Unit 8: Nursing Management of Fluid, Electrolytes, and Acid-Base

What is considered an isotonic fluid

Those with the same osmolality as the cell interior

How do we test for a positive Cvosteks Sign to indicate hypocalcemia

Elicitation: Tapping on the face at a point just anterior
to the ear and just below the zygomatic bone
Postitive response: Twitching of the ipsilateral facial
muscles

How do we test for a positive Trousseaus Sign to indicate hypocalcemia

Elicitation: Inflating a sphygmomanometer cuff above
systolic blood pressure for several minutes
Postitive response: Muscular contraction including flexion
of the wrist and metacarpophalangeal joints,
hyperextension of the fingers, and flexion of the thum

What is considered a hypotonic (hypoosmolar) fluid

Solutions in which the solutes are less concentrated that in the cells

What is considered a hypertonic (hyperosmolar) fluid

fluids with solutes more concentrated than in cells

What is the role of sodium in muscle and nerve function

Sodium ions play a large part (along with potassium) in muscle/nerve functioning by crossing cell membranes to create an electrical signal/nerve impulse or muscle contraction

What is the role of sodium in fluid balance

Sodium works with potassium to maintain normal water balance in the body. They each chemically attract water, assuring that optimal levels of hydration are maintained inside and outside the cells.

What is the main cation of the ECF

Sodium

What is the main cation of the ICF

Potassium

Where does our body absorb sodium

The GI tract absorbs sodium from foods

How does sodium leave our bodies

through urine sweat and feces - the kidneys are the primary regulator of sodium balance

How does our body absorb potassium

from our diet, mainly fruits, dried fruits, and vegetables

How does potassium leave our bodies

The kidneys are the primary route for potassium loss (90%) the rest is lost in stool ad sweat

How much of the water in our bodies is intracellular vs extracellular

intracellular includes 2/3 of our bodies water, and extracellular is 1/3

How much of our ECF is found intravascularly and how much is found interstitially

20% is intravascular as plasma, and 70% is interstitial fluid (the rest is transcellular in specialized body cavities)

What is the function of body fluid

plays an important role in homeostasis by transporting nutrients, electrolytes, and oxygen to cells and carrying waste products away

What are the different mechanisms controlling how body fluids and electrolytes move throughout the body

1.Diffusion
2. Facilitated Diffusion
3. Active Transport
4.Osmosis

What four factors determine fluid movement in and out of capillaries

1. Capillary Hydrostatic pressure
2. Plasma oncotic pressure
3. interstitial hydrostatic pressure
4. interstitial oncotic pressure

What two forces drive water from the capillaries (vascular system) and into the interstitial space

Capillary hydrostatic pressure and interstitial oncotic pressure

What two forces pull water from the interstitial space into the capillaries (vascular system)

Plasma oncotic pressure and Interstitial hydrostatic pressure

What are the three types of fluid spacing

first, second, and third spacing

What is First spacing

the normal distribution of fluid in the ICF and ECF

What is Second Spacing

the abnormal accumulation of interstitial fluid (ex: edema)

What is Third Spacing

fluid that has accumulated in a portion of the body from which it is not easily exchanged with the rest of the ECF

What role does the hypothalamus play in regulation of fluids

it senses a body fluid deficit or increase in plasma osmolality, and stimulates thirst and ADH release (thirst causing person to drink, ADH causes kidneys to increase water reabsorption)

What role do the kidneys play in regulation of fluids

they are the primary fluid/electrolyte regulators. They filter the entire plasma volume many times per day, reabsorbing 99% of the filtrate

What role does the adrenal cortex play in regulation of body fluids

secretes glycocorticoids and mineralocorticoids, glucocorticoids (ie Cortisol) mainly have antiinflammatroy and glucose elevating effects, mineralocorticoids (ie aldostereone) enhance sodum retention and potassium excretion

What role does the heart play in regulation of body fluids

It releasese hormones (ANP, BNP) in response to increased arterial pressure and sodium levels to decrease blood volume and blood pressure

What role does the GI play in regulation of body fluids

1.Most of our water intake comes from oral fluid intake
2. it secretes digestive fluid that is mostly reabsorbed in the GI tract (except in cases of diarrhea and vomiting)

What is insensible water loss

invisible vaporization from the lungs and skin occuring with increased body temp and exercise *not to be confused with sensible perspiration

What are the two ECF volume deficits

hypovolemia and hypervolemia

What are some causes of hypovolemia

abnormal loss of body fluids (skin: perspiration; GI tract: diarrhea, fistula drainage, vomiting, NG; Kidneys: diuretics; Plasma:hemorrhage), or inadequate fluid intake

What are some clinical manifestations of hypovolemia

restlessness, thirst, decreased skin turgor, weight loss, hypotension, tachycardia, decreased urine output

What are some nursing interventions for a patient with hypovolemia

oral/IV fluids, blood products, oral care, skin breakdown prevention

What are some causes of hypervolemia

excessive intake of fluids, increased sodium intake leading to abnormal retention of fluids, heart or renal failure causing impaired fluid regulation

What are some clinical manifestations of hypervolemia

weight gain, peripheral edema, distended neck veins, elevated BP&CVP, confusion/headache/lethargy, tachycardia, moist crackles,dyspnea,cough

What are some nursing interventions for a patient with hypervolemia

Fluid/Sodium restriction, diuretics, maintain oxygenation, prevent skin breakdown

What are some clinical manifestations of hypernatremia

dehydration & shrinkage of cells
intense thirst, agitation, alertness ranging from sleepiness to coma

What are the most common Electrolytes in the body

Sodium, Potassium, Calcium, Magnesium, Chloride, Phosphate

What are some causes of hyponatremia

Water Gain
Sodium Loss
Inadequate sodium intake

What are some clinical manifestations of hyponatremia

cellular swelling (water shifts into the ICF)
irritability, headache, confusion, seizures, coma

What are some nursing interventions for a patient with hyponatremia

monitor sodium levels, urine osmolarity, I&Os, level of conciousness; administer sodium, fluid restriction

What are some potential complications of hyponatremia

seizures and coma leading to irreversible brain damage

Why is risk for injury applicable for hyponatremia

r/t altered sensorium (irritability, headache, confusion) and seizures

Why is risk for electrolyte imbalance applicable for hyponatremia

r/t excessive intake of sodium and/or loss of water

Why is risk for injury applicable for hypernatremia

r/t altered sensorium (agitation), and decreased level of consciousness (ranging from sleepiness to coma)

Why is risk for electrolyte imbalance applicable for hypernatremia

r/t excessive loss of sodium and/or excessive intake or retention of water

What are some potential complications of hypernatremia

severe neurologic changes

What are some causes of hyperkalemia

impaired renal excretion, shift of K from ICF to ECF, or a massive intake of potassium *most common cause is renal failure

What are some clinical manifestations of hyperkalemia

increased cellular excitability
leg cramping & weakness, followed by weakness or paralysis of other skeletal muscles (including respiratory muscles)
*most significant are disturbances in cardiac conduction

What are some potential complications with hyperkalemia

dysrhythmias

Why is risk for injury applicable for hyperkalemia

r/t lower extremity muscle weakness and seizures

Why is risk of electrolyte imbalance applicable for hyperkalemia

excessive retention or cellular release of potassium

What are some causes of hypokalemia

increased loss of potassium, increased shift of K from ECF to ICF, or deficient potassium intake *most common is losses from kidneys or GI tract

What are some clinical manifestations of hypokalemia

hyper-polarization (increased negative charge within cell
cardiac changes with potentially lethal ventricular dysrhythmias
weakness, arrhythmias, potentially shallow respirations & respiratory arrest, alkalosis

Why is risk for electrolyte imbalance applicable for hypokalemia

r/t excessive loss of potassium

Why is risk for injury applicable for hypokalemia

r/t muscle weakness and hyporeflexia (below normal or absent reflexes)

What is a potential complication of hypokalemia

dysrhythmias

What are some causes of hypercalcemia

*most commonly caused by hyperparathyroidism (2/3 of cases)
malignancies, prolonged immobilization, vitamin D overdose, increased calcium intake

What are some clinical manifestations of hypercalcemia

reduced excitability of both muscles and nerves
lethargy, headache, weakness, muscle flaccidity, heart block, anorexia, nausea, and vomiting

Why is risk for electrolyte imbalance applicable for hypercalcemia

r/t excessive bone destruction

Why is risk for injury applicable for hypercalcemia

r/t neuromuscular and sensorium changes

What is a potential complication of hypercalcemia

dysrhythmias, bradycardia & renal calculi

What are some causes of hypocalcemia

any condition that decreases PTH production
removal of or injury to parathyroid glands
pancreatitis

What are some clinical manifestations of hypocalcemia

increased nerve excitability and sustained muscle contraction or tetany *seizures
(Chvosteks sign, Trousseaus sign)
cardiac effects = decreased cardiac contractility
Paresthesia, facial spasms, and muscle tremors

Why is risk for injury applicable for hypocalcemia

r/t tetany and seizures

Why is risk for electrolyte imbalance applicable for hypocalcemia

r/t decreased production of PTH

What causes an acid-base imbalance

when there is an alteration in the 20:1 base and acid content ratio from a primary disease or process

What are the two types of acid-base imbalances

respiratory and metabolic

What causes a respiratory acid-base imbalance

retention or excess of co2

what causes a metabolic acid-base imbalance

a change in the base bicarbonate

What is respiratory acidosis

a metabolic acid-base imbalance caused by an increase in carbonic acid
*occurs with hypoventilation
the pH and PaCO2 change in opposite directions
*The pH decreases, while PaCo2 increases

What is metabolic acidosis

a metabolic acid-base imbalance caused by a decrease in bicarbonate
*pt may develop Kussmaul respiration
pH and PaCO2 change in the same direction
*The pH decreases and the PaCo2 decreases

What is respiratory alkalosis

an acid-base imbalance caused by a decrease in carbonic acid
*occurs with hyperventilation
the pH and PaCO2 change in opposite directions
*The pH increases, while PaCo2 decreases

What is metabolic alkalosis

a metabolic acid-base imbalance caused by an increase in bicarbonate
*results in decreased RR
pH and PaCO2 change in the same direction
*pH increases and PaCo2 increases

What are some clinical manifestations of acid-base imbalances

the CNS is depressed
headache, lethargy, weakness, confusion, leading to coma and death

How can we determine a patients acid-base status

Arterial blood gas values (ABG)

What is a normal ABG result for pH

7.35-7.45

What is a normal ABG result for PaCO2

35-45 mm Hg

What is a normal ABG result for Bicarbonate

22-26 mEq/L

What is a normal ABG result for PaO2

80-100 mm Hg

What is a normal ABG result for SaO2

>95%

What is a normal ABG result for Base excess

(+-) 2.0 mEq/L

What are some common hypotonic solutions used for fluid and electrolyte replacement

0.45% normal saline
5% dextrose in water (isotonic, but physiologically hypotonic)

What are some common isotonic solutions used for fluid and electrolyte replacement

0.9% normal saline
5% Dextrose in 0.225% Saline
Ringer's Solution
Lactated Ringer's solution

What are some common hypertonic solutions used for fluid and electrolyte replacement

10% Dextrose in water
3% Saline
5% Dextrose in 0.9% Saline

What will a hypotonic solution do when used for fluid and electrolyte replacement

provides more water than electrolytes, watch patient for changes in mentation that may indicate cerebral edema

What will an isotonic solution do when used for fluid and electrolyte replacement

expands only ECF, ideal for pts with ECF volume deficit

What will a hypertonic solution do when used for fluid and electrolyte replacement

draws water out of cells into ECF, useful in hypovolemia and hyponatremia
requires frequent bp, lung sounds and serum sodium levels because of risk for intravascular fluid volume excess

What does a low pH indicate

A low pH (normal 7.35-7.45) indicates acidosis

What lab values are important for patients taking loop diuretics

Serum potassium because they have potential to cause hypokalemia

What fluid & electrolyte deficiency can occur from hyperglycemia

Hyperkalemia

What assessments are important if fluid volume excess is suspected

assess the patient's respiratory status and lung sounds

What is an early sign that dehydration has progressed to deficient fluid volume

Restlessness

What is the most reliable means of detecting changes in fluid balance

monitoring weight (Weight loss would indicate the dehydration is worsening, whereas weight gain would indicate restoration of fluid volume)

What is an adequate range for daily fluid I&O

2000-3000 mL

What is an adequate range for daily fluid I&O for a hypercalcemic patient

A daily fluid intake of 3000 to 4000 mL is necessary to enhance calcium excretion and prevent the formation of renal calculi

What are some risk factors that may put a patient at risk for imbalanced fluid volume

abdominal surgery, ascites, burns, intestinal obstruction, pancreatitis, receiving apheresis, sepsis, traumatic injury

What are some risk factors that may cause deficient fluid volume

active fluid volume loss, failure of regulatory mechanisms

What are some defining characteristics that indicate deficient fluid volume

change in mental state, decreased blood pressure/pulse pressure/pulse volume, decreased skin turgur, decreased urine out, decreased venous filling, dru mucous membranes/skin, elevated hematocrit/temperature/pulse rate

What are some defining characteristics that indicate excess fluid volume

adventitious breath sounds, altered electrolytes, anxiety, metal status change, decreased hematocrit/hemoglobin, edema,

What are some risk factors that may cause excess fluid volume

compromised regulatory mechanism, excess fluid intake, excess sodium intake

What are some factors that may put a patient at risk for deficient fluid volume

active fluid volume loss, excessive losses through normal routes, extreme ages/weight, loss of fluid through abnormal routes, pharmaceutical agents

What are some factors that may put a patient at risk for electrolyte imbalance

diarrhea, endocrine dysfunction, fluid imbalance, impaired regulatory mechanisms, renal dysfunction, vomiting

What are some nursing outcome indicators for a patient at risk for electrolyte imbalance

apical heart rate/rhythm, Serum potassium, serum sodium, serum calcium, serum magnesium, serum phosphorus

What are some nursing outcome indicators for a patient at risk for imbalanced fluid volume

BP(normal), palpable peripheral pulses, normal skin turgor, moist mucous membranes, serum electrolytes (within range), hematocrit, bodyweight stable, 24 hour I&Os

What are some nursing outcome indicators for a patient with deficient fluid volume

normal skin turgor, moist mucous membranes, no orthostatic hypotension, 24 hour I&Os

What are some nursing outcome indicators for a patient with excess fluid volume

no peripheral edema, no neck vein distention, no adventitious breath sounds, no body weight increase

What is the role of calcium in the body

99% of calcium keeps bones and teeth strong supporting skeletal structure and function. The rest of plays key roles in cell signaling, blood clotting, muscle contraction and nerve function

Define Electrolytes

Salts and minerals that can conduct electrical impulses in the body and they carry an electrical charge

Define Buffer

a solution that resists changes in pH when acid or alkali is added to it

Define Osmolarity

the concentration of a solution expressed as the total number of solute particles per liter

Define pH

a figure expressing the acidity or alkalinity of a solution on a scale from 0-14

Whatacid-base imbalance can Excessive nasogastric suctioning possibly cause

Metabolic Alkalosis

What acid-base imbalance can Type 1 diabetes mellitus possibly cause

Metabolic Acidosis

What acid-base imbalance can Acute respiratory failure lead to

Respiratory Acidosis

What acid-base imbalance can a traumatic brain injury lead to

Respiratory Alkalosis (from hyperventilation)

What is the daily value of sodium according to nutrition labels

less than 2,400 milligrams (mg) per day

What is the chief regulator of cellular enzyme activity and cellular water content.

Potassium

What electrolyte has an inverse relationship to Phosphorus

Calcium (If Calcium is too high, Phosphorus will be too low)

What is the normal range for serum Phosphorus

2.4-4.4 mg/dL

What is the normal range for Magnesium in the body

1.5-2.5

What electrolyte imbalance can result from excessive antacid and laxative use?

HyperMagnesemia

What are some clinical manifestations of Hypophosphotemia

CNS Depression, Bone weakness,

What are some causes of hyperphosphotemia

low calcium levels, renal failure, chemotherapy, too much intake of phosphate

What are some causes of hypophosphotemia

Malabsorption syndromes-Malnutrition
Glucose or insulin therapy
TPN
Alcohol withdrawal
*Recovery from DKA
Respiratory alkalosis

What are some clinical manifestations of hyperphosphotemia

CNS Stimulation,
Hyperreflexia, muscle cramps, Tetany, seizures

What is the purpose of magnesium in the body

Coenzyme in metabolism of CHOs & proteins
Helps maintain normal calcium & potassium levels

What can cause hypomagenesemia

Prolonged malnutrition (diarrhea, vomiting, Chronic alcoholism,Malabsorption syndromes)
NG Suction
*Poorly controlled DM
Hyperaldosteronism

What are some clinical manifestations of hypomagnesemia

CNS Stimulation
Confusion-Tremors, seizures-Hyperactive deep tendon reflexes-Insomnia-Increased pulse & blood pressure

What can cause hypermagnesemia

Renal failure (lack of excretion) Adrenal insufficiency (lack of excretion) Excessive administration (excessive intake) tumor lysis syndrome
*DKA

What are some clinical manifestations of hypermagnesemia

Depresses neuromuscular & CNS function
Lethargy, drowsiness-Nausea, vomiting-
Diminished deep tendon reflexes-Flushed, warm skin-Decreased pulse, blood pressure-Muscle weakness

What are the three body regulators of pH

Buffer, Respiratory, and Renal Systems

What can cause hypoventilation and what can it lead to

COPD�Pneumonia�Brain damage to respiratory center�Narcotic overdose�Mechanical hypoventilation
leading to retention of CO2 *respiratory acidosis

What can cause hyperventilation and what can it lead to

anxiety, pain, panic, mechanical overventilation
-Hyperventilation leads to excess CO2 *respiratory alkalosis