LPN-C Unit Four Rationale for Intravenous Therapy.

LPN-CLPN-C

Unit Four

Rationale for Intravenous Therapy

What is the Purpose ofWhat is the Purpose ofIntravenous Therapy?Intravenous Therapy?

Maintenance◦Water◦Glucose◦Protein◦Vitamins◦Electrolytes◦pH

Restoration of previous lossesReplacement of present lossesAdministration of medication

WaterWaterWater is necessary for adequate kidney function –

Normal Intake Normal OutputOral liquids 1300mLUrine

1500mLWater in food 1000mL Stool

200mLMetabolism 300mL Lungs

300mLTotal 2600mL Skin

600mLTotal 2600mL

Individual fluid requirements vary◦Total body water percentage is higher in infants

(80% compared to 60% in adults)◦ Infants require more water than older children or

adults◦ Infants are more vulnerable to fluid volume deficit

GlucoseGlucoseConverted to glycogen by the liverHas 4 main uses in parenteral

therapy◦Improves hepatic function◦Supplies the necessary calories for energy

◦Spares body protein◦Minimizes ketosis

Approximately 100 – 150g of glucose is needed daily to minimize protein catabolism

1 liter of 5% dextrose in water supplies 50g of glucose

Dextrose in water is available in 2.5%, 5%, 10%, 20%, and 30%

Glucose (cont’d)Glucose (cont’d)Dextrose concentrations higher than 10% must be given through a central vein◦The exception is 50% dextrose slow IV push at a rate of 3mL/min through a peripheral vein for emergency treatment of hypoglycemia

ProteinProteinAmino acids are the building blocks of the body◦Tissue growth and repair◦Wound healing

Available in concentrations of 3.5 – 15%

Used in TPN centrally and peripherally

Protein (cont’d)Protein (cont’d)Daily requirements = 1g protein/kg body weight◦Amount increases as stress to the body increases

Gluconeogenesis = conversion of protein to glucose to meet energy requirements◦Occurs during starvation, stress, or infection

◦Uses large amount of energy◦Body will use protein for energy if there are inadequate glucose stores

VitaminsVitaminsVitamins B and C are most frequently used◦Vitamin B is needed for the metabolism of carbohydrates and maintenance of GI function

◦Vitamin C promotes wound healing

ElectrolytesElectrolytesCorrection of electrolyte imbalances is important in preventing serious complications

Important in parenteral therapy◦Potassium, sodium, chloride, magnesium, phosphorus, calcium, bicarbonate

Electrolytes (cont’d)Electrolytes (cont’d)Potassium◦Adequate replacement therapy = 20mEq/L◦Patients who need potassium replacement – Stress from tissue injury Wound infection Gastric or bowel surgery Prolonged gastric suction

◦Assess renal function prior to potassium replacement Excreted through the urine Intoxication can occur rapidly and with no

symptoms◦Slow rate of infusion

no more than 20mEq/L per hour via peripheral line

no more than 40mEq/L per hour via central line◦Never give potassium via IV push◦Always use a cardiac monitor with K+ infusion

Electrolytes (cont’d)Electrolytes (cont’d)Potassium (cont’d) --◦Infiltration of potassium is extremely irritating to the tissue Can cause necrosis Imperative to use extravasation

protocol In the case of infiltration, discontinue

the infusion, apply cool compresses, and elevate the extremity by 4 inches

pHpHMost IV solutions are acidic◦Allows for longer shelf life◦The more acidic a solution, the more irritating to the vein

Parenteral NutritionParenteral NutritionPeripheral venous delivery of parenteral nutrition (PPN)◦Glucose concentration is not to exceed 10%

◦Usually utilized for 3 – 7 days◦Assess for metabolic abnormalities

Hyperglycemia Most common metabolic abnormality in PPN Rapid administration of fluid Increased levels of stress hormones

Hypoglycemia can occur if infusion is discontinued abruptly

Hypokalemia Insulin-related shift of potassium from the extracellular compartment to the intracellular compartment

Fluid Balance in Infants and Fluid Balance in Infants and ChildrenChildrenMore vulnerable to fluid volume deficit

Kidneys are immature up to 2 years of age◦Cannot conserve or excrete water or sodium in response to imbalances as efficiently as adults

Body surface area in infants is larger than in adults per size◦Lose more fluid through the skin

Infants have a higher metabolism rate which requires more water per size◦Produce more heat than adults◦Larger amount of metabolic waste to secrete

Less stable regulatory responses to fluid imbalances

Fluid Balance/Infants/Children Fluid Balance/Infants/Children (cont’d)(cont’d)Fevers are higher and last

longer in acute illness◦Increases fluid loss

Symptoms of fluid imbalance◦Decreased appetite◦Less active◦More irritable◦Flaccid appearance◦Diarrhea, vomiting◦Decrease in voiding

Nursing assessment◦Assess concentration of urine

Fluid Balance/Infants/Children Fluid Balance/Infants/Children (cont’d)(cont’d)Nursing assessment (cont’d) --

◦Weigh diapers◦Monitor for diarrhea

Common cause of isotonic dehydration Proportionate loss of water and electrolytes

Formula containing an inappropriately high amount of solute can cause diarrhea that leads to hypertonic dehydration Greater loss of water than electrolytes

◦Monitor for weight changes Record weight before onset of illness

Physician’s records Parent/family/caregiver report

Weight loss resulting from fluid volume deficit is more rapid than with loss of body mass

Fluid Balance/Infants/Children Fluid Balance/Infants/Children (cont’d)(cont’d)Nursing assessment (cont’d) –

◦Monitor vital signs Blood pressure is not always reliable

because elasticity of the blood vessels in children keeps blood pressure stable initially

Tissue turgor◦Skin remains slightly raised for a few seconds with fluid volume deficit

◦Skin turgor begins to decrease after 3-5% body weight is lost as fluid

◦Obese infants/children have deceptive skin turgor Normal in appearance in spite of fluid

volume deficit

Fluid Balance in the ElderlyFluid Balance in the ElderlyAt risk for fluid volume deficit due to normal aging changes◦6% reduction of total body water◦Decrease in ratio of intracellular fluid to ECF

◦Loss of 30-50% glomeruli by the age of 70 Decrease in glomerular filtration rate Decreased ability to concentrate urine Decreased secretion of aldosterone Decrease in the response of the distal tubule

to ADH◦Decrease in glucose tolerance◦Decreased sensation of thirst◦Decreased skin elasticity

Poor indication of turgor◦Atrophy of the sweat glands

Fluid Balance in the Elderly Fluid Balance in the Elderly (cont’d)(cont’d)Normal aging changes (cont’d) --

◦Diminished capillary bed Less effective cooling of body temperature

◦Decreased cardiac output Increased risk for orthostatic hypotension Increased risk for falls

◦Decreased elasticity of arteries◦Immediately assess fluid status with any changes in mental status

Typical assessment findings◦Dehydration frequently seen◦Normal body temperature lower (97°F)◦Mucus membranes less moist◦Positional changes in blood pressure common

Fluid Balance in the Elderly Fluid Balance in the Elderly (cont’d)(cont’d)Typical assessment findings

(cont’d) –◦Most accurate assessment of skin turgor is over the sternum

Special problems in the elderly◦Hypernatremia

Common problem in LTC facilities Immobility Unable to express thirst

◦Reduced motility of GI tract Laxative dependency

◦Heat stroke Elderly more susceptible Decreased efficacy of sweat glands Normal temperature decreases with age

Temperature of 99°F would be high for the body

Fluid Balance in the Elderly Fluid Balance in the Elderly (cont’d)(cont’d)Special problems (cont’d) --

◦Radiocontrast agents (IVP) High in sodium Difficulty excreting due to ↓ glomerular

filtration rate◦Preoperative concerns

Administration of adequate IV fluids before surgery Improves renal blood flow and renal function

Minimum urine output should be 50mL/hour High risk for hypothermia in the operating room

Cool fluids, cool environment, etc.

◦Diminished respiratory function interferes with elimination of carbon dioxide Leads to respiratory acidosis Achieve maximum ventilation through suction,

turning, activity

Fluid Balance in the Elderly Fluid Balance in the Elderly (cont’d)(cont’d)Special problems (cont’d) --

◦Preparation for diagnostic tests Bowel cleansing NPO status

Diet and Lifestyle Factors Diet and Lifestyle Factors Affecting Fluid BalanceAffecting Fluid Balance

Difficulty chewing or swallowing◦Inadequate food/fluid intake

Malnutrition/starvation◦Low protein intake; altered fluid volume status

Excessive alcohol consumption◦Liver damage leading to fluid/electrolyte imbalance

Environmental Factors & Environmental Factors & Fluid BalanceFluid BalanceVigorous exercise increases

metabolism, ventilation, sweating◦Increases fluid demand◦Potential lack of fluid intake

Heat injuries◦Exposure to hot, humid environments increases sweat production to as much as 2L/hour

◦Body fluid weight loss >7% is associated with failure of body cooling mechanisms

Medications Altering Fluid BalanceMedications Altering Fluid BalanceDiuretics = excessive fluid lossChemotherapy = nausea/vomiting,

poor oral intake

Fluid Needs for Those with Fluid Needs for Those with Acute IllnessAcute IllnessSurgery can result in blood and fluid

lossGastroenteritis causes nausea/vomiting and diarrhea

Nasogastric suctioning leads to fluid and electrolyte losses

Brain injury from stroke, trauma, or tumor◦Causes cerebral edema, which may put pressure on the hypothalamus and/or pituitary

◦Alters ADH SIADH Diabetes insipidus Excessive or inadequate ADH production/release

Burns

BurnsBurnsFactors affecting fluid loss --◦Surface area

The larger the burn, the greater the fluid loss

◦Extent, depth, and cause of the burn◦Age of the client◦Pre-existing medical conditions

Diagnostic findings –◦WBC reflects immune function◦Hgb/HCT increases due to fluid loss◦Glucose increases due to stress response

◦Sodium decreases (trapped in third spaces)

◦Potassium increases due to tissue destruction

Burns (cont’d)Burns (cont’d)Third space fluid shifts --◦Phase I → plasma to interstitial space

Occurs rapidly (before the end of the 1st hour)

Plasma leaks out through damaged capillaries at the burn area Edema forms Hypovolemia occurs (may lead to acute tubular necrosis)

Decreased renal perfusion Low urine output Hyperkalemia

Fluid accumulation phase occurs during the first 36 to 48 hours Capillaries have recovered by the end of this time

Burns (cont’d)Burns (cont’d)Third space fluid shifts (cont’d) --◦Phase II → fluid remobilization

Begins approximately 48 hours after burn occurs

Edema at burn site resolving Hypervolemia due to fluid shifting back

into the intravascular compartment Metabolic acidosis due to accumulation

of acids released from the injured tissue Respiratory acidosis due to inhalation

injury that interferes with gas exchange

Nursing assessment –◦Rule of Nines◦Lund-Browder Chart

LUND-BROWDER CHARTRelative Percentage of Body Surface Area Affected by Growth

Age in years 0 1 5 10 15 Adult A-head (back or front) 9½ 8½ 6½ 5½ 4½ 3½ B-1 thigh (back or front) 2¾ 3¼ 4 4¼ 4½ 4¾ C-1 leg (back or front) 2½ 2½ 2¾ 3 3¼ 3½

Burns (cont’d)Burns (cont’d)Treatment --◦Aggressive fluid replacement is necessary to prevent complications Need to induce urine output at 1cc/kg/hour

◦Use large bore IV in a peripheral vein in an area that is unaffected by burn injury 2nd choice = central line in an unaffected area 3rd choice = peripheral line in an affected area Last choice = central line in an affected area

◦Monitor for IV-related sepsis◦Foley catheter placement◦Early burn wound excision◦Timely initiation of enteral nutrition

Fluid Needs for Those with Fluid Needs for Those with Chronic IllnessChronic Illness

Liver disease decreases production of albumin, which affects the ability to maintain vascular volume

Renal disease limits the ability to regulate fluid or electrolytes via urine output

Diabetes increases the risk for hyperglycemia and hypertonic dehydration

Cancer treatment (chemotherapy) induces nausea/vomiting with fluid loss and decreased intake

Diabetic Ketoacidosis Diabetic Ketoacidosis (DKA)(DKA)Occurs in 2 – 5% of people with Type

I Diabetes MellitusMost often begins with an infectionCan also be seen in Type II Diabetes Mellitus if illness or stress exceeds the ability of the pancreas to secrete adequate insulin

Death occurs in 1 – 10% of cases even with appropriate treatment

Onset is sudden (less than 24 hours)Diagnostic criteria includes hyperglycemia, hyperketonemia, and metabolic acidosis

DKA (cont’d)DKA (cont’d)Pathophysiology --Body is unable to utilize carbohydrates◦Not enough insulin to transport glucose into the cells

◦Body resorts to utilizing fats for energyResults in ketones in the blood and urine◦Leads to acidosis

Etiology –Inadequate medication/insulinInfectionChange in diet, exerciseOther stressors

DKA (cont’d)DKA (cont’d)Clinical manifestations --Rapid, weak pulseKussmaul’s respirations“Fruity” breathNausea/vomiting, abdominal painDehydrationPolyuria, polydipsiaNormal/low temperature in the presence of infection

Weight lossDry skinSunken eyes, soft eyeballsLethargy, coma

DKA (cont’d)DKA (cont’d)Lab findings –Serum glucose = >300mg/dLSerum ketones = positiveUrine ketones = positiveSerum pH = <7.35Serum HCO3 = <15mEq/LSerum potassium = ↑ with acidosis, ↓ with dehydration

BUN = >20mg/dL due to dehydration

Creatinine + >1.5mg/dL due to dehydration

DKA (cont’d)DKA (cont’d)Emergency management –Establish a patent airwayAdminister oxygen and NaHCO3 if ↓ pHPlace IV with large bore catheterAdminister NS per IV◦1L/hour for first 2-3 hours to stabilize blood pressure and ensure adequate urine output

IV fluid changed to D5 ½ NS when serum glucose reaches 250mg/dL

Urine output will decrease as osmotic diuresis effect of hyperglycemia is reduced

Careful monitoring of potassium level

DKA (cont’d)DKA (cont’d)Ongoing monitoring –Monitor blood glucoseAssess for hypokalemia◦Potassium will reenter the cell with insulin administration

Will need to decrease infusion rate when blood glucose is ≤300mg/dL

Anticipate order of D5W when blood glucose level is 250mg/dL◦Reduces risk of hypoglycemia

Assess for signs and symptoms of hypoglycemia◦Anxiety, behavior changes, confusion, headache, slurred speech

◦Blurred vision, hunger, cold sweats, tachycardia

Hyperglycemic-Hyperglycemic-Hyperosmolar Nonketotic Hyperosmolar Nonketotic

Syndrome (HHNS)Syndrome (HHNS)HHNS is a medical emergency with a high mortality rate

Hyperosmolar state caused by hyperglycemia◦Blood glucose = 800mg/dL◦Serum osmolarity = possibly >350mOsm/L

Exhibits no ketosisMay be seen in Type II Diabetes Mellitus

Often related to impaired thirst sensation or functional inability to replace fluids

HHNS (cont’d)HHNS (cont’d)Rapid progression◦Hours to days

Clinical manifestations –◦Polyuria, polydipsia, dehydration, aphasia◦Altered mental status (lethargy → coma)◦Postural hypotension, tachycardia◦Seizures, tremors, nystagmus, hyperreflexia

Treatment –◦Management is similar to DKA except HHNS requires greater fluid replacement as patient can have a 9-12L fluid deficit

◦Administer regular insulin at 0.1U/kg/hour until glucose level drops to 250mg/dL

HHNS (cont’d)HHNS (cont’d)Treatment (cont’d) –◦Fluid resuscitation

Administer 1-2L NS for 1st hour Follow with 1L/hour for the next several

hours Hyperglycemia will decrease with fluid

resuscitation May need to give low-dose insulin if

patient is hyperkalemic, acidotic, or in renal failure

◦Support airway, breathing, circulation

Differences between Diabetic Differences between Diabetic Ketoacidosis (DKA) and Ketoacidosis (DKA) and

Hyperglycemic-Hyperosmolar Hyperglycemic-Hyperosmolar Nonketotic Syndrome (HHNS)Nonketotic Syndrome (HHNS)

DKA HHNSOnset Sudden GradualSerum Glucose >300 >800Serum Ketones Yes NoSerum pH <7.35 >7.4Serum HCO3 <15 mEq/L >20

mEq/LSerum K Normal Normal

↑ with acidosis ↓ with dehydration

Serum Osmolarity Variable >350 mOsm/L

BUN ↑ ~ dehydration ↑Creatinine ↑ ~ dehydration ↑Urine Ketones Positive Negative

Gastrointestinal Gastrointestinal DisturbancesDisturbances

The stomach is acidic◦pH = 1.0 – 3.5

Fluid volume deficit possible◦Prolonged vomiting◦Gastric suction

Monitor for hypokalemia◦Potassium is present in gastric juices

Monitor for hyponatremia due to prolonged loss of sodium◦Suctioning◦Nasogastric irrigation with plain water

Fluid Volume DeficitFluid Volume DeficitTypes of fluid volume deficit –◦Isotonic fluid loss◦Hypertonic dehydration◦Third spacing

Isotonic Fluid LossIsotonic Fluid LossFluid and solute are lost equally◦Serum osmolarity remains normal

Intracellular water is not disturbedFluid loss is extracellular fluid◦Can quickly lead to shock◦Requires extracellular fluid replacement◦Emphasis is on increasing vascular volume

Isotonic Fluid Loss (cont’d)Isotonic Fluid Loss (cont’d)Causes –◦Hemorrhage

Loss of fluid, electrolytes, proteins, and blood cells results in inadequate vascular volume

◦Gastrointestinal losses Vomiting, NG suctioning, diarrhea, drainage

from fistulas/tubes

◦Fever, environmental heat, diaphoresis Profuse sweating causes water and sodium

loss through the skin

◦Burns Damages skin capillary membranes Allows fluid, electrolytes, and proteins to

escape into burned tissue area, leaving less vascular volume

Isotonic Fluid Loss (cont’d)Isotonic Fluid Loss (cont’d)Causes (cont’d) –◦Diuretics can cause excessive loss of fluid and electrolytes

◦Third spacing Fluid moves from the vascular space into

extracellular spaces

Treatment –◦Expand extracellular volume with isotonic IV fluids Increases circulating blood volume Restores renal perfusion

◦Provide blood transfusion for hypovolemia caused by hemorrhage

Isotonic Fluid Loss (cont’d)Isotonic Fluid Loss (cont’d)Treatment (cont’d) –◦Administer 1–2L bolus of isotonic fluid for adults Infuse in 30 minutes or less

◦Administer up to an additional 2–3L Improves urine output, blood pressure,

heart rate, and mental status

◦Infuse 20–30 mL/kg bolus of isotonic fluid for infants/young children to improve urine output, heart rate, respiratory rate, and mental status

Hypertonic DehydrationHypertonic DehydrationMore water is lost than solute◦ Creates a solute excess

Primarily sodium◦ Results in fluid volume deficit

Solute can also be gained in excess of water◦ Creates a similar imbalance◦ Most common with sodium or glucose

Serum osmolarity becomes elevated◦ Results in hypertonic extracellular

fluid◦ Pulls fluids into the vessels from the

cells by osmosis◦ Causes cells to shrink and become

dehydrated

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Causes –

Inadequate fluid intake◦Inability to respond to thirst ◦May occur due to age (infants or the elderly), immobility, nausea, anorexia, dysphagia, or being NPO without fluid replacement

Severe or prolonged isotonic fluid losses◦Extracellular fluid becomes hypertonic and draws water from the cells Compensatory mechanisms become exhausted Conservation of water via the kidneys depleted Results in cellular dehydration

◦May occur with nausea/vomiting, diarrhea Loss of more water than solute

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Causes (cont’d) –

Watery diarrhea◦Loss of more water than electrolytes

Diabetes insipidus◦Leads to massive, uncontrolled diuresis of dilute urine As much as 30L/day Can quickly lead to shock and death

◦Usually caused by a brain injury Damages/puts pressure on the

hypothalamus or pituitary gland◦Need to administer parenteral vasopressin

◦In a fluid volume deficit related to diabetes insipidus, urine will be pale, dilute, and high in volume

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Causes (cont’d) –

Increased solute intake◦Excessive salt, sugar, or protein intake without a proportional intake of water

◦Increases plasma osmolarity◦Water is pulled from the cells, leading to cellular dehydration

◦Results in osmotic diuresis, which makes cellular dehydration worse Dangerous for patients with heart or

kidney problems

Conditions that lead to hypertonic dehydration –

Highly concentrated enteral or parenteral feedings

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)

Conditions that lead to hypertonic dehydration (cont’d) –

Improperly prepared infant formulas that are too concentrated

Hyperglycemia and/or diabetic ketoacidosis◦Excessive glucose and ketones in the blood

Increased sodium ingestion◦Ingestion of excessive amounts of seawater

◦Taking salt water tabletsExcessive use of osmotic diuretics

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Clinical manifestations –

Thirst◦Early sign of dehydration◦Unreliable in the elderly and the very young

Concentrated urine◦Dark in color◦High specific gravity (normal is 1.010 – 1.030)

Low urine volume◦Normal output for adults is 30mL/hour

Dry mucus membranes◦When assessing mucus membranes, remember that environmental conditions can also cause dry lips


Clinical manifestations (cont’d) –Dry skin◦Decreased turgor◦Decreased elasticity◦Tenting

Tissues stick together from interstitial fluid loss Unreliable in the elderly due to decreased

elastin Test on sternum, forehead, inner thigh, top of hip instead of arms and legs

Check infant skin over abdomen or inner thighs

Dry tongue with longitudinal furrowsDecreased tearing with dry conjunctiva

Sunken eyes


Clinical manifestations (cont’d) –Sunken or depressed fontanel in infants less than 1 year

Flat neck veins and poor peripheral vein filling◦Jugular veins are nondistended even with the head of bed at <45 degrees

◦When the hand is placed lower than the heart, the hand veins normally distend in 3 – 5 seconds

Tachypnea

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Clinical manifestations (cont’d) –

Low grade fever◦May be higher in severe dehydration

Mental status changes◦Often the first sign noticed in the elderly

◦Irritability, restlessness◦Drowsiness, lethargy◦Confusion

Decreased cardiac output◦Tachycardia (early sign in infants)◦Weak, thready pulse◦Cool extremities with delayed capillary refill


Postural hypotension when rising from lying to standing position◦Pulse increased by greater than 10-15 bpm

◦Fall in systolic blood pressure by greater than 10-15 mmHg

◦The greater the fall in blood pressure or rise in heart rate, the greater the fluid volume deficit

◦Weakness, dizziness, light-headedness, syncope

Frank hypotension◦Exists even when lying down◦Late sign in infants and young children


Acute weight loss◦2% body weight loss

Mild fluid deficit (thirst) 1 – 2 L fluid loss in an adult

◦5% body weight loss Moderate fluid deficit Signs and symptoms of dehydration

appear 3 – 5 L fluid loss in an adult

◦8% body weight loss Severe fluid deficit Frank hypotension 5 – 10 L fluid loss in an adult

◦>15% body weight loss Fatal >10L fluid loss in an adult

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Parenteral therapy –

Hypovolemia and impending shock◦Isotonic fluids administered for adequate circulation and renal perfusion

◦Hypotonic solutions administered to correct cellular dehydration Given slowly to prevent cerebral edema due to

sensitivity of brain cells to hypotonicity

Hypervolemia◦Resulting from excessive sodium intake◦Administer a diuretic with hypotonic fluid to provide free water to cells while preventing vascular volume overload

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Nursing interventions --

Monitor vital signs for changes in heart rate, blood pressure, and respiratory rate

Assess mental status◦Lack of improvement (or worsening) could indicate the infusion of hypotonic fluids is too rapid

Monitor urine output and concentration

Monitor IV rate◦Watch for fluid volume overload

Monitor I&OMonitor weight daily

Hypertonic Dehydration Hypertonic Dehydration (cont’d)(cont’d)Lab findings –

Hemoconcentration◦Plasma becomes concentrated to the red blood cells and urea particles

◦BUN would be highHigh urine specific gravity (>1.030)◦Kidneys conserve water while continuing to excrete solute

◦In cases of diabetes insipidus, specific gravity would be low (<1.010)

Increased plasma concentration◦Elevated serum osmolality (>300mOsm/kg)

◦Elevated serum potassium (>150mEq/L)

◦Elevated serum glucose (>120mg/dL)

Third SpacingThird SpacingThird spaces are extracellular body

spaces where fluid can accumulateThis accumulated fluid is useless

to the body◦Unavailable for use as reserve fluid◦Unable to transport nutrients

Common locations for third space fluid to accumulate –◦Tissue spaces (edema)◦Abdomen (ascites)◦Pleural spaces (pleural effusion)◦Pericardial space (pericardial effusion)

Third Spacing (cont’d)Third Spacing (cont’d)Causes –Injury or inflammation◦Increased capillary permeability allows fluid, electrolytes, and proteins to leak from the vessels Massive trauma Crush injuries Burns Sepsis Cancer Intestinal obstruction Abdominal surgery

Third Spacing (cont’d)Third Spacing (cont’d)Causes (cont’d) –Malnutrition or liver dysfunction◦Prevents liver from producing albumin, which lowers capillary oncotic pressure Starvation Cirrhosis Chronic alcoholism

High vascular hydrostatic pressure◦Pushes abnormal volumes of fluid from the vessels Heart failure Renal failure Other vascular fluid overload

Third Spacing (cont’d)Third Spacing (cont’d)Treatment –Osmotic diuretics are used to mobilize some of the fluid back into the blood vessels for elimination by the kidneys

Fluid Volume ExcessFluid Volume ExcessTypes of fluid volume excess –◦Isotonic fluid excess

Hypervolemia Edema

◦Hypotonic fluid excess Water intoxication

Risk factors that predispose individuals to fluid volume excess --◦Individuals of certain age

Elderly (due to ↓ heart and kidney function) Children < age 2 (due to immature kidneys) Children ages 2 – 12 years (due to unstable

regulatory responses)

Fluid Volume Excess (cont’d)Fluid Volume Excess (cont’d)Risk factors (cont’d) –◦Acute illness

Stimulates the stress response, which releases cortisol, ADH, and aldosterone → promotes water and sodium retention

◦Chronic illness Cardiovascular disease causes sodium

and water retention Reduces the pumping strength of the heart Reduces blood flow to the kidneys

Renal disease leads to abnormal retention of water, sodium, and potassium

◦Medications Long-term glucocorticoid therapy Drugs that act to retain sodium and fluids

Fluid Volume Excess (cont’d)Fluid Volume Excess (cont’d)Risk factors (cont’d) –◦Patients receiving IV fluids

Lab findings –Decreased hematocrit and BUN due to hemodilution◦Returns to normal once excess fluid is removed

Serum osmolarity is lowSerum sodium is very lowChest x-ray may show pleural effusionLow PO2 and PCO2Decreased pH due to respiratory acidosis (results from pulmonary edema)

Fluid Volume Excess (cont’d)Fluid Volume Excess (cont’d)Clinical manifestations –◦Peripheral edema

Legs, ankles, feet, and hands in ambulatory individuals

Sacrum and back in bedridden clients

◦Edema in the legs and feet Indicates local obstruction of veins Edematous skin is often tight and shiny

due to decreased circulation in swollen tissue

◦Puffiness in the face and around the eyes (periorbital edema) Associated with heart or kidney problems

◦Tense or bulging fontanels in children less than 1 year of age

Fluid Volume Excess (cont’d)Fluid Volume Excess (cont’d)Clinical manifestations (cont’d) –◦Pitting edema◦High central venous pressure

Distended neck veins when HOB is elevated Delayed hand vein emptying when hand is

raised above the heart for 3 – 5 seconds

◦Venous congestion Hepatomegaly Splenomegaly

◦Decreased urine output if cardiac or renal function is impaired

◦Weight gain of 3lbs over 2 – 5 days◦Full/bounding pulse, warm extremities

Fluid Volume Excess (cont’d)Fluid Volume Excess (cont’d)Treatment –◦Restrict fluid intake to 1,000 – 1,500mL/day

◦Maintain sodium restriction◦Maintain IV access◦Administer diuretics◦Increase protein intake to increase capillary oncotic pressure to pull fluid out of the tissues

◦Monitor respiratory status◦Monitor venous engorgement◦Monitor I&O, daily weight◦Assess for edema◦Assess neurologic status◦Monitor labs (BUN, HCT, sodium, ABGs, K+)

Isotonic Fluid ExcessIsotonic Fluid ExcessHypervolemia = gain of fluid and

solute (sodium) in proportional amounts◦Overall gain in the extracellular fluid without a change in serum osmolarity

Edema = excess tissue (interstitial) fluid throughout the body or specific to a body tissue or organ

Causes --◦Renal failure

Decreased excretion of water and sodium

◦Rapid infusion of isotonic fluid Exceeds the ability to compensate by the

heart and kidneys

Isotonic Fluid Excess (cont’d)Isotonic Fluid Excess (cont’d)Causes (cont’d) –◦Heart failure

Venous congestion Decreased renal blood flow leading to

decreased renal excretion of fluid and sodium

◦High corticosteroid levels, which results in sodium and water retention Therapy Stress response

◦High aldosterone levels, which results in sodium and water retention Stress response Adrenal dysfunction

Hypotonic Fluid ExcessHypotonic Fluid ExcessGain of more fluid than solute (sodium)◦Creates fluid volume excess◦Results in a deficit of sodium◦Serum osmolarity decreases

Causes hypotonic extracellular fluid that gets pulled into the cells

Cells swell, and cerebral edema occurs

Causes –◦Frequent use of plain water enemas◦Multiple nasogastric tube or bladder irrigations with plain water

◦Infusing hypotonic solutions too rapidly◦Use of improperly prepared infant formula

Hypotonic Fluid Excess Hypotonic Fluid Excess (cont’d)(cont’d)Causes (cont’d) –

◦Increased release of ADH SIADH causes the kidneys to retain large

amounts of water without retaining sodium Creates hypotonic extracellular fluid, which is drawn into the cells

Highly concentrated urine with low urine volume

Stress Surgery, anesthesia Opioid analgesics, pain Tumors of the lung or brain

◦Psychogenic polydipsia Compulsive drinking of excessive amounts

of water associated with psychiatric disorders (i.e. some types of schizophrenia)

Hypotonic Fluid Excess Hypotonic Fluid Excess (cont’d)(cont’d)Causes (cont’d) –

◦Severe or prolonged isotonic fluid volume excess Compensated by increased urine output Clients with heart failure, renal failure, and

diabetes are sensitive to excess fluid administration

Capillary Fluid MovementCapillary Fluid MovementHydrostatic pressure = the pushing force of a fluid against the walls of the space it occupies◦Generated by the heart’s pumping action

◦Varies within the vascular system

Capillary Fluid Movement Capillary Fluid Movement (cont’d)(cont’d)Oncotic pressure = the pulling force

exerted by colloids in a solution◦Albumin is a pulling force for water

Maintains normal serum oncotic pressure Maintains adequate vascular fluid volume

Causes of low capillary oncotic pressure --◦Injury or inflammation (trauma, burns, sepsis) Increases capillary permeability Allows fluids and proteins to leak from the vessels

◦Malnutrition or liver dysfunction (starvation, cirrhosis, chronic alcoholism) Prevents liver from producing albumin ↓ capillary oncotic pressure; fluid remains in

vessels

Capillary Fluid Movement Capillary Fluid Movement (cont’d)(cont’d)Starling’s Law

◦Filtration = movement of fluid into or out of the capillary, determined by the pushing and pulling forces

◦At the arterial end of the capillary, capillary hydrostatic pressure exceeds capillary oncotic pressure Fluid movement is from the capillary into

the tissue Carries nutrients to the tissues

◦At the venous end of the capillary, capillary hydrostatic pressure is less than capillary oncotic pressure Fluid movement is into the capillary from

the tissue Carries wastes away from the tissues

EdemaEdemaEdema = soft tissue swelling due to expansion of the interstitial volume◦Can be localized or generalized◦Fluid moves from the capillaries into the interstitial space and back again, carrying wastes with it

Increased capillary hydrostatic pressure◦Forces more fluid out of the arterial end of the capillary

◦Draws less fluid back into the venous end of the capillary

◦Results in edema as fluid accumulates in the tissues

Edema (cont’d)Edema (cont’d)Decreased capillary oncotic pressure◦Disrupts normal movement of fluid into and out of the capillaries

◦Weaker pulling pressure allows more fluid to be pushed out of the arterial end of the capillary

◦Unable to draw adequate amount of fluid back into the venous end of the capillary

◦Results in edemaCauses◦Hypertension◦Hypervolemia, lymphedema◦Renal failure

Edema (cont’d)Edema (cont’d)Lymphedema occurs when a blockage in the lymphatic system prevents lymph fluid from draining adequately; as the fluid accumulates, swelling continues◦Lymphatic obstruction◦Surgical removal of lymph nodes

Edema (cont’d)Edema (cont’d)Renal failure causes decreased renal perfusion leading to excess aldosterone in the blood◦Causes water retention that elevates the blood pressure

◦Increases hydrostatic pressure within the capillaries, which forces more fluid into the tissues

◦Results in edema

Congestive Heart Failure Congestive Heart Failure (CHF)(CHF)Inability of the heart to pump

enough blood to meet the metabolic needs of the tissues of the body

Associated with hypertension, myocardial infarction (MI), valvular disease

Left ventricular failure seen with pulmonary edema

Right ventricular failure seen with edema in the lower extremities

Failure tends to occur in both ventricles, so client will present with both peripheral and pulmonary edema

CHF (cont’d)CHF (cont’d)Fluid and electrolyte imbalances seen with CHF –◦Fluid volume excess

Decreased renal blood flow associated with decreased cardiac output

◦Hyponatremia ADH causes greater retention of water,

diluting serum sodium level◦Hypokalemia

Caused by diuretics, vomiting, and diarrhea

◦Respiratory acidosis Pulmonary congestion interferes with

carbon dioxide elimination from the lungs◦Metabolic acidosis

Anoxic tissue releases lactic acid

CHF (cont’d)CHF (cont’d)Fluid and electrolyte imbalances (cont’d) --◦Edema

Shift of intravascular fluid into interstitial tissue due to increase in hydrostatic pressure from excessive venous blood volume

Signs and symptoms –◦Fatigue due to decreased cardiac output◦Dyspnea

Cardiac output is inadequate to provide for body’s oxygen requirements

Paroxysmal nocturnal dyspnea occurs when client is in a recumbent position because edema fluid from the extremities returns to the bloodstream, increasing cardiac preload

◦Decreased urine output due to secretion of aldosterone and ADH

CHF (cont’d)CHF (cont’d)Signs and symptoms (cont’d) –◦Cough◦Tachycardia◦Peripheral edema◦Pulmonary edema

Increased pulmonary venous pressure forces serum and blood cells in the alveoli

Severe dyspnea, coughing, pink frothy sputum

◦Distention of the peripheral veins from elevated venous pressure Visible in the hands, face, and neck

◦Orthopnea Increased interstitial edema increases the

work of breathing Upright position fosters air exchange

CHF (cont’d)CHF (cont’d)Signs and symptoms (cont’d) –◦Nocturia

Oxygen demand reduced at night, decreasing renal constriction and increasing glomerular filtration rate

◦Cardiomegaly Hypertrophy of the myocardium that

helps to maintain stroke volumeNursing interventions –◦Lessen cardiac preload and afterload

Give diuretics per IV◦Administer ACE inhibitors (arterial vasodilators)

◦Restrict fluids◦Monitor I&O

Pulmonary EdemaPulmonary EdemaPulmonary edema is a medical emergency◦Place patient in high Fowler’s position◦Administer oxygen◦Administer IV morphine

Reduces preload through peripheral dilation Reduces afterload through decreased blood

pressure Reduces anxiety

Signs and symptoms –◦Tachypnea, dyspnea, labored breathing, cough, moist rales, decreased oxygen saturation

◦Third spacing as fluids are forced out of the vessels and into spaces that normally do not contain much fluid (ascites, pleural effusion)

◦Acute, rapid weight gain

Basic Classifications of Basic Classifications of Infusates Infusates

1. Crystalloids2. Colloids3. Hydrating solutions4. Hypertonic-hyperosmolar

preparations5. Blood or blood componentsCrystalloids -- Capable of crystallization Forms a solution Can diffuse through membranes Includes electrolyte solutions that

may be isotonic, hypotonic, and hypertonic

Classifications of Infusates Classifications of Infusates (cont’d)(cont’d)

Colloids –Cannot form a solution (does not dissolve)

Cloudy in appearanceRaises osmotic pressurePlasma or volume expanderTypes of colloids --◦Albumin◦Dextran◦Plasmanate◦Hetastarch◦Artificial blood substitute


Hydrating Solutions (cont’d) –Supplements calorie intakeSupplies nutrientsProvides free water◦Maintenance◦Rehydration

Promotes effective renal outputFrequently used hydrating solutions◦Dextrose 2½% in 0.45% saline◦Dextrose 5% in water (D5W)◦Dextrose 5% in 0.45% saline◦Dextrose 5% in 0.2% saline◦Sodium chloride 0.45%


Hydrating Solutions (cont’d) –Electrolytes in IV solutions are measured in mEq/L

Milliequivalents measure how many chemically active ions are present in a solution

Sodium chloride contains 154 mEq/L of sodium and 154 mEq/L of chloride, which equals 308 mOsm/L

0.45% NaCl (1/2 strength saline) has 77 mEq/L of sodium and 77 mEq/L of chloride, which equals 154 mOsm/L


Dextrose Solutions –Manufactured as a percentage of the concentration in water or sodium chloride

Expressed as the number of grams of solute per 100mL of solvent

5% dextrose in water solution contains 5g of dextrose in 100mL of water

Isotonic InfusionsIsotonic InfusionsD5W◦Osmolarity = 252.52 mOsm/L◦Best solution for hydration

Isotonic in bag Hypotonic once dextrose metabolized

◦Does not contain electrolytes◦Not given to patient with increased intracranial pressure

◦ADH secretion is increased as a stress response to surgery Use cautiously in early post-operative

period to prevent water intoxication◦Hypokalemia can occur due to cellular use of glucose Potassium shifts from the extracellular

fluid to the intracellular fluid

Isotonic Infusions (cont’d)Isotonic Infusions (cont’d)D5W (cont’d) --◦Use cautiously in patients with signs of fluid overload and congestive heart failure Dehydration with rapid infusion due to

osmotic diuresis◦May alter insulin/oral hypoglycemic needs in diabetics Contraindicated in diabetic coma

◦Should not be used in patients with allergies to corn and corn products

◦Medication incompatibilities –Ampicillin DiazepamErythromycin Fat emulsionsPhenytoin sodium

ProcainamideSodium bicarbonate Warfarin

sodium Whole blood Vitamin B12

Isotonic Infusions (cont’d)Isotonic Infusions (cont’d)0.9% normal saline (NS)◦Osmolarity = 308 mOsm/L◦Only infusate compatible with a blood infusion

◦Maintains patency of heparin locks◦Used as a diluent for medications◦Replaces extracellular fluid losses by expanding intravascular space

◦Corrects hyponatremia◦Used to treat hypovolemia◦Can cause intravascular overload

Monitor I&O

◦Can cause hypokalemia Saline promotes potassium excretion

Isotonic Infusions (cont’d)Isotonic Infusions (cont’d)NS (cont’d) –◦Can cause hypernatremia

Sodium may be retained in intraoperative and early post-operative situations

Excessive sodium retention when used with glucocorticoids

Contraindicated in patients with edema and sodium retention

◦Does not provide free water or calories

◦Used with caution in certain patients Decreased renal function Altered circulatory function Elderly

Isotonic Infusions (cont’d)Isotonic Infusions (cont’d)NS (cont’d) –◦Medication incompatibilities –

Amphotericin B (antifungal)Chlordiazepoxide HCl (Librium)DiazepamFat emulsionsLevarterenol (norepinephrine)MannitolMethylprednisolone sodium

succinate(Solu-Medrol)

Phenytoin sodium

IV Fluid RemindersIV Fluid RemindersThe body is in a state of homeostasis when the serum osmolarity is the same as other body fluids◦Approximately 280 – 300 mOsm/L

To change the osmolarity, glucose and/or electrolytes must be added to the solvent◦Increases the total number of particles in the solution

◦Increases osmotic pressure

LPN-C Unit Four Rationale for Intravenous Therapy.

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Transcript of LPN-C Unit Four Rationale for Intravenous Therapy.