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Fluid & Electrolytes:

K, Ca, Mg, Phosphorus, Cl

Potassium

• Major electrolyte in intracellular fluid (98% of k in the body is inside the cell. The 2% in the ECF and that 2% is important for neuromuscular function)

• Normal serum K+ is 3.5 to 5.0 mEq/L

• Influences both skeletal and cardiac muscle activity

• Minor variations are significant

• Renal system important in keeping balanced potassium – kidneys adjust the amt of K to be excreted in the urine and as K levels rise, this creates movement of K into the renal tubules with the loss of K in the urine. Renal failure is the #1 cause of Hyperkalemia.

• Body does not conserve potassium. Needs to be adjusted daily. Bananas are the best source

Hypokalemia

• K+ < 3.5 mEq/L

• Cause

– GI suction, vomiting, diarrhea

– TPN or IVF without K+ replacement

– Trauma – K leaves the cells when injured

– Diabetes – uncontrolled

– Low oral intake of K+

– Sweat loss

– Medications – diuretics (could use aldactone for K sparing), laxatives, insulin

Renal Loss of K+

• Diuretics

• Hyperaldosteronism (causes increased retention or Na & H2O then increases excretion of K)

• High dose Na+ PCNs

• Large dose corticosteroids

S/S Hypokalemia

• Fatigue

• Anorexia, N/V, Decrease bowel motility

• Muscle weakness & leg cramps

• Impaired glucose tolerance

• Paresthesias (numbness & tingling)

• Impaired renal concentrating ability

• Diminished deep tendon reflexes

• Flaccid paralysis – late sign

• Increased sensitivity to digitalis

• Dysrhythmias

• Severe hypokelemia – death by cardiac arrest

Hypokalemia commonly accompanies alkalosis

Hypokalemia & Cardiac Changes

• ↓ strength of contraction

• Myocardium irritability

• ST segment depression

• K+ < 2.7 mEq/L may result in PACs, PVC's, Vfib or cardiac arrest

• K+ < 3.5 assoc. with metabolic alkalosis, high pH & high HCO3

• Digoxin toxicity – Hypokalemia potentiates the action of digoxin

Works by inhibiting the myocardial cell Na/K pump thereby increasing the cellular K

Hypokalemia: Lab Results

• K+ deficit < 3.5 mEq/L

• K+ < 3.5mEq/L often assoc. with metabolic alkalosis, high pH, & high HCO3

• K+ < 2.7 may result in dangerous dysrhythmias - Danger signs: arrhythmias, cardiac arrest, dig toxicity, muscle paralysis, resp arrest

• ↑ pH & HCO3

Medical Treatment Hypokalemia

• K+ replacement (PO or IV)

• Increase on a daily basis

– 40-80 mEq/day

• At risk patient

– 50-100 mEq/day

• K+ rich foods

• Treat the underlying cause

Oral K+ Supplements

• Minimize GI irritation

– Dilute liquid & effervescent supplement

– Give tabs & capsules w/ 8 oz. H2O

– Give K+ with food

• Adverse reaction – N/V, diarrhea, GI bleed

Oral Potassium Supplements

• Avoid overdose (hyperkalemia)

• ↓ K+ dose if using K+ salt substitute

• Not used with K+ sparing diuretics

Intravenous K+ Supplement

• Must be diluted

• Do NOT give by direct IVP – causes cardiac arrest!

• Max. dose is 60 mEq at a time

• Must use IV pump

• Monitor renal output

• CHS policy – pt on heart monitor

• Monitor IV site for extravasation

Nursing Interventions: Hypokalemia

• Identify pt at risk – esp. if on Digoxin

• Monitor ECG & BP

• Monitor serum K+

• Pt education – diuretics & laxatives

• Administer K+ supplements PO or IV

• ↑ dietary K+

• Monitor urine output

Hyperkalemia

• Serum K+ > 5.5 mEq/L

• Causes

– Renal failure is the #1 cause

– Release of K+ from damaged cells – ex: chemo kills cells and causes the release

– Acidosis

– Addison’s Disease

– K+ sparing diuretics

– High K+ intake

– Medications

– If you’re giving blood, the longer the blood sits there the higher the K gets

S/S Hyperkalemia

• Main effects cardiac function

• Muscle weakness and paralysis

• Ventricular conduction is slowed

• Paresthesias & irritability

– Respiratory and speech muscles

• Flaccid muscular paralysis

– Legs→trunk→arms (including respiratory)

• GI hyperactivity

– N/V, colic, & diarrhea

As the K level increases, symptoms changes from irritability to weakness

Hyperkalemia & Cardiac Changes

• Slows heart rate

• ECG changes

– Tall, peaked T wave, short QT interval

– Longer PR interval, widening QRS complex

– Risk for Heart Block, A-fib, or, V-fib

• Severe ↑ K+

– Decreased heart contraction strength

– Dilated & flaccid heart (when K is greater than 7)

ECG & Potassium Hyperkalemia: Lab Data

• Serum potassium > 5.5 mEq/L

• ECG abnormalities

• Arterial blood gases – low pH indicating acidosis

Metabolic acidosis is usually accompanied by hyperkalemia

Hyperkalemia Medical Treatment

• K+ restricted diet

• Stop K containing medications

• Monitor for “Digitalis toxicity”

• Cation-exchange resins

– Kayexalate – PO or PR – substitutes Na for K and gets it out of the system

– 1Gm of resin removes 1 mEq K+

• Dialysis - If conservative methods not suffice

Emergency Medical Treatment: Hyperkalemia

• Ca Gluconate – IV

– Does NOT ↓ K+

– Antagonizes K+ action on heart

– Always has to be on ECG

• Hypertonic Glucose & Insulin

– Insulin - facilitates K+ movement into cells

– Glucose - ↑ insulin release from pancreas

• NaHCO3

– K+ shifts into cells

Nursing Interventions: Hyperkalemia

• Be aware of pt at risk

• Monitor for:

– Generalized weakness & dysrhythmias

– Irritability & GI symptoms

– Nausea & intestinal colic

– ECG or lab abnormalities

• Prevention of hyperkalemia

• Educate pt: medication & diet

• Do NOT draw blood above K+ infusion site

Calcium

• Serum Ca++ level 8.6 – 10.2 mg/dl (total)

• 99% stored in bones (bones & teeth)

• Found in three forms:

- bound: to proteins (less than 50%)

- ionized: found in serum (50% of calcium and is most important)

- complexed: combined with nonprotein anions: phosphate, citrate, and carbonate

Ionized Calcium

• Activate body chemical rxn

• Muscle contractions and relaxation

• Promote transmission of nerve impulse

• Cardiac contractility & automaticity

• Formation of prothrombin

Calcium and Phosphorus have a reciprocal relationship

Ca low=Phos high

Ca high=Phos low

Calcium Regulators

• Parathyroid Hormone (PTH) pulls

– Releases Ca from the bone

– Increases Ca absorption from GI

Increases Ca absorption from renal tubules

• Calcitonin – secreted by thyroid (keeps)

– Antagonist of PTH

– Secretion stimulated by high serum Ca++

– Inhibits Ca reabsorption from bone

• Phosphate

– Reciprocal relationship with Ca

– ↑Ca = ↓ Phos

• Vitamin D

– Necessary for absorption & utilization of Ca

Hypocalcemia

• Serum Ca++ < 8.5 mg/dl

• Causes include:

- hypoparathyroidism & surgical hypoparathyroidism

- malabsorption syndrome

- vitamin D deficiency

- prolonged admin. of Ca free IVF

- acute pancreatitis

Causes

- Excessive admin. of citrated blood

- Alkalosis

- Hyperphosphatemia

- Hypomagnesemia

- Thyroid cancer

- Low serum albumin

- Cimetidine (Tagamet)

- Alcohol Abuse

- Medications

S/Sx

• Tetany (# 1 sign)

• Vary with severity, duration & rate of development

• Numbness & tingling

• Spasms of muscles of extremities & face

• Pain

• Hyperactive deep tendon reflexes

• Abdominal muscle spasms

• Respiratory effects

• Altered mood & memory

• Convulsion/Seizures

• Laryngeal spasm

• + Trousseau’s

• + Chvostek’s

+ Trousseau’s Sign

• Carpopedal spasm of hand when

o Blood supply ↓

o Pressure on nerve

• Occurs several minutes after BP cuff inflated > systolic BP

+ Chvostek’s Sign

• Spasm of muscles innervated by facial nerve

• Tap facial nerve anterior to ear lobe below zygomatic process

Cardiac Effects

• Prolonged QT interval

• Prolonged ST segment

• ↓ cardiac contractility

• ↓sensitivity to Digoxin

Lab Data

• Serum calcium levels < 8.5 mg/dl

• Albumin/protein levels can give incorrect levels of Ca

• Ionized (serum) levels of Ca should be obtained for accurate results

• PTH levels rise in response to hypocalcemia

• Magnesium and phosphorus levels should also be obtained

Low Magnesium=Low Calcium

High Phosphorus=Low Calcium

High pH=Low Calcium

Hypocalcemia Medical Treatment

• Acute symptomatic ↓ Ca is emergency.

– Requires prompt adm. of IV Calcium

• 10% Ca-Gluconate

– For severe symptoms

• Ca-Chloride

– Never give IM – faster than Ca-Gluconate

• Oral Ca or Vitamin D

Nursing Interventions Hypocalcemia

• Identify pt at risk

• Seizure precautions if severe ↓Ca

• Monitor airway

• Monitor ECG

• Educate pt: Ca loss & risks & Ca rich foods (green leafy veggies, canned salmon, sardines, fresh oysters, dairy products)

Hypercalcemia

• Calcium > 10.5 mg/dl

• If severe – dangerous with ↑ mortality

• Causes include:

– Hyperparathyroidism – most common cause

– malignant neoplastic disease and chemotherapies – second most common

– prolonged immobilization

– large doses Vit. D & Vit. A

S/S

• Decreased neuromuscular excitability:Muscle weakness and incoordination

• ↓ GI motility: anorexia, N/V, constipation – leads to dehydration

• Altered memory, confusion, slurred speech, lethargy, acute psychotic behavior, & coma

• Depressed deep tendon reflexes

• Bone pain & abdominal pain

• Hypercalcemic crisis: severe polyuria & polydipsia, intractable nausea, abdominal cramps, lethargy, coma and cardiac arrest

• Can cause kidney stones

Cardiac Changes – focus on cardiac changes inn Na & K – not so much these

• Calcium: inotropic effect on heart & reduces heart rate (decreases the contractility)

• Shorten ST segment & QT interval

• Prolonged PR interval

• Potentiate digoxin toxicity

Lab Data

• Serum calcium > 10.2 mg/dl

• ECG-dysrythmias

• PTH- increased

• X-ray-reveal osteoporosis

• Urine

Medical Treatment

• Treat underlying cause

• Dilute serum Ca++ with NS – encourages dieresis to get Ca out

• Lasix/furosemide

• IV phosphate

• Calcitonin

• Glucocorticoids – inhibit the intestinal absorption of Ca

• Hemodialysis or CAPD

Nursing Interventions

• Monitor for pt risk

• ↑activity & fluids if possible

• ↓ Ca++ intake

• Safety measures for confusion

• Monitor ECG, I&O, breath sounds

• Monitor for Digoxin toxicity

• Prevent Ca++ renal stones

Magnesium

• Normal 1.3 – 2.3 mEq/L

• Mg is important for neuromuscular function

• Activator for enzymes

• Carbohydrate & protein metabolism

• Vasodilation in peripheral arteries

• Found in bone and tissue

• Eliminated by kidneys

Magnesium is the 2nd most abundant cation in the intracellular compartment, next to K

Hypomagnesemia

• Mg < 1.3 mEq/L

• 1/3 Mg is bound to protein, 2/3 remains as free cation

• Causes include:

• GI loss

-Alcoholism: decrease dietary intake, impairs renal conservation, intestinal malabsorption, intermittent diarrhea and vomiting

The kidney is the primary route of magnesium excretion

Chronic alcoholism is the most common cause – because of poor dietary intake

Causes

• Intestinal malabsorption syndromes

• Diarrhea

• Diuretics

• Prolonged admin. Mg free IVF/TPN

• NG Suction

• Renal or liver disease

• Diabetic ketoacidosis

• Lower GI tract has the highest magnesium concentration

S/Sx

• Usually occur Mg < 1.0 mEq/L

• Most are neuromuscular: hyperexcitability with muscle weakness, tremors & athetoid movements (slow, involuntary movement)

• Tetany

• + Trouseau’s and Chvostek’s

• Seizures

• Laryngeal stridor

• Signs of low hypocalcemia r/t low PTH

• Alterations in mood: apathy, depression, agitation, dizziness, insomnia, audio or visual hallucinations, psychoses

• Digoxin Toxicity

Cardiac Changes

• Predisposes to dysrhythmias

– PVC or V-fib

• ↑risk for digoxin toxicity

• ECG:

– Prolonged PR & QT intervals

– Widening QRS complex

– depressed ST segment

– Flattened T waves

– Prominent U waves

Lab Data

• Mg < 1.3 mEq/L

• Potassium

• Calcium

• ECG

• Urine Mg. level

Medical Treatment

• Diet

– Can be used alone for mild _ Mg

– Green vegetables, meat, seafood, nuts, seeds, legumes, whole grains,peanut butter, cocoa

– Spinach is the best source

• Mg replacement

– Assess renal function – route of Mg elimination

– PO Slow-Mag

• Diarrhea possible side effect

– IV or IM

– MOM helps for constipation

– Because the kidneys are the main route of excretion, u have to watch the BUN, creatinine

Admin. Of Mg Sulfate IV

• Monitor rate closely

– Too rapid: risk cardiac arrest

– Dose: based on severity

– Rate not to exceed 150 mg/min or 67 mEq over 8 hours (severe)

• Contraindicated in heart block

Before u start the med, check DTR FIRST

• Monitor urinary output

– 100 ml q 4 hr

• Assess patellar reflexes

• Monitor respiratory status

– Risk respiratory arrest

Nursing Interventions

• Identify & monitor pt at risk

• Asses of digoxin toxicity

• Seizure precautions

• Monitor airway

• Safety for confusion / psychosis

• Pt education: diuretics & laxative use

• Pt education: diet

Hypermagnesemia

• Mg > 2.5 mEq/L

• Causes

– Hemolyzed blood samples – can get a false high level

– Renal failure – most common cause

– Addison’s Disease

– Excessive use antacids and laxatives

– Untreated ketoacidosis

– Excessive infusion

– Hypothermia

– Lithium toxicity

S/S

• Acute elevations: peripheral and CNS depression

• Mild increases:

-low blood pressure

-N/V

-facial flushing

-sensations warmth

• Higher increases:

-lethargy

-dysarthria – difficulty articulating; damage to a central or peripheral motor nerve

-drowsiness

-loss of deep tendon reflexes

-muscle weakness and paralysis

-depressed respirations

-coma

Cardiac Changes

• Sinus Bradycardia

• Prolonged PR, & QT intervals

• Tall T waves

• Widened QRS

• Heart Block

• Cardiac arrest in diastole

Lab Data

• Mg > 2.5 mEq/L

• ECG

• K+ increased

• Ca- increased

• Creatinine clearance decreases to less than 3.0 ml/min.

Medical Treatment

• Prevention is key

• Avoid administration of Mg in renal failure

• Hemodialysis

• Emergency treatment if respiratory or cardiac problems develop

– Ventilator support

– Calcium Gluconate

• Direct antagonist to Magnesium

• 5 – 10 mEq may reverse cardiac or respiratory problems

• Lasix

• NaCL or LR

Nursing Interventions

• Monitor pt at risk

• Monitor vital signs

– Low BP

– Shallow resp. with apnea

• Assess patellar reflexes

– Absent reflexes implies Mg > 7.0

• Monitor LOC

– Drowsy, lethargy, coma

• Monitor pt at risk

• Monitor vital signs

– Low BP

– Shallow resp. with apnea

• Assess patellar reflexes

– Absent reflexes implies Mg > 7.0

• Monitor LOC

– Drowsy, lethargy, coma

Phosphorus

• Normal 2.5-4.5 mg/dl (adult)

• Essential for fxn of muscle & RBCs

• Essential to nervous system

• Essential to metabolism of:

– Carbohydrate

– Protein

– Fats

• Aids in the formation of ATP and 2,3 diphosphoglycerate

• Maintenance in acid-base balance

• 85% is located in bones and teeth

• 14% located in soft tissue

• 1% in ECF

• Critical to nerve and muscle function

Important for WBC Phagocytosis & platelet function

Hypophosphatemia

• Phosphorus < 2.5 mg/dl

• Causes

–Severe protein –

• calorie malnutrition

• Anorexia

• Alcoholism

• Overfeeding with simple carbohydrates

• Elderly debilated & unable to eat

• Hepatic encelopathy

• Prolonged intense hyperventilation

– Alcohol withdrawal

– Diabetic ketoacidosis

– Major thermal burns

Total phosphorus in the body is related to dietary intake, hormonal regulation, kidney excretion, and transcellular shifts

S/S

• Most signs & symptoms 2nd to deficiency

– Impaired cellular energy resources (ATP)

– Impaired oxygen delivery to tissues (2,3Diph) DPG

• Neurological

– Irritability, Apprehension, weakness,

– Numbness, confusion

– Seizure, fatigue, parasthesia, coma

• Hyperglycemia

– 2nd to predisposed insulin resistance

• Muscle damage

– 2nd to _ ATP level in muscle tissue

– Muscle weakness & pain

– Acute rhabdomyolysis

• Disintegration of striated muscle

– Impaired ventilation

o 2nd to weakened respiratory muscles

Lab Data

• Phos < 2.5 mg/dl

• Glucose/insulin administration causes a decrease in phosphorus

• PTH

• Alkaline phosphatase

• X-ray

Medical Treatment

• Prevention

• TPN & TF should have adequate Phos.

• Phosphorus – PO

– Aluminum Phosphate (Phosphojel)

• Phosphorus < 1.0 mg/dl (severe)

– K-Phosphate or Na-Phosphate

• 0.2 mMol /kg/hr is max. rate

• Risk of hypocalcemia & tetany

Giving a high phosphate=risk for low calcium due to inverse relationship

Nursing Interventions

• Identify & monitor pt at risk

• Gradual introduction of TPN & TF

– Avoid rapid shift of phosphorus

• Prevent infection

• Monitor serum phosphate levels

• Administer meds safely

• Teach about diet

Hyperphosphatemia

• Phosphorus > 4.5 mg/dl

• Causes

– Renal failure = most common cause due to the kidney’s inability to excrete phosphorus

o ↓Excretion of phosphorus

– Chemotherapy for neoplastic disease – due to significant cell destruction

– ↑Phosphorus intake

– Profound muscle necrosis

– Hypoparathyroidism

S/S

• Similar to S/S of hypocalcemia

• Tetany

– Mild to moderate: Tingling then numbness – fingertips & around mouth

– Severe: Spreads proximally to limbs & face ↑ severity

• Muscle spasm & pain

• Progressive renal impairment

Lab Data

• Phos > 4.5 mg/dl

• Calcium will be low

• X-ray

• PTH • Bun and creatinine

Medical Treatment

• Treat underlying disorder

• If 2nd to tumor cell lysis

– Allopurinol – prevent urate nephropathy

• If 2nd to renal failure

– Phosphate binding gels – take it out of the circulatory system by binding to it

– ↓ phosphate diet

– Dialysis

• Acute hyperphosphatemia

– NS – IVF

o Promotes renal excretion

– Hypertonic dextrose & regular insulin

o Drive phosphorus into cells

– Hemodialysis or Peritoneal dialysis

– Surgery

Nursing Interventions

• Identify & monitor pt at risk

• Monitor lab results

• Pt education: Avoid meds with Phos.

– Laxatives & enemas

• Change in urine output

Nursing Interventions

• Pt education: Avoid ↑Phos. Foods

– Dried fruit & vegetables

– sardines

– Hard cheeses,

– Whole grain cereal

– Nuts

Chloride

• Normal: 97 – 107 mEq/L

• Major anion in ECF along with Na

• Chloride in ISF & lymph > in IVF

• Assists in maintaining serum osmolality & osmotic pressure

• Component in gastric fluid , pancreatic fluid, & in sweat

• Inverse relationship to bicarbonate

↑Cl = ↓HCO3

Hypochloremia

• Cl < 96 mEq/L

• Causes

– Prolonged vomiting

– Prolonged NG suctioning

– Prolonged diarrhea

– GI drainage

– Salt restricted diet

– Diuretics

S/S

• ↑ Bicarbonate level

• ↓ Na level

• Hyperexcitability of muscles

– Tetany, twitching, weakness

• Hyperactive deep tendon reflexes

• Cardiac dysrhythmia

• Water excess

Lab Data

• Cl < 96 mEq/L

• Sodium

• Potassium

• Arterial Blood Gases: metabolic alkalosis

• Urine chloride level

Medical Treatment

• Correct the cause

• IV therapy: NS or ½NS

• Ammonium chloride

– Dose calculated on chloride deficit

– 100mEq / 500ml NS – give slowly

– Treat metabolic alkalosis

– Foods high in chloride

Nursing Interventions

• Monitor I&O

• Monitor bicarbonate & sodium level

• Assess LOC, muscle strength & movement

Avoid bottled water

• Pt education: food ↑ in chloride

– Tomato juice = best source of chloride

– canned vegetables

– broth, fruit, processed meat

Hyperchloremia

• Cl > 107 mEq/L

• Causes:

– Loss of bicarbonate

o Kidney

o GI tract

S/S - rarely produces s/sx on its on major symptoms are usually due to metabolic acidosis

• S/S same as those of metabolic acidosis, hypervolemia and hypernatremia.

• ↑Na level

• Fluid retention

• Tachypnea

• Weakness

• Lethargy

• ↓Cognitive ability

• HTN

• If Untreated

– ↓Cardiac output

– Dysrhythmias

– Coma

Medical Treatment

• IV fluid – Lactated Ringer’s - slowly

• Diuretics

• Restrict –

– Sodium

– Chloride

– Fluids other than LR until Cl level ↓

Lab Data

• Cl > 108 mEq/L

• Sodium >145

• pH ................
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