Chapter 42 Fluid, Electrolyte, and Acid-Base Balance (Week 11)

Recognizing the cues of hypertonic FVD also includes a neurologic assessment to identify any neurologic manifestations caused by shrinkage of brain cells. Neurologic manifestations often predominate until the deficit is moderately severe. Common neurologic findings include?

-Confusion -Lethargy -Coma

What are common s/s of a a decreasing interstitial fluid?

-Decreased skin turgor (not reliable in older adults) -Dry mucous membranes -Absence of tears and sweat -Sunken eyes

What type of questions should you ask yourself in a health history?

-Has the patient been thirsty? -Has the patient gained 2.2 lb (1 kg) or more over 24 hours? -Has the patient had an increase or decrease in urinary frequency?

Cerebral edema (swelling of brain cells inside the rigid skull) increases intracranial pressure. Excess fluid in the lungs cause pulmonary congestion and pulmonary edema. Associated clinical manifestations include?

-Neurologic manifestations: Decreased level of consciousness that may include: Confusion, Seizures, or Coma -Pulmonary manifestations: *Dyspnea (shortness of breath) *Abnormal lung sounds (crackles) *Pink, frothy sputum *Cough

The effects on circulating volume are the same as for isotonic FVE, resulting in cardiovascular manifestations such as?

-Sudden weight gain -Hypertension -Bounding peripheral pulses -Jugular venous distension (observed best when the person is upright or semiupright)

Increased circulating volume is visible in the cardiovascular system. What are some examples?

-Sudden weight gain of 2.2 lb (1 kg) or more in 24 hours in an adult -Hypertension -Bounding peripheral pulses -Jugular venous distension (observed best when the person is upright or semiupright)

Edema may be observed by?

-Tight rings or shoes from minor swelling of hands or feet with mild FVE -Visible edema in dependent portions of the body with substantial FVE

When interviewing a patient about fluid intake what are some questions you can ask them?

-What is your normal fluid intake each day? What type of fluids do you normally drink? Has that changed? -What do you normally eat in a 24-hour period? Do you add salt to your food or cook with salt? -Do you often feel thirsty? How much water do you drink in a day? -Are you on a special diet or have restrictions? Do you have food allergies? -What prescription and over-the-counter medications do you take on a routine basis? (Look for laxatives, diuretics, corticosteroids, nonsteroidal antiinflammatory drugs [NSAIDs], effervescent antacids, and other effervescent preparations.) -Do you have a history of renal disease, diabetes mellitus, diabetes insipidus, or heart failure? -Do you have a recent history of surgery, trauma (including burns), gastroenteritis, head injury, vomiting, diarrhea, or fever?

What assessments are done to determine hypertonic FVD?

-body weight -intravascular volume -interstitial volume

What are s/s of pulmonary edema?

-tachypnea -labored, shallow respirations -restlessness -apprehensiveness -air hunger -cyanosis -blood-tinged or frothy -pink sputum -The peripheral and neck veins are usually engorged -BP and heart rate are increased -the pulse may be full and pounding or weak and thready. -edema of the extremities, adventitious breath sounds in the lungs -respiratory acidosis -profuse diaphoresis

2.2 lb (1 kg) is equivalent to how many Liters?

1 liter (1000 mL) of fluid

What are the two assessment principles of isotonic FVD?

1. 1 liter of fluid weighs 2.2 lb (1 kg). 2. The fluid is deficient in the intravascular and interstitial areas.

Which patients would a nurse conclude are experiencing fluid volume deficit (FVD)? Select all that apply. 1. An 86-year-old woman with a fever who has dry mucous membranes and decreased urination 2. A 50-year-old man with mild hypertension and flat neck veins while seated who has lost 8% total body weight over a year's time 3. An infant with diarrhea who has increased respiratory rate, tachycardia, and sunken fontanel 4. A 75-year-old woman with orthostatic hypotension and tachycardia after an increase in her blood pressure medication dosage 5. A 40-year-old woman with bleeding who has a weak, thready pulse and decreased skin turgor

1. An 86-year-old woman with a fever who has dry mucous membranes and decreased urination Dry mucous membranes and decreased urinary output are clinical manifestations of FVD. These signs can also have other causes, so further assessment of fluid status is necessary. 3. An infant with diarrhea who has increased respiratory rate, tachycardia, and sunken fontanel Because children have smaller bodies, they are more susceptible to FVD. The nurse would suspect possible dehydration in a baby who presents with these signs. 5. A 40-year-old woman with bleeding who has a weak, thready pulse and decreased skin turgor Weak, thready pulse and decreased skin turgor in a person who has been bleeding are likely to be manifestations of FVD.

Which test measure renal function?

1. BUN 2. Creatinine

Which descriptions would a nurse provide when educating a patient about edema? Select all that apply. 1. Edema is caused by excessive fluid in the interstitial space. 2. Edema develops when fluid moves into the intravascular space faster than it is absorbed. 3. Dependent edema occurs in the sacral area of patients on bedrest. 4. Edema causes tissue to become quite fragile. 5. Increased circulating plasma proteins are a major cause of edema.

1. Edema is caused by excessive fluid in the interstitial space. Edema is caused by fluid moving into the interstitial area at a faster rate than it is reabsorbed into the intravascular space. 3. Dependent edema occurs in the sacral area of patients on bedrest. When the patient is bedbound, edema can often be found in the sacral area of the lower back. 4. Edema causes tissue to become quite fragile. Where edema is present, the cells are pushed apart and away from nearby capillaries, making the affected tissue fragile.

Which laboratory results would a nurse expect when caring for a patient with vomiting and diarrhea who has developed rapid onset isotonic fluid volume deficit (FVD)? Select all that apply. 1. Elevated red blood cell (RBC) levels 2. Increased blood urea nitrogen (BUN) and creatinine levels 3. Low serum osmolality 4. Decreased urine specific gravity 5. Decreased urine osmolality

1. Elevated red blood cell (RBC) levels Elevated RBC levels are found when an FVD has developed rapidly. Increased RBC indicates a concentration of blood cells and too little circulating fluid. 2. Increased blood urea nitrogen (BUN) and creatinine levels The increased BUN and creatinine levels are a result of too little fluid passing through the kidneys.

What are the 3 essential components of a fluid balance assessment?

1. Health History 2. Focused Assessment 3. Review of Laboratory Results

Which specific clinical findings would be expected by a nurse caring for an adult patient with isotonic fluid volume deficit (FVD)? Select all that apply. 1. Hypotension 2. Flat neck veins when supine 3. Confusion 4. Low urine output 5. Slow, thready pulse

1. Hypotension The patient with either type of FVD can develop hypotension as a result of decreased circulating volume. 2. Flat neck veins when supine The patient with either type of FVD typically develops flat neck veins when lying in a supine position. 4. Low urine output The patient with either type of FVD can develop decreased urine output (oliguria) as a result of diminished cardiac output caused by decreased circulating fluid volume.

What are the 4 primary causes of edema formation?

1. Increased hydrostatic pressure caused by intravascular fluid overload from FVE 2. Decreased circulating plasma proteins 3. Obstruction of lymphatic drainage 4. Increased capillary permeability caused by inflammation

What body systems are assessed for Hydration

1. Neurological 2. Cardiovascular 3. Respiratory 4. Musculoskeletal 5. Urinary

A patient who received hypotonic intravenous (IV) fluids has developed the signs and symptoms of hypotonic fluid volume excess (FVE). Which neurologic signs or symptoms are consistent with this fluid imbalance? Select all that apply. 1. Seizures 2. Paralysis 3. Tingling sensations in the lower extremities 4. Confusion 5. Facial numbness

1. Seizures Decreased level of consciousness, including confusion, seizures, and coma, can result from hypotonic FVE, caused by cerebral edema and increased intracranial pressure. 4. Confusion Decreased level of consciousness, including confusion, seizures, and coma, can result from hypotonic FVE, caused by cerebral edema and increased intracranial pressure.

Edema from extracellular FVE is commonly visible in?

1. The ankles and feet in an upright person 2. The sacral area in a bedbound person 3. Other areas of the body if severe; generalized edema can occur with certain disorders

What is measured in the urine?

1. Urine specific gravity 2. Urine osmolality They measure the solute concentration in the urine

What are the main things involved when doing a focused assessment?

1. Vital signs 2.I&O 3. Weight 4. Mucous Membranes 5. Lungs Sounds

What are the two Signs and Symptoms of Hypotonic FVE?

1. increased Circulating Volume 2. increased Cellular Edema

What are the 2 clinical manifestations associated with isotonic FVE?

1. increased interstitial fluid 2. Increased Circulating volume

What are the two types of FVE?

1. isotonic FVE 2. hypotonic FVE

Sudden weight gain of 1. 2%? 2.5%? 3. 8%?

1. mild FVE 2. moderate FVE 3. severe FVE

What are Associated signs and symptoms with a decreasing circulating volume?

1. vital signs change: -Orthostatic hypotension -Hypotension -Tachycardia -Weak, thready pulse -Increased respiratory rate in children not adults 2. Other changes: -light headed -Flat neck veins when supine (adults) -Low urine output (oliguria) -Thirst (may be impaired in older adults) -Sunken fontanel (infants)

The severity of dehydration is categorized based on the percentage of total body weight. What percentage is considered life-threatening (fatal) dehydration?

15%

The severity of dehydration is categorized based on the percentage of total body weight. What percentage is considered mild dehydration?

2%

Which questions would be appropriate for the nurse to ask to obtain fluid balance information? Select all that apply. 1. "What types of fiber-containing food do you eat during a typical day?" 2. "Have you lost or gained weight recently?" 3. "Do you have a history of renal disease or diabetes mellitus?" 4. "Have you noticed swelling of your hands and feet?" 5. "Do you have any food allergies?"

2. "Have you lost or gained weight recently?" Weight gain or loss, especially when rapid and unintentional, would support the presence of a fluid imbalance. 3. "Do you have a history of renal disease or diabetes mellitus?" Patients with renal diseases and diabetes mellitus are at increased risk for development of fluid imbalance. 4. "Have you noticed swelling of your hands and feet?" Swelling (edema) in hands and especially feet and ankles may indicate dependent edema, which would support the presence of a fluid imbalance.

Which patient assessments would suggest a significant fluid volume deficit (FVD) in an acutely ill patient brought into the urgent treatment center? Select all that apply. 1. Hypertension 2. Elevated serum blood urea nitrogen (BUN) and creatinine levels 3. Rapid, weak, thready pulse 4. Weight loss of 0.5 kg over the past 2 days 5. Dry, cracked lips and furrows on the tongue

2. Elevated serum blood urea nitrogen (BUN) and creatinine levels Elevated serum BUN and creatinine levels can occur from too little fluid passing through the kidneys. 3. Rapid, weak, thready pulse A pulse that is rapid (tachycardia) and also weak and thready suggests significant FVD. 5. Dry, cracked lips and furrows on the tongue Mucous membranes and the tongue can become very dry and cracked with significant FVD.

For FVD how much weight is lost?

2.2 lb (1 kg) or more in 24 hours is significant.

For FVE how much weight is gained?

2.2 lb (1 kg) or more in 24 hours is significant.

Which laboratory results would a nurse expect in a patient who has developed a hypertonic fluid volume deficit? Select all that apply. 1. Decreased urine specific gravity 2. Decreased hematocrit levels 3. Increased blood urea nitrogen (BUN) and creatinine levels 4. Low red blood cell (RBC) count 5. Elevated serum osmolality

3. Increased blood urea nitrogen (BUN) and creatinine levels Increased BUN and creatinine levels are indicators of poor renal function or low fluid volume. 5. Elevated serum osmolality Elevated serum osmolality indicates hypertonic fluid volume deficit or hypernatremia.

The severity of dehydration is categorized based on the percentage of total body weight. What percentage is considered moderate dehydration?

5%

The severity of dehydration is categorized based on the percentage of total body weight. What percentage is considered severe dehydration?

8%

Which sign or symptom in a patient with fluid volume deficit would be a result of decreased interstitial fluid? A. Decreased skin turgor B. Weak, thready pulse C. Lightheadedness D. Sunken fontanel in an infant

A. Decreased skin turgor Skin turgor is altered by interstitial fluid levels. Assessing skin turgor is a quick assessment for fluid deficit.

Which manifestation, specifically caused by an increase in interstitial fluids, would a nurse expect when caring for a patient who has developed fluid volume excess (FVE)? A. Confusion B. Dependent edema C. Bounding peripheral pulses D. Jugular vein distension

B. Dependent edema Edema is caused by increased fluid in the interstitial space. It occurs when fluid accumulates faster than it can be absorbed and is a common manifestation of FVE.

Which type of fluid imbalance would a nurse suspect when the morning patient assessment reveals bounding peripheral pulses and jugular venous distention? A. Increased interstitial fluids B. Increased circulating volume C. Increased intracellular volume D. Increased transcellular volume

B. Increased circulating volume Bounding peripheral pulses and jugular venous distention are caused by increased circulating fluid volume, which occurs when excessive fluid is retained in the cardiovascular system.

Which degree of fluid volume excess (FVE) would a nurse document for an adult patient with a 5% weight gain over the last 24 hours because of fluid retention? A. Mild FVE B. Moderate FVE C. Irreversible FVE D. Severe FVE

B. Moderate FVE

Which patient health history finding would alert the nurse to the possibility of a fluid volume imbalance? A. Weight loss of 5 kg over the past month B. Weight gain of 2 kg since yesterday morning C. Loss of appetite for the past few weeks D. Occasional headaches

B. Weight gain of 2 kg since yesterday morning An increase of 1 or more kg over a 24-hour period is a very strong indicator of a fluid volume excess.

Which Lab test is a Indicator of overall renal function?

BUN & Creatinine

Which amount of fluid would the nurse calculate has been lost by a patient with a fluid volume deficit reporting a 10 kg loss of total body weight in the last 48 hours as a result of vomiting and diarrhea? A. 1 liter of fluid B. 5 liters of fluid C. 10 liters of fluid D. 15 liters of fluid

C. 10 liters of fluid The principle states that 1 liter of fluid weighs 1 kg; therefore, if the patient has lost 10 kg of total body weight, around 10 liters of fluid have been lost.

Which sign or symptom suggests that a patient is experiencing hypertonic fluid volume deficit (FVD)? A. Hypotension B. Oliguria C. Confusion D. Dry mucous membranes

C. Confusion The patient with hypertonic FVD develops neurologic clinical manifestations caused by brain cell dysfunction when water shifts out of the brain cells, shrinking them. This does not occur in patients with isotonic FVD.

Which level on the dehydration scale would a nurse use to describe a patient with a weight loss of 8% of total body weight secondary to vomiting and diarrhea? A. Mild dehydration B. Moderate dehydration C. Severe dehydration D. Life-threatening dehydration

C. Severe dehydration A weight loss of 8% of total body weight is categorized as severe dehydration. Severe dehydration requires prompt treatment to prevent the patient from progressing to life-threatening dehydration.

What is one of the most common causes of pulmonary edema?

CHF

If a patient has FVE what do there lungs sound like?

Crackles in the lung bases

Which datum would support the presence of fluid volume excess (FVE) in a patient with associated risk factors? A. Weak, thready pulse B. Weight loss of 1 kg since yesterday C. Poor skin turgor D. Crackles auscultated in lung bases

D. Crackles auscultated in lung bases Crackles in the lung bases occur with fluid in the lungs and is associated with FVE.

Which explanation would a nurse give to a student regarding the primary cause of edema resulting from fluid volume excess? A. Increased capillary permeability B. Obstruction of lymphatic drainage C. Decreased circulating plasma proteins D. Increased hydrostatic pressure

D. Increased hydrostatic pressure Increased hydrostatic pressure is the pressure exerted against vessel walls as blood rushes through the vasculature. As pressure increases with fluid volume excess, fluid leaves the blood vessels, entering the interstitial spaces.

Which rationale would explain the neurologic signs and symptoms caused by hypertonic fluid volume deficit? A. Decreased serum osmolality causes water to shift out of brain cells by osmosis. B. Decreased intracellular osmolality causes water to shift into the brain cells by osmosis. C. Increased intracellular osmolality causes sodium to shift into the brain cells by osmosis. D. Increased serum osmolality causes water to shift out of brain cells by osmosis.

D. Increased serum osmolality causes water to shift out of brain cells by osmosis. As water shifts out of the cells, they shrink and become dysfunctional, causing neurologic signs and symptoms.

Explain 4+ pitting edema

Deep indentation (8 mm) that remains for several minutes

Explain 2+ pitting edema

Deeper indentation (4mm) that lasts longer

What type of questions should you ask yourself for reviewing Lab results?

Do certain lab values indicate fluid volume imblance?

What type of questions should you ask yourself in a Focused Assessment?

Does the patient have visible edema, a bounding or thready pulse, shortness of breath, or other signs of fluid imbalance?

What does a patients mucous membranes look like when they are FVD?

Dry lips; dry, sticky mucous membranes; and furrows in the tongue

If a patient has FVE what might the skin look like?

Edema

If the patient has a FVD what happens to the BUN & Creatinine?

Elevated values from too little fluid passing through the kidneys

If the patient has FVD what happens to their CBC?

Elevated with FVD that develops rapidly (concentration of blood cells, too little circulating fluid)

What is ascites?

Excess fluid accumulation in the abdominal cavity

When a patient has Isotonic fluid volume excess (FVE) what is retained in the body and what does that do to the body?

Excess water and sodium are retained in the same proportion, which results in increased circulating blood volume without a change in serum osmolality.

Associated blood loss from hypovolemic shock may rise from?

GI bleeding, internal or external hemorrhage, or excessive reduction of intravascular plasma volume and body fluids.

What is isotonic?

Having the same solute concentration as another solution.

What does it mean if a patient has a Decreased urine osmolality?

Isotonic FVD would result in reduced urine output that is more concentrated (has increased urine osmolality).

What can occur if a patient has hypertonic FVD?

It can cause neurologic manifestations because of the decreased intracellular fluid.

What happens if a patient has severe isotonic FVE?

It can cause pulmonary venous congestion that may progress to life-threatening pulmonary edema

What happens if there is more than 20% decrease in the bodies blood volume?

It can lead to hypovolemic shock and potentially irreversible organ and tissue damage or death.

Explain Isotonic fluid volume excess (FVE)

It is an overload of fluid in both the interstitial and intravascular spaces.

If the patient has a FVD what happens to their blood serum osmolality?

It may be elevated with hypertonic FVD

What happens when the Interstitial fluid decreases?

Loss of interstitial fluid results in noticeable changes in the skin and mucous membranes.

If the patient has FVE what happens to their CBC?

Normal or low

If the patient has a FVE what happens to their blood serum osmolality?

Normal with isotonic FVE but low with hypotonic FVE

Explain 3+ pitting edema

Obvious indentation (6 mm) that lasts several seconds

What is hypertonic FVD?

Proportionately more water than sodium is lost. Water moves out of cells by osmosis, causing them to shrink.

Which lab Measures of the oxygen-carrying capacity of the blood?

RBC, H&H

Which lab Helps determine hydration status, useful in managing fluid requirements?

Serum Osmolality

What labs do you want to assess when checking for fluid imbalance?

Serum electrolyte levels, renal function, and hydration along with the oxygen-carrying capacity of blood cells. Urinalysis may also provide information regarding fluid balance.

Explain 1+ pitting edema

Slight indentation (2mm) and returns to normal pretty quickly.

What are some signs of Fluid volume excess (FVE)?

Strong, bounding pulse; increased blood pressure

What is a common clinical manifestation of FVE?

Swelling or edema

S/S of isotonic FVD related to a decreasing circulating volume?

The cardiac output is directly impacted by decreased circulating volume, reducing transport of oxygen and nutrients to the tissues.

Where is the excess fluid found ?

The excess fluid is present in both the intravascular and interstitial areas because it distributes by capillary filtration.

What are examples of how a patient experiences Isotonic fluid volume deficit (FVD)?

The patient is losing fluid from bleeding, diarrhea, or vomiting.

What are you looking for when inspecting a patients mucous membranes?

The patients tongue and mucous membranes should be moist with no cracks.

Explain what happens to the sodium concentration when a patient has Hypertonic Fluid Volume Excess?

The sodium concentration within the cells becomes higher than the extracellular concentration, and water enters the cells by osmosis. The cells swell (cellular edema) and become dysfunctional.

What occurs when a patient is experiencing Isotonic fluid volume deficit (FVD)?

Their extracellular fluid is decreased

What happens to the blood volume and serum osmolality? Hypotonic fluid volume excess (FVE)

There is an increase in circulating blood volume with a decreased serum osmolality (hemodilution)

If a patient has FVE what happens?

They have an excess of extracellular fluid in the body.

What does it mean if a patient has a low serum osmolality?

This is normally seen in patients that have a hypotonic fluid volume excess, or hyponatremia

Which lab Measures of the concentration of solutes in the urine?

Urine osmolality

If the patient has FVD what happens to their urinalysis?

Urine specific gravity and osmolality increase (unless caused by antidiuretic hormone [ADH] deficiency)

If the patient has FVE what happens to their urinalysis?

Urine specific gravity is low with hypotonic fluid volume excess; serum osmolality is normal or decreased

What does it mean if a patient has an Increased urine specific gravity?

Urine specific gravity typically elevates in isotonic FVD from increased concentration of solutes in the urine. Although urine specific gravity provides supportive data during data clustering, it is not considered a reliable indicator of FVD.

If the patient has a FVE what happens to the BUN & Creatinine?

Values may be normal if the FVE is not caused by renal dysfunction

What is isotonic FVD?

Water and sodium are lost in the same proportion as in normal body fluids.

What are some signs of Fluid volume deficit (FVD)?

Weight loss Postural hypotension Dryness of mucous membranes Decreased skin turgor (test forehead or sternum for elderly) Weak, rapid pulse Sunken eyeballs Oliguria (less than 500 mL/day or 30 mL/hr) Pale skin Increase in urine specific gravity (> 1.030) Increased hematocrit - less H2O, more stuff Increased BUN - protein in kidneys

What is a Positive fluid balance?

When intake is greater than output

What is a Negative fluid balance?

When intake is less than output

What is hemodilution?

a condition in which the concentration of erythrocytes or other blood elements is lowered, usually resulting from an increase in plasma volume.

What is dehydration accompanied by?

a disturbance in the balance of essential electrolytes, particularly sodium, potassium, and chloride.

What is hypovolemic shock?

a state of physical collapse and prostration caused by massive blood loss, about one fifth or more of total blood volume.

Where do you assess a patient for Edema?

at the forehead, anterior chest, and medial forearm by gently pinching to see whether the pinched skin returns to normal or remains pinched.

How can edema be graded?

based on depth of the indentation when edematous skin is pressed.

Increased circulating volume is visible in the?

cardiovascular system

What are the S/S of FVD stemmed from?

decreased circulating fluid volume and decreased interstitial fluid.

What is FVD characterized by?

dehydration and a decrease in fluid in the intravascular and interstitial spaces of the body.

What are some disorders that may cause hypovolemic shock?

dehydration from excessive perspiration, severe diarrhea, protracted vomiting, intestinal obstruction, peritonitis, acute pancreatitis, and severe burns, which deplete body fluids.

Increased interstitial fluid manifests as?

edema

Describe Edema

excessive fluid in the interstitial space

What is dehydration?

excessive loss of water from body tissues.

What is pulmonary edema?

fluid in the lung tissues and alveoli

What is hypertonic?

having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid.

What is the abbreviation H&H is often used in place of?

hemoglobin and hematocrit.

What does RBCs and hemoglobin, and hematocrit levels measure?

if the blood is able to carry oxygen

Where does the fluid accumulate mostly if a patient has FVE?

in the dependent parts of the body such as the legs and feet or sacrum when lying down.

In hypotonic FVE, water shifts ?

into cells, causing them to swell and causing cerebral edema and pulmonary congestion or edema

What are the common signs of a hypovolemic shock?

low BP, thready pulse, clammy skin, tachycardia, rapid breathing, and reduced urinary output.

In hypertonic FVD, water shifts?

out of cells, causing them to shrink.

What are signs of dehydration?

poor skin turgor (not a reliable sign in the elderly), flushed dry skin, coated tongue, dry mucous membranes, oliguria, irritability, and confusion.

What is the rule for accurate weights?

same scale, same time, same clothing

If a patient has FVD what might happen to the skin?

skin turgor, when skin remains pinched (not accurate in older adults).

What does serum osmolality measure?

solute concentration in the blood and helps determine hydration status. (blood chemistry)

What is osmosis?

the movement of a pure solvent, such as water, through a differentially permeable membrane from a solution that has a lower solute concentration to one that has a higher solute concentration. Movement across the membrane continues until the concentrations of the solutions equalize.

What is hydrostatic pressure?

the pressure exerted by a liquid.

When does Hypotonic fluid volume excess (FVE) occur?

when excess water is retained in a higher proportion than sodium.

How does edema develop?

when fluid moves into the interstitial area at a faster rate than it can be reabsorbed into the intravascular space. Fluid pushes cells farther apart and away from the capillaries that provide their nourishment. This makes edematous tissue fragile.