Fluid & Electrolytes - PowerPoint Presentation

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Fluid & ElectrolytesAcid Base ImbalancesChapter 17

Megan McClintockWinter 2012Slide2

HomeostasisMaintained by the intake and output of water and electrolytes and regulation by the renal and pulmonary systems

Acid-base balance is necessary for many physiologic processes (respiration, metabolism, function of the CNS)Many disease and treatments affect this balanceSlide3

WaterMore important to life than any other nutrient

60% of an adult’s body weight, more in a child, less in the elderlyFound in foods (but not in alcohol)Daily need is about 2000

mL1 liter of water weighs 1 kgSlide4

Urine specific gravityMeasures the kidney’s ability to concentrate or dilute urine

1.002 – 1.028 High is dehydratedLow is overhydrated (or unable to concentrate)Kidney failure often causes a fixed specific gravitySlide5

ElectrolytesCations (positively charged)

K+, Na+, Ca+, Mg+Transmit nerve impulses to muscles and contract skeletal and smooth musclesAnions (negatively charged)Attached to cations

Cl-, HCO3-, PO4-, SO4-Are always kept in balanceSlide6

Distribution of body fluids & ElectrolytesIntracellular (2/3) – K+, PO4-

Extracellular (1/3) – Na+, Cl-Interstitial (lymph)Intravascular (blood plasma)Transcellular

(cerebrospinal, pleural, peritoneal, synovial fluids)Slide7

Regulation of Fluid & Electrolyte MovementSlide8

OsmolalityIndicates the water balance of the bodySerum

osmolality (275 - 295)High is

water deficitLow is water excess Urine osmolality

(100-1300)High is concentratedLow is diluteSlide9

Fluid SpacingFirst spacing

NormalSecond spacingEdemaThird spacing

AscitesBurn edemaSlide10

Regulation of Water Balance

Hypothalmic RegulationThirst is stimulatedADH (vasopressin) release is stimulatedPituitary Regulation

ADH (vasopressin) is releasedAdrenal Cortical RegulationGlucocorticoids &

mineralocorticoids are releasedRenal RegulationAdjust urine volume and electrolyte excretion

Normal is 1.5 Liters of urine/daySlide11

Regulation of water balance (cont.)Cardiac RegulationANP & BNP will stop the action of the adrenal cortex and the kidney

GI RegulationIntake and output are reabsorbed hereDiarrhea and vomiting can lead to significant lossesInsensible Water Loss

600-900 mL/day from the lungs and skinIncreases with fever, exerciseSlide12

Gerontologic considerations

Structural changes in the kidney and decreased renal blood flowDecreased GFRDecreased

creatinine clearanceLoss of ability to concentrate urine and thus conserve waterDecrease in renin

and aldosteroneIncrease in ADH and ANPLoss of subcutaneous tissue

Decrease in thirst mechanism

Musculoskeletal changes

Mental status changes

IncontinenceSlide13

Fluid Volume Deficit

What causes it?

What can you do?Slide14

Fluid Volume Excess

What causes it?

What can you do?Slide15

Nursing interventionsStrict I/O

Intake – oral, IV, tube feedings, retained irrigantsOutput – urine, excess sweating, wound/tube drainage, vomitus, diarrheaUrine specific gravity

Assessment of CV, Resp, Neuro, Skin statusDaily weight under standardized conditions

Don’t “catch up” IV fluidsNo water with NG suction, use isotonic salineKeep fluids accessible and within reachGive warm or cold fluids (not room temperature)Slide16

Serum Electrolytes

Sodium (Na) 135 - 145Primarily responsible for maintaining osmotic pressure (intracellular and extracellular fluids)Increased with fluid deficit

Decreased with fluid excess

Potassium (K) 3.5 – 5.0Major component of cardiac functionIncreased with poor kidney function

Decreased with excessive urination, diarrhea or vomiting

Chloride (

Cl

) 96 – 106

Works with Na to maintain osmotic pressure

Increased with poor kidney function

Decreased with excessive vomiting or

diarrhea

Calcium (Ca) 8.6 – 10.2

Transmission of nerve impulses, heart and muscle contractions, blood clotting, formation of teeth and bone

Phosphate (PO4) 2.4 – 4.4

Function of muscle,

RBCs

, and the nervous systemSlide17

The Magic fours

Electrolyte Range Magic 4

Potassium 3.5 - 5.0 4Chloride 96 - 106 104

Sodium 135 - 145 140pH 7.35 - 7.45 7.4

CO2 35 - 45 40

HCO3 22 - 26 24

Hematocrit

normal is 3 times the hemoglobinSlide18

Sodium (135 - 145)Major cation of ECF

Primary determinant of osmolalityGI tract absorbs sodium from foodRegulated by kidneys, ADH, aldosteroneSodium level reflects the ratio of sodium to water

Imbalances are typically associated with fluid volume problemsSlide19

Hypernatremia (high sodium)

What can you do?

What causes it?Slide20

Hyponatremia (low sodium)

What causes it?

What can you do?Slide21

Potassium (3.5 - 5.0)Major cation

of ICFSodium-potassium pump requires magnesiumMoves into cells during formation of new tissues and leaves the cell during tissue breakdownDiet is the source of potassiumKidneys are primary route of lossSlide22

Hyperkalemia (high potassium)

What can you do?

What causes it?Slide23

Hypokalemia (low potassium)

What causes it?

What can you do?Slide24

Calcium (8.6 – 10.2)Primary source is bonesRegulated by parathyroid hormone,

calcitonin, and vitamin DAffects transmission of nerve impulses, heart and muscle contractions, blood clotting, and forming of teeth and boneSlide25

Hypercalcemia (high calcium)

What can you do?

What causes it?

What are the symptoms?Slide26

Hyp0calcemia (Low calcium)Slide27

Phosphate ImbalancesHyperphosphatemia

Cause - renal failureS/S – calcium deposits in joints, skin, kidneys, eyes; hypocalcemia, tetany, neuromuscular irritabilityTx

– decrease intake of dairy products, good hydration, fix hypocalcemiaHypophosphatemiaCause

– malnutrition, malabsorption syndrome, alcohol withdrawalS/S – CNS depression, confusion, muscle weakness,

dysrhythmias

Tx

–

oral supplements (

Neutra-Phos

), lots of dairy products, IV phosphate (but this can cause sudden

hypocalcemia

)Slide28

Magnesium ImbalancesHypermagnesemia

Cause – increased intake (ie. MOM, Maalox) with chronic kidney diseaseS/S – lethargy, n/v, loss of

DTRs, can have respiratory and cardiac arrestTx – avoid magnesium-containing drugs, IV calcium, increased fluid intake, may need dialysisHypomagnesemia

Cause – prolonged fasting or starvation, chronic alcoholism, diureticsS/S – confusion, hyperactive

DTRs

, tremors, seizures, cardiac

dysrhythmias

Tx

–

oral supplements, increase green veggies, nuts, bananas, oranges, peanut butter, chocolate; IV or IM magnesium (if given too rapidly can cause cardiac or respiratory arrest)Slide29

MedicationsLoop diuretics

Thiazide diureticsPotassium sparing diuretics

Electrolytes

KayexolateSlide30

Acid Base BalanceSlide31

Regulation of Acid-Base BalanceBuffer

system (immediate)Primary regulatorWon’t work without good functioning respiratory and renal symptomsRespiratory system (

minutes, max in hours)Excretes CO2 and waterRenal system (2-3 days to max respond)

Reabsorbs HCO3Slide32

Arterial Blood GaspH (7.35 – 7.45)

CO2 (35 – 45)HCO3 (22 – 26)

Base excess (+2 to -2)If high, metabolic alkalosis

If low, metabolic acidosisSlide33

Determining Acid–Base Balance

Is pH acid, base or normal?Is CO2 acid, base or normal?

Is HCO3 acid, base or normal?

Which of the components match?Is there compensation?

Is non-matching reading abnormal? – partial compensation

Is non-matching reading normal? – no compensation

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Respiratory AlkalosisSlide37

Respiratory AlkalosisCausesHyperventilation

Pulmonary diseaseHigh altitudesSigns/symptomsHyperventilationFeels “light-headed”Arrhythmias

Anxiety

TreatmentBreathe into paper bagRebreather maskAnti-anxiety medicine

Relaxation techniques

Reduce stimulation

Treat pain/fever

Assess:

Resp

rate/depth

HR & BP

Serum K levels

Hydration status

Check for digitalis toxicitySlide38

Respiratory acidosisSlide39

Respiratory AcidosisCausesCNS depression

Loss of lung surfaceNeuromuscular diseaseImmobilityMechanical ventilationSigns/symptomsDyspnea

HypoxiaDrowsinessTachycardiaSeizures

Diaphoresis

Treatment

Turn, cough, deep breathe

Semi-Fowler’s position

Suction

Incentive

spirometer

Seizure precautions

Decrease use of sedatives

Bronchodilators

May need ventilator

Assess:

Resp

rate/depth

HR & BP

Patiency

of airwaySlide40

Metabolic alkalosisSlide41

Metabolic AlkalosisCausesNG suctioning

Prolonged vomitingDiuretic useMultiple blood transfusionsCPR (given bicarb)

Signs/symptomsDizzinessDysrhythmiasConvulsionsConfusion

Muscle cramps (late sign)

Treatment

Identify and treat the cause!

IV fluids

Stop giving bicarbonate

Give

antiemetics

Give

Diamox

Assess:

Resp

rate/depth

HR & BP

Serum K levels (usually low)

Hydration status (tend to be dehydrated)

Check for digitalis toxicity

ParasthesiasSlide42

Metabolic acidosisSlide43

Metabolic acidosisCausesDiabetic

ketoacidosisRenal or liver failureSevere diarrheaVomitingStarvationSigns/symptoms

Kussmaul respirationsHypotensionArrythmias

Warm to hot ,flushed skinConfusion

Treatment

Identify and treat the cause!

Administer insulin (if due to

ketoacidosis

)

Give

antiemetics

IV fluids

IV bicarbonate

Assess:

Renal function (BUN,

creatinine

)

Serum K levels (tends to go up but down once insulin given)

Hydration statusSlide44

IV Fluids

IsotonicNSD5WLR

Hypertonic3% NSD51/2NS

D10WHypotonic

1/2NS

Plasma ExpandersSlide45

Central Venous access devicesCentrally inserted catheters (

CVCs)Peripherally inserted central catheters (PICCs)

Implanted infusion portsSlide46

Nursing care of CVADs

Inspect site for redness, edema, warmth, drainage, painDressing change/cleaning with sterile technique using chlorhexidine (back and forth scrub to generate friction)Maintain transparent dressing c/d/I

Change injection caps using sterile techniqueTeach pt to turn head away from insertion site during cleaning and cap changeHave patient Valsalva

during cap change if unable to clampUse push-pause method to flush (creates turbulence)Removal of non-tunneled CVCs and PICCs

may be done by a trained nurse (have pt

Valsalva

as last of catheter is withdrawn, apply pressure immediately, inspect catheter tip)