Chapter 39 Fluid, Electrolyte, Acid-Base Balance

Functions of Water in the Body

* Act as a solvent for electrolytes and non electrolytes. * Help maintain normal body temperature. * Facilitate digestion and promote elimination. * Act as a tissue lubrican.

Lab Studies to Assess for Imbalances

* Complete blood count. * Serum electrolytes, blood urea nitrogen, and creatinine levels. * Urine pH and specific gravity. * Arterial blood gases.

Two Compartments of Fluid in the Body

* Intracellular fluid (ICF): fluid within cells [70%). * Extracellular fluid (ECF): fluid outside cells [30%) Includes intravascular and interstitial fluids

Osmolarity of a Solution

* Isotonic: same concentration of particles as plasma. * Hypertonic: greater concentration of particles than plasma. * Hypotonic: lesser concentration of particles than plasma.

Primary Organs of Homeostasis

* Kidneys normally filter 170 L of plasma and excrete 15 L of urine. * The cardiovascular system pumps and carries nutrients and water in body.

Primary Organs of Homeostasis

* Lungs regulate oxygen and carbon dioxide levels of the blood. * Adrenal glands help the body conserve sodium, save chloride and water, and excrete potassium. * The pituitary gland stores and releases ADH.

Magnesium

* Magnesium: metabolism of carbohydrates and proteins, vital actions involving enzymes. * Chloride: maintains osmotic pressure in blood, produces hydrochloric acid

Parameters of Assessment

* Nursing history and physical assessment. * Fluid intake and output. * Daily weights. * Laboratory studies.

Primary Organs of Homeostasis

* Parathyroid glands regulate the level of calcium in ECF. * The GI tract absorbs water and nutrients that enter the body through this route.

Sodium

* Sodium: controls and regulates volume of body fluids * Potassium: chief regulator of cellular enzyme activity and water content. * Calcium: nerve impulse, blood clotting, muscle contraction, B12 absorption.

Fluid Balance

* Solvents: liquids that hold a substance in solution (water) Solutes: substances dissolved in a solution (electrolytes * and nonelectrolytes)

Primary Organs of Homeostasis

* The thyroid gland increases the blood flow in the body and increases renal circulation. * The nervous system inhibits and stimulates mechanisms influencing fluid balance.

Functions of Water in the Body

* Transport nutrients to cells and wastes from cells. * Transport hormones, enzymes, blood platelets, and red and white blood cells. * Facilitate cellular metabolism and proper cellular chemical functioning.

Implementing

-Dietary modifications. -Modifications of fluid intake. -Medication administration. -IV therapy. -Blood and blood products replacement. -TPN. -Allaying patient anxiety as needed. -Appropriate patient and family teaching.

3 buffer systems

1. carbonic acid-sodium bicarbonate buffer system 2. phospate buffer system 3. the protein buffer system

Homeostatic regulators of hydrogen ions

1. chemical buffer systems 2. respiratory mechanisms 3. renal mechanisms

Total body fluid

50-60% of body weight in normal adult

The normal pH of arterial blood is:

7.35-7.45

Overhydration

: above-normal amounts of water in extracellular spaces

Hypervolemia

: excessive retention of water and sodium in ECF

Filtration

: passage of fluid through a permeable membrane from the area of higher to lower pressure

Diffusion

: tendency of solutes to move freely throughout a solvent ("downhill")

Where is a PICC line placed

A nurse places a PICC line into a large vein in your arm and guides the catheter up into the main vein near your heart where blood flows quickly. The nurse sutures (stitches) the PICC line in place and covers the site with a sterile bandage. An x-ray is done to make sure that the catheter is in the right place.

Buffer

A substance that prevents body fluids from becoming overly acidity or alkaline

Acid-base imbalances occur

Acid-base imbalances occur when the carbonic acid or bicarbonate levels become disproportionate. When there is a single primary cause, these disturbances are known as respiratory acidosis or alkalosis and metabolic acidosis or alkalosis.

infant

An infant has considerably more body fluid and ECF than an adult; more prone to fluid volume deficits

Central venous access

Central venous access devices provide access for a variety of IV fluids, medications, blood products, and TPN solutions and allow a means for hemodynamic monitoring and blood sampling.

Of the three ways the body maintains a normal pH, which is the fastest system?

Chemical Buffers

Hypotonic solution

Decrease osmotic pressure which moves fluid into the cell causing the cell to swell, put fluid into the cell -Used for those with a hypertonic fluid imbalance such as those when a patient has a loss of intracellular fluid -Cellular replacement given over time -0.45 NS, 0.33 NS -Used with diabetes insidious, diabetic ketoacidosis and in children

Interstital fluid

Fluid between the cells (surrounding the cells)

women and obese people

Gender and amount of fat cells affect body water; women and obese people have less body water

Which of the following is a strong acid, releasing more hydrogen ions in solution and, thus, lowering the pH more than the others?

HCl

Variations in Fluid Content. Healthy person

Healthy person: total body water is 50% to 60% of body weight

Hypertonic solution

Increase osmotic pressure pulls fluid out from the cells causing them to shrink -Use cautioulsl because your pulling fluid out into the vascular space which could lead to pulmonary edema -D10W, D5 in 0.9% NS, D5 0.45% NS, D5 in LR

Osmolarity of a Solution

Isotonic. Hypertonic. Hypotonic.

Expected Outcomes

Maintain approximate fluid intake and output balance (2,500-mL intake and output over 3 days).

Urinary specific gravity (SG) is a measure of the concentration of solutes in the urine. It measures the ratio of urine density compared with water density and provides information on the kidney's ability to concentrate urine. A urinary specific gravity measurement is a routine part of urinalysis

Maintain urine specific gravity within normal range (1,010-1,025).

Major electrolytes in the ECF

Major electrolytes in the ECF include sodium, chloride, calcium, and bicarbonate.

Major electrolytes in the ICF

Major electrolytes in the ICF include potassium, phosphorus, and magnesium

Metabolic

Metabolic acidosis: proportionate deficit of bicarbonate in ECF. Metabolic alkalosis: primary excess of bicarbonate in ECF.

Vomiting (with a loss of HCl acid from the stomach) will cause which type of acid/base disturbance? What would be the compensation?

Metabolic alkalosis; decreased respiration

Anion

Negative charge -Chloride, bicarbonate, phosphate

When pH is low in the plasma, the kidney uses three mechanisms to restore pH. The first mechanism is reabsorption of filtered bicarbonate. What are the other two mechanisms?

New bicarbonate ions are generated and hydrogen ions are secreted.

Metabolic acidosis

Occur when carbonic acid or bicarbonate levels become disproportionate

Alkalosis

Occurs when there is a lack of H ions or gain of base ions and the pH exceeds 7.45

Trancellular

Pleural (lungs), CSF, intraocular (eyes), synovial fluid (joints) periotoneal (abdomen)

Active transport

Process that requires energy for the movement of substances through a cell membrane, agains the concentration gradient from area of lesser solute concentration to an area of higher solute concentration -Requires ATP (energy)

Respiratory acidosis

Respiratory acidosis: primary excess of carbonic acid in ECF. Respiratory alkalosis: primary deficit of carbonic acid in ECF.

Emphysema can lead to which acid/base disturbance? What would be the compensation?

Respiratory acidosis; kidneys will retain more HCO3 and excrete H+

Severe anxiety would cause which type of acid/base disturbance? What would be the compensation?

Respiratory alkalosis; excrete HCO3

Capillary filtration

Results from the force of blood pushing against the walls of the capillaries

Isotonic solution

Same as body fluid and same concentration of particles as plasma; used for extracellular volume replacement -givent to dehydrated patients or vomiting patients to replace volume -Most common solution -LR, 0.9% NS, and D5W

Major Electrolyte

Sodium. Potassium. Calcium. Magnesium. Chloride. Bicarbonate. Phosphate.

Base

Substance that can accept or trap H+ ions, such as bicarbonate ion

Electrolytes

Substances that are capable of breaking into particles called ions

Diffusion

Th tendency of solutes to move freely throughout a solvent from an area of higher to an area of lower concentration -Oxygen and carbondioxide exchange in the lungs use diffusion

Question: The nursing instructor is explaining how the respiratory system is involved in hydrogen ion regulation to maintain normal pH. The instructor places the steps in order once the CO2 in the blood has increased resulting in increased respirations to eliminate CO2. 1 pH becomes more alkaline 2 Decreased respirations 3 H2CO3 level in the blood decreases 4 Carbonic acid formed 5 Carbon dioxide retention 6 Blood level of CO2 decreases

The Correct Order: H2CO3 level in the blood decreases pH becomes more alkaline Blood level of CO2 decreases Decreased respirations Carbon dioxide retention Carbonic acid formed When respirations are increased, the H2CO3 level begins to decrease, causing the pH to become more alkaline. When the blood level of CO2 decreases, respirations slow, resulting in CO2 retention and the formation of carbonic acid, signaling stabilization of the pH balance.

How long can a PICC line stay in place

The PICC line can stay in your arm for as long as 12 months, although the average length is usually about 6 months, depending on your treatment requirements

Acidosis

The condition characterized by and excess of H ions or loss of base ions in the ECF in which the pH falls below 7.35

dehydration

The loss of our deprivation of water form the body

Hydrostatic pressure

The pressure that the fluid exerts on the walls of its container.

Hydrostatic pressure

The pushing force, force solutes out into intersitiial space

A physician has asked the nurse to use microdrip tubing to administer a prescribed dosage of IV solution to a client. What is the standard drop factor of microdrip tubing? a) 60 drops/mL b) 30 drops/mL c) 120 drops/mL d) 90 drops/mL

a) 60 drops/mL Microdrip tubing, regardless of manufacturer, delivers a standard volume of 60 drops/mL. Macrodrip tubing manufacturers, however, have not been consistent in designing the size of the opening. Therefore, the nurse must read the package label to determine the drop factor (number of drops/mL)

The oncoming nurse is assigned to the following patients. Which patient should the nurse assess first? a) A newly admitted 88-year-old with a two-day history of vomiting and loose stools b) A 60-year-old who is 3 days post-myocardial infarction and has been stable c) A 20-year-old, 2 days post-operative open appendectomy who refuses to ambulate today d) A 47-year-old who had a colon resection yesterday and is complaining of pain

a) A newly admitted 88-yr old with a two day history of vomiting and loose stool

Which nursing diagnosis would the nurse make based on the effects of fluid and electrolyte imbalance on human functioning? a) Acute Confusion related to cerebral edema b) Constipation related to immobility c) Risk for Infection related to inadequate personal hygiene d) Pain related to surgical incision

a) Acute confusion related to cerebral edema

The nurse is caring for a male client who has a diagnosis of heart failure. Today's laboratory results show a serum potassium of 3.2 mEq/L. For what complications should the nurse be aware, related to the potassium level? a) Cardiac dysrhythmias b) Fluid volume excess c) Tetany d) Pulmonary embolus

a) Cardiac dysrhythmias

The nurse is caring for elderly patients in a long-term care facility. What age-related alteration should the nurse consider when planning care for these patients? a) Cardiac volume intolerance b) An increased sense of thirst c) Increased renal blood flow d) Increase in nephrons in the kidneys

a) Cardiac volume intolerance The elderly patient is more likely to experience cardiac volume intolerance related to the heart having less efficient pumping ability. The elderly typically experience a decreased sense of thirst, loss of nephrons, and decreased renal blood flow.

A client is taking a diuretic such as furosemide. When implementing client education, what information should be included? a) Decreased potassium levels b) Decreased oxygen levels c) Increased potassium levels d) Increased sodium levels

a) Decreased potassium levels Many diuretics such as furosemide are potassium wasting; hence, potassium levels are measured to detect hypokalemia.

A nurse is measuring intake and output for a patient who has congestive heart failure. What does not need to be recorded? a) Fruit consumption b) Frozen fluids c) Parenteral fluids d) Sips of water

a) Fruit Consumption Any water consumption must be recorded in order to closely monitor a patient who has congestive heart failure. Many of these patients are on fluid restrictions. Sips of water, parenteral fluids, and frozen fluids count as fluid intake. The amount of water in fruits cannot be measured.

Endurance athletes who exercise for long periods of time and consume only water may experience a sodium deficit in their extracellular fluid. What is this electrolyte imbalance known as? a) Hyponatremia b) Hyperkalemia c) Hypokalemia d) Hypernatremia

a) Hyponatremia Hyponatremia refers to a sodium deficit in the extracellular fluid caused by a loss of sodium or a gain of water. Hypernatremia refers to a surplus of sodium in the ECF. Hypokalemia refers to a potassium deficit in the ECF. Hyperkalemia refers to a potassium surplus in the ECF.

A young man has developed gastric esophageal reflux disease. He is treating it with antacids. Which acid-base imbalance is he at risk for developing? a) Metabolic alkalosis b) Respiratory acidosis c) Metabolic acidosis d) Respiratory alkalosis

a) Metabolic Alkalosis Endocrine disorders and ingestion of large amounts of antacids cause metabolic alkalosis.

A nurse monitoring a client's IV infusion auscultates the client's lung sounds and finds crackles in the bases of lungs that were previously clear. What would be the appropriate intervention in this situation? a) Notify the primary care provider immediately for possible fluid overload. b) No intervention is necessary as this is a normal finding with IV infusion. c) Check all clamps on the tubing and check tubing for any kinking. d) Notify the primary care provider immediately because these are signs of speed shock.

a)Notify primary care provider immediately for possible fluid overload

A patient with type AB blood has experienced a precipitous drop in his hemoglobin levels due to a gastrointestinal bleed and now requires a blood transfusion. Which of the following blood types may this patient safely receive? Select all that apply. a) A b) O c) AB d) B

a, b, c, d

What signs of complications and their probable causes may occur when administering an IV solution to a patient? (Select all that apply.) a) Swelling, pain, coolness, or pallor at the insertion site may indicate infiltration of the IV. b) Engorged neck veins, increased blood pressure, and dyspnea occur when a thrombus is present. c) Bleeding at the site when the IV is discontinued indicates an infection is present. d) A pounding headache, fainting, rapid pulse rate, increased blood pressure, chills, back pains, and dyspnea occur when an air embolus is present. e) Redness, swelling, heat, and pain at the site may indicate phlebitis. f) Local or systemic manifestations may indicate an infection is present at the site.

a, e, f

Which actions would a nurse perform after selecting a site and palpating accessible veins in order to start an IV infusion? (Select all that apply.) a) Advance the needle or catheter into the vein. A sensation of "give" can be felt when the needle enters the vein. b) Enter the skin gently with the catheter held by the hub in the non-dominant hand, bevel side down, at a 10- to 30-degree angle. c) Clean the entry site with saline, followed by an alcohol swab according to agency policy. d) Place the dominant hand about 4 inches below the entry site to hold the skin taut against the vein. e) When blood returns through the lumen of the needle or the flashback chamber of the catheter, advance device into the vein until the hub is at the venipuncture site. f) Release the tourniquet, quickly remove the protective cap from the IV tubing, and attach the tubing to the catheter or needle.

a, e, f

central venous catheter

also called a central line, is a long, thin, flexible tube used to give medicines, fluids, nutrients, or blood products over a long period of time, usually several weeks or more. A catheter is often inserted in the arm or chest through the skin into a large vein.

Solvents

are liquids that hold a substance in solution

Solutes

are substances that are dissolved in a solution

A nurse is measuring the intake and output of a patient who is dehydrated. What is the average adult daily fluid intake in milliliters that the nurse would use as a comparison? a) 2,300 mL b) 2,600 mL c) 1,800 mL d) 1,500 mL

b) 2600 mL The average adult daily fluid source is: 1,300 mL from ingested water, 1,000 mL from ingested food, and 300 mL from metabolic oxidation, totaling 2,600 mL fluid.

A nurse is calculating the output of a client with renal failure and takes into account all modes of fluid loss. When addressing the client's insensible fluid loss, which amount would the nurse anticipate as the usual average? a) 200 mL/day b) 300 to 400 mL/day c) 100 to 200 mL/day d) 1500 mL/day

b) 300 to 400 ml/day

Which fluid should be administered slowly to prevent circulatory overload? a) 0.45% NaCl b) 5% NaCl c) 0.9% NaCl d) Dextrose 5%

b) 5% NaCl When a hypertonic solution is infused, it raises serum osmolarity, pulling fluid from the cells and the interstitial tissues into the vascular space. Examples of hypertonic solutions include 3% (NaCl) and 5% saline (NaCl).

When caring for a client who is on intravenous therapy, the nurse observes that the client has developed redness, warmth, and discomfort along the vein. Which of the following interventions should the nurse perform for this complication? a) Elevate the client's head. b) Apply a warm compress. c) Position the client on the left side. d) Apply antiseptic and a dressing.

b) Apply a warm compress Prolonged use of the same vein can cause phlebitis; the nurse should apply a warm compress after restarting the IV. The nurse need not elevate the client's head, position the client on the left side, or apply antiseptic and a dressing. The client's head is elevated if the client exhibits symptoms of circulatory overload. The client is positioned on the left side if exhibiting signs of air embolism. The nurse applies antiseptic and a dressing to an IV site in the event of an infection.

A home care nurse is teaching a client and family about the importance of a balanced diet. The nurse determines that the education was successful when the client identifies which of the following as a rich source of potassium? a) Processed meat b) Apricots c) Dairy products d) Bread products

b) Apricots

A client loses consciousness after strenuous exercise and needs to be admitted to a health care facility. The client is diagnosed with dehydration. The nurse knows that the client needs restoration of which of the following? a) Interstitial fluid b) Electrolytes c) Non-electrolytes d) Colloid solution

b) Electrolytes

Which solution is a crystalloid solution that has the same osmotic pressure as that found within the cells of the body and is used to expand the intravascular volume? a) Colloid b) Isotonic c) Hypertonic d) Hypotonic

b) Isotonic fluids Isotonic fluids have an osmolarity of 250-375 mOsm/L, which is the same osmotic pressure as that found within the cell.

The nurse writes a nursing diagnosis for a patient of "Fluid Volume: Excess." What risk factor would the nurse assess in this patient? a) Excessive use of laxatives b) Renal failure c) Diaphoresis d) Increased cardiac output

b) Renal Failure Excess fluid volume may result from increased fluid intake or from decreased excretion, such as occurs with progressive renal disease. Excessive use of laxatives, diaphoresis, and increased cardiac output may lead to a fluid volume deficit.

A home care nurse is visiting a client with renal failure who is on fluid restriction. The client tells the nurse, "I get thirsty very often. What might help?" Which of the following would the nurse include as a suggestion for this client? a) Eat crackers and bread. b) Use regular gum and hard candy. c) Avoid salty or excessively sweet fluids. d) Use an alcohol-based mouthwash to moisten your mouth.

c) Avoid salty or excessively sweet fluids

Major control over the extracellular concentration of potassium within the human body is exerted by: a) albumin. b) testosterone. c) aldosterone. d) progesterone.

c) aldosterone Aldosterone exerts major control over the extracellular concentration of potassium. It also enhances renal secretion of potassium.

A physician orders an infusion of 250 mL of NS in 100 minutes. The set is 20 gtt/mL. What is the flow rate? a) 40 gtt/min b) 30 gtt/min c) 20 gtt/min d) 50 gtt/min

d) 50 gtt/min

A client who is admitted to the health care facility has been diagnosed with cerebral edema. Which of the following intravenous solutions needs to be administered to this client? a) Hypotonic solution b) Isotonic solution c) Colloid solution d) Hypertonic solution

d) Hypertonic solution Hypertonic solutions are used in extreme cases when it is necessary to reduce cerebral edema or to expand the circulatory volume rapidly because it is more concentrated than body fluid and draws cellular and interstitial water into the intravascular compartment. Hypotonic solutions are administered to clients with fluid losses in excess of fluid intake, such as those who have diarrhea or vomiting. Isotonic solution is generally administered to maintain fluid balance in clients who may not be able to eat or drink for a short period. Colloid solutions are used to replace circulating blood volume because the suspended molecules pull fluid from other compartments. However, these solutions are not related to clients with cerebral edema.

A nurse needs to select a venipuncture site to administer a prescribed amount of IV fluid to a client. The nurse looks for a large vein when using a needle with a large gauge. Which of the following reasons explains the nurse's action? a) To avoid restriction of mobility b) To reduce the potential for blood clots c) To prevent pain and discomfort d) To prevent compromising circulation

d) To prevent compromising circulation

When hydrogen ion concentration decreases, acidity __________, and pH __________.

decreases; increases

Edema

excessive ECF accumulates in tissue spaces

peripherally inserted central catheter (PICC or PIC line)

is a form of intravenous access that can be used for a prolonged period of time (e.g. for long chemotherapy regimens, extended antibiotic therapy, or total parenteral nutrition

Colloid osmotic pressure

is a form of osmotic pressure exerted by proteins, notably albumin, in a blood vessel's plasma (blood/liquid) that usually tends to pull water into the circulatory system.

Extracellular fluid (ECF)

is all the fluid outside of the cells, accounting for about 30% of the total body water or 20% of the adults body weight -Interstitial -Transcellular -intravascular

A loss of bicarbonate due to diarrhea can lead to a ____________ (name the acid/base disturbance) with ____________ (metabolic or respiratory) compensation.

metabolic acidosis; respiratory

Interstitial-to-plasma shift:

movement of fluid from space surrounding cells to blood

Cellular metabolism generates CO2, which is eliminated by the lungs. If respiration decreases, what will happen to the pH of the blood?

pH decreases

Cation

positive charge -sodium, potassium, calcium, hydrogen, magnesium ions

Colloid omotic pressur

pulling fores or reabsorption of fluid back into the capillaries

Active transport

requires energy for movement of substances through the cell membrane from the lesser solute concentration to the higher solute concentration

Acid

substance containing H+ that can bet liberated or released such as carbonic acid

Intravascular fluid

the fluid in the blood vessels (blood plasma)

Intracellular fluid (ICF)

the fluid within cells, constituting for about 70% of total body water of 40% of adults body weight

osmosis

water (solvent) passes from area of lesser solute concentration and more water to areas with greater solute concentration and lesser water

Osmosis:

water passes from an area of lesser solute concentration to greater concentration until equilibrium is established