FLUIDS

60 %

Intracellular Fluid 40% or 2/3

Intravascular 5% or 1/4

Transcellular fluid 1-2%ie csf, pericardial, synovial,

pleural,lymph system, intraocular

Arterial Fluid Arterial Fluid 2%2%

Extracellular Fluid 20% or 1/3

Interstitial 15% or 3/4

Venous Fluid 3%

FLUIDS

• Maintain homeostasis• Ensure adequate tissue perfusion• Help maintain body temperature and cell shape• Help transport nutrients, gases and wastes

Fluids

• 60% of an adult’s body weight * 70 Kg adult male: 60% X 70= 42

Liters

• Infants = more water

• Elderly = less water

• More fat = ↓water

• More muscle = ↑water

• Infants and elderly - prone to fluid imbalance

Factors that influence amount of body fluids:

1. age - younger people have higher

percentage of body fluid than older people

2. gender- male > women

3. body fats- obese people have less fluids than

thin people (fat cells contain little water)

Intravascular space - fluid within the blood vessels , contains plasma

- approximately 3L of the average 6L of blood is

made up of plasma

Interstitial space - contains fluids that surround the cell; about 11-12 liters Transcellular space - contains 1 L of fluid

ex. Cerebrospinal, pericardial, synovial, intraocular and digestive secretion

Sources of Fluids Fluid Intake1. Exogenous sources• Fluid intake

oral liquids – 1, 300 ml water in food – 1, 000 ml water produced by metabolism – 300 ml • IVF• Medications• Blood products

2. Endogenous sources• By products of metabolism• secretions

Fluid OutputSensible loss

• Urine - 1, 500 ml

• Fecal losses – 200 ml

Insensible loss

• skin – 600 ml

• Lungs – 300 ml

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Third-space fluid shift/Third “spacing”

- loss of ECF into a space that does not contribute to equilibrium between ICF and ECF

- ie ascites, burns, peritonitis, bowel obstruction, massive bleeding

Mechanisms of Body Fluid Movement (i.e. movement of solutes, solvents across different extracellular locations)A. Osmosis: water is mover; water moves from lower concentration to higher concentration1. Normal Osmolality of ICF and ECF: 275 – 295 mOsm/kg

Types of solutions according to osmolalitya. Isotonic: all solutions with osmolality same as that of plasma

Body cells placed in isotonic fluid: neither shrink nor swell

b. Hypertonic: fluid with greater concentration of solutes than plasma

Cells in hypertonic solution: water in cells moves to outside to equalize concentrations: cells will shrink

c. Hypotonic: fluid with lower concentration of solutes than plasma

Cells in hypotonic solution: water outside cells moves to inside of cells: cells will swell and eventually burst (hemolyze)

• Different intravenous solutions, used to correct some abnormal conditions, categorized according to osmolality:

a. Hypertonic: 5%glucose, 45% NaCl solutionb. Isotonic: 9% NaCl, Lactated Ringers solutionc. Hypotonic: 45% NaCl

B. Diffusion: solute molecules move from higher concentration to lower concentration 1. Solute, such as electrolytes, is the mover; not the water2. Types: simple and facilitated (movement of large water-soluble molecules)

C. Filtration: water and solutes move from area of higher hydrostatic pressure to lower hydrostatic pressure 1. Hydrostatic pressure is created by pumping action of heart and gravity against capillary wall

2. Usually occurs across capillary membranes

D. Active Transport: molecules move across cell membranes against concentration gradient; requires energy, e.g. Na – K pump

Transport Mechanisms

• fluids from different compartments move from one compartment to the other to maintain fluid balance.

• movement is dictated by the transport mechanism principle :A. PASSIVE B. ACTIVE TRANSPORT A. Passive Transport Process

– substances transported across the membrane w/o energy input from the cell- high to low concentration 2 Types of Passive Transport1. Diffusion – substances/solutes move from high concentration to low concentrationie exchange of O2 and CO2 b/w pulmonary capillaries and alveoli

2. Filtration – water and solutes forced through membrane by fluid or hydrostatic pressure from intravascular to interstitial area

- solute containing fluid (filtrate) from higher pressure to lower pressure

- an example of this process is urine formation

- increased hydrostatic pressure is one mechanism producing edema

B. Active Transport Process

- Cell moves substances across a membrane through ATP because:

- They may be too large

- Unable to dissolve in the fat core

- Move uphill against their concentration gradient

Types of Active Transport1. Active transport – requires protein carriers using ATP to energize it ie Amino acids Sodium potassium pump – 3Na out, 2K in

2. Endocytosis – moves substances into the cell3. Exocytosis – moves substances out of the cell

Osmosis

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• Movement of water from low solute to high solute concentration in order to maintain balance between compartments.

• Osmotic pressure – amount of hydrostatic pressure needed to stop the flow of water by osmosis

• Oncotic pressure – osmotic pressure exerted by proteins

Types of FluidTonicity

• This is the concentration of solutes in a solution

• A solution with high solute concentration is considered as HYPERTONIC

• A solution with low solute concentration is considered as HYPOTONIC

• A solution having the same tonicity as that of body fluid or plasma is considered ISOTONIC

• In a HYPERTONIC solution, fluid will go out from the cell, the cell will shrink.

• In a HYPOTONIC solution, fluid will enter the cell, the cell will swell.

• In an ISOTONIC solution, there will be no movement of fluid.

Isotonic Fluid - no movement of fluid.

Isotonic Fluids

• 0.9% NaCl/ Normal Saline/NSS -Na=154-Cl=154-308 mOsm/L - not desirable as routine maintenance solution- only solution administered with blood products

Rx: hypovolemia, shock, DKA, metabolic alkalosis, hypercalcemia, mild NA deficit

CI: caution in renal failure, heart failure and edema

• D5W - 5% Dextrose in water - 170 cal and free water- 252 mOsm/LRx: hypernatremia, fluid loss and dehydrationCI: early post op when ADH inc d/t stress, sole treatment in FVD (dilutes plasma), head injury (inc ICP), fluid resuscitation (hyperglycemia), caution in renal and cardiac dse (fluid overload), px with NA

deficiency (peripheral circulatory collapse and anuria)

• 10% Dextran 40 in 5% Dextrose isotonic (252 mOsm/L)

• Lactated Ringer’s Solution isotonic - Na 130 mEq/L- K 4 mEq/L-Ca 3 mEq/L- Cl 109 mEq/L- 273 mOsm/L Rx:hypovolemia, burns, fluids lost as bile/diarrhea, acute blood lossCI: ph>7.5, lactic acidosis, renal failure(cause HyperK)  Hypotonic Fluid

- fluid will enter the cell, the cell will swellHypotonic Fluids

• 0.45% NaCl (half strength saline) - provides Na, Cl and free water

- Na 77 mEq/L- Cl 77 mEq/L- 154 mOsm/L Rx: hypertonic dehydration, Na and Cl depletion, gastric fluid loss

CI : 3rd space fluid shifts and inc ICP

Hypertonic Fluid- fluid will go out from the cell, the

cell will shrink Hypertonic Fluids

• 3% NaCl (hypertonic saline)- no calories- Na 513 mEq/L- Cl 513 mEq/L-1026 mOsm/LRx: critical situations to treat HypoNa, assist in removing ICF excessCI: administered slowly and cautiously (IVF overload and pulmonary edema)

• 5% NaCl• D10W - 10% Dextrose in water hypertonic (505 mOsm/L)• D10W - 20% Dextrose in water hypertonic (1011 mOsm/L) • D50W - 50% Dextrose in water hypertonic (1700 mOsm/L)• D5NS - 5% Dextrose & 0.9NaCl hypertonic (559 mOsm/L) • D10NS - 10% Dextrose & 0.9NaCl hypertonic (812 mOsm/L) • D5LR - 5% Dextrose in Lactated Ringers hypertonic (524 mOsm/L

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Colloid solutions

• Dextran 40 in NS or 5% D5W- volume/plasma expander

- decrease coagulation- remains for 6H in circulatory systemRx: hypovolemia in early shock, improve microcirculation (dec RBC aggregation)CI: hemorrhage, thrombocytopenia, renal disease and severe dehydration

Mechanisms that Regulate Homeostasis: How the body adapts to fluid and electrolyte changes A.Thirst: primary regulator of water intake (thirst center in brain)B.Kidneys: regulator of volume and osmolality by controlling excretion of water and electrolytesC.Renin-angiotension-aldosterone mechanism: response to a drop in blood pressure; results from vasoconstriction and sodium regulation by aldosteroneD.Antidiuretic hormone: hormone to regulate water excretion; responds to osmolality and blood volume E.Atrial natriuretic factor: hormone from atrial heart muscle in response to fluid excess; causes increased urine output by blocking aldosterone

Organs involved in homeostasis• Kidneys• Lungs• Heart • Adrenal glands • Parathyroid glands• Pituitary glands • Other mechanisms

1. baroreceptor2. renin-angiotensin-aldosterone

system3. ADH and thirst 4. osmoreceptor 5. release of atrial natriuretic

peptide

• Organs involved in homeostasisA. Kidney - vital to regulation of fluid and electrolytes - filters 170 L of plasma everyday

- urine output in an adult is 1-2 liters / day - releases RENIN

- regulates sodium and water balance

Functions include :1. regulation of ECF volume and osmolality by selective retention and excretion of body fluids

2. regulation of electrolytes levels in the ECF by selective retention of needed substance and excretion of unneeded substance 3. regulation of pH of the ECF by retention of hydrogen ions4. excretion of metabolic waste and toxic substances

B. Heart and blood vessels - pumping action of the heart to maintain renal perfusionC. Lungs - maintain homeostasis through exhalation

- remove approximately 300 – 400 ml of water daily-loss is greater if there is increase in respiratory depth or rate or in dry climate

D. Pituitary function - hypothalamus manufactures ADH - ADH used for water retention or excretion of water by the kidney and in regulating blood volume

E. Adrenal function - secretes aldosterone, has effect on fluid regulation - secretes also cortisol – has a fraction effect of aldosterone

F. Parathyroid function - regulates calcium and phosphate

- influences bone resorption , Ca absorption from the intestine, and Ca reabsorption from the renal tubules

• Other mechanisms:1. baroreceptors - are small nerve receptors that detect pressure within blood vessels and transmit information to the CNS- responsible for monitoring for circulating volume and they regulate sympathetic and parasympathetic neural activity and endocrine function types: low-pressure high-pressure

• High pressure - are nerve endings in the aortic arch and in the cardiac sinus - another is seen in the afferent arteriole of the juxtaglomerular apparatus of nephron

• Low pressure - are located in cardiac atria, particularly in the left atria

2. renin-angiotensin – aldosterone system:- renin : an enzyme that convert angiotensinogen to

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angiotensin I, it is released from juxtaglomerular cells of the kidney to decrease renal perfusion

then angiotensin I is converted to angiotensin II by angiotensin converting enzymes ,w/c is a vasoconstrictor w/c in turn

increases arterial perfusion and stimulates thirst,

aldosterone is released

factors that influence aldosterone secretion:1. increased release of renin2. increased serum

potassium3. decreased Na serum4. ACTH increase

3. ADH and THIRST - have important role in maintaining sodium concentration and oral intakes of fluids thirst: oral intake is controlled by thirst center located in the hypothalamus : serum osmolality or blood volume

stimulate thirst center ADH - controls water excretion - determines concentration of urine

4. osmoreceptors - located in the surface of hypothalamus

- sense changes in Na concentration osmotic pressure (neurons become dehydrated) releases impulses to posterior pituitary to

release ADH

increases permeability of membrane to

H2O (kidney, causing reabsorption of water and decreased urine output)

5. Release of atrial natriuretic peptide - released by cardiac cells in the atria of the heart in response to increased atrial pressure

- action of this is direct opposite of RAAS and decreases blood pressure and volume

- ANP level is 20 to 77 pg /ml (ng/ml)

Regulation of Body Fluid1. The Kidney

• Regulates primarily fluid output by urine formation 1.5L

• Releases RENIN

• Regulates sodium and water balance

2. Endocrine regulation

• thirst mechanism – thirst center in hypothalamus

• ADH increases water reabsorption on collecting duct

• Aldosterone increases Sodium and water retention retention in the distal nephron

• ANP Promotes Sodium excretion and inhibits thirst mechanism

3. Gastro-intestinal regulation - GIT digests food and absorbs water

- Only about 200 ml of water is excreted in the fecal material per day

4. Heart and Blood Vessel Functions- pumping action of heart circulates blood through kidneys

5. Lungs – insensible water loss through respirationOther Mechanisms1. Baroreceptors – carotid sinus and aortic arch- causes vasoconstriction and increased blood pressure

Dec arterial pressure SNS inc cardiac rate, contraction, contractility, circulating blood volume, constriction of renal arterioles and increased aldosterone

2. Osmoreceptors – surface of hypothalamus senses changes in Na concentration

Inc osmotic pressure neurons dehydrated release ADH

KIDNEY• Nephron: glomerulus and tubule• Filtration• Retention/ Reabsorption• Excretion• 170-180 L/day

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• Filtrate= urine (1-2 L urine/ day)

• Fluid excess excretes dilute urine (rids body of excess fluid while conserving electrolytes)

ADH (Antidiuretic hormone)

• Vasopressin

• Water-retainer

• Hypothalamus produces ADH

• Posterior pituitary gland stores and releases ADH

• Restores blood volume by reducing diuresis and increasing water retention

ADHLow blood volume/

Pituitary glandIncreased serum osmolality

secretes ADH

into the bloodstream

ADH causes the Water retentionKidneys to retain water increases blood

volume/ decreases

serum osmolalityADH Regulation

• ADH - produced by the Hypothalamus - stored and secreted by the posterior pituitary gland

• less water in plasma, ADH secreted to conserve water by reducing urine output

• fluid overload in plasma, ADH secretion stops to excrete fluid in the kidneys by increasing urine outputADH Disorder

• Abnormally high ADH concentration - SIADH reduced urine output (oliguria)water retention (fluid overload)

• Abnormally low ADH – Diabetes Insipidus increased urine output (polyuria)water loss (fluid deficit)

ADH Disorder

• SIADH– Abnormally high ADH concentration – urine output is reduced (oliguria)– water retention (fluid overload)

– Urine SG is high (normal: 1.005 – 1.030)– Hct is low (43-48%)

• DI– Abnormally low ADH – urine output is increased (polyuria)– water loss (fluid deficit) – Urine SG is low– Hct is highRAAS (Renin-Angiotensin-Aldosterone System)

• To help maintain a balance of sodium and water, a healthy blood volume and blood pressure, the juxtaglomerular cells near each glomerulus secrete RENIN

• Leads to production of Angiotensin II, a powerful vasoconstrictor

• Angiotensin II causes peripheral vasoconstriction, stimulating production of Aldosterone

• Both increase blood pressure.

Aldosterone ProductionDecreased JG cells

Renin travels blood flow to the secrete

to theglomerulus Renin

liver

Renin converts Angiotension 1Angiotensin 1

Angiotensin in travels to thein the lungs is

the liver to lungsconverted to

Angiotensin 1Angiotensin II

Angiotensin II Angiotensin IItravels to the stimulates theAdrenal glands adrenal glands to

produce AldosteroneAldosterone

Angiotensin II AldosteroneSodium and

stimulates the causes kidneys water retentionadrenal glands to to retain sodium leads to increasedproduce Aldosterone and water

fluid volume and

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sodium level

Aldosterone Disorders

• Addison’s Disease

– Abnormally low aldosterone

– Serum Na is low, serum potassium is high

– FVD

• Cushing’s Disease

– Abnormally high aldosterone

– Serum Na is high, serum potassium is low

– FVE

ANP (Atrial Natriuretic Peptide)

• Cardiac hormone

• Stored in the cells of the atria

• Released when atrial pressure increases

• Counteracts the effects of the RAAS by decreasing blood pressure and reducing intravascular blood volume

• When blood volume and BP rise and stretch the atria, ANP shuts off RAAS

ANP

• Suppresses serum renin levels

• Decreases aldosterone release from the adrenal glands

• Increases glomerular filtration, which increases urine excretion of sodium and water

• Decreases ADH release from the posterior pituitary gland

• Reduces vascular resistance by causing

vasodilation

Examples of causes of atrial stretching(which result to increased release of ANP)

• Orthostatic changes

• Atrial tachycardia

• High sodium intake

• Sodium chloride infusions

• Use of drugs that cause vasoconstriction

• Physiology/pathophysiology

increased blood volume increased blood pressure

increased stretch of atria

increased

ANP release

vascular resistance decrease ADH increase GFR w/c increases urinary excretion of Na and Decrease blood pressure water

Suppression of serum renin

decrease vascular volume decrease BP, decrease preload and afterload

Thirst mechanism

• Regulated by the hypothalamus

• Stimulated by an increase in ECF and drying of mucous membrane

• Causes a person to drink fluids, which is absorbed by the intestines, moved to the bloodstream and distributed between the compartments

• Leads to increased amount of fluid in the body and a decrease in concentration of solutesDecreased Blood Volume

THIRST mechanism

• ADH secretion is increased

• ANP secretion is decreased

• RENIN secretion is increased

• BARORECEPTOR vasoconstricton

• ALDOSTERONE secretion is increased

Increased Blood Volume

• NO THIRST mechanism

• ADH secretion is decreased

• ANP secretion is increased

• RENIN secretion is increased

• BARORECEPTOR vasodilation

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• ALDOSTERONE decreased

Fluid status can be assessed through:

• Mucus membrane• Skin integrity• Body weight• Jugular vein• BP, PAWP 6-12 mm Hg • CVP (most accurate) 0-7 mm Hg or 5-10 cm of H2O• I&O• Pulse• Temperature• Lung sound and heart sound• Urine output• Urine SG 1.005-1.030• Hematocrit 48%• Plasma osmolality• LOC

Evaluation of fluid statusOsmolality – concentration of fluid that affects movement of water between fluid compartments by osmosis

- measures the solute concentration per kg in blood and urine

- measure of solution’s ability to create osmotic pressure and affect the movement of sodium

- reported as mOsm/kg- normal value= 280-300 mOsm/kg

Osmolarity – concentration of solutions- measures the solute concentration

per L in blood and urine- mOsm/L

urine specific gravity - measures the kidneys ability to excrete or conserve water

urine specific gravity: 1.010 - 1.025

Blood urea nitrogen - made up of urea, end product of metabolism of protein

10-20mg/dl (3.5-7mmol/l)

BUN: not most reliable indicator of renal disease BUN:creatinine ratio better indicator

Normal 10:1.

increased BUN due to:1. renal function2. GI bleeding3. dehydration

4. increased protein intake

5. fever and sepsis

decreased BUN due to :1. end-stage liver

disease2. low protein

intake3. starvation4.condition that

expands fluid volume ex.

pregnancy

Creatinine

• byproduct of muscle metabolism & excreted

by kidneys regardless of fluid intake, diet, etc.

• measures kidney function; 50% renal function lost BEFORE ↑ in serum creatinine level

• better indicator of renal function

• .7 to 1.5 mg/dl

Hematocrit - indication of hydration status - measures the volume percentage of red blood

cells in whole blood and normally ranges from

44% to 52% for male39% - 47% in females

hematocrit due to: 1. dehydration

2. polycythemia

hematocrit due to: 1. overhydration2. anemia

• Urine sodium values: change with sodium intake and status of fluid volume

- normal level ranges from 50 - 220mEq/24h

- used to assess volume status and in the diagnosis of hyponatremia and acute renal failure

Fluid volume disturbances

• I and O must be equal

• 2.5 L per day

• Fluid volume deficit (hypovolemia)

• Fluid volume excess (hypervolemia)

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I&O ImbalanceFluid Volume Deficit

• output, normal intake

• Normal output, intake

• No intake

Fluid Volume Excess

• intake, normal output

• Normal intake, output

• No output

1. Fluid volume deficit- occurs when loss of ECF volume

exceeds the intake of fluid causes:1. abnormal fluid losses

vomiting, diarrhea, GI suctioning and sweating

Diabetes InsipidusAdrenal insufficiencyOsmotic diuresisHemorrhage3rd space fluid shift

2. decreased intake

signs and symptoms : 1. acute weight loss

2. decreased skin turgor 3. oliguria 4. concentrated urine 5. postural hypotension,

weak and rapid heart rate 6. flattened neck veins,

decreased CVP, cool clammy skin 7. Thirst, anorexia 8. Muscle weakness and

cramps

Assessment of FVD

• ICF cellular dehydration

• ITF skin poor skin turgor

• IVF artery ↓BP, pulse (rapid thready)vein ↓CVP

assessment : 1. elevated BUN 2. elevated Hct.

3. serum electrolyte changes may also exist

1. hypokalemia- GI and renal losses

2. hyperkalemia- adrenal insufficiency

3. hyponatremia- increased thirst and ADH release

4. hypernatremia- increased insensible losses and diabetes insipidus Medical Management

• Oral intake when mild

• IV route, acute or severe

• Isotonic fluids ie LR lactated ringers or .9% NaCl for hypotensive patients to expand plasma volumeNursing Management

• measure I and O accurately

• monitoring of body weight - loss of .5 kg means a loss of 500ml

• monitoring of V/S

• skin turgor assessment

• Assess CVP, LOC, breath sounds and skin color

• Monitor urinary concentration

• Monitor mental function

2. fluid volume excess (hypervolemia)

- refers to an isotonic expansion of the ECF caused by the abnormal retention of water and Na in approx. same proportion

- usually 2nd to increase in total body Na content

Pathophysiology:1. related to simple fluid

overload 2. diminished function of

the homeostatic mechanism responsible for

regulating fluid balance

Causes of FVE

• Heart failure

• renal failure

• cirrhosis of the liver

• consumption of excessive amount of salt

• Excessive administration of Na containing fluids in a patient w/ impaired regulatory mechanism

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• SIADH

Clinical Manifestations

• Distended neck veins

• Tachycardia

• Inc weight

• Increased urine output

• Shortness of breath and wheezing/ crackles

• Inc CVP

• Edema

• increased BP

• increased pulse pressure

Assessment of FVE

• ICF cellular edema - ↓LOC pulmonary edema - crackles (bibasilar), wheezing,

shortness of breath, Inc RR

• ITF skin - bipedal pitting edema, periorbital edema and ANASARCA

• IVF artery - ↑BP, pulse (rapid bounding)vein - ↑CVP

Edema

• common manifestation of FVE

• d/t inc capillary fluid pressure, decreased capillary oncotic pressure, increased interstitial oncotic pressure

• Localized or generalized

• Etiology: obstruction to lymph flow, plasma albumin level < 1.5-2 g/dl, burns and infection, Na retention in ECF, drugs

• Labs: Dec Hct, respiratory alkalosis and hypoxemia, dec serum Na and osmolality, inc BUN Crea, Dec Urine SG, dec urine Na level

• Mgmt: diuretics, fluid restriction, elevation of extremities, elastic compression stockings, paracentesis, dialysisLaboratory (FVE)

• Dec BUN

• Dec Hct

• CRF – serum osmolality and Na level dec

• chest x-ray may reveal pulmonary congestionMedical Management

• Discontinue administration of Na solution

• Diureticsie Thiazide – block Na reabsorption

in distal tubule Loop diuretics – block Na reabsorption in ascending loop of Henle

• Restrict fluid and salt intake

• Dialysis

Nursing Management

• Measure intake and output

• Weigh patient daily 2 lb wt gain = 1 L fluid

• Assess breath sounds

• Monitor degree of edemaie ambulatory – feet and ankles

bedridden – sacral area

• Promote rest – favors diuresis/inc venous return

• Administer appropriate medication

Electrolytes

• elements or compounds when dissolved in water will dissociate into ions and are able to conduct an electric current.

FUNCTIONS:1. Regulate fluid balance and osmolality2. Transmission of nerve impulse3. Stimulation of muscle activity

• ANIONS - negatively charged ions: Bicarbonate, chloride, PO4-, CHON

• CATIONS - positively charged ions: Sodium, Potassium, magnesium, calcium

Cations Sodium , Potassium , Calcium , Magnesium , hydrogen ions

Anions Chloride, bicarbonate , phosphate, sulfate, proteinate ions

• Sodium - positively charged ions , major cation in the ECF

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-important in regulating the volume of body fluids -retention of Na- associated with fluid retention

-loss of Na- decreased volume of body fluids

• Potassium - major cation in the ICF

• Chloride - major anion in the ECF

• Phosphate - major anion in the ICF

Regulation of Electrolyte Balance1. Renal regulation

• Occurs by the process of glomerular filtration, tubular reabsorption and tubular secretion

• Urine formation– If there is little water in the body, it is conserved– If there is water excess, it will be eliminated

2. Endocrinal regulation

• Aldosterone promotes Sodium retention and Potassium excretion

• ANP promotes Sodium excretion

• Parathormone increased bone resorption of Ca, inc Ca reabsorption from renal tubule or GI tract

• Calcitonin oppose PTH

• Insulin and Epinephrine – promotes uptake of Potassium by cells The Cations

• SODIUM

• POTASSIUM

• CALCIUM

• MAGNESIUMSODIUM (Na)

• MOST ABUNDANT cation in the ECF• 135-145 mEq/L• Aldosterone increases sodium reabsorption • ANP increases sodium excretion• Cl accompanies Na

FUNCTIONS:1. assists in nerve transmission and muscle contraction2. Major determinant of ECF osmolality3. Primary regulator of ECF volume

a. HYPERNATREMIA

• Na > 145 mEq/L

• Assoc w/ water loss or sodium gain

• Etiology: inadequate water intake, excessive salt ingestion /hypertonic feedings w/o water supplements, near drowning in sea water, diuretics, Diabetes mellitus/ Diabetes Insipidus

S/SX: polyuria, anorexia, nausea, vomiting, thirst, dry and swollen tongue, fever, dry and flushed skin, restlessness, agitation, seizures, coma, muscle weakness, crackles, dyspnea, cardiac manifestations dependent on type of hypernatremia

Dx: inc serum sodium and Cl level, inc serum osmolality, inc urine sp.gravity, inc urine osmolality

Mgmt: sodium restriction, water restriction, diuretics, isotonic non saline soln. (D5W) or hypotonic soln, Desmopressin Acetate for Diabetes Insipidus

Nsg considerations History – diet, medication Monitor VS, LOC, I and O, weight, lung sounds

Monitor Na levelsOral careinitiate gastric feedings slowlySeizure precaution

b. HYPONATREMIA

• Na < 135 mEq/L

• Etiology: diuretics, excessive sweating, vomiting, diarrhea, SIADH, aldosterone deficiency, cardiac, renal, liver disease

• Dx: dec serum and urine sodium and osmolality, dec Cl

• s/sx: headache, apprehension, restlessness, altered LOC, seizures(<115meq/l),coma, poor skin turgor, dry mucosa, orthostatic hypotension, crackles, nausea, vomiting, abdominal cramping

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Mgmt: sodium replacement, water restriction, isotonic soln for moderate hyponatremia, hypertonic saline soln for neurologic manifestations, diuretic for SIADH

Nsg. ConsiderationMonitor I and O, LOC, VS, serum

NaSeizure precautiondiet

Potassium (K)

• MOST ABUNDANT cation in the ICF

• 3.5-5.5 mEq/L

• Major electrolyte maintaining ICF balance

• maintains ICF Osmolality

• Aldosterone promotes renal excretion of K+

• Mg accompanies K

FUNCTIONS:1. nerve conduction and muscle contraction2. metabolism of carbohydrates, fats and proteins3. Fosters acid-base balance

a. HYPERKALEMIA

• K+ > 5.0 mEq/L

• Etiology: IVF with K+, acidosis, hyper-alimentation and excess K+ replacement, decreased renal excretion, diuretics, Cancer

• s/sx: nerve and muscle irritability, tachycardia, colic, diarrhea, ECG changes, ventricular dysrythmia and cardiac arrest, skeletal muscle weakness, paralysis

• Dx: inc serum K levelECG: peaked T waves and wide QRS

ABGs – metabolic acidosis

Mgmt: K restriction (coffee, cocoa, tea, dried fruits, beans, whole grain breads, milk, eggs)

diuretics Polystyrene Sulfonate (Kayexalate)IV insulin Beta 2 agonist IV Calcium gluconate – WOF Hypotension

IV NaHCo3 – alkalinize plasmaDialysis

Nsg consideration:Monitor VS, urine output, lung

sounds, Crea, BUNmonitor K levels and ECG

observe for muscle weakness and dysrythmia, paresthesia and GI symptoms

b. HYPOKALEMIA

• K+ < 3.5 mEq/L

• Etiology: use of diuretic, corticosteroids and penicillin, vomiting and diarrhea, ileostomy, villous adenoma, alkalosis, hyperinsulinism, hyperaldosteronism

• s/sx: anorexia, nausea, vomiting, decreased bowel motility, fatigue, muscle weakness, leg cramps, paresthesias, shallow respiration, shortness of breath, dysrhythmias and increased sensitivity to digitalis, hypotension, weak pulse, dilute urine, glucose intolerance

Dx: dec serum K level ECG - flattened , depressed T waves, presence of “U” waves ABGs - metabolic alkalosis

Medical Mgmt: diet ( fruits, fruit juices, vegetables, fish, whole grains, nuts, milk, meats)oral or IV replacement

Nsg mgmt: monitor cardiac function, pulses, renal functionmonitor serum potassium concentrationIV K diluted in saline monitor IV sites for phlebitis

Normal ECG

Hypokalemia

Hyperkalemia

Regulation:

• GIT absorbs Ca+ in the intestine with the help of Vitamin D

• Kidney Ca+ is filtered in the glomerulus and reabsorbed in the tubules

• PTH increases Ca+ by bone resorption, inc intestinal and renal Ca+ reabsorption and activation of Vitamin D

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• Calcitonin reduces bone resorption, increase Ca and Phosphorus deposition in bones and secretion in urinea. HYPERCALCEMIA

• Serum calcium > 10.5 mg/dL

• Etiology: Overuse of calcium supplements and antacids, excessive Vitamin A and D, malignancy, hyperparathyroidism, prolonged immobilization, thiazide diuretic

• s/sx: anorexia, nausea, vomiting, polyuria, muscle weakness, fatigue, lethargy

• Dx: inc serum CaECG: Shortened QT interval, ST segments

inc PTH levels xrays - osteoporosis

• Mgmt: 0.9% NaCl IV PhosphateDiuretics – Furosemide IM Calcitonincorticosteroidsdietary restriction (cheese, ice cream, milk, yogurt, oatmeal, tofu)

Nsg Mgmt: Assess VS, apical pulses and ECG, bowel sounds, renal function, hydration status safety precautions in unconscious patients inc mobility inc fluid intake

monitor cardiac rate and rhythmb. HYPOCALCEMIA

• Calcium < 8.5 mg/dL

• Etiology: removal of parathyroid gland during thyroid surgery, Vit. D and Mg deficiency, Furosemide, infusion of citrated blood, inflammation of pancreas, renal failure, thyroid CA, low albumin, alkalosis, alcohol abuse, osteoporosis (total body Ca deficit)

• s/sx: Tetany, (+) Chovstek’s (+) Trousseaus’s, seizures, depression, impaired memory, confusion, delirium, hallucinations, hypotension, dysrythmia

• Dx: dec Ca level ECG: prolonged QT interval

• Mgmt:Calcium salts

Vit Ddiet (milk, cheese, yogurt, green

leafy vegetables) • Nsg mgmt monitor cardiac status, bleeding

monitor IV sites for phlebitisseizure precautionsreduce smoking

Magnesium Mg

• Second to K+ in the ICF

• Normal range is 1.3-2.1 mEq/L

FUNCTIONS1. intracellular production and utilization of ATP2. protein and DNA synthesis3. neuromuscular irritability4, produce vasodilation of peripheral arteries

a. HYPERMAGNESEMIA

• M > 2.1 mEq/L

• Etiology: use of Mg antacids, K sparing diuretics, Renal failure, Mg medications, DKA, adrenocortical insufficiency

• s/sx: hypotension, nausea, vomiting, flushing, lethargy, difficulty speaking, drowsiness, dec LOC, coma, muscle weakness, paralysis, depressed tendon reflexes, oliguria, ↓RR

• Mgmt: discontinue Mg supplementsLoop diuretics

IV Ca gluconateHemodialysis

Nsg mgmt:monitor VSobserve DTR’s and changes in LOC

seizure precautions

b. HYPOMAGNESEMIA• Mg < 1.5 mEq/l

• Etiology: alcohol w/drawal, tube feedings, diarrhea, fistula, GIT suctioning, drugs ie antacid, aminoglycosides, insulin therapy, sepsis, burns, hypothermia

• s/sx: hyperexcitability w/ muscle weakness, tremors, tetany, seizures, stridor,

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Chvostek and Trousseau’s signs, ECG changes, mood changes

• Dx: serum Mg level ECG – prolonged PR and QT interval, ST depression, Widened QRS, flat T waves low albumin level

• Mgmt:diet (green leafy vegetables, nuts, legumes, whole grains, seafood, peanut butter, chocolate)IV Mg Sulfate via infusion pump

• Nsg Mgmt:seizure precautionsTest ability to swallow, DTR’sMonitor I and O, VS during Mg

administrationThe Anions

• CHLORIDE

• PHOSPHATES

• BICARBONATES

Chloride (Cl)

• The MAJOR Anion in the ECF

• Normal range is 95-108 mEq/L

• Inc Na reabsorption causes increased Cl reabsorptionFUNCTIONS1. major component of gastric juice aside from H+2. together with Na+, regulates plasma osmolality3. participates in the chloride shift – inverse relationship with Bicarbonate4. acts as chemical buffer a. HYPERCHLOREMIA

• Serum Cl > 108 mEq/L

• Etiology: sodium excess, loss of bicarbonate ions

• s/sx: tachypnea, weakness, lethargy, deep rapid respirations, diminished cognitive ability and hypertension, dysrhytmia, coma

• Dx: inc serum Cldec serum bicarbonate

Mgmt: Lactated Ringers solnIV Na BicarbonateDiuretics

Nsg mgmt:monitor VS, ABGs, I and O, neurologic, cardiac and respiratory changesb. HYPOCHLOREMIA

• Cl < 96 mEq/l

• Etiology: Cl deficient formula, salt restricted diets, severe vomiting and diarrhea

• s/sx: hyperexcitability of muscles, tetany, hyperactive DTR’s, weakness, twitching, muscle cramps, dysrhytmias, seizures, coma

• Dx: dec serum Cl levelABG’s – metabolic alkalosis

Mgmt:Normal saline/half strength saline

diet ( tomato juice, salty broth, canned vegetables, processed meats and fruits avoid free/bottled water)

Nsg mgmt:monitor I and O, ABG’s, VS, LOC,

muscle strength and movementPhosphates (PO4)• The MAJOR Anion in the ICF• Normal range is 2.5-4.5 mg/L• Reciprocal relationship w/ Ca• PTH inc bone resorption, inc PO4 absorption from GIT, inhibit PO4 excretion from kidney• Calcitonin increases renal excretion of PO4

FUNCTIONS1. component of bones2. needed to generate ATP3. components of DNA and RNA

a. HYPERPHOSPHATEMIA

• Serum PO4 > 4.5 mg/dL

• Etiology: excess vit D, renal failure, tissue trauma, chemotherapy, PO4 containing medications, hypoparathyroidism

• s/sx: tetany, tachycardia, palpitations, anorexia, vomiting, muscle weakness, hyperreflexia, tachycardia, soft tissue calcification

• Dx: inc serum phosphorus leveldec Ca levelxray – skeletal changes

Mgmt:

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diet – limit milk, ice cream, cheese, meat, fish, carbonated beverages, nuts, dried food, sardines

Dialysis

Nsg mgmt:dietary restrictionsmonitor signs of impending

hypocalcemia and changes in urine output

b. HYPOPHOSPHATEMIA

• Serum PO4 < 2.5 mg/dl

• Etiology: administration of calories in severe CHON-Calorie malnutrition (iatrogenic), chronic alcoholism, prolonged hyperventilation, poor dietary intake, DKA, thermal burns, respiratory alkalosis, antacids w/c bind with PO4, Vit D deficiency

• s/sx: irritability, fatigue, apprehension, weakness, hyperglycemia, numbness, paresthesias, confusion, seizure, coma

• Dx: dec serum PO4 level

Mgmt:oral or IV Phosphorus correction diet (milk, organ meat, nuts, fish,

poultry, whole grains)

Nsg mgmt:introduce TPN solution graduallyprevent infection

• Fluids D1

• Electrolytes D2

• Acid-Base D3

• Burns D3

• Shock D4

• GUT D5

• MASTERY D6

Acid Base Balance

• Acid- substance that can donate or release hydrogen ionsie Carbonic acid, Hydrochloric acid

** Carbon dioxide – combines with water to form carbonic acid

• Base- substance that can accept hydrogen ionsIe Bicarbonate

• BUFFER- substance that can accept or donate hydrogen

- prevent excessive changes in pH

TYPES OF BUFFER1. Bicarbonate (HCO3): carbonic acid buffer (H2CO3) 2. Phosphate buffer3. Hemoglobin buffer

Dynamics of Acid Base Balance

• Acids and bases are constantly produced in the body

• They must be constantly regulated

• CO2 and HCO3 are crucial in the balance

• A HCO3:H2CO3 ratio of 20:1 should be maintained

• Respiratory and renal system are active in regulation

Kidney- Regulate bicarbonate level in ECF

1. RESPIRATORY/METABOLIC ACIDOSIS

- kidney excrete H and reabsorbs/generates Bicarbonate2. RESPIRATORY/METABOLIC ALKALOSIS

- kidney retains H ion and excrete Bicarbonate

Lung

- Control CO2 and Carbonic acid content of ECF

1. METABOLIC ACIDOSIS- increased RR to eliminate CO2

2. METABOLIC ALKALOSIS- decreased RR to retain CO2

• pH - measures degree of acidity and

alkalinity- indicator of H ion concentration

- Normal ph 7.35-7.45

• ACIDOSIS- decreased pH; < 7.35

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- increased Hydrogen

• ALKALOSIS - increased pH-; > 7.45 - decreased Hydrogen

ACUTE AND CHRONIC METABOLIC ACIDOSIS

- Low pH

- Increased H ion concentration

- Low plasma BicarbonateEtiology: diarrhea, fistulas, diuretics, renal insufficiency, TPN w/o Bicarbonate, ketoacidosis, lactic acidosisS/sx: headache, confusion, drowsiness, inc RR, dec BP, cold clammy skin, dysrrythmia, shock

• Dx: ABG – low Bicarbonate, low pH, Hyperkalemia, ECG changes

• Rx: Bicarbonate for pH < 7.1 and Bicarbonate level < 10monitor serum KdialysisACUTE AND CHRONIC METABOLIC ALKALOSIS

• High pH

• Decreased H ion concentration

• High plasma Bicarbonate

Etiology: vomiting, diuretic, hyperaldosteronism, hypokalemia, excesive alkali ingestion

s/sx: tingling of toes, dizziness, dec RR, inc PR, ventricular disturbances

• Dx:ABG – pH > 7.45, serum Bicarbonate > 26 mEq/L, inc PaCO2

• Rx: restore normal fluid balance correct hypokalemia

Carbonic anhydrase inhibitorsACUTE AND CHRONICRESPIRATORY ACIDOSIS

• Ph < 7.35PaCO2 > 42 mmHg

Etiology: pulmonary edema, aspiration, atelectasis, pneumothorax, overdose of seatives, sleep apnea syndrome, pneeumonia

s/sx: sudden hypercapnia produces inc PR, RR, inc BP, mental cloudinesss, feeling of fullness in head, papiledema and dilated conjunctival blood vessels

• Dx: ABG – pH < 7.35PaCO2 - > 42 mmHg

• Rx: improve ventilationpulmonary hygienemechanical ventilation

ACUTE AND CHRONICRESPIRATORY ALKALOSIS

• pH > 7.45

• PaCO2 < 38 mmHg

Etiology: extreme anxiety, hypoxemia

s/sx: lightheadednes, inability to concentrate, numbness, tingling, loss of consciousness

• Dx: ABG – pH > 7.45 PaCO2 < 35 dec K

dec Ca

Rx: breathe slowly sedative

ARTERIAL BLOOD GAS ANALYSIS

Evaluating ABG’s

Note the pHpH = 7.35 – 7.45 (normal)

pH = < 7.35 (acidosis)pH = > 7.45 (alkalosis)

compensated – normal pHuncompensated – abnormal pH

2. Determine primary cause of disturbance2.1 pH > 7.45

a. PaCo2 < 40 mmHg – respiratory alkalosisb. HCO3 > 26 mEq/L – metabolic alkalosis

2.2 pH < 7.35a. PaCo2 > 40 mmHg – respiratory acidosisb. HCO3 < 26 mEq/L – metabolic acidosis

3. Determine compensation by looking at the value other than the primary disturbance

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4. Mixed acid-base disorders

Thank You!

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