Fluid and Electrolytes Handouts

ST LOUIS REVIEW CENTERIligan City

MS: Fluid and ElectrolytesCompiled by: Roquee Hospicio H. Paragoso, BSN, RN

ANATOMY AND PHYSIOLOGY

A. Fluida. Accounts for about 60% of adult’s total body weightb. ICF is 2/3 of this amount while ECF is 1/3 of this amountc. ECF – intravascular space (fluid within blood vessels), interstitial

space (fluid that surrounds the cell) and transcellular fluid (digestive juices, water and solutes in the renal tubules and bladder, pleural fluid

d. 3rd space fluid shift – loss of ECF into a space that does not contribute to equilibrium between the ICF and ECF

e. Body water distribution according to age:i. Infant – 80% of body weightii. Male – 60% of body weightiii. Female – 50% of body weight

B. Electrolytesa. Substance that dissociates and forms ions when mixed with

waterb. ICF – K and PO4 are major electrolytesc. ECF – Na and Cl are major electrolytes; Na level is the primary

determinant of ECF concentrationd. Normal Values:

i. Na – 135-145 mEq/Lii. K – 3.5-5.5 mEq/Liii. Ca – 4.5-5.5 mEq/Liv. HPO4 – 1.7-2.6 mEq?Lv. Cl – 98-108 mEq/Lvi. Mg – 1.5-2.5 mEq/L

C. Acid-Base Balancea. Acid – substance that ionizes water and forms H+ ions and

anions; hydrogen donorb. Base – substance that can bind to hydrogen ions; hydrogen

acceptorc. pH – hydrogen ion concentration in the blood; the more the

hydrogen, the more acidic is the medium, the lower its pH. Normal pH: 7.35-7.45

D. Regulatory Mechanismsa. Osmosis – fluid shifting from an area of low solute concentration

to an area of higher solute concentrationb. Diffusion – fluid movement from an area of high solute

concentration to one of lower solute concentrationsc. Filtration – removal of particles from a solution through the

movement of fluid across a membrane or other partial barrierd. Active transport – energy-requiring process that transport ions

across the cell membrane against a concentration gradient

↓ Na

1 | P a g e S t L o u i s R e v i e w C e n t e r – I l i g a n

↓ Blood volume↓ Blood pressure

↓Angiotensinogen

↓Angiotensin I

↓Angiotensin II

↓Vasoconstriction ↑ Aldosterone

↓ ↓↑ Peripheral Resistance ↑ Na and water retention

(kidneys)↓

↑ Blood Pressure↑ Blood Volume

E. Sources of normal fluid lossa. Kidneys – output of 1-2 L dailyb. Sensible losses – 0-1 L daily depending on the temperaturec. Insensible losses – 600 ml daily; increase during feverd. Lungs – 300-400 ml daily; increase with fevere. GI – 100-200 ml daily

F. Homeostatic mechanismsa. Kidneys

i. Filters 170 L of plasma dailyii. Reabsorbs HCO3 and secrete H+ and produce NH3iii. Slower than the lungs; takes days to achieve homeostasis

b. Cardiovascular systemi. Normal ABG values:

1. pH – 7.35-7.452. PO2 – 80-100 mmHg3. PCO2 – 35-45 mmHg4. HCO2 – 22-26 mEq/L

c. Lungsi. Controls CO2 and H2CO3 excretionii. PCO2 – most powerful respiratory stimulant

d. Buffer systemsi. Chemical systems that maintain body pH by releasing H

ionsii. HCO3 and H2CO3 – primary buffer system; 20:1 ratioiii. HCO3 – regulated by kidneysiv. H2CO3 – regulated by lungsv. Phosphate and protein buffers – less important

e. Endocrine i. ADH – secreted by pituitary glandii. Aldosterone – adrenal cortex; causes sodium retention and

potassium lossiii. Parathormone – regulates calcium and phosphate balance

ABNORMALITIES

A. Fluid Volume Deficit – hypovolemia; excessive loss of water and electrolytes in equal proportion; vascular, cellular or intracellular dehydration


a. Causes: ↓ fluid intake, ↑ output (diarrhea, vomiting, hemorrhage), massive third-space fluid shifting

b. Manifestations: dry mucous membranes, poor skin turgor, hypotension, tachycardia, severe thirst, weight loss, weakness and mental status changes, renal shutdown and coma

c. Laboratory: urine specific gravity - >1.020; BUN>creatinine; ↑ Hct

d. Management: i. Monitor I/O, urine specific gravity and weight (same time,

same clothes)ii. Adequate hydration through oral or IV supplementationiii. Ongoing assessment iv. Maintain skin integrityv. Tell patient to change positions slowly

B. Fluid Volume Excess – hypervolemia; excessive retention of water and electrolytes in equal proportion; increased local or total body fluid volume

a. Causes: ↑ fluid intake, ↓ ability to excrete fluid (renal disease), abnormal fluid retention (CHF), ↑ Na intake

b. Manifestations: Weight gain, dependent edema, dyspnea and crackles, mental status changes, bounding pulse, jugular vein distention

c. Laboratory: ↓ BUN and Hctd. Management:

i. Monitor I/O, weigh the client daily (same time, same clothes), assess V/S, presence of sacral and peripheral edema

ii. Monitor IV rate regularly.iii. Assess lung sounds; if pulmonary edema occurs, elevate

head of bed, have the client turn and cough and deep breathe q 2 hours

iv. Turn the client q 2 hours; edematous tissue is prone to skin breakdown.

v. Administer diureticsvi. DIET: sodium and water restrictionvii. Check medications if they contain Na.

C. Hyponatremia – serum Na level below 135 mEq/L resulting from excessive Na loss or excessive water gain

a. Causes: fluid loss (vomiting, diarrhea, fistulas, diaphoresis, diuretic therapy, NG suctioning), adrenal insufficiency (↓ aldosterone), SIADH, ↑ water gain from intake of Na-deficient parenteral fluids, compulsive water drinking

b. Manifestations: Anorexia, nausea and vomiting, muscle cramps, altered LOC (lethargy, disorientation, headache, confusion), convulsions (Na <115 mEq/L)

c. Laboratory: Na <135 mEq/L, urinalysis – (+) urine Na, ↑ specific gravity (SIADH) or ↓ specific gravity (Na loss)

d. Management: i. Monitor I/O, weigh daily, assess for signs of FVDii. Na supplementation (oral, IV, parenteral)iii. Infuse hypotonic solutions cautiouslyiv. Assess neurologic (lethargy, confusion, muscle twitching,

seizures) and GI status (anorexia, nausea, vomiting, abdominal cramping)

v. Maintain SEIZURE PRECAUTIONSvi. Monitor serum Na levels


vii. Strict water restrictionD. Hypernatremia - serum Na level above 145 mEq/L caused by a gain of

sodium in excess of water or loss of water in excess of Naa. Cause: water loss (diarrhea, fever, hyperventilation, diabetes

insipidus), ↓ water replacement (↓ intake of water by the elderly, cognitively impaired, comatose), inability to swallow, seawater ingestion, ↑ sodium intake

b. Manifestations: Thirst, poor skin turgor, edematous dry tongue and sticky mucous membranes, ↑ body temperature, lethargy and restlessness, peripheral and pulmonary edema

c. Laboratory: Na >145 mEq/L, serum osmolality >295 mOs/kg, urinalysis - ↑ specific gravity and urine osmolality

d. Management:i. Monitor I/O, weigh dailyii. ↑ fluid intake as appropriateiii. Infuse hypertonic solution cautiouslyiv. Monitor serum Na levelsv. Assess V/S, skin turgor, neurologic status and thirstvi. Reposition the client frequentlyvii. Raise side rails

E. Hypokalemia – serum K level below 3.5 mEq/La. Cause: ↓ K intake, excessive K loss (diuretic therapy, gastric

suctioning, colostomy, ileostomy, GI disorders, diaphoresis and renal disorders), metabolic alkalosis, hyperaldosteronism

b. Manifestations: anorexia, nausea and vomiting, fatigue, muscle weakness, leg cramps or paresthesia, cardiac arrhythmias, ↓ bowel motility, ileus or abdominal distention

c. Laboratory: K < 3.5 mEq/l, ECG – flattened T wave, prominent U wave, depressed ST segment and prolong PR interval

d. Management: i. Oral K replacements dailyii. Assess for abdominal pain or GI bleeding – may indicate

bowel lesions that require interventioniii. Infuse parenteral K supplement; dilute in at least 100 ml of

solution, administer on an IV pump and monitor ECG during therapy

iv. Never administer K by IV push or IM!v. DIET: ↑ K-rich foods: Apricots, Bananas, Cantaloupe, Dates,

Orange juice, Potatoes, Peachvi. Assess the clients on digitalis therapy (toxicity: GI distress)

F. Hyperkalemia – K level above 5.5 mEq/La. Causes: ↓ renal excretion due to renal failure,

hypoaldosteronism, acidosis, severe tissue trauma, ↑ K supplementation

b. Manifestations: cardiac arrhythmias, muscle weakness, paresthesias and possibly paralysis, irritability and anxiety, abdominal cramps with diarrhea

c. Laboratory: K >5.5 mEq/L, ECG – tall T waves, prolong PR interval and QRS duration, absent P waves and ST depression

d. Management:i. Kayexalate (cation-exchange resins) – oral or by retention

enema; draws K into the bowel so that it may be excreted in the feces

ii. Ca gluconate administration – counters abnormal cardiac conditions

iii. NaHCO3 – causes a temporary shift of K into cells


iv. Regular insulin + glucose administration – temporary shift of K into cells

v. Hemodialysisvi. Assess for signs of muscular weakness, cardiac

arrhythmias, paresthesias, nausea and intestinal colicvii. Monitor ECG, serum K levelsviii. Administer K IV cautiouslyix. DIET: ↓ K-rich foodsx. Use salt-substitutes sparingly: contains 60 mEq of K/

teaspoonG. Hypocalcemia – serum calcium level < 8 mg/dl (Normal: 8.5-10.5

mg/dl)a. Causes: hypoparathyroidism, pancreatitis, inadequate Vit D

intake or synthesis, renal failure, drug therapy, insufficient calcium intake

b. Manifestations: tetany (tingling in fingers and circumoral area, muscle spasms associated with pain in extremities and face), Trousseau’s sign (carpopedal spasm) and Chvostek sign (twitching of facial muscles when facial nerve is tapped), hyperactive DTR and seizures due to neuromuscular irritability

c. Laboratory: Ca <8.5 mg/dL, ECG – prolonged QT intervald. Management:

i. SEIZURE PRECAUTIONSii. Administer parenteral Ca; prevent infiltration – causes

tissue necrosisiii. Administer parenteral Ca cautiously in patients with

digitalis therapy – may cause cardiac arrestiv. Provide a relaxed, quiet environment and promote

adequate restv. Vitamin D - ↑ Ca absorption from the GI tractvi. Diet: ↑ Ca intake to 1000-1500 mg/dayvii. Regular exercise; ↓ bone loss of calcium

H. Hypercalcemia – serum Ca level above 10.5 mg/dla. Causes: ↑ Ca intake, movement of Ca from bones to serum

(prolonged immobilization and malignant neoplastic disorders), ↓ renal excretion due to renal failure, drug therapy with thiazide diuretics, hyperparathyroidism

b. Manifestations: Anorexia, nausea, vomiting, constipation, muscular weakness, incoordination, altered LOC, polyuria, polydipsia, cardiac arrhythmias, hypoactive DTR

c. Laboratory: Ca > 10.5 mg/dl, ECG – shortened QT interval, bradycardia, heart blocks

d. Management:i. PNSS – dilutes serum calcium and inhibit tubular

reabsorption of Caii. PO4 – enhances deposition of calciumiii. Furosemide - ↑ Ca excretioniv. Treat the underlying causev. Assess for DHN, mental confusion and psychotic behaviorvi. 3-4 quarts of fluid daily to facilitate excretion, ↑ fiber diet

for constipationvii. Bed side rails up; secure all invasive lines!viii. Teach about early ambulation and daily weight-bearing

activities.I. Metabolic Acidosis – excessive absorption or retention or acid or

excessive excretion of HCO3; Bicarbonate deficit


a. Causes: ketoacidosis, lactic acidosis,, prolonged fasting, salicylic poisoning, oliguric renal disease, abnormal HCO3 losses, which can occur in loss of fluid from the lower GI tract from surgery, drains or severe diarrhea

b. Manifestationsi. Headacheii. Mental dullnessiii. Kussmaul’s respirationiv. K excess

c. Managementi. Treatment of underlying cause and restoration of

electrolyte balanceii. Na bicarbonate IViii. Maintain good respiratory functioniv. Fluid replacement, measure I/Ov. Protect from injury

J. Metabolic Alkalosis – Results from loss of hydrogen ions or addition of base to body fluids

a. Causes: excessive ingestion of NaCO3 or baking soda, vomiting, gastric suctioning, intestinal fistulas

b. Manifestations: depressed breathing, mental confusion, dizziness, numbness and tingling of fingers and toes, muscle twitching, tetany convulsions, K deficit

c. Management:i. NaCl or Ammonium chloride oral or IVii. Carbonic anhydrase inhibitor (Diamox) – increase excretion

of bicarbonate by kidneysiii. Maintain good respiratory functioniv. Protect from injury

K. Respiratory Acidosis – caused by failure of the respiratory system to remove CO2 from body fluids as fast as it is produced in the tissues

a. Causes: obstructive/restrictive lung disease, impaired movement of thoracic cage, depressed respiratory centers, neuromuscular disease

b. Manifestations: Hyperpnea, visual disturbances, headaches, ventricular fibrillation, late: confusion, drowsiness, coma, K excess

c. Management:i. Bronchodilatorsii. Postural drainageiii. Chest clappingiv. Na bicarbonate for ventricular fibrillation or potassium

excessL. Respiratory Alkalosis – caused by loss of CO2 from the lungs at a faster

rate than it is produced in the tissuesa. Causes: Anxiety, fever, meningitis, ASA poisoning, pneumoniab. Manifestations: lightheadedness, numbness or tingling of fingers

or toes, tetany, convulsions, K deficitc. Management:

i. Treat underlying conditionsii. Encourage slow, deep breathing; instruct the client to

breathe into and out of a paper bagiii. SEIZURE PRECAUTIONS


Fluid and Electrolytes Handouts

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