NCLEX: Fluids and electrolytes

Fluids and electrolytes: A look at fluids

Focus topic: Fluids and electrolytes

Where would we be without body fluids? Nowhere. Fluids are vital to all forms of life. They help maintain body temperature and cell shape, and they help transport nutrients, gases, and wastes. Let’s take a close look at fluids and the way the body balances them.

Fluids and electrolytes: Making gains  losses

Focus topic: Fluids and electrolytes

The skin, the lungs, the kidneys — just about all major organs — work together to maintain a proper balance of fluid. To maintain proper balance, the amount of fluid gained throughout the day must equal the amount lost. Some of those losses can be measured (sensible losses); others can’t (insensible losses).

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Fluids and electrolytes: Following the fluid

Focus topic: Fluids and electrolytes

The body holds fluid in two basic areas, or compartments — inside the cells and outside the cells. Fluid found inside the cells is called intracellular fluid (ICF); fluid found outside them, extracellular fluid (ECF). Capillary walls and cell membranes separate the intracellular and extracellular compartments. To maintain proper fluid balance, the distribution of fluid between the two compartments must remain relatively constant. ECF can be broken down further into interstitial fluid, which surrounds the cells, and intravascular fluid, or plasma, which is the liquid portion of blood. In an adult, interstitial fluid accounts for about 75% of the ECF. Plasma accounts for the remaining 25%.

Fluids and electrolytes: A look at electrolytes

Focus topic: Fluids and electrolytes

Electrolytes work with fluids to maintain health and well-being. They’re found in various concentrations, depending on whether they’re inside or outside the cells. Electrolytes are crucial for nearly all cellular reactions and functions. Let’s take a look at what electrolytes are, how they function, and what upsets their balance.

Fluids and electrolytes

Fluids and electrolytes: Anions and cations

Focus topic: Fluids and electrolytes

Electrolytes are substances that, when in solution, separate (or dissociate) into electrically charged particles called ions. Some ions are positively charged; others, negatively charged. Anions are electrolytes that generate a negative charge; cations are electrolytes that produce a positive charge. An electrical charge makes cells function normally. Chloride, phosphorus, and bicarbonate are anions; sodium, potassium, calcium, and magnesium are cations.

Fluids and electrolytes: Electrolyte balance

Focus topic: Fluids and electrolytes

Sodium and chloride, the major electrolytes in ECF, exert most of their effects outside the cell. Calcium and bicarbonate are two other electrolytes found in ECF. Potassium, phosphate, and magnesium are among the most abundant electrolytes inside the cell. Although electrolytes are concentrated in one compartment or another, they aren’t locked or frozen in these areas. Like fluids, electrolytes move about trying to maintain balance and electroneutrality.

Fluids and electrolytes: Fluid and electrolyte movement

Focus topic: Fluids and electrolytes

Just as the heart beats constantly, fluids and solutes move constantly within the body. That movement allows the body to maintain homeostasis, the constant state of balance the body seeks.

Fluids and electrolytes: Compartmentalize

Focus topic: Fluids and electrolytes

Solutes within the body’s intracellular, interstitial, and intravascular compartments move through the membranes separating those compartments in different ways. The membranes are semipermeable, meaning that they allow some solutes to pass through, but not others. Fluids and solutes move through membranes at the cellular level by diffusion, active transport, and osmosis and through the capillaries by capillary filtration and reabsorption.

Fluids and electrolytes: Diffusion goes with the flow

Focus topic: Fluids and electrolytes

In diffusion, solutes move from an area of higher concentration to an area of lower concentration, which eventually results in an equal distribution of solutes within the two areas. Diffusion is a form of passive transport because no energy is required to make it happen; it just happens. Like fish swimming downstream, the solutes simply go with the flow.

Fluids and electrolytes

Fluids and electrolytes: Actively transporting

Focus topic: Fluids and electrolytes

In active transport, solutes move from an area of lower concentration to an area of higher concentration. Like fish swimming upstream, active transport requires energy to make it happen. The energy required for a solute to move against a concentration gradient comes from a substance called adenosine triphosphate (ATP). Stored in all cells, ATP supplies energy for solute movement in and out of cells. Some solutes, such as sodium and potassium, use ATP to move in and out of cells in a form of active transport called the sodium potassium pump. With the help of this pump, sodium ions move from ICF (an area of lower concentration) to ECF (an area of higher concentration). With potassium, the reverse happens: A large amount of potassium in intracellular fluid causes an electrical potential at the cell membrane. As ions rapidly shift in and out of the cell, electrical impulses are conducted. These impulses are essential for maintaining life. Other solutes that require active transport to cross cell membranes include calcium ions, hydrogen ions, amino acids, and certain sugars.

Fluids and electrolytes: Osmosis lets fluids through

Focus topic: Fluids and electrolytes

Osmosis refers to the passive movement of fluid across a membrane from an area of lower solute concentration and comparatively more fluid into an area of higher solute concentration and comparatively less fluid. Osmosis stops when enough fluid has moved through the membrane to equalize the solute concentration on both sides of the membrane.

Fluids and electrolytes: Boy, these walls are thin

Focus topic: Fluids and electrolytes

Within the vascular system, only capillaries have walls thin enough to let solutes pass through. The movement of fluids and solutes through the walls of the body’s capillaries plays a critical role in fluid balance.

Fluids and electrolytes: The pressure is on

Focus topic: Fluids and electrolytes

The movement of fluids through capillaries — a process called capillary filtration — results from blood pushing against the walls of the capillary. That pressure, called hydrostatic (or “fluid-pushing”) pressure, forces fluids and solutes through the capillary wall. When the hydrostatic pressure inside a capillary is greater than the pressure in the surrounding interstitial space, fluids and solutes inside the capillary are forced out into the interstitial space. When the pressure inside the capillary is less than the pressure outside of it, fluids and solutes move back into the capillary.

Fluids and electrolytes

Fluids and electrolytes: Keeping the fluid in

Focus topic: Fluids and electrolytes

A process called re-absorption prevents too much fluid from leaving the capillaries no matter how much hydro static pressure exists within the capillaries. When fluid filters through a capillary, the protein albumin remains behind in the diminishing volume of water. Albumin is a large molecule that usually can’t pass through capillary membranes. As the concentration of albumin inside a capillary increases, fluid begins to move back into the capillaries through osmosis. Think of albumin as a “water magnet.” The osmotic, or pulling, force of albumin in the intravascular space is referred to as the plasma colloid osmotic pressure. The plasma colloid osmotic pressure in capillaries averages about 25 mm Hg.

Fluids and electrolytes: You’re free to leave the capillaries

Focus topic: Fluids and electrolytes

As long as capillary blood pressure (the hydro static pressure) exceeds plasma colloid osmotic pressure, water and solutes can leave the capillaries and enter the interstitial fluid. When capillary blood pressure falls below plasma colloid osmotic pressure, water and diffusible solutes return to the capillaries. Normally, blood pressure in a capillary exceeds plasma colloid osmotic pressure in the arteriole end and falls below it in the venule end. As a result, capillary filtration occurs along the first half of the vessel; re-absorption, along the second half. As long as capillary blood pressure and plasma albumin levels remain normal, the amount of water that moves into the vessel equals the amount that moves out. Occasionally, extra fluid filters out of the capillary. When that happens, the excess fluid shifts into the lymphatic vessels located just outside the capillaries and eventually returns to the heart for re-circulation.

Fluids and electrolytes: Maintaining the balance

Focus topic: Fluids and electrolytes

Various elements and processes in the body work together to maintain fluid and electrolyte balance. Because one problem can affect the entire fluid-electrolyte maintenance system, it’s important to keep all problems in check. Here’s a closer look at what makes this balancing act possible.

Fluids and electrolytes: Kidneys

Focus topic: Fluids and electrolytes

The kidneys play a vital role in fluid and electrolyte balance. If the kidneys don’t work properly, the body has great difficulty controlling fluid balance. The workhorse of the kidney is the nephron, which forms urine. The body puts the nephrons through their paces every day. A nephron consists of a glomerulus and a tubule. The tubule, sometimes convoluted, ends in a collecting duct. The glomerulus is a cluster of capillaries that filters blood. Like a vascular cradle, Bowman’s capsule surrounds the glomerulus. Capillary blood pressure forces fluid through the capillary walls and into Bowman’s capsule at the proximal end of the tubule. Along the length of the tubule, water and electrolytes are either excreted or retained according to the body’s needs. If the body needs more fluid, for instance, it retains more. If it needs less fluid, less is reabsorbed and more is excreted. Electrolytes, such as sodium and potassium, are either filtered or reabsorbed throughout the same area. The resulting filtrate, which eventually becomes urine, flows through the tubule into the collecting ducts and eventually into the bladder as urine.

Fluids and electrolytes: Super absorbent

Focus topic: Fluids and electrolytes

Nephrons filter about 125 ml of blood every minute, or about 180 L/day. That rate, called the glomerular filtration rate, leads to the production of 1 to 2 L of urine per day. The nephrons reabsorb the remaining 178 L or more of fluid, an amount equivalent to more than 30 oil changes for the family car!

Fluids and electrolytes: A strict conservationist

Focus topic: Fluids and electrolytes

If the body loses even 1% to 2% of its fluid, the kidneys take steps to conserve water. Perhaps the most important step involves reabsorbing more water from the filtrate, which produces a more concentrated urine. The kidneys must continue to excrete at least 20 ml of urine every hour (500 ml/day) to eliminate body wastes. A urine excretion rate that’s less than 20 ml/hour usually indicates renal pathology. The minimum excretion rate varies with age. The kidneys respond to fluid excesses by excreting a more dilute urine, which rids the body of fluid and conserves electrolytes.

Fluids and electrolytes: Other organs and glands

Focus topic: Fluids and electrolytes

In addition to the kidneys, other organs and glands are essential to maintaining fluid and electrolyte balance. Sodium, potassium, chloride, and water are lost from the GI tract; however, electrolytes and fluid are also absorbed from the GI tract.The parathyroid glands also play a role in electrolyte balance, specifically the balance of calcium and phosphorus. The thyroid gland is also involved by balancing the body’s calcium level.

Fluids and electrolytes: Antidiuretic hormone

Focus topic: Fluids and electrolytes

Several hormones affect fluid balance, among them a water retainer called antidiuretic hormone (ADH). (You may also hear this hormone called vasopressin.) The hypothalamus produces ADH, but the posterior pituitary gland stores and releases it. If you can remember what ADH stands for, you can remember its job: to restore blood volume by reducing diuresis and increasing water retention.

Fluids and electrolytes: Sensitive to changes

Focus topic: Fluids and electrolytes

Increased serum osmolality or decreased blood volume can stimulate the release of ADH, which in turn increases the kidneys’ re-absorption of water. The increased re-absorption of water results in more concentrated urine. Likewise, decreased serum osmolality or increased blood volume inhibits the release of ADH and causes less water to be reabsorbed, making the urine less concentrated. The amount of ADH released varies throughout the day, depending on the body’s needs. This up-and-down cycle of ADH release keeps fluid levels in balance all day long. Like a dam on a river, the body holds water when fluid levels drop and releases it when fluid levels rise.

Fluids and electrolytes:  Renin and angiotensin

Focus topic: Fluids and electrolytes

To help maintain a balance of sodium and water in the body as well as to maintain a healthy blood volume and blood pressure, special cells (juxtaglomerular cells) near each glomerulus secrete an enzyme called renin. Through a complex series of steps, renin leads to the production of angio ten sin II, a powerful vasoconstrictor. Angiotensin II causes peripheral vasoconstriction and stimulates the production of aldo sterone. Both actions raise blood pressure. As soon as the blood pressure reaches a normal level, the body stops releasing renin and this feedback cycle of renin to angio tensin to aldosterone stops.

Fluids and electrolytes: The ups and downs of renin

Focus topic: Fluids and electrolytes

The amount of renin secreted depends on blood flow and the level of sodium in the bloodstream. If blood flow to the kidneys diminishes, as happens in a patient who’s hemorrhaging, or if the amount of sodium reaching the glomerulus drops, the juxtaglomerular cells secrete more renin. The renin causes vasoconstriction and a subsequent increase in blood pressure. Conversely, if blood flow to the kidneys increases, or if the amount of sodium reaching the glomerulus increases, juxtaglomerular cells secrete less renin. A drop-off in renin secretion reduces vasoconstriction and helps to normalize blood pressure.

Fluids and electrolytes

Fluids and electrolytes: Aldosterone

Focus topic: Fluids and electrolytes

The hormone aldosterone also plays a role in maintaining blood pressure and fluid and electrolyte balance. Secreted by the adrenal cortex, aldosterone regulates the reabsorption of sodium and water within the nephron.

Fluids and electrolytes: Triggering active transport

Focus topic: Fluids and electrolytes

When blood volume drops, aldosterone initiates the active transport of sodium from the distal tubules and the collecting ducts into the bloodstream. That active transport forces sodium back into the bloodstream. When sodium is forced into the bloodstream, more water is reabsorbed and blood volume expands.

Fluids and electrolytes: Atrial natriuretic peptide

Focus topic: Fluids and electrolytes

The renin-angiotensin system isn’t the only factor at work balancing fluids in the body. A cardiac hormone called atrial natriuretic peptide (ANP) also helps keep that balance. Stored in the cells of the atria, ANP is released when atrial pressure increases. The hormone opposes the renin-angiotensin system by decreasing blood pressure and reducing intravascular blood volume.

This powerful hormone:

  • 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.

Fluids and electrolytes: Thirst

Focus topic: Fluids and electrolytes

Perhaps the simplest mechanism for maintaining fluid balance is the thirst mechanism. Thirst occurs as a result of even small losses of fluid. Losing body fluids or eating highly salty foods leads to an increase in ECF osmolality. This increase leads to the drying of mucous membranes in the mouth, which in turn stimulates the thirst center in the hypothalamus.

Fluids and electrolytes: Quenching that thirst

Focus topic: Fluids and electrolytes

Usually, when a person is thirsty, he drinks fluid. The ingested fluid is absorbed from the intestine into the bloodstream, where it moves freely between fluid compartments. This movement leads to an increase in the amount of fluid in the body and a decrease in the concentration of solutes, thus balancing fluid levels throughout the body.

Fluids and electrolytes: Fluid and electrolyte imbalances

Focus topic: Fluids and electrolytes

Fluid and electrolyte balance is essential for health. Many factors, such as illness, injury, surgery, and treatments, can disrupt a patient’s fluid and electrolyte balance. Even a patient with a minor illness is at risk for fluid and electrolyte imbalance.

Fluids and electrolytes: Dehydration

Focus topic: Fluids and electrolytes

The body loses water all the time. A person responds to the thirst reflex by drinking fluids and eating foods that contain water. However, if water isn’t adequately replaced, the body’s cells can lose water. This causes dehydration, or fluid volume deficit. Dehydration refers to a fluid loss of 1% or more of body weight.

Signs and symptoms of dehydration include:

  • dizziness
  • fatigue
  • weakness
  • irritability
  • delirium
  • extreme thirst
  • dry skin and mucous membranes
  • poor skin turgor
  • ncreased heart rate
  • falling blood pressure
  • decreased urine output
  • seizures and coma (in severe dehydration).

Laboratory values may include a serum sodium level above 150 mEq/L and serum osmolality above 305 mOsm/kg. The patient may also have an increase in his blood urea nitrogen and hemoglobin levels.
Treatment of dehydration involves determining its cause (such as diarrhea or decreased fluid intake) and replacing lost fluids — either orally or I.V. Most patients receive hypotonic, low sodium fluids such as dextrose 5% in water (D5W).

Fluids and electrolytes: Hypervolemia

Focus topic: Fluids and electrolytes

Hypervolemia refers to an excess of isotonic fluid (water and sodium) in ECF. The body has compensatory mechanisms to deal with hypervolemia. However, if these fail, signs and symptoms develop.
Hypervolemia can occur if a person consumes more fluid than needed, if fluid output is impaired, or if too much sodium is retained. Conditions that may lead to hypervolemia include kidney failure, cirrhosis, heart failure, and steroid therapy.

Depending on the severity of hypervolemia, signs and symptoms may include:

  • edema
  • weight gain

Fluids and electrolytes

Fluids and electrolytes

Fluids and electrolytes

Fluids and electrolytes

Fluids and electrolytes

  • distended neck and hand veins
  • heart failure
  • initially, rising blood pressure and cardiac output; later, falling values.

Laboratory tests may reveal a serum sodium level above 135 mEq/L and serum osmolality below 275 mOsm/kg.
Treatment involves determining the cause and treating the underlying condition. Typically, patients require fluid and sodium restrictions and diuretic therapy.

Fluids and electrolytes: Water intoxication

Focus topic: Fluids and electrolytes

Water intoxication occurs when excess fluid moves from the ECF to the ICF. Excessive low-sodium fluid in the ECF is hypotonic to cells; cells are hypertonic to the fluid. As a result, fluids shift into the cells, which have comparatively less fluid and more solutes. The fluid shift, in turn, balances the concentrations of fluid between the two spaces.

Fluids and electrolytes: Acting inappropriately

Focus topic: Fluids and electrolytes

Water intoxication may occur in a patient with syndrome of inappropriate antidiuretic hormone, which can result from central nervous system or pulmonary disorders, head trauma, tumors, or the use of certain drugs. Other causes of water intoxication include:

  • rapid infusion of hypotonic solutions
  • excessive use of tap water as a nasogastric tube irrigant or enema
  • psychogenic polydipsia, a psychological disturbance in which a person drinks large amounts of fluid even when they aren’t needed.

Fluids and electrolytes: I.V. fluid replacement

Focus topic: Fluids and electrolytes

To maintain health, the balance of fluids and electrolytes in the intracellular and extracellular spaces must remain relatively constant. Whenever a person experiences an illness or a condition that prevents normal fluid intake or causes excessive fluid loss, I.V. fluid replacement may be necessary.

Fluids and electrolytes: Quick and predictable

Focus topic: Fluids and electrolytes

I.V. therapy that provides the patient with life-sustaining fluids, electrolytes, and medications offers the advantages of immediate and predictable therapeutic effects. The I.V. route is, therefore, the preferred route — especially for administering fluids, electrolytes, and drugs in an emergency.
This route also allows for fluid intake when a patient has GI malabsorption. I.V. therapy permits accurate dosage titration for analgesics and other medications. Potential disadvantages associated with I.V. therapy include drug and solution incompatibility,adverse reactions, infection, and other complications.

Fluids and electrolytes: Types of solutions

Focus topic: Fluids and electrolytes

Solutions used for I.V. fluid replacement fall into the broad categories of crystalloids (which may be isotonic, hypotonic, or hypertonic) and colloids (which are always hypertonic).

Crystalloids

Crystalloids are solutions with small molecules that flow easily from the bloodstream into cells and tissues. Isotonic crystalloids contain about the same concentration of osmotically active particles as ECF, so fluid doesn’t shift between the extracellular and intracellular areas.
Hypotonic crystalloids are less concentrated than ECF, so they move from the bloodstream into the cell, causing the cell to swell. In contrast, hypertonic crystalloids are more highly concentrated than ECF, so fluid is pulled into the bloodstream from the cell, causing the cell to shrink.

Isotonic solutions

Isotonic solutions, such as D5W, have an osmolality (or concentration) of 275 to 295 mOsm/kg. The dextrose metabolizes quickly, however, acting like a hypotonic solution and leaving water behind. Large amounts of the solution may cause hyperglycemia.

Fluids and electrolytes

Fluids and electrolytes: Did someone ring for more isotonic solutions?

Focus topic: Fluids and electrolytes

Normal saline solution, another isotonic solution, contains only the electrolytes sodium and chloride. Other isotonic fluids are more similar to ECF. For instance, Ringer’s solution contains sodium, potassium, calcium, and chloride. Lactated Ringer’s solution contains those electrolytes plus lactate, which the liver converts to bicarbonate.

Hypotonic fluids
Hypotonic fluids are those fluids that have an osmolality less than 275 mOsm/kg. Examples of hypotonic fluids include:

  • half-normal saline solution
  • 0.33% sodium chloride solution
  • dextrose 2.5% in water.

Fluids and electrolytes: It makes a cell swell

Focus topic: Fluids and electrolytes

Hypotonic solutions should be given cautiously because fluid then moves from the extracellular space into cells, causing them to swell. That fluid shift can cause cardiovascular collapse from vascular fluid depletion. It can also cause increased intracranial pressure (ICP) from fluid shifting into brain cells.
Hypotonic solutions shouldn’t be given to a patient at risk for increased ICP — for example, those who have had a stroke, head trauma, or neurosurgery. Signs of increased ICP include a change in the patient’s level of consciousness, motor or sensory deficits, and changes in the size, shape, or response to light in the pupils. Hypotonic solutions also shouldn’t be used for patients who suffer from abnormal fluid shifts into the interstitial space or the body cavities — for example, as a result of liver disease, a burn, or trauma.

Hypertonic solutions
Hypertonic solutions are those that have an osmolality greater than 295 mOsm/kg. Examples include:

  • dextrose 5% in half-normal saline solution
  • dextrose 5% in normal saline solution
  • dextrose 5% in lactated Ringer’s solution
  • dextrose 10% in water.

Fluids and electrolytes: The incredible shrinking cell

Focus topic: Fluids and electrolytes

A hypertonic solution draws fluids from the intracellular space, causing cells to shrink and the extracellular space to expand. Patients with cardiac or renal disease may be unable to tolerate extra fluid. Watch for fluid overload and pulmonary edema.Because hypertonic solutions draw fluids from cells, patients at risk for cellular dehydration (patients with diabetic ketoacidosis,for example) shouldn’t receive them.

Colloids
The practitioner may prescribe a colloid (plasma expander) if your patient’s blood volume doesn’t improve with crystalloids.
Examples of colloids that may be given include:

  • albumin (available in 5% solutions, which are osmotically equal to plasma, and 25% solutions, which draw about four times their volume in interstitial fluid into the circulation within 15 minutes of administration)
  • plasma protein fraction
  • dextran
  • hetastarch.

Fluids and electrolytes: Flowing into the stream

Focus topic: Fluids and electrolytes

Colloids pull fluid into the bloodstream. The effects of colloids last several days if the lining of the capillaries is normal. The patient needs to be closely monitored during a colloid infusion for increased blood pressure, dyspnea, and bounding pulse, which are all signs of hypervolemia.
If neither crystalloids nor colloids are effective in treating the imbalance, the patient may require a blood transfusion or other treatment.

Fluids and electrolytes: Delivery methods

Focus topic: Fluids and electrolytes

The choice of I.V. therapy delivery is based on the purpose of the therapy and its duration; the patient’s diagnosis, age, and health history; and the condition of the patient’s veins. I.V. solutions can be delivered through a peripheral or a central vein. Catheters are chosen based on the therapy and the site to be used. Here’s a look at how to choose a site — peripheral or central — and which equipment you’ll need for each.

Peripheral lines
Peripheral I.V. therapy is administered for short-term or intermittent therapy through a vein in the arm, hand, leg or, rarely, foot. Potential I.V. sites include the metacarpal, cephalic, basilic, median cubital, and greater saphenous veins. Using veins in the leg or foot is unusual because of the risk of thrombophlebitis. Also keep in mind that dextrose concentrations greater than 10% shouldn’t be administered peripherally because of the risk of vein irritation.

Central lines
Central venous therapy involves administering solutions through a catheter placed in a central vein, typically the subclavian or internal jugular vein, less commonly the femoral vein.
Central venous therapy is used for patients who:

  • have inadequate peripheral veins
  • need access for blood sampling
  • require a large volume of fluid
  • need a hypertonic solution to be diluted by rapid blood flow in a larger vein
  • need to receive vessel-irritating drugs
  • need a high-calorie nutritional supplement.
    Types of central venous catheters include the traditional multilumen catheter for short-term therapy and a peripherally inserted central catheter or a vascular access device (such as a Broviac or Hickman catheter) for long-term therapy.

Fluids and electrolytes: Complications of I.V. therapy

Focus topic: Fluids and electrolytes

Caring for a patient with an I.V. line requires careful monitoring as well as a clear understanding of the possible complications, what to do if they arise, and how to deal with flow issues.

Infiltration
During infiltration, fluid may leak from the vein into surrounding tissue. This occurs when the access device dislodges from the vein. Look for coolness at the site, pain, swelling, leaking, and lack of blood return. Also look for a sluggish flow that continues even if a tourniquet is applied above the site. If you see infiltration, stop the infusion, elevate the extremity, and apply warm soaks.

Fluids and electrolytes: Smaller is better

Focus topic: Fluids and electrolytes

To prevent infiltration, use the smallest catheter that will accomplish the infusion, avoid placement in joint areas, and secure the catheter in place.

Infection
I.V. therapy involves puncturing the skin, one of the body’s barriers to infection. Look for purulent drainage at the site, tenderness, erythema, warmth, or hardness on palpation. Signs and symptoms that the infection has become systemic include fever, chills, and an elevated white blood cell count.

Fluids and electrolytes: This monitoring is vital

Focus topic: Fluids and electrolytes

Nursing actions for an infected I.V. site include monitoring vital signs and notifying the practitioner. Swab the site for culture and remove the catheter as ordered. Always maintain sterile technique to prevent this complication.

Phlebitis and thrombophlebitis
Phlebitis is inflammation of a vein. Thrombophlebitis is an irritation of the vein along with the formation of a clot; it’s usually more painful than phlebitis. Poor insertion technique or the pH or osmolality of the infusing solution or medication can cause these complications. Look for pain, redness, swelling, or induration at the site; a red line streaking along the vein; fever; or a sluggish flow of the solution.

Fluids and electrolytes: Prevention begins with big veins

Focus topic: Fluids and electrolytes

When phlebitis or thrombophlebitis occurs, remove the I.V. line, monitor the patient’s vital signs, notify the practitioner, and apply warm soaks to the site. To prevent these complications, choose large veins and change the catheter according to your facility’s policy when infusing a medication or solution with high osmolality.

Extravasation
Extravasation, similar to infiltration, is the leakage of fluid into surrounding tissues. It results when medications, such as dopamine, calcium solutions, and chemotherapeutic agents, seep through veins and can produce blistering andnecrosis. Initially, the patient may experience discomfort, burning, or pain at the site. Also, look for skin tightness, blanching, and lack of blood return. Delayed reactions include inflammation and pain within 3 to 5 days and ulcers or tissue necrosis within 2 weeks.

Fluids and electrolytes: Review policy

Focus topic: Fluids and electrolytes

When administering medications that may extravasate, know your facility’s policy. Nursing actions include stopping the infusion, notifying the practitioner, removing the catheter, applying ice early and warm soaks later, and elevating the extremity. The doctor may inject an antidote into the site. Assess the circulation and nerve function of the limb.

Air embolism
An air embolism occurs when air enters the vein. It can cause a decrease in blood pressure, an increase in the pulse rate, respiratory distress, an increase in ICP, and a loss of consciousness.

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Fluids and electrolytes: Problems in the air

Focus topic: Fluids and electrolytes

If the patient develops an air embolism, notify the practitioner and clamp off the I.V. line. Place the patient on his left side and lower his head to allow the air to enter the right atrium, where it can disperse more safely by way of the pulmonary artery. Monitor the patient and administer oxygen. To avoid this serious complication, prime all tubing completely, tighten all connections securely, and use an air detection device on an I.V. pump.

How you intervene
Nursing care for the patient with an I.V. line includes the following actions:

  • Check the I.V. order for completeness and accuracy. Most I.V. orders expire after 24 hours. A complete order should specify the amount and type of solution, specific additives and their concentrations, and the rate and duration of the infusion. If the order is incomplete or confusing, clarify the order with the prescriber before proceeding.
  • Measure intake and output carefully at scheduled intervals. The kidneys attempt to restore fluid balance during dehydration by reducing urine production. Urine output less than 30 ml/hour signals retention of metabolic wastes. Notify the practitioner if your patient’s urine output falls below 30 ml/hour.
  • Monitor daily weights to document fluid retention or loss. A 2% increase or decrease in body weight is significant. A 2.2-lb (1-kg) change corresponds to 1 qt (1 L) of fluid gained or lost.
  • Always carefully monitor the infusion of solutions that contain medication because rapid infusion and circulation of the drug can be dangerous.
  • Note the pH of the I.V. solution. The pH can alter the effect and stability of drugs mixed in the I.V. bag. Consult medication literature, the pharmacist, or the prescriber if you have questions.
  • Using sterile technique, change the site, dressing, and tubing as often as facility policy requires. Solutions should be changed at least every 24 hours.
  • When changing I.V. tubing, be sure not to move or dislodge the I.V. catheter. If you have trouble disconnecting the used tubing, use a hemostat to hold the I.V. hub while twisting the tubing. Don’t clamp the hemostat shut because doing so may crack the hub.
  • Always report needle-stick injuries immediately so that treatment
    can be initiated. Exposure to a patient’s blood increases the risk of infection with blood-borne viruses, such as human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, and cyto megalovirus. About 1 out of 300 people with occupational needle-stick injuries become HIV-seropositive.
  • Always follow standard precautions when inserting, caring for, or discontinuing an I.V. line.

Fluids and electrolytes: Focus on the patient

Focus topic: Fluids and electrolytes

  • Always listen to your patient carefully. Subtle statements such as “I just don’t feel right” may be your clue to the beginning of an allergic reaction.
  • Provide appropriate patient teaching. (See Teaching about I.V. therapy.)
  • Keep in mind that a candidate for home I.V. therapy must have a family member or friend who can safely and competently administer the I.V. fluids as well as a backup helper, a suitable home environment, a telephone, available transportation, adequate reading skills, and the ability to prepare, handle, store, and dispose of equipment properly. Procedures for caring for the I.V. line are the same at home as in a health care facility, except at home the patient uses clean technique instead of sterile technique.
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