Fluid and Electrolyte Imbalances (Fundamentals Ch 57) Flashcards Preview

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-minerals present in all body fluids
-regulate fluid balance and hormone production
-strengthen skeletal structures
-act as catalysts in nerve response, muscle contraction, and metabolism of nutrients


Fluid volume deficits (FVDs)

Isotonic FVD (hypovolemia)


Isotonic FVD

-loss of water and electrolytes from the ECF
-referred to as hypovolemia because intravascular fluid is also lost



-loss of water from body w/o loss of electrolytes
-this hemoconcentration results in increases in Hct, serum electrolytes, and urine specific gravity


Compensatory mechanisms for FVD

-sympathetic nervous system response of:
1) increased thirst
2) antidiuretic hormone (ADH) release
3) aldosterone release


Are older adults at increased risk for dehydration?

-due to decreased total body mass


Causes of isotonic FVD (hypovolemia)

1) abnormal GI losses--vomiting, ng suctioning, diarrhea
2) abnormal skin losses--diaphoresis
3) abnormal renal losses--diuretic therapy, diabetes insipidus, kidney disease, adrenal insufficiency
4) third spacing--peritonitis, intestinal obstruction, ascites, burns
5) hemorrhage
6) altered intake--impaired swallowing, confusion, NPO


Causes of dehydration

1) hyperventilation
2) prolonged fever
3) diabetic ketodacidosis
4) enteral feeding w/o sufficient water intake


Subjective and objective data of FVD

1) vital signs--hypothermia, tachycardia, thready pulse, hypotension, orthostatic hypotension, decreased central venous pressure, tachypnea, hypoxia
2) neuromusculoskeletal--dizziness, syncope, confusion, weakness, fatigue
3) GI--thirst, dry mucous membranes, dry furrowed tongue, N/V, anorexia, acute weight loss
4) renal--oliguria (decreased production of urine)
5) other clinical findings--diminished cap. refill, cool clammy skin, diaphoresis, sunken eyeballs, flattened neck veins, absence of tears, decreased skin turgor


Lab findings associated with FVD

1) Hct--increased in both hypovolemia and dehydration (unless FVD is due to hemorrhage)
2) serum osmolarity--dehydration--increased hemoconcentration osmolarity (greater than 300 mOsm/kg)- increased protein, BUN, electrolytes, glucose
3) urine sp. gravity and osmolarity--increased concentration (urine sp. gravity > 1.030)
4) serum sodium--dehydration--increased hemoconcentratin


Nursing care for FVD

1) assess respiratory rate, symmetry, effort
2) monitor SOB and dyspnea
3) check urinalysis, SaO2, CBC, electrolytes
4) administer supplemental O2 as prescribed
5) measure client's weight daily at same time of day using same scale
6) observe for N&V
7) assess & monitor VS (check for hypotension & orthostatic hypotension)
8) check neurological status to determine LOC
9) assess heart rhythm (may be irregular, tachycardic)
10) initiate & maintain IV access
11) place client in shock position ( on back with legs elevated)
12) fluid replacement: administer IV fluids as prescribed (isotonic solutions--Lactated Ringer's or 0.9% NaCl; blood transfusion)
13) monitor I&O--encourage as tolerated; notify provider of urine output less than 30 mL/hr
14) monitor LOC and ensure client safety
15) assess level of gait stability
16) encourage client to use call light for assistance
17) encourage client to change positions slowly
18) check cap refill
19) provide frequent oral care
20) prevent skin breakdown


Fluid volume excess (FVE)

-isotonic retention of water and sodium in abnormally high proportions


(hypoosmolar fluid imbalance)

-gain of more water than electrolytes
-hemodilution results in decreases in Hct, serum electrolytes, and protein


Compensatory mechanisms for FVE

1) increased release of natriuretic peptides--result in increased excretion of sodium and water by kidneys
2) decreased release of aldosterone


Causes of hypervolemia

1) chronic stimulus to kidneys to conserve Na and water (heart failure, cirrhosis, increased glucocorticosteroids)
2) abnormal kidney function w/ reduced excretion of Na and water (kidney failure)
3) interstitial to plasma fluid shifts (hypertonic fluids, burns)
4) age-related changes in CV and kidney function
5) excessive Na intake from IV fluids, diet, medications (Na bicarbonate antacids, hypertonic enema solutions)


Causes of overhydration

1) water replacement w/o electrolyte replacement (strenuous exercises w/ diaphoresis)
2) SIADH--excess secretion of ADH
3) head injuries
4) barbiturates
5) anesthetics


Subjective and objective data of FVE

1) VS--tachycardia, bounding pulse, hypertension, tachypnea, increased central venous pressure
2) neuromusculoskeletal--confusion, muscle weakness
3) GI--weight gain, ascites
4) respiratory--dyspnea, orthopnea, crackles
5) other clinical findings--edema, distended neck veins


Lab findings associated w/ FVE

1) Hct--hypervolemia: decreased Hct; overhydration: decreased Hct = hemodilution
3) serum osmolarity--overyhdration: < 280 mOsm/kg
4) serum Na--hypervolemia: Na within expected range (136-145 mEq/L)
5) electrolytes, BUN, creatinine--hypervolemia&overhydration: decreased
6) ABGs--respiratory alkalosis (decreased PaCO2, increased pH)


Nursing care for FVE

1) assess respiratory rate, symmetry, effort
2) assess breath sounds in all lung fields (may be diminished w/ crackles)
3) monitor for SOB and dyspnea
4) check ABGs, SaO2, CBC, CX-ray results (may indicated pulmonary congestion)
5) position client in semi-Fowler's
6) measure client's weight daily
7) monitor and document edema (pretibial, sacral, periorbital)
8) monitor I&O
9) implement prescribed fluid and Na intake restrictions
10) administer supplemental O2 as needed
11) reduce IV flow rates
12) administer diuretics as prescribed (osmotic, loop)
13) monitor and document circulation to extremities
14) reposition client at least q 2 hr
15) support arms and legs to decrease dependent edema as appropriate


Clients at greatest risk for electrolyte imbalances

1) infants and children
2) older adults
3) clients who have cognitive disorders
4) chronically ill clients


Sodium (Na+)

-major electrolyte found in ECF
-present in most body fluids or secretions
-essential for maintenance of acid-base and fluid balance, active and passive transport mechanisms, and irritability and conduction of nerve and muscle tissue
-136-145 mEq/L



-serum Na+ level < 136 mEq/L
-a net gain of water or loss of sodium-rich foods
-delays and slows depolarization of membranes
-water moves from ECF to ICF, causes cells to swell (cerebral edema)


Causes of hyponatremia

1) deficient ECF volume
2) abnormal GI losses--vomiting NG suctioning, diarrhea, tap water enemas
3) renal losses--diuretics, kidney disease, adrenal insufficiency, excessive sweating
4) skin losses--burns, wound drainage, GI obstruction, peripheral edema, ascites
5) increased or normal ECF volume--excessive oral water intake, SIADH
6) edematous states--heart failure, cirrhosis, nephrotic syndrome
7) excessive hypotonic IV fluids
8) inadequate Na+ intake (NPO status)
9) age-related risk factors--older adults greater risk due to incidences of chronic illnesses, use of diuretic medications, and risk for insufficient Na+ intake


Subjective and objective data of hyponatremia

1) physical assessment findings--vary with a normal, decreased, or increased ECF volume
2) VS--hypothermia, tachycardia, rapid thready pulse, hypotension, orthostatic hypotension
3) neuromusculoskeletal--headache, confusion, lethargy, muscle weakness w/ possible respiratory compromise, fatigue, decreased deep tendon reflexes (DTRs), seizures, coma
4) GI--increased motility, hyperactive bowel sounds, abdominal cramping, anorexia, nausea, vomiting


Lab findings associated with hyponatremia

1) serum Na+ -- decreased < 136 mEq/L
2) serum osmolality--decreased < 280 mOsm/kg



-serum sodium > 145 mEq/L
-serous electrolyte imbalance--can cause significant neurological, endocrine, and cardiac disturbances
-causes hypertonicity of serum--causes shift of water out of cells, making them dehydrated


Risk factors for hypernatremia

1) water deprivation (NPO)
2) heat stroke
3) excessive Na+ intake--dietary, hypertonic IV fluids, hypertonic tube feedings, bicarbonate intake
4) excessive Na+ retention--kidney failure, Cushing's syndrome, aldosteronism, some meds (glucocorticosteroids)
5) fluid losses--fever, diaphoresis, burns, respiratory infection, diabetes insipidus, hyperglycemia, watery diarrhea
6) age-related changes--decreased total body water content and inadequate fluid intake related to altered thirst mechanism
7) compensatory mechanisms--increased thirst and increased production of ADH


Subjective and objective data of hypernatremia

1) VS--hyperthermia, tachycardia, orthostatic hypotension
2) neuromusculoskeletal--restlessness, disorientation, irritability, muscle twitching, muscle weakness, seizures, decreased LOC, reduced to absent DTRs
3) GI--thirst, dry mucous membranes, dry and swollen tongue red in color, increased motility, hyperactive bowel sounds, abdominal cramping, nausea
4) other clinical findings--edema, warm flushed skin, oliguria


Lab findings associated with hypernatremia

1) serum Na+-- increased, > 145 mEq/L
2) serum osmolarity--increased, > 300 mOsm/kg


Nursing care for hypernatremia

1) report abnormal lab findings to provider
2) fluid loss--based on serum osmolarity (administer hypotonic IV fluids-0.225% NaCl)
3) Excess sodium--encourage water intake, discourage Na+ intake and administer diuretics (loop diuretics)
4) monitor LOC and ensure safety
5) provide oral hygiene and other comfort measures to decrease thirst
6) monitor I&O, alert provider if urinary output inadequate


Potassium (K+)

-major cation in ICF
-plays vital role in cell metabolism; transmission of nerve impulses; functioning of cardiac, lung, and muscle tissues; and acid-base balance
-reciprocal action w/ Na+
-Expected levels 3.5-5 mEq/L



- < 3.5 mEq/L
-result of increase loss of K+ from body or movement of K+ into the cells


Risk factors for hypokalemia

-abnormal GI losses--vomiting, NG suctioning, diarrhea, inappropriate laxative use
-renal losses--excessive use of K+-excreting diuretics (furosemade (Lasix)), corticosteroids
-skin losses--diaphoresis, wound losses
-insufficient K+
-inadequate dietary intake (rare)
-prolonged administration of non-electrolyte-containing IV solutions (5% dextrose in water)
-ICF--metabolic alkalosis, after correction of acidosis (treatment of DKA), during periods of tissue repair (burns, trauma, starvation), total parental nutrition (TPN)


Subjective and objective data of hypokalemia

1) VS-hyperthermia, weak irregular pulse, hypotension, respiratory distress
2) neuromusculoskeletal-ascending bilateral muscle weakness w/ respiratory collapse and paralysis, muscle cramping, decreased muscle tone and hypoactive reflexes, paresthesias, mental confusions
3) ECG-PVCs, bradycardia, blocks, v-tach, flattening T waves, and ST depression
4) GI-decreased motility, hypoactive bowel sounds, abdominal distention, constipation, ileus, nausea, vomiting, anorexia
5) other clinical findings-polyuria (excretion of dilute urine)


Lab findings associated with hypokalemia

1) serum potassium < 3.5 mEq/L
2) ABGs--metabolic acidosis pH > 7.45


Diagnostic procedures associated with hypokalemia

ECG shows findings of dysrhythmias (PVCs, ventricular tachycardia, flattening T waves, ST depression)


Nursing care for hypokalemia

1) report abnormal findings to provider
2) treat underlying cause
3) replace potassium: provide dietary education and encourage foods high in K+ (avocados, dried fruit, cantaloupe, bananas, potatoes, spinach); provide oral K+ supplementation
4) IV K+ supplementation: mixed by pharmacist and checked by 2 nurses; max. rec. rate is 10-20 mEq/hr; NEVER IV bolus (high risk of cardiac arrest)
5) monitor for phlebitis (tissue irritant)
6) monitor for and maintain adequate urine output
7) monitor for shallow, ineffective respirations and diminshed breath sounds
8) monitor cardiac rhythm and intervene promptly as needed
9) monitor clients receiving digoxin (hypokalemia increases risk of digoxin toxicity)
10) monitor LOC and ensure safety
11) monitor bowel sounds and abdominal distention and intervene as needed



-serum K+ > 5 mEq/L
-results from increased intake of K+, movement of K+ out of the cells, or inadequate renal excretion
-uncommon in clients w/ adequate renal function
-potentially life-threatening due to risk of cardiac arrhythmias and cardiac arrest


Risk factors for hyperkalemia

1) increased total body K+ -- IV K+ admin., salt substitutes, blood transfusion
2) ECF shift--decreased insulin, acidosis (DKA), tissue catabolism (sepsis, trauma, surgery, fever, MI)
3) hypertonic states--uncontrolled diabetes mellitus
4) decreased excretion of K+ -- kidney failure, severe dehydration, K+ sparing diuretics, ACE inhibitors, adrenal insufficiency
5) older adult clients -- greater risk due to decreased kidney function and medical conditions resulting in use of salt substitutes, ACE inhibitors, and K+ sparing diuretics


Subjective and objective data of hyperkalemia

1) VS-slow, irregular pulse; hypotension
2) neuromusculoskeletal-irritability, confusion, weakness with ascending flaccid paralysis, parethesias, lack of reflexes
3) ECG-ventricular fibrillation, peaked T waves, widened QRS, cardiac arrest
4) GI-increased motility, diarrhea, abdominal cramps, hyperactive bowel sounds
5) other clinical findings-oliguria


Lab findings associated with hyperkalemia

1) serum potassium -- increased > 5 mEq/L
2) ABGs -- metabolic acidosis pH < 7.35


Diagnostic procedures associated with hyperkalemia

1) ECG will show dysrhythmias (ventricular fibrillation, peaked T waves, widened QRS)


Nursing care fro hyperkalemia

1) report abnormal findings to provider
2) decrease K+ intake--stop infusion of IV potassium, withhold oral K+, provide K+ restricted diet, dialysis may be required for extremely high levels
3) promote movement of K+ from ECF to ICF--administer IV fluids w/ dextrose and regular insulin
4) monitor cardiac rhythm and intervene promptly as needed
5) medications to increase K+ excretion--administer loop diuretics (furosemide-Lasix) if kidney function adequate; administer sodium polystyrene sulfonate (kayexalate) orally or as enema (increase excretion from GI tract)
6) maintain IV access
7) prepare client for dialysis if prescribed



-found in body's cells, bones, and teeth
-expected range 9-10.5 mg/dL
-balance essential for proper functioning of CV, neuromuscular, and endocrine systems, blood clotting and bone and teeth formation



-serum Ca+ < 9 mg/dL


Risk factors for hypocalcemia

1) increased Ca+ output--chronic diarrhea, steatorrhea (as w/ pancreatitis--binding of Ca+ to undigested fat)
2) inadequate Ca+ intake or absorption--malabsorption syndrome (Crohn's disease); vitamin D deficiency (alcohol use disorder, kidney failure)
3) Ca+ shift from ECF into bone or to an inactive form--repeated blood transfusion; post-thyroidectomy; hypoparathyroidism


Subjective and objective data for hypocalcemia

1) muscle twitches/tetany--numbness and tingling (extremities, circumoral); frequent, painful muscle spasms at rest that can progress to tetany; hyperactive DTRs; + Chvostek's sign (tapping facial nerve triggering facial twitching); + Trousseau's sign (hand/finger spasms w/ sustained bp cuff inflation)
2) cardiovascular--decreased myocardial contractility (decreased HR and hypotension)
3) GI--hyperactive bowel sounds, diarrhea, abdominal cramping
4) CNS--seizures due to overstimulation of CNS


Lab findings associated with hypocalcemia

-Ca+ level < 9 mg/dL


Diagnostic procedures associated with hypocalcemia

-ECG--prolonged QT interval and ST segments


Nursing care for hypocalcemia

1) administer oral or IV Ca+ supplements (carefully monitor respiratory and CV status)
2) initiate seizure precautions
3) keep emergency equipment on standby
4) encourage foods high in Ca+ (dairy products, dark green vegetables)



-serum Ca+ level > 10.5 mg/dL


Risk factors for hypercalcemia

1) decreased Ca+ output--thiazide diuretics
2) increased Ca+ intake and absorption
3) Ca+ shift from bone to ECF--hyperparathyroidism; bone cancer; Paget's disease; chronic immobility


Subjective and objective data for hypercalcemia

1) neuromuscular--decreased reflexes; bone pain; flank pain if renal calculi develop
2) CV--dysrhythmias
3) GI--anorexia, nausea, vomiting, constipation
4) CNS--weakness, lethargy; confusion, decreased LOC


Lab findings associated with hypercalcemia

-Ca+ level > 10.5 mg/dL


Diagnostic procedures associated with hypercalcemia

-ECG--shortened QT interval and ST segment


Nursing care for hypercalcemia

1) increase client activity level
2) limit dietary Ca+
3) encourage fluid to promote urinary excretion
4) encourage fiber to promote bowel elimination
5) implement safety precautions if client is confused
6) monitor for pathologic fractures
7) encourage acid-ash fluids (prune, cranberry juice) to decrease risk for renal Ca+ stone formation



-most of body's Mg is found in bones
-smaller amounts found within body cells
-very small amount found in ECF
-expected range 1.3-2.1 mEq/L



-serum Mg level < 1.3 mEq/L


Risk factors for hypomagnesemia

1) increased Mg output--GI losses (diarrhea, NG suction); thiazide or loop diuretics
2) inadequate Mg intake or absorption--malnutrition; alcohol use disorder; laxative use


Subjective/objective data for hypomagnesemia

1) neuromuscular--increased nerve impulse transmission (hyperactive DTRs, paresthesias, muscle tetany); positive Chvostek's and Trousseau's signs
2) GI--hypoactive bowel sounds, constipation, abdominal distention, paralytic ileus
3) CV--dysrhythmias, tachycardia, hypertension


Nursing care for hypomagnesemia

1) discontinue Mg-losing medications
2) administer oral or IV MgSO4 following safety protocols (IV route used because IM can cause pain and tissue damage. Oral Mg can cause diarrhea and increase Mg depletion. Monitor closely)
3) encourage foods high in Mg (whole grains and dark green vegetables)
4) implement seizure precautions



-serum Mg level > 2.1 mEq/L


Risk factors for hypermagnesemia

1) decreased Mg output--kidney failure; adrenal insufficiency
2) increased Mg intake and absorption--laxatives or antacids containing Mg


Subjective/objective data for hypermagnesemia

1) neuromuscular--diminished DTRs; muscle paralysis; shallow respirations, decreased RR
2) CV--bradycardia, hypotension; dysrhythmias, cardiac arrest
3) CNS--lethargy