Nur 221

Fluid and Electrolytes:Balance and Disturbances

Fluid and Electrolyte BalanceNecessary for life and homeostasis

Nursing role is to help prevent and treat fluid and electrolyte disturbances

FluidApproximately 60% of the Wt of a typical adult is fluid

(water &electrolyte)

Varies with age, body size, and gender

Intracellular fluid ICF (fluid inside the cell)

Extracellular fluid ECF (fluid outside the cell)

- Intravascular

- Interstitial

- Transcellular

Muscle, skin, and blood have higher amount of water.2\3 of body fluid are ICF 1\3 in ECF (3 compartment)IV (fluid in blood vessel), 5- 8 % IS (fluid that surround the cell), 25 % TC (as CSF, IO, pericardial, pleural fluid, synovial fluid),

1- 2 % “Third spacing” or 3rd space fluid shift: loss of ECF into a

space that does not contribute to equilibriumSigns of 3rd space fluid shift (intravascular FVD) are:

decrease u.o, increase HR, decrease( BP, CVP), edema, increase Bwt, and imbalance in I&O

It occurs in burn, ascites, peritonitis, bowel obstruction.

Electrolytesare active chemicals that carry positive (cations) and negative (anions) electrical charges

Major cations: Sodium PotassiumCalciumMagnesium Hydrogen ions

Major anions:Chloride Bicarbonate Phosphate Sulfate Proteinate

ions

Major cation in ECF

Sodium (important in regulating volume of body fluid)

Major cation in ICF

Potassium

Phosphate

(See Table 14-1)

Regulation of FluidMovement of fluid through capillary walls depends on:

Hydrostatic pressurePressure exerted by the fluid on the walls of

blood vessels Osmotic pressure

Pressure exerted by the protein in the plasmaThe direction of fluid movement depends on the differences

of hydrostatic and osmotic pressure

Regulation of Fluid (cont.)Osmosis

Diffusion

Filtration

Active transport ( Na- K pump)

OsmosisMovement of fluid from and area of lower solute

concentration to an area of higher solute concentration

DiffusionMovement of molecules and ions from an area of higher

concentration to an area of lower concentration (e.g exchange of O2 and CO2 between capillaries and alveoli, Na movement from ECF to ICF)

FiltrationMovement of water and solutes from an area of higher

hydrostatic pressure to an area of lower hydrostatic pressure

Examples (kidney filtration, water and electrolyte movement from capillary bed to ISF).

Active TransportPhysiologic pump that moves fluid from an area of lower

concentration to one of higher concentration

Movement against the concentration gradient

Sodium-potassium pump maintains the higher concentration of extracellular sodium and intracellular potassium

Requires adenosine (ATP) for energy

Routes of Gains and Losses

Gain

Dietary intake of fluid and food or enteral feeding

Parenteral fluids ( IV or SC)

Loss

Kidney: urine output normal 1ml\kg\hr

Skin loss: sensible (visible sweating) and insensible losses (through perspiration as fever)

Lungs through increase RR or depth

GI tract through diarrhea, fistula.

Other

Regulation of water balanceOrgan involved in homeostasis:

Kidneys, lung, heart, adrenal gland, parathyroid gland, and pituitary gland.

Other Mechanisms: Baroreceptors, Renin – Angiotensin – Aldesterone system, ADH, Osmoreceptors, ANP.

)ANP (in Maintenance of Fluid Balance

Laboratory testing for evaluating fluid statusOsmolarity or Osmolality: - concentration of fluid that affect the movement of water between

fluid compartment by osmosis.- Normal S. Osmolarity is 280-300mOsm\kg- Normal urine Osmolarity is 200-800mOsm\kgBUN: - made up of urea (end product of protein from muscle and dietary

intake metabolism by the liver).- Normal range 10-20mg\dl (3.6-7.2mmol\l)- Increase due to: decrease renal function, GI bleeding, dehydration,

increase protein intake and from fever and sepsis- Decrease due to: end stage liver disease, low protein diet,

starvation, pregnancy

Createnine:- End product of muscle metabolism- Normal range 0.7-1.4mg\dl (62-124mmol\l)- Increase with decrease renal function - It is more important than BUN in detecting renal problemHCT:- Measure the volume percentage of RBC's- Range from 42-52% for male and from 35-47% for female.- Level increase: with dehydration, and polycythemia- Level decrease: with over hydration and anemia.

Urine Na value:- Normal level range from 75-200meq\24hr’s (75-200mmol\

24hr’s)- Used to assess :Volume statusDiagnosis of hyponatremia and acute renal failure.Changed with Na intake and status of fluid volume

Gerontologic Considerations

Reduced homeostatic mechanisms: cardiac, renal, and respiratory function

Decreased body fluid percentage to muscle mass

Medication use affect renal and cardiac function

Presence of concomitant conditions

Dehydration is common as a result of decrease reserve capacity of the kidney.

Fluid Volume Imbalances

Fluid volume deficit (FVD): hypovolemia

Fluid volume excess (FVE): hypervolemia

Fluid Volume DeficitIt occur when the loss of ECF > intake.Loss of extracellular fluid exceeds intake ratio of water,

and electrolytes are lost in the same proportion as they exist in normal body fluids

Dehydration refers to loss of water alone with increased serum sodium level

May occur in combination with other imbalances

Causes:

fluid loss from vomiting, diarrhea, GI suctioning, sweating, decreased intake, and inability to gain access to fluid, 3rd space fluid shift.

Additional causes: diabetes insipidus, adrenal insufficiency, osmotic diuresis, hemorrhage, coma.

Can be mild, moderate, sever depend on degree of fluid loss

Manifestations: rapid weight loss, decreased skin turgor, oliguria, concentrated urine, postural hypotension, rapid and weak pulse, increased temperature, cool and clammy skin due to vasoconstriction, lassitude, thirst, nausea, muscle weakness, flattened neck vein and cramps

Laboratory data: elevated BUN in relation to serum creatinine, increased hematocrit, and possible serum electrolyte changes

Medical management: provide fluids to meet body needs

Oral fluids

IV solutions: if loss acute or sever see Table 14-3 shock may occur if fluid loss >25% of IV volume.

Fluid Volume Deficit—Nursing Management

Monitor intake and output (I&O) q8hr’s or hourly and Wt, V/s, LOC, and breathing sound.

Monitor for symptoms: skin and tongue turgor, mucosa, urinary output (UO), and mental status

Initiate measures to minimize fluid loss, asssess pt at risk to prevent FVD

To correct FVD:

- Provide oral care

- Administer oral fluids

- Administer parenteral fluids

Fluid Volume ExcessIt is an isotonic expansion of the ECF caused by

abnormal retention of water and Na.

Due to fluid overload or diminished homeostatic mechanisms

Risk factors: heart failure, renal failure, and cirrhosis of the liver

Contributing factors: excessive dietary sodium or sodium-containing IV solutions

Manifestations: edema; distended neck veins; abnormal lung sounds (crackles); tachycardia; increased BP, pulse pressure, and CVP; increased weight; increased UO; shortness of breath; and wheezing

Laboratory finding: decrease HCT and BUN level. CXR reveal pulmonary congestion.

Medical management: is directed at the cause, restriction of fluids and sodium, and the administration of diuretics

Fluid Volume Excess—Nursing Management

Take I&O and daily weights; assess for lung sounds, edema, and other symptoms; monitor responses to medications such as diuretics (loop diuretic)

Hemodialysis for sever renal failure.Promote adherence to fluid restrictions and patient

teaching related to sodium and fluid restrictionsMonitor and avoid sources of excessive sodium; include

medications Promote rest Use semi-Fowler’s position for orthopneaProvide skin care and positioning/turning

Electrolyte Imbalances

Sodium (Na) ImbalancesIt is the abundant electrolyte in the ECFNormal concentration from 135 – 145mEq\l (135 – 145 mmol\dl)Primary determination to ECF osmolalityNa regulated by :( ADH, thirst, renin-angiotensein- aldesterone

system)Function:Controlling water distribution throughout the bodyRegulating of ECF volumeEstablishing electrochemical state necessary for muscle

contraction and nerve impulses transmission.Na imbalances: Na excess (Hypernatremia), Na Deficit

(Hyponatremia)

HyponatremiaSerum sodium less than 135 mEq/L

Causes: adrenal insufficiency, water intoxication, SIADH, and losses by vomiting, diarrhea, sweating, and diuretics, low salt diet

Manifestations: poor skin turgor, dry mucosa, headache, decreased salivation, decreased BP, nausea, abdominal cramping, and neurological changes

When S. Na level decrease to <115mEq\l signs of increased ICP appear (lethargy, confusion, hemiparesis, seizures)

Diagnostic finding

S. Na level <135mEq\LUrinary Na <20mEq\LSpecific gravity for the urine low (1.002 – 1.004)

Hyponatremia (cont.)

Medical management: water restriction( 800ml in 24hr’s) and sodium replacement (by mouth, NGT, IV)

If neurological symptoms occur, small volume of hypertonic solutions administered ( 3% or 5% NaCl)

Nursing management:

Identification and monitoring of at-risk patients and the effects of medications (diuretics and lithium)

monitor Na level

Nursing managements : (continue)Encourage foods and fluids with a high Na contentAvoid excess water supplements in pt receiving isotonic or

hypotonic eternal feeding

assessment of neurological changes.

I&O and daily body Wt

monitoring of dietary sodium and fluid intake,

HypernatremiaSerum sodium greater than 145mEq/L

Causes:Common causes:- Fluid deprivation- excess water loss- Administer of hypertonic eternal feeding- Watery diarrhea- Increased insensible water loss (hyperventilation , burns)- diabetes insipidusLess common causes:- heat stroke- Near drawing in sea water- Malfunction in hemodialysis and peritoneal dialysis - Administration of hypertonic IV solutions

Clinical ManifestationRestlessness and weaknessDisorientation, delusion, hallucination ThirstDry swollen tongueSticky MM Flushed skinPeripheral and pulmonary edemaPostural hypotensionIncreased muscle tone and deep tendon reflexesIncrease body temperature

Diagnostic finding:- S.Na >145mEq\L- S.osmolality >300mOsm\kg- Increased urine specific gravity and osmolarity

Medical Management:- Infusion of hypotonic saline solution or an isotonic non saline

solution- Diuretics

Nursing Management:- Monitor fluid gain or loss- Assess for OTC medication that contain Na- Observe pt temp, thirst, change in behavior- Provide sufficient water with tube feeding- Ensure adequate water intake in unconscious and pt with

diabetes insipidus- Monitor pt response to the fluid by serial reviewing of S.Na

level and any neurological changes.

Potassium (K) ImbalanceMajor ICF electrolyteNormal serum concentration 3.5- 5mEq\L 80% excreted by kidney and the other 20% excreted

through the bowel and sweat. K imbalance associated with:-Various disease- Injuries- Medications (diuretics, laxatives, AB)- Parenteral nutrition and chemotherapy.Function:- Affect skeletal and cardiac muscle activity

K deficit ( Hpokalemia)Below-normal serum potassium (<3.5 mEq/L) may occur with

normal potassium levels in alkalosis due to shift of serum potassium into cells

Causes: GI losses, medications (K- losing diuretics as thiazide and corticosteroids), alterations of acid–base balance(Alkalosis), hyperaldosteronism, and poor dietary intake, vomiting, gastric suction, diarrhea, persistent insulin hypersecretion, magnesium depletion.

Manifestations:

fatigue, anorexia, nausea, vomiting, Dysrhythmias, muscle weakness, leg cramps, parasthesia, glucose intolerance, decreased muscle strength, and deep tendon reflexes (DTRs)

Medical management:

-Increased dietary potassium,

-potassium replacement, oral (food high in K as most fruit and vegetables, legumes, whole grains, milk, meat and melon) and IV for severe deficit (KCl, K acetate, K phosphate)

Diagnostic finding:Serum K levelABG’s ( Metabolic and respirator

Alkalosis)HX to identify causes24 Hr’s urine collection for K level to Id

renal causesECG changes.

Effect of K in ECG

In Hpokalemia:

Moderate:- Flattening of the T

wave- Appearance of the U

wave

Extreme:- Depressed T wave

(ischemia)- Prominent U wave.

Nursing management:

- Assessment of the C\M (severe hpokalemia is life-threatening),

- Monitoring of electrocardiogram (ECG),

- Arterial blood gases (ABGs) monitored for elevation in HCO3 and PH levels.,

- Dietary rich potassium, and providing nursing care related to IV potassium administration

- Administer K only after adequate urine flow

- If pt receiving K replacement check BUN, Createnine and U.O

HyperkalemiaGreater than normal serum potassium (>5 mEq/L), seldom occurs

in pt with normal renal function.

Causes:

- usually treatment-related,

- impaired renal function (decrease renal excretion of K).

- Hypoaldosteronism.

- tissue trauma (as in burns, sever infection), and acidosis.

- medications ( KCl, heparin, ACE inhibitors, captopril, NSAID’s, K sparing diuretics)

- chemotherapy

Manifestations:

- Cardiac changes.

- Dysrhythmias.

- Muscle weakness.

- Potential respiratory impairment.

- Parasthesia.

- GI manifestations.(N, V and D)

Diagnostic finding:- S.K level- ABG’s (metabolic acidosis)- ECG changes.

In Hyperkalemia:Moderate- Moderate elevation with

wide flat P wave- Wide QRS complex- Peaked T wave

Extreme:- Absence of P wave- Widening of QRS

complex

Medical Management:- Monitor ECG for changes- Repeat S.K level from vein without an IV

infusing of K or presence of tourniquet.- Limit dietary potassium and k containing

medications- Cation exchange resin (Kayexalate) either

orally or by retention enema.

- IV sodium bicarbonate, - IV calcium gluconate in emergency

elevation of K and monitor BP- IV administration of regular insulin and

hypertonic dextrose IV, - -2 agonists( as ventolin)- Dialysis

Nursing management:

- Id pt at risk for K excess (renal failure)

- Look for C\M of K excess

- Assess serum potassium levels

- Avoid using tourniquet during drawing sample for K

- Inform the pt not to exercise the extremity immediately before the blood sample is obtained.

- Mix well IVs containing K+, monitor medication effects.

- Initiate dietary potassium restriction and dietary teaching for patients at risk

Pseudohyperkalemia

Causes:- Use of tourniquet around an exercising extremity while

drawing blood sample- Hemolytic of sample before analysis- Marked leukocytes ( increase WBC’s count > 200,00)- Thrombocytosis ( platelet count > I million)- Drawing blood above a site where K infusing

Calcium ImbalanceMore than 99% of Ca located in skeletal muscleNormal total serum Ca is 8.6- 10.2 mg\dl (2.2 – 2.6 mmol\

L)It is present in plasma in 3 forms ( ionized, bound,

complex)Ionized form (50% of S.Ca) important for neuromuscular

activity and blood coagulationNormal ionized serum Ca 4.5 – 5.1mg\dL (1.1 – 1.3mmol\

L)Ca absorption need gastric acid and vit DS.Ca level is regulated by PTH & calcitonin

Function :- Role in transmitting nerve impulses- Regulate muscle contraction (cardiac muscle)- Activating enzymes- Role in blood coagulation

Hypocalcemia ( Ca deficit) Serum level less than 8.5 mg/dL. Causes:- Hypoparathyroidism. - Malabsorption.- Pancreatitis.- alkalosis. - massive transfusion of citrated blood.- renal failure.- medications (aminoglycosides, loop diuretic,

corticosteroid) - inadequate vit D consumption,

Manifestations: • Tetany (tingling (tips of finger, around the mouth,

feet), Spasms of muscles in the extremity and face, • Trousseau’s sign• Chovstek's sign• Seizures• Mental changes ( depression, impaired memory,

confusion) • Prolonged QT interval

• Respiratory symptoms of dyspnea and laryngeospasm

• Abnormal clotting.• Hyperactive bowel sound • Dry and brittle hair and nail• Hyperactive DTR’s

• osteoporosis

Trousseau’s SignElicited by inflating BP

cuff on the upper arm to 20mmHg above systolic pressure within 2-5mint carpal spasm occure due to ulnar nerve ischemia.

Medical Management:• IV administration of Ca (CaCl, or Ca

gluconate).• Keep pt in bed during administration due to

postural hypotension• Ca and vit D supplement.• Increase dietary intake of Ca.

Nursing Management:• Seizures precaution • Teach pt about dietary Ca & medication ( over use of

laxative and antacid that contain PO4)• Emphasize the importance of decreasing weight bearing

exercise to decrease bone loss • Teaching about the monthly medication to reduce the rate of

bone loss ( fosamax & actonel)

Hypercalcemia (Ca excess)Serum level above 10.5 mg/dL

Causes:

• Malignancy (most common cause)

• Hyperparathyroidism (most common cause)

• Immobility (bone loss)

• Thiazide diuretics (potentate PTH action on the kidney, decrease renal Ca excreation)

• Vit A&D intoxication

Manifestations:

• muscle weakness

• incoordination.

• Anorexia.

• Constipation (decrease bowel movement).

• Nausea, vomiting.

• abdominal and bone pain.

• polyuria, thirst.

• ECG changes, and Dysrhythmias.

• Confusion, impaired memory, slurred speech, lethargy.

Medical management:

• Treat underlying cause.• Administer fluids (o.9% NaCl).• Furosemide.• Phosphate, and biphosphonates administration• Calcitonin administration, phosphate.• Mobilization

Nursing management: • Encourage ambulation.• Instruct pt to take fluids of 3 to 4 L/d.• provide fluids containing sodium unless contraindicated• Adequate fiber for constipation. • Safety precaution are implemented.• Assess pt for S&S of digitalis toxicity• Monitor cardiac rate and rhythm for abnormality.• Restrict diet rich in Ca.

Mg ImbalanceNormal serum level 1.3 – 2.3 mEq\LImportant in neuromuscular function, affect CV

system, produce peripheral vasodilation, inhibit release of acetylcholine

HypomagnesemiaSerum level less than 1.8 mg/dL; evaluate in conjunction with

serum albuminCauses: - Alcoholism. - GI losses.- Enteral or Parenteral feeding deficient in magnesium. - Inflammatory bowel disease. - Medications ( cyclosporine, diuretics, digitalis).- Rapid administration of citrated blood. - Contributing causes include diabetic ketoacidosis, sepsis,

burns, and hypothermia.

Manifestations:• Neuromuscular irritability. • Muscle weakness. • Tremors. • Athetoid movements (slow, involuntary twisting). • ECG changes ( prolonging of QRS, depress ST

segment ) and Dysrhythmias, • Alterations in mood and level of consciousness

Medical management: diet, oral magnesium, and magnesium sulfate IV

Nursing management: assessment for S&S, ensure safety, patient teaching related to diet rich in Mg, medications ( laxative, diuretics) , avoid alcohol use, and nursing care related to IV magnesium sulfate.

Hypomagnesemia is often accompanied by HypocalcemiaMonitor and treat potential HypocalcemiaDysphagia is common in magnesium-depleted patients; assess

ability to swallow with water before administering food or medications

Hypermagnesemia

Serum level more than 2.7 mg/dL

Causes: renal failure, diabetic ketoacidosis, and excessive administration of magnesium, excessive use of laxative and antacids.

Manifestations: flushing, lowered BP, nausea, vomiting, hypoactive reflexes, drowsiness, muscle weakness, depressed respirations, ECG changes, and Dysrhythmias, delayed thrombin formation.

Medical management: IV calcium gluconate, loop diuretics, IV NS of RL, hemodialysis, discontinue administration of Mg IV or orally

Nursing management: assessment, V\S, avoid administering medications containing magnesium, and provide patient teaching regarding magnesium-containing OTC medications

HypophosphatemiaSerum level below 2.5 mg/dLCauses: alcoholism, refeeding of patients after

starvation, pain, heat stroke, respiratory alkalosis, hyperventilation, diabetic ketoacidosis, hepatic encephalopathy, major burns, hyperparathyroidism, low magnesium, low potassium, diarrhea, vitamin D deficiency, and diuretic and antacid use

Manifestations: neurological symptoms, confusion, muscle weakness, tissue hypoxia, muscle and bone pain, and increased susceptibility to infection, bruising and bleeding from platelet dysfunction.

Medical management: oral or IV phosphorus replacement

Nursing management: assessment, encourage foods high in phosphorus, and gradually introduce calories for malnourished patients receiving parenteral nutrition

HyperphosphatemiaSerum level above 4.5 mg/dLCauses: renal failure, excess phosphorus, excess

vitamin D, acidosis, increase intake or decrease intake of PO4, DKA, hypoparathyroidism, and chemotherapy.

Manifestations: Tetany, ANV, bone and joint pain, muscle weakness, hyperreflexia, tachycardia, soft-tissue calcifications, symptoms occur due to associated Hypocalcemia.

Medical management: treat underlying disorder; use vitamin D preparations, calcium-binding antacids, phosphate-binding gels or antacids, loop diuretics, NS IV, and dialysis

Nursing management: assessment, avoid high-phosphorus foods, and provide patient teaching related to diet, phosphate-containing substances, and signs of hypocalcemia

HypochloremiaSerum level less than 96 mEq/L

Causes: reduced chloride intake, GI loss, fever, burns, medications, and metabolic alkalosis

Loss of chloride occurs with loss of other electrolytes, potassium, and sodium

Manifestations: agitation, irritability, weakness, hyperexcitability of muscles, dysrhythmias, seizures, and coma

Medical management: replace chloride—IV, NS, or 0.45% NS

Nursing management: assessment, avoid free water (water without electrolyte) , encourage high-chloride foods, and provide patient teaching related to high-chloride foods, V\S, respiratory assessment

HyperchloremiaSerum level more than 108 mEq/L

Causes: excess sodium chloride infusions with water loss, head injury, hypernatremia, dehydration, severe diarrhea, metabolic acidosis, hyperparathyroidism, and decrease u.o

Manifestations: tachypnea, lethargy, weakness, rapid & deep respirations, hypertension, and cognitive changes, decrease CO, dysrhythmias.

Medical management: restore electrolyte and fluid balance (as hypotonic IV fluid), LR, sodium bicarbonate IV, and diuretics, Na, Cl and fluid are restricted.

Nursing management: assessment, provide patient teaching related to diet and hydration, monitor (V\S, ABG’s, I&O)