Week 2 Monika Electrolytes &fluids

Question 1

The reference range for ; Calcium
• Chloride
• Magnesium
-Phosphorus
• Potassium
• Sodium

Answer 1

Calcium 8.8 - 10.4 mg/dL
• Chloride 96 - 106 mEq/L
• Magnesium 1.8 - 2.6 mg/dL
• Phosphorus 2.7 - 4.5 mg/dL
• Potassium 3.5 - 5 mEq/L
• Sodium 135 - 145 mEq/L

Question 2

Electrolytes

Answer 2

• Substances whose molecules dissociate into ions
when placed in water
• Cations: positively charged
• Anions: negatively charged
• Concentration of electrolytes is often expressed in
milliequivalents (mEq)/L
• Electrolyte concentrations differ depending on
fluid compartments
• Normal serum ranges can vary depending on
facility*
• Follow facility ranges

Question 3

Electrolyte imbalance is

Answer 3

an abnormality in the concentration of
electrolytes in the body.

Question 4

Electrolytes
help to
regulate:

Answer 4

cardiac and neurological function
fluid balance
oxygen delivery
acid–base balance

Question 5

Diffusion

Answer 5

Movement of mainly molecules
across a permeable membrane
from high to low concentration
• Simple diffusion is passive

Question 6

Facilitated
diffusion

Answer 6

Uses carrier to move molecules
• Glucose cannot enter most cell
membranes without help of
insulin

Question 7

Active
transport

Answer 7

Process in which molecules
move against
concentration gradient
• External energy is required
for this process
• Example: sodium-potassium
pump
• ATP is used to move
sodium out of the cell and
potassium into the cell.

Question 8

Sodium (Na)

Answer 8

• Plays a major role in
• ECF volume and concentration (osmolality)
• Generation and transmission of nerve impulses
• Muscle contractility
• Acid-base balance

Question 9

Sodium (Na)
Normal Serum Sodium

Answer 9

: 135-145 mEq/L
Serum sodium level reflects the ratio of sodium to water
Major cation of ECF
Obtained from food/fluids in GI tract
Excreted through urine, sweat, feces
Kidneys primary regulator
Imbalances typically associated with equivalent changes in
osmolality

Question 10

Hypernatremia
Serum Sodium:

Answer 10

> 145 mEq/L
• Excess serum sodium
• Elevated serum sodium occurring with water loss or
sodium gain
• Causes hyperosmolality leading to cellular
dehydration
• Primary protection is thirst from hypothalamus

Question 11

hypernatremia is

Answer 11

hypernatremia is defined and named
after Na, it’s not really a sodium disorder, it is a
water disorder. Hypernatremia develops with a
loss of water not compensated for by adequate
ingestion of water or adequate generation of
electrolyte free water by the kidney. Also, gain of
Na can cause hypernatremia if the increased Na
load is not adequately matched with water
ingestion and generation of electrolyte free
water by the kidney. Hypernatremia is thus the
conjunction of too little water and/or too much
salt.

Question 12

Hypernatremia Causes

Answer 12

Excess sodium
intake
• High sodium diet
• Hypertonic IVF
• Fluid deprivation
• Heat Stroke
• DI

Question 13

Hypernatremia
• Occurs in patients with:

Answer 13

• normal fluid volume
• FVD
• FVE
• Most affected are the very old, very
young, and cognitively impaired

Question 14

Hyponatremia
Serum Sodium:

Answer 14

<135 mEq/L
• Insufficient serum sodium
• Loss of more salt than water
• Inadequate Na intake
• Fasting, starvation, confusion
• Excess water intake
• fluid overload in surgical/sepsis patient

Question 15

Hyponatremia Common Causes:

Answer 15

• Disease processes/symptoms
• SIADH, N/V/D, adrenal insufficiency
• Acute: Fluid overload in surgical/sepsis patient
• Chronic: outpatient, longer duration
• Exercise associated: extreme temperature,
excess water intake, prolonged exercise
• Medications
• anticonvulsants, SSRIs, or desmopressin
acetate

Question 16

Potassium
Normal Serum Potassium:

Answer 16

3.5-5 mEq/L
• Major ICF cation
• Primary source is food
• Kidneys primary regulator (also GI tract and
sweat)
• Necessary for
• Transmission and conduction of nerve and smooth
muscle impulses
• Cellular growth
• Maintenance of cardiac rhythms
• Acid-base balance

Question 17

Hyperkalemia
Serum Potassium:

Answer 17

> 5 mEq/L
• Excessive serum potassium

Question 18

Hyperkalemia Causes

Answer 18

• Excess intake
• Salt Substitutes
• Rapid parenteral administration
• Internal shift: K+ shifting out of cells
• Acidosis (DKA*)
• Rhabdomyolysis, severe burns, or crush injuries
• Retention
• Renal Injury or Disease
• ARBs (losartan), ACE inhibitors (Lisinopril), BB
(propranolol)

Question 19

Hyperkalemia Clinical Manifestations

Answer 19

• Increased cell excitability
• Changes in cardiac conduction (loss of P wave,
prolonged PR interval, widening of QRS)
• Tall, peaked T waves
• Heart block, ventricular fibrillation, cardiac arrest
• Muscle weakness
• Abdominal and/or leg cramps
• Diarrhea
• See Table 10-7

Question 20

Hypokalemia
Serum Potassium:

Answer 20

<3.5 mEq/L
• Low serum potassium caused by
• Increased loss of K+ via the kidneys
• Loop or thiazide diuretics
• GI tract losses
• Increased shift of K+ from ECF to ICF
• Magnesium deficiency
• Metabolic alkalosis
• Dietary K+ deficiency (anorexia, fasting)

Question 21

Hypokalemia Clinical Manifestations

Answer 21

• Hyperpolarization of cells impairs muscle
contraction
• Cardiac (ST segment depression, prolonged QRS,
Heart blocks, ventricular dysrhythmias)
• Skeletal muscle weakness (legs), cramps
• Weakness of respiratory muscles
• Decreased GI motility (constipation)
• Impaired regulation of arteriolar blood flow
• Hyperglycemia
• See Table 10-7

Question 22

Nursing Implementation

Answer 22

• Monitor:
• ECG for changes
• UOP before administering K+
• KCl supplements orally or IV
• Always dilute IV KCL
• NEVER give KCL via IV push or as a bolus
• Should not exceed 10 mEq/hr
• To prevent hyperkalemia and cardiac arrest

Question 23

Calcium
Normal Serum Calcium:

Answer 23

8.8 mg/dL-10.4 mg/dL
Functions
Formation of teeth and bone
Blood clotting
Transmission of nerve impulses
Myocardial contractions
Muscle contractions

Question 24

Calcium

Answer 24

• Obtained from ingested foods
• Vitamin D needed to absorb
• 99% is in bones
• Present in three forms: Ionized calcium is
biologically active
• Changes in pH
• Serum albumin affects total Ca levels

Question 25

Calcium Balance controlled by

Answer 25

• Parathyroid hormone (PTH) • production and release stimulated by low serum calcium levels • PTH increases bone resorption, increases GI absorption of calcium, and increases renal reabsorption of calcium • Calcitonin • produced by the thyroid gland • stimulated by high serum calcium levels. It opposes the action of PTH

Question 26

Hypocalcemia Serum Calcium

Answer 26

<8.8 mg/dL • Less Ca entering blood: • Inadequate vitamin D, malnutrition (poor Ca intake) • Decreased production of PTH (hypothyroidism, surgery) • Chronic Renal Failure • Excess Excretion • Renal insufficiency • Burns, Rhabdo • Pancreatitis, Cirrhosis • Diarrhea, laxative abuse • Multiple blood transfusions

Question 27

Hypocalcemia Clinical Manifestations

Answer 27

• Tetany • Positive Trousseau’s or Chvostek’s sign • Laryngeal stridor • Dysphagia • Perioral Tingling • Cardiac dysrhythmias • See Table 10-8

Question 28

Hypercalcemia Serum Calcium

Answer 28

>10.5 mg/dL High serum calcium level Hyperparathyroidism (2/3 of cases) Malignancy (1/3 of cases) Rare causes Excessive intake Prolonged immobilization Excess Vitamin D

Question 29

Hypercalcemia Clinical Manifestations • Neuro: •

Answer 29

Fatigue, lethargy, muscle weakness, stupor, coma, depressed reflexes, decreased memory, confusion, personality changes, psychosis • ECG changes • Anorexia, nausea, vomiting • Bone pain, fractures • Flank pain from nephrolithiasis (renal calculi) • Polyuria, dehydration • See Table 10-

Question 30

Phosphate Normal Serum Phosphate:

Answer 30

2.7 - 4.5 mg/dL • Primary anion in ICF • Most phosphorus located in bones & teeth • Essential to function of muscle, red blood cells, and nervous system • Involved in • acid-base buffering system • ATP production • cellular uptake of glucose • metabolism of carbohydrates, proteins, and fats

Question 31

Phosphate

Answer 31

• Serum levels controlled by parathyroid hormone • Maintenance requires adequate renal functioning • Reciprocal relationship with calcium • high phosphate level tends to cause a low calcium concentration in the serum 33

Question 32

Hyperphosphatemia Serum Phosphate

Answer 32

>4.5 mg/dL High serum PO4 3- caused by AKI or CKD Chemotherapy Hypoparathyroidism Increase phosphate reabsorption Tumor lysis, rhabdo Excessive intake of phosphate or vitamin D Laxatives Dairy products

Question 33

Hyperphosphatemia Clinical Manifestations

Answer 33

Often asymptomatic unless Ca binds to PO43- (hypocalcemia) Neuromuscular irritability and tetany (hypocalcemia) Long term increase results in calcified deposits in soft tissue such as: Joints Arteries Skin Kidneys Corneas

Question 34

Hypophosphatemia Serum Phosphate

Answer 34

< 2.7 mg/dL Low serum PO43- caused by: • Malnourishment/malabsorption • Diarrhea • ETOH abuse • Use of phosphate-binding antacids • Tums • During parenteral nutrition with inadequate replacement

Question 35

Hypophosphatemia Clinical Manifestations

Answer 35

• Mild to moderate, often asymptomatic. • CNS depression, confusion • Muscle weakness and pain • Cardiomyopathy • Respiratory failure • See Table 10-10

Question 36

Magnesium Normal Serum Magnesium:

Answer 36

1.8 mg/dL-2.6 mg/dL • Required for DNA & protein synthesis • Necessary for sodium-potassium pump • Important for normal cardiac function • 50% to 60% contained in bone • Absorbed in GI tract • Excreted by kidneys & stool

Question 37

Hypermagnesemia Causes Serum Magnesium

Answer 37

> 2.6 mg/dL • High serum Mg caused by • Increased intake or ingestion of products containing magnesium when renal insufficiency or failure is present • Maalox, MOM • Treatment of migraines or menstrual cramps • Excess intravenous magnesium administration • Tx of eclampsia • Decreased output • ESRD, AKI, adrenal insufficiency

Question 38

Hypermagnesemia Clinical Manifestations

Answer 38

• ECG changes • Hypotension • Lethargy / Somnolence • N/V • Impaired reflexes • Respiratory and cardiac arrest • See Table 10-9

Question 39

Hypomagnesemia Serum Magnesium

Answer 39

< 1.8 mg/dL • Low serum Mg caused by • Prolonged fasting or starvation • Chronic alcoholism • Fluid loss from gastrointestinal tract • Prolonged parenteral nutrition without supplementation • Diuretics • Large blood transfusion

Question 40

Hypomagnesemia Clinical Manifestations

Answer 40

• Hyperactive deep tendon reflexes • Muscle cramps • Tremors • Seizures • Cardiac dysrhythmias • Torsade de pointes, Vfib • Corresponding hypocalcemia and hypokalemia • See Table 10-9