiac- slow heart
- GI:
- Constipation
- Anorexia, N&V
- Kidney stones
-
Hypercalcemia
Nursing interventions
- ◦Keep client well hydrated
- ◦Discourage excessive dietary milk products
- ◦Fiber in diet
- ◦Safety precautions for confusion, weakened bones
- ◦Eliminate calcium supplements & avoid calcium based antacids
- ◦Prevention: Encourage mobility to the extent possible
-
Electrolytes- other
- Magnesium
- •Found in bone & ICF
- •1.5- 2.5 mEq/L
- •Foods: grains, nuts, dried fruit, legumes, green leafy veges
- •Alcoholism leads to low levels
- Chloride
- •Bound to other ions
- ◦95-108 mEq/L
- ◦Regulates osmolality & blood volume
- Phosphate
- •Bound with calcium in teeth and bones; inverse relationship
- Bicarbonate
- •Regulated by kidneys to maintain acid-base balance
-
Assessment
- }Nursing History
- ◦Environmental factors- temperature
- ◦Diet-intake of fluids & foods containing lytes
- ◦Lifestyle- exercise, alcohol consumption
- ◦Medications
- Diuretics, Steroids, Potassium supplements, Respiratory center depressants, Antibiotics
- }Physical Assessment – Table 52-8 pg 1446
- ◦Skin, mucus membranes, cardiovascular, respiratory & neurological systems
- }Clinical measurements
- ◦Vital signs
- ◦I/O’s
- ◦Weights
- }Lab values: Electrolytes, CBC (hematocrit), BUN,
- Creatinine, Urine specific gravity, Serum osmolality
-
Nursing Diagnosis
- }Deficient fluid volume
- }Excess fluid volume
- }Risk for imbalanced fluid volume
- }Impaired oral mucous membranes
- }Impaired skin integrity
- }Acute confusion
-
Implementation
- Preventing Fluid & Electrolyte Imbalances
- Promoting Wellness
- ◦Client teaching: Promoting Fluid & Electrolyte
- Balance, p. 1453
- Dietary Changes
- ◦Potassium- box 52-1
- Oral Electrolyte supplements- K, Ca
- Fluid Intake modifications
- ◦Facilitating Fluid Intake- pg 1454
- ◦Facilitating Fluid Restriction- pg 1454
- Enteral Replacement
-
Practice Guidelines Facilitating Fluid Intake
- }Explain reason for required intake and amount needed
- }Establish 24 hour plan for ingesting fluids
- }Set short term goals
- }Identify fluids client likes and use those
- }Help clients select foods that become liquid at room temperature
- }Supply cups, glasses, straws
- }Serve fluids at proper temperature
- }Encourage participation in recording intake
- }Be alert to cultural implications
-
Implementation
- }Parenteral Replacement
- ◦Isotonic- expand ECF volume
- ◦Hypertonic- osmolality > body fluids-
- pulls fluid from ICF & interstitial into vascular compartment. Check kidneys 1st
◦Hypotonic- osmolality < body fluids- IV fluid pushed into cells for rehydration
-
Administration Of IV Fluids
- }Type of solution
- ◦0.9% NS
- ◦D5W
- ◦D5 1/2NS
- }Vascular Access – pg 1456-7
- ◦Peripheral
- ◦PICC
- ◦Central
}Pumps
-
Parental Replacement
- Side Effects to be aware of
- }Infiltration
- ◦Localized swelling,
- pallor,
- ◦coldness,
- ◦pain around infusion site
- }Phlebitis
- ◦Localized redness,
- ◦warmth,
- ◦mild edema of the vein above insertion site
}Air embolism
-
Potassium-rich foods
- Avacado
- Spinach
- Raw carrot
- baked potato
- Raw tomato
- banana
- dried fruits
- apricot
- cantalopue
- orange
-
Elder considerations for Fluid and Electrolyte imbalance
- decrease in thirst sensations
- decrease in ability of kidneys to concentrate urine
- decrease in ICF and total body water
- decrease in response to body hormones that help regulate fluid & lyte balance
- Increase use of diuretics for hypertension & heart disdease
- Decrease intake of food & water
- Prep for tests that have client NPO for long periods of time or diarrhea from laxative preps
-
Hypernatremia
- Risk Factors
- Loss of water:
- profuse sweating
- diarrhea
- water deprivation
- Gain of sodium:
- high salt intake
- hypertonic tube feedings with inadequate water
- Excess administration of hypertonic saline, sodium bicarb
-
Hypernatremia
Nursing interventions
- ◦Monitor I/O
- ◦Assess for abnormal water loss or low water intake
- ◦Increase water intake
- ◦Restrict dietary sodium
- ◦Prevention: if using tube feedings, give enough water to keep Na and BUN levels in normal limits
- ◦Medical: hypotonic IVs
|
|