Fluids And Electrolytes-backup



Help maintain body temperature and cell shape



Help transport nutrients, gasses and wastes

Fluid  Is

used to indicate that other substances are also found in these compartments and that they influence the water balance in and between compartments.

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

60 % Intracellular Fluid 40% or 2/3 Arterial Fluid 2%

Venous Fluid 3%

Extracellular Fluid 20% or 1/3

Intravascular

Interstitial 15% or 3/4

5% or 1/4 Transcellular fluid 1-2% ie csf, pericardial, synovial, intraocular, sweat

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

Fluid Movement From Pressure Changes  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 Transport 1. Diffusion – substances/solutes move from high concentration to low concentration ie 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

B. Active Transport Process -

2. 3. 4.

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 Transport 1. 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 cell 3. Exocytosis – moves substances out of the cell

Active Transport

Osmosis 

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

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

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Oncotic pressure – osmotic pressure exerted by proteins

Osmosis

Osmosis

Diffusion

Regulation of Body Fluid 1. 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 increase water reabsorption on collecting duct  Aldosterone increases Sodium and water retention retention in the distal nephron  ANP Promotes Sodium excretion and inhibits thirst mechanism

Atrial Natriuretic Peptide: Regulates Na+ & H2O Excretion

ADH 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 output 

ADH 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)

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 respiration

Other Mechanisms 1. 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

Evaluation of fluid status Osmolality – concentration of fluid that affects movement of water between fluid compartments by osmosis - measures the solute concentration per kg in blood and urine - reported as mOsm/kg - normal value= 280-300 mOsm/kg Osmolarity – concentration of solutions - mOsm/L

Intake and Output I and O must be equal  2.6 L per day  Essential = Measurable = Sensible  Non essential = estimated Measurement= Insensible 

Sources of Fluids Fluid Intake 1. Exogenous sources  Fluid intake 2, 600 ml 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 Output Sensible loss  Urine - 1, 500 ml  Fecal losses – 200 ml Insensible loss  skin – 600 ml  Lungs – 300 ml

2, 600 ml

I&O Imbalance Fluid Volume Deficit ↑output, normal intake  Normal output, ↓ intake  No intake or prolonged decreased intake 

Causes of FVD Vomiting, diarrhea, GI suctioning, sweating  Diabetes Insipidus  Adrenal insufficiency  Osmotic diuresis  Hemorrhage  3rd space fluid shift 

Assessment of FVD ICF cellular dehydration Acidosis  ITF skin poor skin turgor  IVF artery ↓BP, pulse (rapid thready) vein ↓CVP, ↓PAWP 

Clinical manifestations         

Weight loss Oliguria Concentrated urine Postural hypotension Flattened neck veins Increased Temp Dec CVP Thirst, anorexia Muscle weakness and cramps

Laboratory BUN:Crea > 20:1  Inc Hct – RBC suspended in Dec plasma volume  Dec K – GI and renal losses  Inc K – adrenal insufficiency  Dec Na – inc thirst and ADH  Inc Na – insensible losses and DI 

Medical Management Oral intake when mild  IV route, acute or severe  Isotonic fluids ie LR for hypotensive patients to expand plasma volume  Assess I and O, weight, CVP, LOC, breath sounds and skin color  Fluid challenge test – 100-200 ml x 15 min 

Nursing Management Monitor and measure I and O  Monitor VS closely  Monitor skin turgor and tongue furrows  Monitor urinary concentration  Monitor mental function 

Fluid Volume Excess ↑ intake, normal output  Normal intake, ↓ output  No output 

Nursing Management    

 

Measure intake and output Weigh daily 2 lb wt gain = 1 L fluid Assess breath sounds Monitor degree of edema ie ambulatory – feet and ankles bedridden – sacral area Promote rest – favors diuresis/inc venous return Administer appropriate medication

Causes of FVE 

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Heart failure, renal failure, cirrhosis of the liver – d/t aldosterone stimulation/Congestion Increased consumption of table salt Excessive administration of Na containing fluids in a patient w/ impaired regulatory mechanism SIADH

Assessment of FVE 

ICF cellular edema ↓LOC pulmonary edema crackles (bibasilar), wheezing, shortness of breath, Inc RR

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ITF skin bipedal pitting edema, periorbital edema and ANASARCA

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IVF artery vein

↑BP, pulse (rapid bounding) ↑CVP, ↑PAWP

Clinical Manifestations Distended neck veins  Tachycardia  Inc weight  Increased urine output  Shortness of breath and wheezing/crackles  Inc 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 

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

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Mgmt: diuretics, fluid restriction, elevation of extremities, elastic compression stockings, paracentesis, dialysis

Laboratory Dec BUN  Dec Hct  CRF – serum osmolality and Na level dec  Cxr – pulmonary congestion 

Medical Management  

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Discontinue administration of Na solution Diuretics ie Thiazide – block Na reabsorption in distal tubule Loop diuretics – block Na reabsorption in ascending loop of Henle Restrict fluid and salt intake Dialysis

Types of Fluid

• Tonicity - ability of solutes to cause osmotic driving forces

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: hpovolemia, shock, DKA, metabolic alkalosis, hypercalcemia, mild NA deficit CI: caution in renal failure, heart failure and edema

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D5W - 5% Dextrose in water - 170 cal and free water - 252 mOsm/L Rx: hypernatremia, fluid loss and dehydration CI: early post op when ADH inc d/t stress, sole treatment in FVD (dilutes plasma), head injury (inc ICP), flid resuscitation (hyperglycemia), caution in renal and cadiac dse (fluid overload), px with NA deficiency (peripheral circulatory collapse and anuria)

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

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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:hypovelemia, burns, flids lost as bile/diarrhea, acute blood loss CI: ph>7.5, lactic acidosis, renal failure(cause HyperK)

Hypotonic Fluid - fluid will enter the cell, the cell will swell

Hypotonic 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/L Rx: critical situations to treat HypoNa, assist in removing ICF excess CI: administered slowly and cautiously (IVF overload and pulmonary edema)

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5% NaCl

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D10W - 10% Dextrose in water hypertonic (505 mOsm/L)

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D10W - 20% Dextrose in water hypertonic (1011 mOsm/L)

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D50W - 50% Dextrose in water hypertonic (1700 mOsm/L)

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D5NS - 5% Dextrose & 0.9NaCl hypertonic (559 mOsm/L)

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D10NS - 10% Dextrose & 0.9NaCl hypertonic (812 mOsm/L)

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D5LR - 5% Dextrose in Lactated Ringers hypertonic (524 mOsm/L

Colloid solutions 

Dextran 40 in NS or 5% D5W - volume/plasma expander - decrease coagulation - remains for 6H in circulatory system Rx: hypovolemia in early shock, improve microcirculation (dec RBC aggregation) CI: hemorrhage, thrombocytopenia, renal disease and severe dehydration

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 osmolality 2. Transmission of nerve impulse 3. Stimulation of muscle activity

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

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

Regulation of Electrolyte Balance 1. 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  MAGNESIUM 

SODIUM (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 contraction 2. Major determinant of ECF osmolality 3. Primary regulator of ECF volume

a. HYPERNATREMIA 

Na > 145 mEq/L



Assoc w/ water loss or sodium gain

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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 levels Oral care initiate gastric feedings slowly Seizure 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

Mgmt: sodium replacement, water restriction, isotonic soln for moderate hyponatremia, hypertonic saline soln for neurologic manifestations, diuretic for SIADH Nsg. Consideration Monitor I and O, LOC, VS, serum Na Seizure precaution diet

Hyponatremia

Hypernatremia

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 contraction 2. metabolism of carbohydrates, fats and proteins 3. Fosters acid-base balance

a. HYPERKALEMIA 

K+ > 5.0 mEq/L

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

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

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Dx: inc serum K level ECG: 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 plasma Dialysis Nsg consideration: Monitor VS, urine output, lung sounds, Crea, BUN monitor 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

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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 function monitor serum potassium concentration IV K diluted in saline monitor IV sites for phlebitis

Normal ECG

Hypokalemia

Hyperkalemia

CALCIUM (Ca)   

Majority of calcium - bones and teeth Normal serum range 8.5-10.5 mg/dL Ca has an inverse relationship with PO4

FUNCTIONS 1. formation and mineralization of bones/teeth 2. muscular contraction and relaxation 3. cardiac function 4. blood coagulation 5. Promotes absorption and utilization of Vit B12

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  Calcitonin reduces bone resorption, increase Ca and Phosphorus deposition in bones and secretion in urine

a. 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

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

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Dx: inc serum Ca ECG: Shortened QT interval, ST segments inc PTH levels xrays - osteoporosis

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Mgmt: 0.9% NaCl IV Phosphate Diuretics – Furosemide IM Calcitonin corticosteroids dietary 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 rhythm

b. 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)

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

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

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Dx: dec Ca level ECG: prolonged QT interval Mgmt: Calcium salts Vit D diet (milk, cheese, yogurt, green leafy vegetables) Nsg mgmt monitor cardiac status, bleeding monitor IV sites for phlebitis seizure precautions reduce smoking

Magnesium Mg Second to K+ in the ICF  Normal range is 1.3-2.1 mEq/L 

FUNCTIONS 1. intracellular production and utilization of ATP 2. protein and DNA synthesis 3. neuromuscular irritability 4, 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

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

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Mgmt: discontinue Mg supplements Loop diuretics IV Ca gluconate Hemodialysis

Nsg mgmt: monitor VS observe 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

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s/sx: hyperexcitability w/ muscle weakness, tremors, tetany, seizures, stridor, Chvostek and Trousseau’s signs, ECG changes, mood changes

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

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

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Nsg Mgmt: seizure precautions Test ability to swallow, DTR’s Monitor I and O, VS during Mg administration

The 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 reabsorption

FUNCTIONS 1. major component of gastric juice aside from H+ 2. together with Na+, regulates plasma osmolality 3. participates in the chloride shift – inverse relationship with Bicarbonate 4. acts as chemical buffer

a. HYPERCHLOREMIA 

Serum Cl > 108 mEq/L



Etiology: sodium excess, loss of bicarbonate ions

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



Dx: inc serum Cl dec serum bicarbonate

Mgmt: Lactated Ringers soln IV Na Bicarbonate Diuretics Nsg mgmt: monitor VS, ABGs, I and O, neurologic, cardiac and respiratory changes

b. HYPOCHLOREMIA 

Cl < 96 mEq/l



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

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

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Dx: dec serum Cl level ABG’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 movement

Phosphates (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

FUNCTIONS 1. component of bones 2. needed to generate ATP 3. 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

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



Dx: inc serum phosphorus level dec Ca level xray – skeletal changes

Mgmt: diet – limit milk, ice cream, cheese, meat, fish, carbonated beverages, nuts, dried food, sardines Dialysis Nsg mgmt: dietary restrictions monitor 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 gradually prevent infection

Acid Base Balance 

Acid - substance that can donate or release hydrogen ions ie Carbonic acid, Hydrochloric acid ** Carbon dioxide – combines with water to form carbonic acid



Base - substance that can accept hydrogen ions Ie Bicarbonate



BUFFER- substance that can accept or donate hydrogen - prevent excessive changes in pH

TYPES OF BUFFER 1. Bicarbonate (HCO3): carbonic acid buffer (H2CO3) 2. Phosphate buffer 3. 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 Bicarbonate 2. 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 - increased Hydrogen



ALKALOSIS - increased pH-; > 7.45 - decreased Hydrogen

ACUTE AND CHRONIC METABOLIC ACIDOSIS Low pH - Increased H ion concentration - Low plasma Bicarbonate Etiology: diarrhea, fistulas, diuretics, renal insufficiency, TPN w/o Bicarbonate, ketoacidosis, lactic acidosis S/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 < 10 monitor serum K dialysis

ACUTE 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 inhibitors

ACUTE AND CHRONIC RESPIRATORY ACIDOSIS 

Ph < 7.35 PaCO2 > 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 < 7.35 PaCO2 - > 42 mmHg



Rx: improve ventilation pulmonary hygiene mechanical ventilation

ACUTE AND CHRONIC RESPIRATORY 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 Parameter

Normal Value

pH

7.35 – 7.45

PaCO2

35 – 45 mmHg

HCO3

22-26mEq/L

O2 saturation

93 - 98%

Evaluating ABG’s 1.

Note the pH pH = 7.35 – 7.45 (normal) pH = < 7.35 (acidosis) pH = > 7.45 (alkalosis) compensated – normal pH uncompensated – abnormal pH

2. Determine primary cause of disturbance 2.1 pH > 7.45 a. PaCo2 < 40 mmHg – respiratory alkalosis b. HCO3 > 26 mEq/L – metabolic alkalosis 2.2 pH < 7.35 a. PaCo2 > 40 mmHg – respiratory acidosis b. HCO3 < 26 mEq/L – metabolic acidosis

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

PaCO2 HCO3

7.20

60 mmHg

24 mEq/L

7.40

60 mmHg

37 mEq/l

Uncompensated Respiratory acidosis Compensated Respiratory acidosis

4. Mixed acid-base pH disorders Metabolic and Respiratory Acidosis

7.21

Dec acid

PaCO2

52

Inc acid

HCO3

13

Dec acid

Thank You!