POTASSIUM POTASSIUM

IMBALANCESIMBALANCES HYPOCALEMIA & HYPOCALEMIA &

HYPERCALEMIAHYPERCALEMIA

2 JULY 20042 JULY 2004

POTASSIUM BALANCEPOTASSIUM BALANCE

1.1. Potassium (K) is the major intracellular electrolyte; Potassium (K) is the major intracellular electrolyte;

98% of the body’s potassium is inside the cell.98% of the body’s potassium is inside the cell.

2.2. The remaining 2% is in the ECF.The remaining 2% is in the ECF.

3.3. Normal serum K level ranges from 3.5 - 5.0 mEq/L Normal serum K level ranges from 3.5 - 5.0 mEq/L

4.4. The daily dietary requirement of K is about 40 mEq; The daily dietary requirement of K is about 40 mEq;

the average daily intake is 60 – 100 mEqthe average daily intake is 60 – 100 mEq

5.5. Functions:Functions:

a)a) K maintains cell electroneutrality and cell K maintains cell electroneutrality and cell

osmolality.osmolality.

b)b) K directly affects cardiac muscle contraction K directly affects cardiac muscle contraction

and electrical conductivity.and electrical conductivity.

c)c) K aids neuromuscular transmission of nerve K aids neuromuscular transmission of nerve

impulses.impulses.

6.6. RegulationRegulationa)a) K must be ingested daily because the body K must be ingested daily because the body

does not conserve it.does not conserve it.

b)b) The kidneys eliminate about 80% of The kidneys eliminate about 80% of ingested K; about 20 – 40 m Eq are lost in ingested K; about 20 – 40 m Eq are lost in each liter of urine.each liter of urine.

c)c) The remaining K is secreted in feces; 5 – 10 The remaining K is secreted in feces; 5 – 10 mEq are lost in each liter of GI fluid.mEq are lost in each liter of GI fluid.

d)d) Aldosterone secretion leads to renal Na Aldosterone secretion leads to renal Na reabsorption and K excretion.reabsorption and K excretion.

HYPOKALEMIAHYPOKALEMIA

1.1. Hypokalemia – potassium level Hypokalemia – potassium level < 3.5 mEq/L.< 3.5 mEq/L.

2.2. Hypokalemia is usually results Hypokalemia is usually results from excessive excretion or from excessive excretion or inadequate intake of Kinadequate intake of K

3.3. Hypokalemia is a dangerous Hypokalemia is a dangerous condition because it increase condition because it increase the risk of the risk of dysrhythmia.dysrhythmia.

CausesCauses

1.1. Renal losses Renal losses

a)a) Potassium-losing diuretics such as thiazides.Potassium-losing diuretics such as thiazides.

b)b) Excess aldosterone production.Excess aldosterone production.

c)c) Excessive steroid administration – arthritis, Excessive steroid administration – arthritis,

asthma.asthma.

d)d) Medication – Gentamicin.Medication – Gentamicin.

2.2. Gastrointestinal lossesGastrointestinal lossesa)a) Vomiting and gastric suction.Vomiting and gastric suction.

b)b) Diarrhea and prolonged intestinal suction.Diarrhea and prolonged intestinal suction.

c)c) Laxative abuseLaxative abuse

3.3. Poor intakePoor intakea)a) Anorexia nervosaAnorexia nervosa

b)b) AlcoholismAlcoholism

c)c) Debilitation.Debilitation.

Clinical ManifestationsClinical Manifestations

1.1. Clinical signs are usually not present Clinical signs are usually not present until the potassium level falls below 3.0 until the potassium level falls below 3.0 mEq/L.mEq/L.

2.2. The diagnosis is usually made by The diagnosis is usually made by measurement of the serum potassium measurement of the serum potassium level.level.

3.3. Cardiovascular effects.Cardiovascular effects.

a)a) Abnormalities of electrophysiology and Abnormalities of electrophysiology and contractility.contractility.

b)b) Increase the risk of dysrhythmia.Increase the risk of dysrhythmia.

4.4. Muscular changesMuscular changes

a)a) Muscle weakness (begin with extremities and Muscle weakness (begin with extremities and move up to trunk)move up to trunk)

b)b) Impaired respiratory muscle functions.Impaired respiratory muscle functions.

c)c) Symptoms such as anorexia, nausea, Symptoms such as anorexia, nausea, vomiting, gaseous distention are due to vomiting, gaseous distention are due to weakness of the smooth muscle of the GI weakness of the smooth muscle of the GI tract.tract.

5.5. Renal changesRenal changesa)a) Dilute urineDilute urine

b)b) PolyuriaPolyuria

c)c) NocturiaNocturia

d)d) Polydipsia.Polydipsia.

TreatmentTreatment

1.1. The best treatment for hypokalemia is prevention.The best treatment for hypokalemia is prevention.

2.2. For patients at risk, a diet with potassium content For patients at risk, a diet with potassium content

should be provided.should be provided.

3.3. However, once hypokalemia has developed, dietary However, once hypokalemia has developed, dietary

potassium intake maybe ineffective replacement potassium intake maybe ineffective replacement

because most potassium in food is complexed to because most potassium in food is complexed to

anions that metabolize into bicarbonate.anions that metabolize into bicarbonate.

4.4. Therefore, patients with significant hypokalemia Therefore, patients with significant hypokalemia

associated with metabolic alkalosis should be associated with metabolic alkalosis should be

given potassium chloride (KCl).given potassium chloride (KCl).

5.5. Because KCl is efficiently absorbed through the Because KCl is efficiently absorbed through the

GI tract, no solution should be given orally.GI tract, no solution should be given orally.

6.6. When potassium cannot be consumed in When potassium cannot be consumed in

adequate amounts in the diet, and when oral adequate amounts in the diet, and when oral

potassium supplements are not feasible, the IV potassium supplements are not feasible, the IV

route is indicated for replacement.route is indicated for replacement.

The IV is mandatory for The IV is mandatory for

patients with severe patients with severe

hypokalemia (<2.5 hypokalemia (<2.5

mEq/L)mEq/L)

Nursing interventionsNursing interventions

1.1. Be aware of patients at risk for hypokalemia and Be aware of patients at risk for hypokalemia and monitor for its occurrence. Because hypokalemia monitor for its occurrence. Because hypokalemia can be life threatening, it is important to detect it can be life threatening, it is important to detect it early.early.

2.2. Take measures to prevent hypokalemia Take measures to prevent hypokalemia when possible.when possible.

a)a) Encourage extra potassium intake for at risk Encourage extra potassium intake for at risk patients.patients.

b)b) When hypokalemia is due to abuse of laxatives When hypokalemia is due to abuse of laxatives or diuretics, education of the patient may help or diuretics, education of the patient may help alleviate the problem.alleviate the problem.

3.3. Educate clients regarding the use of salt Educate clients regarding the use of salt

substitutes.substitutes.

a)a) Salt substitutes may contain from 50 to 60 Salt substitutes may contain from 50 to 60

mEq/L per teaspoon.mEq/L per teaspoon.

b)b) Risk for hyperkalemia with excessive use.Risk for hyperkalemia with excessive use.

4.4. Administer IV K supplement infusion Administer IV K supplement infusion

cautiously; always dilute and mix cautiously; always dilute and mix

thoroughly in adequate amounts of fluid.thoroughly in adequate amounts of fluid.

a)a) The usual dose is 20 – 40 mEq/L infused over The usual dose is 20 – 40 mEq/L infused over

1 hour.1 hour.

b)b) Such patients should be placed on a cardiac Such patients should be placed on a cardiac

monitor.monitor.

5.5. Never administer K as IV push or as a Never administer K as IV push or as a

bolus, which could prove fatal.bolus, which could prove fatal.

6.6. Monitor heart rate, rhythm and ECG Monitor heart rate, rhythm and ECG

tracing in severely hypokalemic in a tracing in severely hypokalemic in a

patientpatient

a)a) With serum K level less than 3 mEq/LWith serum K level less than 3 mEq/L

b)b) Receiving greater than 5mEq/L per hour IVReceiving greater than 5mEq/L per hour IV

c)c) Receiving IV K at a concentration greater Receiving IV K at a concentration greater

than 40 mEq/L to 1L of fluid.than 40 mEq/L to 1L of fluid.

HYPERKALEMIAHYPERKALEMIA

Hyperkalemia refers to a greater Hyperkalemia refers to a greater than normal serum potassium than normal serum potassium

concentration.concentration.

Hyperkalemia results from Hyperkalemia results from impaired renal excretion of K or impaired renal excretion of K or

excessive K intake.excessive K intake.

1.1. Increased dietary K intake, especially with Increased dietary K intake, especially with

decreased urine output.decreased urine output.

2.2. Excessive administration of K supplement.Excessive administration of K supplement.

3.3. Excessive use of salt substitutes, most of Excessive use of salt substitutes, most of

which use some form of K as a substitute which use some form of K as a substitute

for Na.for Na.

Etiology Etiology

4.4. Use of K-sparing diuretics, such as Use of K-sparing diuretics, such as

spironolactone (Aldocton)spironolactone (Aldocton)

5.5. Severe, widespread cell damage, such as Severe, widespread cell damage, such as

from burns, trauma, crush injuries, and from burns, trauma, crush injuries, and

intravascular hemolysis.intravascular hemolysis.

6.6. Administration of large volumes of blood Administration of large volumes of blood that is nearing the expiration date (‘old’ that is nearing the expiration date (‘old’ blood undergoes increased cell hemolysis, blood undergoes increased cell hemolysis, resulting in the release of K as cells die)resulting in the release of K as cells die)

7.7. Lysis of tumor cells from chemotherapy Lysis of tumor cells from chemotherapy (K is released from dying cells into the (K is released from dying cells into the ECF)ECF)

8.8. HyponatremiaHyponatremia

9.9. Hypoaldosteronism.Hypoaldosteronism.

10.10. Metabolic or respiratory acidosis.Metabolic or respiratory acidosis.

11.11. Acute of chronic renal failure.Acute of chronic renal failure.

Clinical manifestationsClinical manifestations

1.1. Neuromuscular effectsNeuromuscular effects

a)a) Muscular weaknessMuscular weakness

b)b) Flaccid muscle paralysis (first noticed in Flaccid muscle paralysis (first noticed in legs, later in arms and trunk)legs, later in arms and trunk)

c)c) Paresthesias of face, tongue, feet and Paresthesias of face, tongue, feet and hands.hands.

2.2. CardiovascularCardiovascular

a)a) Cardiac arrestCardiac arrest

b)b) Ventricular arrhythmiasVentricular arrhythmias

3.3. Gastrointestinal systemGastrointestinal systema)a) NauseaNausea

b)b) Intermittent intestinal colic or diarrheaIntermittent intestinal colic or diarrhea

4.4. Diagnostic FindingsDiagnostic Findingsa)a) Serum potassium >5.0 mEq/LSerum potassium >5.0 mEq/L

b)b) Decreased arterial pH.Decreased arterial pH.

c)c) ECG abnormalitiesECG abnormalities

Treatment Treatment

1.1. Restriction of potassium intake and drugs Restriction of potassium intake and drugs potentiating hyperkalemia.potentiating hyperkalemia.

2.2. Promote potassium excretion.Promote potassium excretion.a)a) Sodium polystyrene sulfanateSodium polystyrene sulfanate

b)b) DialysisDialysis

c)c) DiureticsDiuretics

d)d) Calcium gluconateCalcium gluconate

e)e) Sodium bicarbonateSodium bicarbonate

f)f) Insulin and glucose.Insulin and glucose.

Nursing interventionsNursing interventions

1.1. Be aware of patients at risk for hyperkalemia.Be aware of patients at risk for hyperkalemia.

2.2. Take measures to prevent hyperkalemia when Take measures to prevent hyperkalemia when

possible by following guidelines for possible by following guidelines for

administering potassium safely both orally and administering potassium safely both orally and

IV.IV.

3.3. Avoid administration of potassium-conserving Avoid administration of potassium-conserving

diuretics, potassium supplements or salt diuretics, potassium supplements or salt

substitutes to patient with poor renal function.substitutes to patient with poor renal function.

4.4. Cardiac monitoring and a 12-lead ECG are indicated Cardiac monitoring and a 12-lead ECG are indicated with elevated serum K.with elevated serum K.

5.5. Assess cardiovascular status by monitoring pulse Assess cardiovascular status by monitoring pulse rate and rhythm and blood pressure.rate and rhythm and blood pressure.

6.6. Assess for hyperactive bowel sounds and diarrhea.Assess for hyperactive bowel sounds and diarrhea.

7.7. Monitor serum K levels to determine treatment Monitor serum K levels to determine treatment effectiveness.effectiveness.

8.8. Caution hypercalemic patients to avoid foods high Caution hypercalemic patients to avoid foods high in potassium content.in potassium content.

9.9. To avoid false report of hyperkalemia To avoid false report of hyperkalemia (pseudohyperkalemia), take the following (pseudohyperkalemia), take the following precautions:precautions:

a)a) Avoid prolonged use of a tourniquet while Avoid prolonged use of a tourniquet while drawing blood sample.drawing blood sample.

b)b) Do not allow patient to exercise extremity Do not allow patient to exercise extremity immediately before drawing blood sample.immediately before drawing blood sample.

c)c) Take blood sample to laboratory as soon as Take blood sample to laboratory as soon as possible.possible.

d)d) Avoid drawing blood specimen from a site above Avoid drawing blood specimen from a site above an infusion of potassium solution.an infusion of potassium solution.

HYPOCALCEMIAHYPOCALCEMIANursing InterventionsNursing Interventions

1.1. Carefully assess patients at increased risk for Carefully assess patients at increased risk for

hypocalcemia especially after parathyroidectomy hypocalcemia especially after parathyroidectomy

or massive transfusions.or massive transfusions.

2.2. Remember that seizure precautions may indicated Remember that seizure precautions may indicated

based on the extent of musculoskeletal based on the extent of musculoskeletal

complications. complications.

3.3. Institute safety precautions, such as padded bed Institute safety precautions, such as padded bed

rails to prevent injury, especially if the patient is rails to prevent injury, especially if the patient is

confused.confused.

4.4. Remember that Ca may be given initially Remember that Ca may be given initially

as a slow IV bolus, followed by a slow IV as a slow IV bolus, followed by a slow IV

drip infusion if Ca deficit is acute. drip infusion if Ca deficit is acute.

5.5. Administer IV Ca replacement carefully, Administer IV Ca replacement carefully,

ensuring that the vein is patent; infiltration ensuring that the vein is patent; infiltration

can cause tissue necrosis.can cause tissue necrosis.

6.6. Place the patient on a cardiac monitor, and Place the patient on a cardiac monitor, and

observe for changes in heart rate and observe for changes in heart rate and

rhythm.rhythm.

7.7. Monitor a patient receiving IV Ca for arrhythmias, Monitor a patient receiving IV Ca for arrhythmias,

especially if the patient is also taking digitalis especially if the patient is also taking digitalis

glycosides. glycosides.

8.8. Expect to administer oral Ca supplements or Vit.D Expect to administer oral Ca supplements or Vit.D

for mild to moderate hypocalcemia.for mild to moderate hypocalcemia.

9.9. Keep the calcium gluconate at the bedside of a Keep the calcium gluconate at the bedside of a

patient recovering from parathyroid or thyroid patient recovering from parathyroid or thyroid

surgery to andminister if a rapid drop in serum Ca surgery to andminister if a rapid drop in serum Ca

level occurs.level occurs.

10.10. Teach the patients and familyTeach the patients and family

a)a) Foods and fluids high in Ca such as dairy Foods and fluids high in Ca such as dairy products and green leafy vegetable.products and green leafy vegetable.

b)b) Exercise enhances Ca mobilization from bone Exercise enhances Ca mobilization from bone to replenish ECF level.to replenish ECF level.

c)c) Female hormones, such as estrogen may be Female hormones, such as estrogen may be administered to maintain adequate Ca level in administered to maintain adequate Ca level in patients with osteoporosis.patients with osteoporosis.

HYERCALCEMIAHYERCALCEMIA Nursing InterventionsNursing Interventions

1.1. Monitor patients at risk for hypercalcemia, Monitor patients at risk for hypercalcemia,

especially those with hyperparathyroidism or especially those with hyperparathyroidism or

cancer and those on long-term bed rest.cancer and those on long-term bed rest.

2.2. Ambulate the patient as soon as possible to Ambulate the patient as soon as possible to

prevent Ca mobilization from the bone.prevent Ca mobilization from the bone.

3.3. Have the patient drink 3-4L of fluids daily (if not Have the patient drink 3-4L of fluids daily (if not

contraindicated) to stimulate renal Ca excretion.contraindicated) to stimulate renal Ca excretion.

4.4. Offer the patient foods or fluids high in Na (if not Offer the patient foods or fluids high in Na (if not

contraindicated) because the kidney excrete Ca in contraindicated) because the kidney excrete Ca in

favor of Na. favor of Na.

5.5. In a patient with acute moderate to severe In a patient with acute moderate to severe

hypercalcemia (levels greater than 13 mg/dl), hypercalcemia (levels greater than 13 mg/dl),

administer isotonic normal saline solution, administer isotonic normal saline solution,

usually at a rate of 200 to 500 ml/hr, to reserve usually at a rate of 200 to 500 ml/hr, to reserve

dehydration and promote urinary Ca excretion. dehydration and promote urinary Ca excretion.

6.6. Place client in cardiac monitor to detect Place client in cardiac monitor to detect arrhythmias.arrhythmias.

7.7. Institute safety precautions such as elevated side Institute safety precautions such as elevated side rails for a confused and disoriented patient.rails for a confused and disoriented patient.

8.8. Teach the patient to avoid Ca-containing foods and Teach the patient to avoid Ca-containing foods and fluids, particularly dairy products, to prevent fluids, particularly dairy products, to prevent increased serum Ca level.increased serum Ca level.

9.9. Monitor serum Ca levels to determine treatment Monitor serum Ca levels to determine treatment effectiveness and to detect new imbalance effectiveness and to detect new imbalance resulting from therapyresulting from therapy

HYPOPHOSPHATEMIAHYPOPHOSPHATEMIA Nursing InterventionsNursing Interventions

1.1. Monitor patients at risk for hypophosphatemia, Monitor patients at risk for hypophosphatemia,

especially those receiving TPN without P especially those receiving TPN without P

replacement.replacement.

2.2. Assess for paresthesia, particularly in the Assess for paresthesia, particularly in the

circumoral area – an early sign of circumoral area – an early sign of

hypophosphatemia.hypophosphatemia.

3.3. Initiate safety precautions for a patient with Initiate safety precautions for a patient with

confusion or decreased level of conciousness.confusion or decreased level of conciousness.

4.4. Assess for signs and symptoms of infection; in Assess for signs and symptoms of infection; in

hypophosphatemia, granulocytes have less ability hypophosphatemia, granulocytes have less ability

to fight foreign bodies.to fight foreign bodies.

5.5. Expect to administer oral P supplements to a Expect to administer oral P supplements to a

patient with mild to moderate hypophosphatemiapatient with mild to moderate hypophosphatemia

Use caution when administering Use caution when administering

parenteral P to a patient with parenteral P to a patient with

severe hypophosphatemia; severe hypophosphatemia;

hypocalcemia may occur as P hypocalcemia may occur as P

levels rise.levels rise.

HYPERPHOSPHATEMIAHYPERPHOSPHATEMIA Nursing InterventionsNursing Interventions

1.1. Monitor patients at risk, particularly those with Monitor patients at risk, particularly those with hypocalcemia.hypocalcemia.

2.2. Initiated seizure precautions in patients with Initiated seizure precautions in patients with elevated P levels.elevated P levels.

3.3. Monitor for neuromuscular irritability, which Monitor for neuromuscular irritability, which accompanies high P levels. accompanies high P levels.

4.4. Administer Ca supplements to promote elevation Administer Ca supplements to promote elevation of serum Ca, which lowers serum P levels.of serum Ca, which lowers serum P levels.

5.5. Teach the patient and family to avoid foods and Teach the patient and family to avoid foods and

fluids high in P, such as cheeses, nuts, whole-fluids high in P, such as cheeses, nuts, whole-

grain cereals, dried fruits and vegetables.grain cereals, dried fruits and vegetables.

6.6. Teach the patient and family to avoid excessive Teach the patient and family to avoid excessive

use of enema and laxatives containing P.use of enema and laxatives containing P.

HYPOMAGNESEMIAHYPOMAGNESEMIA Nursing InterventionsNursing Interventions

1.1. Monitor patients at risk for hypomagnesemia, Monitor patients at risk for hypomagnesemia, particularly those with hypokalemia and those particularly those with hypokalemia and those receiving TPN without Mg replacement.receiving TPN without Mg replacement.

2.2. Institute cardiac monitoring in a patient with severe Institute cardiac monitoring in a patient with severe hypomagnesemia.hypomagnesemia.

3.3. Remember that hypomagnesemia may be treated Remember that hypomagnesemia may be treated with oral, IM or IV Mg salt.with oral, IM or IV Mg salt.

4.4. Administer IV Mg slowly because too rapid infusion Administer IV Mg slowly because too rapid infusion can cause cardiac or respiratory arrest.can cause cardiac or respiratory arrest.

5.5. During IV Mg therapy, monitor urine output; it During IV Mg therapy, monitor urine output; it

should be at least 120 ml every 4 hours.should be at least 120 ml every 4 hours.

6.6. Monitor serum Mg and K levels to evaluate Monitor serum Mg and K levels to evaluate

treatment effectiveness.treatment effectiveness.

7.7. Initiate safety precautions, such as elevated bed Initiate safety precautions, such as elevated bed

rails, for a confused patient.rails, for a confused patient.

8.8. Teach the patient and family about foods high in Teach the patient and family about foods high in

Mg, such as green vegetables, nut, beans and fruits.Mg, such as green vegetables, nut, beans and fruits.

HYPERMAGNESEMIAHYPERMAGNESEMIA Nursing InterventionsNursing Interventions

1.1. Monitor patients at risk, especially those with Monitor patients at risk, especially those with

conditions predisposing to hypermagnesemia, conditions predisposing to hypermagnesemia,

such as renal failure.such as renal failure.

2.2. Monitor vital signs, particularly BP which can Monitor vital signs, particularly BP which can

drop precipitously and respirations which may be drop precipitously and respirations which may be

depressed and can progress to apnea.depressed and can progress to apnea.

3.3. Assess neuromuscular status for deficits; Assess neuromuscular status for deficits;

evaluate reflexes, grip strength and respiratory evaluate reflexes, grip strength and respiratory

muscle function.muscle function.

4.4. Institute cardiac monitoring for a patient with Institute cardiac monitoring for a patient with

serum Mg level greater than 7mEq/L because serum Mg level greater than 7mEq/L because

this patients has an increased risk for cardiac this patients has an increased risk for cardiac

arrest.arrest.

5.5. Be prepared to administer calcium gluconate, an Be prepared to administer calcium gluconate, an

Mg antagonist to temporarily relieve symptoms Mg antagonist to temporarily relieve symptoms

in an emergency.in an emergency.

6.6. Monitor serum Mg levels for changes to Monitor serum Mg levels for changes to evaluate the patient’s response to therapy.evaluate the patient’s response to therapy.

7.7. Teach the pt & family to minimize intake of Teach the pt & family to minimize intake of foods high in Mgfoods high in Mg

THANK YOUTHANK YOU