Fluids and Electrolytes Metropolitan Community College Fall 2013 Jane Miller, RN MSN.
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Transcript of Fluids and Electrolytes Metropolitan Community College Fall 2013 Jane Miller, RN MSN.
Fluids and Electrolytes
Metropolitan Community CollegeFall 2013
Jane Miller, RN MSN
Objectives• Discuss the nurse’s role in understanding fluid
and electrolytes as needed for safe IV therapy.• Examine the importance of maintaining
hemostasis.• Review extracellular fluid, intracellular fluid,
and interstitial fluid dynamics.• Examine solute and solvent in relation to
osmotic pressure and importance of maintaining hemostasis.
• Identify the major electrolytes, their function, and location.
• Describe abnormalities of fluid and electrolyte balance, and evaluate how each affects homeostasis.
• Discuss the differences between isotonic, hypertonic, and hypotonic IV solutions and their actions in osmosis, indications for and contraindications in various pathophysiological conditions.
• Identify normal acid-base balance.• Examine abnormalities in acid-base balance.• Identify the body’s regulatory mechanism for acid-base
balance.• Examine hormonal regulation of fluid and electrolyte
balance.
Fluid Basics• Water comprises 70% of living cells• Average healthy person needs 2 - 2.5 liters of water per
day to meet fluid requirements• Fluid is lost through– Respirations– Urine– Feces– Perspiration– Vomit– Diarrhea– Wound drainage
Functions of Body Fluid• Transport of nutrients, electrolytes, and
oxygen to the cells
• Excretion of waste products
• Regulation of body temperature
• Lubrication of joints and membranes
• Medium for food digestion
Fluid Compartments• Intracellular (ICF)– All fluid within the cell wall
• Extracellular (ECF)– All fluid outside of the cell wall• Interstitial fluid• Plasma• CSF• Sweat• Urine• GI secretions
Osmolality• The number of molecules of solute (sodium,
urea, and glucose) per kilogram of water
• Osmolality of blood is 275-295 mOsm/kg
• Isotonic fluids 275-295 mOsm/kg– Same solute concentration as plasma
• Hypertonic fluids > 295 mOsm/kg– Higher solute concentration than plasma
• Hypotonic fluids < 275 mOsm/kg– Lower solute concentration than plasma
Body Fluid Regulation• Osmosis– The movement of water from an area of lower
particle concentration to one of higher particle concentration
Body Fluid Regulation• Diffusion– The movement of molecules from an area of
higher concentration to an areas of lower concentration
• Filtration– The movement of molecules from an area of
higher concentration to one of lower concentration as a result of hydrostatic pressure
– Hydrostatic pressure is the pressure exerted on tissue due to the presence of water. It is generated by the pumping action of the heart.
– Seen in the capillary system• Arterial pressure is 32 mmHg• Venous pressure is 15 mmHg
Body Fluid Regulation
Homeostasis• Serum osmolality is regulated by the
osmoreceptors of the hypothalamus
• When fluid is lost the hypothalamus stimulates the pituitary gland to secrete ADH
• ADH signals the kidneys to conserve water
• Promotes the sensation of thirst
Isotonic Fluids• 275-295 mOsm/kg
• Same solute concentration as plasma
• No net fluid shift
• Examples– 0.9% NaCl
– Lactated Ringers
– D5W (can be considered hypotonic due to metabolism of dextrose)
Hypertonic Fluids• > 295 mOsm/kg• Higher solute concentration than plasma• Draw water from the cells and tissues• Expands plasma volume• Examples– 3% NaCl– D10W
– D5NS
Hypotonic Fluids• < 275 mOsm/kg• Lower solute concentration that plasma• Causes water to move out of the plasma to
the tissues and cells• Examples– 0.45% NaCl– 0.33% NaCl– D2.5W
Administration of a IV fluid with an osmolality of 288 mOsm/kg represents
what kind of fluid?
A. IsotonicB. HypertonicC. Hypotonic
Evaluation of Fluid Status
• Specific gravity of urine– Normal 1.005-1.030– < 1.005 = overhydration– > 1.030 = dehydration
• Hematocrit– Normal Male 42-52%– < 42% = overhydration– > 52% = dehydration
• Electrolytes– < normal = overhydration– > normal = dehydration
Causes of Overhydration
• Renal failure• Congestive heart failure• Liver cirrhosis• Syndrome of inappropriate antidiuretic
hormone (SIADH)• Excessive oral or IV intake
Clinical ManifestationsOverhydration
• Edema• Crackles in the lung bases• Dyspnea• SOB• Serum pH <7.35, respiratory acidosis• Ascites• Increased blood pressure• Bounding pulses• Extra heart sound (most common in children)• Activity intolerance• Increase in body weight
Nursing ManagementOverhydration
• I&O• Daily weights• Vital signs• Labs – CBC, BMP, Urinalysis, BUN, Creatinine• Prop pt up in bed to reduce dyspnea• Allow adequate time for rest• Skin assessment and daily care• Administer diuretics• Stop or slow IV fluids• Pt teaching – diet, fluid restriction, diuretics, daily
weights, S&S to report
Causes of Dehydration• Decreased oral intake– Elderly– Altered mental status
• Diabetes Insipidus• Diabetes Mellitus• Vomiting and diarrhea• Burns• Excessive sweating• Overuse of diuretics
Clinical ManifestationsDehydration
• Severe thirst (may be absent in the elderly)• Dry mucous membranes• Decreased skin turgor• Tachycardia• Weak pulse• Hypotension• Decreased urine output• Headache• Dizziness• Mental status changes• Mottled extremities
• I&O• Daily weights• Vital signs• Labs – CBC, BMP, Urinalysis, BUN, Creatinine• Monitor neurological status• Provide oral care• Assess for signs of constipation• Administer IV fluids• Pt teaching – hydration needs, S&S to report
Nursing ManagementDehydration
Electrolyte Overview• Calcium, Chloride, Magnesium, Phosphorus,
Potassium, and Sodium
• Support normal bodily functions• Have either a positive or negative charge
• Each electrolyte has a normal range where there is optimal body function
• When outside of this normal range dysfunction occurs
Sodium: Na+
• 135-145 mEq/L
• Most numerous cation in the ECF
• Maintains ECF volume through osmotic pressure
• Regulates acid-base balance by combining with chloride and bicarb
• Conducts nerve impulses via sodium channels in cell
Regulation• Aldosterone: Secreted by the adrenal cortex – Low ECF sodium levels– Increased ICF potassium– Low cardiac output– Stress
• ADH: Secreted by the pituitary gland– Increased ECF osmolality
• Atrial natriuretic peptide (ANP): Secreted by the atrium of the heart– Excessively stretched atria
Increases retrieval of sodium from kidney filtrate
Antagonist to aldosterone
Hypernatremia• > 145mEq/L• Causes– Cushing’s syndrome– Diabetes insipidus– Excessive sweating– Increased oral intake– Infusion of 3% NaCL– Severe vomiting– Decreased renal function
Clinical Manifestations
• Thirst• Dry mucous membranes• Low-grade fever• Edema• Tachycardia• Mental status changes• Seizures
> 180mEq/L = high mortality
Nursing Management• Administer medications to control Cushing’s Syndrome• Administer ADH (diabetes insipidus)• Use 3% NaCl infusions carefully• Monitor labs• Oral care• Skin care and turning• Vital signs• Monitor neurological status• Low sodium diet• Encourage oral intake of water
Which of these situations can cause an increased serum sodium level?
a. Excessive use of table saltb. Consuming large quantities of canned soupc. Increased water intaked. Use of intravenous 3% NaCle. Use of diureticsf. Severe vomiting
Hyponatremia• < 135mEq/L• Causes– Inadequate oral intake– Excessive water intake– Diuretics– Vomiting and diarrhea– Infusion of 5% Dextrose– Burns– Head trauma– Syndrome of inappropriate antidiuretic hormone– Addison’s disease
Clinical Manifestations• Headache• Confusion• Seizures• Tachycardia• Hypotension• Muscle weakness• Abdominal cramping• Possibly no manifestations
< 115 mEq/L = high mortality
Nursing Management• Monitor VS• Monitor labs• Monitor neurological status• Fluid restriction• Administer 0.9% NaCl• Administer 3% NaCl carefully• Allow plenty of time for rest
Potassium: K+
• 3.5 – 5.0 mEq/L• Intracellular cation• 98% is found within the cells• Essential for cellular integrity• Transmission of neuromuscular impulses• Acid-base balance• Conversion of carbs to energy• Formation of amino acids into proteins
Hyperkalemia• > 5.0 mEq/L• Causes– Increased oral or IV intake– Decreased urinary excretion– Cellular damage– Severe acidosis– Potassium sparing diuretics– Addison’s disease
Clinical Manifestations• Muscle cramps• Tachycardia• Nausea• Diarrhea• Weakness• Numbness• Oliguria or anuria• ECG changes
– Peaked T waves, shortened QT interval, prolonged PR followed by a disappearance of the P wave, Prolonged QRS.
• Cardiac arrest
Peaked t-wave
Nursing Management• Monitor VS & ECG• Monitor labs• Diet restriction• Slow or stop IV fluids with potassium added– Normally no more than 10mEq of KCL per hour
• Administer Kayexalate• Administer insulin and glucose (temporary tx)• Administer IV sodium bicarb (temporary tx)
Hypokalemia• < 3.5 mEq/L• Causes– Potassium wasting diuretics– Decreased oral intake– Alcoholism– Vomiting– Diarrhea– Alkalosis– Steroid use
Clinical Manifestations• Nausea & Vomiting• Diarrhea• Abdominal distention• Vertigo• Malaise• Confusion• ECG changes– Flat or inverted T waves, depressed ST, may have a U
wave
Nursing Management• Monitor VS & ECG• Monitor labs• Encourage diet rich is potassium– Sweet potatoes, broccoli, bananas, squash
• Administer potassium supplement– Irritating to the gastric mucosa, give with 6-8
ounces of water• Use caution when administering IV• Never give K+ as a bolus
Your patient has this ECG tracing. What do you suspect?
Calcium: Ca2+
• Normal serum values 8.5- 10.5 mg/dL• Ionized calcium 4.0 – 5.5 mg/dL• Cation found in both ECF and ICF, but greater
concentration in ECF• Maintains cellular membrane stability • Sedative effect on nerves• 98% in bones and teeth, 2% in the serum• Serum pH greatly affects calcium levels – metabolic
acidosis increases levels, alkalosis opposite effect
Functions of Calcium• Neuromuscular
– transmission of nerve impulses and contraction of skeletal muscle
• Cardiac– contraction of the myocardium
• Cellular and Blood– Maintains cellular permeability - decreased calcium
increases cellular permeability– Promotes clotting by converting prothrombin into thrombin
• Bone and teeth construction– Calcium along with phosphorous forms bones and teeth
Regulation of Calcium• Vitamin D– Aides in absorption of calcium from the gut
• Calcitonin from the thyroid gland– Increases renal excretion, deposits it in the bones
• PTH from the parathyroid gland– Mobilizes calcium from the bone and increases
reabsorption by the kidneys
Hypercalcemia• Serum calcium > 10.5 mg/dL• Ionized calcium > 5.5 mg/dL• Causes– Primary hyperparathyroidism– Bone malignancy– Drug toxicity• Thiazide diuretics, lithium carbonate, vitamin A & D
– Prolonged bed rest– Rhabdomyolysis– Excessive use of calcium supplements
Clinical Manifestations
• Fatigue• Weakness• Headache• Confusion• Polyuria• Kidney stones• Nausea & vomiting• ECG changes
– Shortening of the ST segment and QT interval, prolonged PR interval
• Soft tissue calcifications• Pathological fractures
Nursing Management• Monitor VS & ECG• Monitor labs• Stop vitamin A, D and calcium supplements• Low calcium diet• Discontinue thiazide diuretics• Allow plenty of time for rest• Administer antiemetics• Turn and reposition carefully• Monitor neurological status
Hypocalemia• Serum < 8.5 mg/dL• Ionized Ca is < 4.0 mg/dL• Causes
– Decreased oral intake (rare)– Inadequate vitamin D– Hypoalbuminemia– Citrated blood transfusions– Decreased PTH– Alkalosis– GI surgery– Chronic pancreatitis– Small bowel disease– Loop diuretics
Clinical Manifestations• Numbness and tingling of the fingers• Muscle cramps• Hyperactive reflexes• Anxiety• Bradycardia• Hypotension• ECG changes– Prolonged QT intervals
Clinical Tests
Chvotsek’s Sign Trousseau’s Sign
Inflate BP cuff 20 mm above systolic pressure for 3 minutes
Tap the facial nerve just below the temple on the zygomatic arch
Nursing Management• Monitor VS & ECG• Monitor labs• Give oral supplements of calcium and Vit. D• Infuse IV calcium supplements slowly– 60mg/min
• Do not give with sodium bicarb because precipitation could result
• Encourage dietary consumption– Yogurt, cheese, spinach, sardines
Magnesium: Mg2+
• 1.4- 2.1 mg/dL• Intracellular cation• Neuromuscular activity transmission• Cardiac contraction• Cellular
– Activates enzymes for carbohydrate and protein metabolism– Responsible for proper transportation of sodium and
potassium across cell membranes– Influences utilization of K, Ca, and proteins– Magnesium deficits are FREQUENTLY accompanied by a
Potassium and/or Calcium deficit
Hypermagnesemia• > 2.1 mg/dL• Causes– Renal failure– IV infusion (common in OB)– Adrenal insufficiency– Intake of magnesium containing antacids• Maalox, MOM, Mylanta
Clinical Manifestations• Hypotension• Bradycardia• Nausea & Vomiting• Decreased deep tendon reflexes• Drowsiness• Respiratory depression• Flushing
Nursing Management• Stop magnesium-containing products• IV push calcium gluconate• Monitor VS & ECG• Monitor labs• Assess neurological status• Administer 0.45% NaCl and diuretics• Dialysis
Hypomagnesemia• < 1.4 mg/dL• Causes– Malnutrition– Alcoholism– Loop diuretics– Vomiting– Diarrhea– Increased calcium intake– Diuresis from diabetic ketoacidosis
Clinical Manifestations• Confusion• Lethargy• Seizures• Tetany• Increased tendon reflexes• Hypertension• PVCs• V tach• V fib
Nursing Management• Monitor VS & ECG• Monitor labs• Assess neurological status• Administer magnesium supplements• Monitor IV administration closely• Encourage dietary intake– Spinach, nuts, fish, beans
Phosphorus
• 2.5 – 4.5 mg/dL• Major intracellular anion• 85% is in teeth and bones• Essential for carb, protein, and fat metabolism• Nerve and muscle function• Form ATP and ADP• Essential for acid-base balance
Hyperphosphatemia• > 4.5 mg/dL• Causes– Excessive oral intake– Decreased levels of PTH– Chemotherapy– Radiation therapy– Rhabdomyolysis– Renal insufficiency– Acidosis
Clinical Manifestations• Calcium phosphate deposits in soft tissues• Muscle weakness• Tachycardia• Nausea• Diarrhea• Abdominal cramps
Nursing Management• Monitor VS & ECG• Monitor labs• Administer phosphorous binding antacids – Calcium carbonate, calcium acetate
• Dietary restriction• Administer insulin and glucose (temp tx)
Hypophosphatemia• < 2.0 mg/dL• Causes– Vitamin D deficiency– Phosphate binding antacids– Alcoholism– Vomiting & diarrhea– Diabetic ketoacidosis– Elevated PTH– Alkalosis– Burns
Clinical Manifestations• Confusion• Seizures• Peripheral neuropathy• Tissue hypoxia• Dysrhythmias• Bleeding from platelet dysfunction• Weakness• Bone pain• Tremors• Anorexia
Nursing Management
• Monitor VS & ECG• Monitor labs• Watch for signs of bleeding• Monitor neurological status• Administer oral supplements• Encourage dietary intake– Dried beans, fish, organ meats, whole grains
Chloride: Cl-
• 95-108 mEq/L• Primary anion in the ECF• Combines with sodium to create electrical
neutrality• Assists in reabsorption of sodium from kidneys• Combines with hydrogen to for hydrochloric
acid for digestion• Buffers carbonic acid• Used to calculate the anion gap
Hyperchloremia• > 108 mEq/L• Causes– Hyperparathyroidism– Dehydration– Metabolic acidosis– Respiratory alkalosis– Excessive dietary intake
Clinical Manifestations• Increased depth and rate of respirations• Lethargy• Stupor• Disorientation• Coma
Hypochloremia
• < 95 mEq/L• Causes– Vomiting– Excessive sweating– Diuretics– Diabetic ketoacidosis– It rarely occurs in isolation
Clinical Manifestations
• Reflects alkalosis• Paresthesias of the face and extremities• Muscle spasms• Slow shallow respirations• Hypoxia• Tetany• Confusion• Hypertension• Dehydration
Resources
• Osborn, Wraa, & Watson chapter 18• Fluid and Electrolyte Balance
http://www.nlm.nih.gov/medlineplus/fluidandelectrolytebalance.html
• I.V. fluids: What nurses need to know. http://www.nursingcenter.com/lnc/pdf?AID=1156868&an=00152193-201105000-00010&Journal_ID=54016&Issue_ID=1156791
• IV Fluid Basics http://faculty.weber.edu/kbarton1/IV%20Therapy%20Basics.pdf
