Fluid Imbalances

Question 1

The process by which solutes move from an area of higher concentration to one of lower concentration is called ________________________.

Answer 1

Diffusion

Question 2

Tonicity is fluid _________________or the effect that osmotic pressure of a solution with impermeable solutes exerts on cell size because of water movement across the cell membrane.

Answer 2

Tension

Question 3

TRUE or FALSE
The cardinal feature of metabolic acidosis is a decrease in the serum bicarbonate level.

Answer 3

True

Question 4

TRUE or FALSE
A nurse should assess a patient with hypervolemia for indicators of hypotension, increased hematocrit and hemoglobin, and oliguria.

Answer 4

False

Question 5

TRUE or FALSE
Body fluid is located in two fluid compartments: the intracellular space (fluid in the cells) and the extracellular space (fluid outside the cells).

Answer 5

True

Question 6

TRUE or FALSE
Vital to the regulation of fluid and electrolyte balance, the kidneys of a well-hydrated adult excrete 1 to 2 L of urine per day.

Answer 6

True

Question 7

The major electrolytes in the extracellular fluid are ________________ and chloride.

Answer 7

Sodium

Question 8

________________ is the unintentional administration of a nonvesicant solution or medication into surrounding tissue.

Answer 8

Infiltration

Question 9

________________ is the excretion of less than 400 mL or urine per day in an adult.

Answer 9

Oliguria

Question 10

TRUE or FALSE
The nurse monitoring a patient’s potassium level knows tall, tented, “T” waves on an ECG are an indication of hypokalemia.

Answer 10

False

Question 11

How much fluid is lost through the kidneys?

Answer 11

1 mL/kg/hr

Question 12

What are the gerontological considerations for fluid imbalances?

Answer 12

• Clinical manifestations may be subtle
• Fluid deficit may cause delirium
• Level of conciousness may be affected
• Decreased cardiac reserve
• Reduced renal function
• Dehydration is common
• Blunted response to the thirst signal
• Age related thinning of the skin, loss of strength and elasticity = more fluid loss

Question 13

What is intercellular fluid?

Answer 13

• Fluid in the cells
• Contained in skeletal muscle mass
• makes up 2/3 of bodily fluid
• 40% of typical adult body weight

Question 14

What is extracellular fluid?

Answer 14

• Fluid in the Intravascular space (blood vessels)
• Fluid in the interstitial space (lymph)
• Transcellular fluid = cerebrospinal fluid, pericardial fluid, synovial fluid
• 20% of typical adult body weight

Question 15

What is osmolality?

Answer 15

• Determined by the solutes in body fluid
• Normal serum = 280-295 mOsm/kg
• Normal urine = 100-1300 mOsm/kg
• Lots of solutes = high osmolality = water moves IN
• Fewer solutes = low osmolality = water moves OUT

Question 16

What is osmosis?

Answer 16

Water moving from an area of low solute concentration to an area of high solute concentration

Question 17

What determines fluid moving through capillary walls?

Answer 17

• Osmotic pressure = exerted by the proteins in plasma (draws water INTO the vessels)
• Hydrostatic pressure = exerted on walls of blood vessels by plasma (Pushes water and small particles OUT of the vessels)

Question 18

How can you affect osmotic pressure?

Answer 18

Administering colloids or hypertonic solutions INCREASES osmotic pressure and draws more fluid INTO plasma from interstitial spaces

Question 19

What mainly affects hydrostatic pressure?

Answer 19

Blood pressure
Higher blood pressure = higher hydrostatic pressure = more fluids LEAVE the vessels and enter interstitial space

Question 20

Why does fluid shift into interstitial spaces in the body?

Answer 20

• Increase in venous pressure (pushing fluid out of vessels)
• Increase in interstitial oncotic pressure (drawing fluid into interstitial space)
• Decrease in plasma oncotic pressure

Question 21

How are interstitial fluid shifts decreased?

Answer 21

• Reduce venous pressure = Administer colloids, mannitol, hypertonic solutions
• Increase tissue hydrostatic pressure = wear elastic stockings (TED hose)

Question 22

What is first spacing?

Answer 22

Fluids in the normal distribution (ECF, ICF)

Question 23

What is second spacing?

Answer 23

Abnormal accumulation of fluid in the interstitial space (edema)

Question 24

What is third spacing?

Answer 24

Fluid is trapped where it is difficult or impossible for it to move back into cells or blood vessels
(ascites)

Question 25

Explain the Hypothalmic-Pituitary regulation of water balance

Answer 25

* **Osmoreceptors** in the hypothalamus sense changes in body fluids * In **fluid deficit** = stimulates **thirst** and triggers release of **ADH** * In **fluid excess** = supresses release of **ADH**

Question 26

Explain the Adrenal Cortical Regulation of Water Balance

Answer 26

* Hormones are released to regulate water and electrolytes * Glucocorticoids = **Cortisol** = may cause Sodium and fluid **retention** * Mineralcorticoids = **Aldosterone** = causes sodium retention (with water) and Potassium excretion

Question 27

Explain the Renin-Angiotensin II Regulation of Fluid Balance

Answer 27

1. Kidneys detect a drop in BP, loss in sodium, or low Blood Volume 2. Kidneys release **Renin** 3. Renin converts **Angiotensinogen** (made by liver) to **Angiotensin I.** 4. Angiotensin I travels to lungs where enzyme **ACE** (Angiotensin converting enzyme) converts it to **Angiotensin II** 5. Angiotensin II = powerful **vasoconstrictor** (raises BP), stimulates **Aldosterone**release (retain Na and water), stimulates **ADH** release (retain water), stimulates thirst signal 6. Result = retained fluids, increase in BP and blood volume

Question 28

Explain the Cardiac regulation of Water Balance

Answer 28

**Natriuretic peptides** antagonize the RAAS system **ANP** and **BNP** are produced by cardiomyoctes in response to increased atrial pressure and/or high Na levels End result = **lower blood pressure and volume**

Question 29

Explain the gastrointestinal regulation of water balance

Answer 29

* Oral route accounts for most water intake * Small amounts of water are eliminated by the GI tract in the feces * Diarrhea and vomiting can lead to significant fluid and electrolyte loss

Question 30

What is dehydration?

Answer 30

Loss of WATER ALONE with increased Na levels More common in: children, elderly, confused, with overexertion

Question 31

What is Fluid Volume Deficit (hypovolemia)?

Answer 31

* ECF fluid loss exceeds intake ratio of water * Electrolytes lost in same proportion as they exist in normal body fluids

Question 32

What is Fluid Volume Excess (hypervolemia)?

Answer 32

* Isotonic expansion of the ECF caused by abnormal retention of water and sodium (in the same proportions as they normally are)

Question 33

What are possible causes of **Fluid Volume Deficit** (hypovolemia)?

Answer 33

* Abnormal fluid loss (vomiting, diarrhea, sweating, GI suctioning) * Decreased Intake (nausea, lack of access to fluids) * Third Space Fluid Shifts (due to burns or ascites, or edema) * Diabetes insipidus * Adrenal insufficiency * Hemorrhage * Trauma

Question 34

What are some causes of **Fluid Volume Excess** (hypervolemia)?

Answer 34

* Heart failure * Renal injury/failure * Liver failure (cirrhosis) * Excessive IV solutions and/or blood transfusions * Excessive oral sodium intake * Abnormal retention of fluids and sodium * Fluid shift increasing to intravascular volume * Pregnancy * Medication side effects * SIADH *(Syndrome of Inappropriate Antidiuretic Hormone secretion)*

Question 35

What are colloids?

Answer 35

* Human plasma products (albumin, fresh frozen plasma, blood) * Semisynthetics (dextran and starches, Hespan) * Sometimes referred to as volume or plasma expanders * Stays IN vascular space and increases osmotic pressure (Pulls fluid INTO blood vessels)

Question 36

What are crystalloids?

Answer 36

* Solutions with small molecules which can move around easily when injected into body * 0.9% NaCl (NS) **isotonic** * Lactated Ringers (LR) **isotonic** * 0.45% NaCl **hypotonic** * 3% NaCl **hypertonic** * 5% Dextrose in water (D5W) **both hypotonic and isotonic)**

Question 37

What do **hypotonic** IV fluids do?

Answer 37

* **ECF ➡️ ICF** * Moves water **OUT of vessels** and **INTO cells** * 🦛 Hypo = "Hippo" = **PLUMPS cells** 🦛 * Contains more water than electrolytes * *Never inject pure water into a vein - will lyse RBCs* * Monitor for changes in mentation

Question 38

What do **isotonic** IV fluids do?

Answer 38

**Stays in the ECF** * Expands volume in ECF only

Question 39

What do **hypertonic** IV fluids do?

Answer 39

* **ICF ➡️ ECF** * Raises osmolality of ECF * Pulls water out of cells and into blood vessels * Cells **shrink** * Requires frequent monitoring of: blood pressure, lung sounds, serum sodium levels *used for severe hyponatremia and cerebral edema*

Question 40

Clinical manifestations of **FVD (hypovolemia)**

Answer 40

* Hypotension * Tachypnea * Tachycardia * lethargy, weakness * dizziness * seizures, coma * increased thirst * decreased skin turgor, cap refill, urine output

Question 41

Treatment for **FVD** (hypovolemia)

Answer 41

* Correct underlying cause * Oral route preferred * Isotonic solutions (0.9% NS, LR) * Blood Products * Hypertonic Solutions (very carefully monitored)

Question 42

**FVD (hypovolemia)** Nursing Management

Answer 42

* Monitor I/O * Daily weights * Vital signs closely monitored * Assess skin and tongue turgor, mucosa, urine output, mental status * Minimize fluid loss * Administer oral fluids * Administer parenteral fluids

Question 43

Clinical manifestations of **FVE (hypervolemia)**

Answer 43

* Hypertension * Pulmonary edema * crackles in lungs * S3 heart sound * headache * increased urine output * weight gain * peripheral/sacral edema * bounding pulse

Question 44

Treatment for **FVE** (hypervolemia)

Answer 44

* Remove fluid while maintaining adequate electrolyte composition (osmolality) of ECF * Diuretics * Fluid restriction * Restrict sodium intake * Aquapheresis (ultrafiltration) * For 24 hr fluid restriction: give ~ 70% during day hours, ~ 30% at night

Question 45

Treatment for **second spacing** hypervolemia

Answer 45

* Hypertonic fluids (mannitol, D5 1/2 NS) * Plasma proteins (albumin) to shift water from interstitial space to vascular space; followed by diuretics

Question 46

Treatment for **third spacing** hypervolemia

Answer 46

* Thoracentesis * Paracentesis * Albumin

Question 47

**FVE (hypervolemia)** Nursing Management

Answer 47

* Monitor I/Os * Daily weights * Monitor VS * Assess respiratory changes/lung sounds * Assess CV status * Monitor edema * Monitor lab values * Skin assessment (turgor, color, temperature)