FLUIDS AND ELECTROLYTE PHYSIOLOGY

Question 1

What are the percentages of total body water (TBW) for a newborn, 1-3 years old, and adult?

Answer 1

“Newborn: 75-80%
1-3: 65%
Adult: 55-60%

Question 2

What is the main cation and anion in the plasma?

Answer 2

“Main cation: Sodium
main Anion: Chloride

Question 3

What is the main cation and anion in intracellular fluid (ICF)?

Answer 3

“Main cation: Potassium
Main Anion: Phosphorus

Question 4

What is the percentage of extracellular fluid (ECF) for a newborn, 1-3 years old, and adult?

Answer 4

“Newborn: 45%
1-3: 25%
adult: 25%

Question 5

What is the percentage of intracellular fluid (ICF) for a newborn, 1-3 years old, and adult?

Answer 5

“Newborn: 35%
1-3: 40%
adult: 40%

Question 6

What happens to total body water (TBW) as a person ages?

Answer 6

“Total body water decreases with age

Question 7

What is tonicity?

Answer 7

“Tonicity is a measure of the effective pressure gradient defined by the water potential of two solutions separated by a semi-permeable membrane.”

Question 8

Define hypotonic solution and its effect on red blood cells.

Answer 8

“In a hypotonic solution RBC’s swell-lower concentration of olutes OUTSIDE the cell + BURSTINGG (LYSIS)

Question 9

Define isotonic solution and its effect on red blood cells.

Answer 9

“In an isotonic solution, concentration of solutes EQUAL inside & outside

Question 10

Define hypertonic solution and its effect on red blood cells.

Answer 10

“In a hypertonic solution, solute concentration is HIGHER OUTSIDE the cell= SHRINK(CRENATION)

Question 11

What is the source of water loss in the body?

Answer 11

“Urine (60%)
Insensible loss (30%) skin & lungs
Stool (5%)

Question 12

What are the goals of maintenance fluids?

Answer 12

● Prevent dehydration
● Prevent electrolyte disorders
● Prevent ketoacidosis
● Prevent protein degradation

Question 13

How do you calculate maintenance fluid requirement for the first 10 kg of body weight in pediatrics?

Answer 13

multiply by 100 mL/kg”

Question 14

How do you calculate maintenance fluid requirement for the second 10 kg of body weight in pediatrics?

Answer 14

” multiply by 50 mL/kg”

Question 15

How do you calculate maintenance fluid requirement for the third 10 kg or remaining weight in pediatrics?

Answer 15

“multiply by 20 mL/kg”

Question 16

What is the Holliday-Segar Method for maintenance fluid requirement for a weight of 3-10 kg?

Answer 16

“100 mL/kg”

Question 17

What is the Holliday-Segar Method for maintenance fluid requirement for a weight of 11-20 kg?

Answer 17

“1000 mL + 50 mL/kg (for excess over 10 kg)”

Question 18

What is the Holliday-Segar Method for maintenance fluid requirement for a weight greater than 20 kg?

Answer 18

“1500 mL + 20 mL/kg (for excess over 20 kg)”

Question 19

How do you calculate daily maintenance fluid volume using the body weight method for a child weighing 0-10 kg?

Answer 19

“100 mL/kg”

Question 20

How do you calculate daily maintenance fluid volume using the body weight method for a child weighing 11-20 kg?

Answer 20

“1000 mL + 50 mL/kg (for each kg >10 kg)”

Question 21

How do you calculate daily maintenance fluid volume using the body weight method for a child weighing over 20 kg?

Answer 21

“1500 mL + 20 mL/kg (for each kg >20 kg)”

Question 22

What is the main electrolyte in the extracellular fluid?

Answer 22

“Sodium (Na)”

Question 23

What is the main electrolyte in the intracellular fluid?

Answer 23

“Potassium (K)”

Question 24

Where is the majority of potassium found in the body?

Answer 24

“Potassium is mainly found in muscles and in small amounts in the plasma.”

Question 25

What is the dietary potassium requirement?

Answer 25

"1-2 mEq/kg"

Question 26

How do you calculate the sodium requirement for a 10 kg patient?

Answer 26

"Na requirement = 10 kg x 3 = 30 mEq/100 mL H2O"

Question 27

How do you calculate the potassium requirement for a 10 kg patient?

Answer 27

"K requirement = 10 kg x 2 = 20 mEq/100 mL H2O"

Question 28

What is the goal of deficit therapy?

Answer 28

"Restore intravascular volume and replace fluid losses from pathologic causes."

Question 29

How is oral rehydration therapy administered?

Answer 29

"Oral rehydration therapy is administered orally or via nasogastric tube (NGT) for patients who can tolerate it."

Question 30

When is parenteral (intravenous) fluid therapy used?

Answer 30

"Parenteral fluid therapy is used for patients who cannot drink or are vomiting

Question 31

What are the fluid replacement therapy amounts for mild dehydration in a patient weighing <12 kg?

Answer 31

"50 mL/kg/8 hours."

Question 32

What are the fluid replacement therapy amounts for moderate dehydration in a patient weighing <12 kg?

Answer 32

"100 mL/kg/8 hours."

Question 33

What are the fluid replacement therapy amounts for severe dehydration in a patient weighing <12 kg?

Answer 33

"150 mL/kg/8 hours."

Question 34

What are the fluid replacement therapy amounts for mild dehydration in a patient weighing >12 kg?

Answer 34

"30 mL/kg/8 hours."

Question 35

What are the fluid replacement therapy amounts for moderate dehydration in a patient weighing >12 kg?

Answer 35

"60 mL/kg/8 hours."

Question 36

What are the fluid replacement therapy amounts for severe dehydration in a patient weighing >12 kg?

Answer 36

"90 mL/kg/8 hours."

Question 37

How should fluids be administered in moderate dehydration?

Answer 37

Give 1/4 in 1 hour Give 3/4 in the next 7 hours

Question 38

How should fluids be administered in severe dehydration?

Answer 38

Give 1/3 in 1 hour Give 2/3 in the next 7 hours

Question 39

What fluids are used for moderate dehydration?

Answer 39

Plain LRS, PNSS D5 LRS

Question 40

What fluids are used for severe dehydration?

Answer 40

Plain LRS, PNSS D5 LRS

Question 41

What are the signs of severe dehydration?

Answer 41

Mental status: Lethargy/ unconsciousness - Sunken eyes - Unable to drink or drink poorly - Skin turgor: skin pinch goes back very slowly (≥2 seconds)

Question 42

What are the signs of some dehydration?

Answer 42

Restlessness, irritability - Sunken eyes - Drinks eagerly, thirsty

Question 43

What defines no dehydration?

Answer 43

"Not enough signs to classify as some or severe dehydration."

Question 44

What is the first step in managing dehydration?

Answer 44

"Assess the patient according to the level of dehydration—mild, moderate & severe

Question 45

What is the formula for computing fluid replacement therapy for a patient under 12 kg with mild dehydration?

Answer 45

"Wt (kg) x 50 mL/kg/8 hours."

Question 46

What is the formula for computing fluid replacement therapy for a patient over 12 kg with mild dehydration?

Answer 46

"Wt (kg) x 30 mL/kg/8 hours."

Question 47

How should a patient be reassessed after 8 hours of fluid replacement therapy?

Answer 47

"If dehydration has resolved

Question 48

What are the sources of water loss in the gastrointestinal system?

Answer 48

Diarrhea, vomiting, nasogastric suctioning, ostomies

Question 49

What are the sources of water loss in the renal system?

Answer 49

Diuretics, tubular-concentrating disorders, adrenal insufficiency, diabetes insipidus

Question 50

What are the sources of water loss in the skin?

Answer 50

Burns, sweat losses in endurance exercise, fever

Question 51

What are the sources of water loss in third spacing?

Answer 51

Intestinal obstruction, bleeding (trauma patients, massive bleeding), sepsis, anaphylaxis

Question 52

What are the sources of water loss from inadequate fluid intake?

Answer 52

Physical impairment, altered mental status, dysphagia

Question 53

What factors increase water needs from the skin?

Answer 53

radiant warmer Phototherapy Fever Sweat Burns

Question 54

What factors decrease water needs from the skin?

Answer 54

"Incubator (for premature infants)."

Question 55

What factors increase water needs from the lungs?

Answer 55

"Tachypnea & Tracheostomy

Question 56

What factors decrease water needs from the lungs?

Answer 56

"Humidified ventilator."

Question 57

What factors increase water needs from the GIT?

Answer 57

"Diarrhea Emesis Nasogastric suction

Question 58

What factors increase water needs from the renal system?

Answer 58

"Polyuria."

Question 59

What factors decrease water needs from the renal system?

Answer 59

"Oliguria/anuria."

Question 60

What factors increase water needs from miscellaneous sources?

Answer 60

"Surgical drain

Question 61

What is parenteral fluid therapy?

Answer 61

"Parenteral fluid therapy involves intravenous administration of crystalloids colloids, or blood products

Question 62

What are crystalloids?

Answer 62

"Crystalloids are aqueous solutions with varying concentrations of electrolytes and are most commonly used fluids in a hospital setting."

Question 63

What is the main purpose of crystalloids?

Answer 63

"Crystalloids increase intravascular volume."

Question 64

What are colloids?

Answer 64

"Colloids are high molecular weight substances that remain in the intravascular compartment longer than crystalloids

Question 65

What is the disadvantage of using colloids for extended periods?

Answer 65

"Colloids generate oncotic pressure and decrease blood coagulability."

Question 66

What is the cost difference between crystalloids and colloids?

Answer 66

"Colloids are more expensive than crystalloids."

Question 67

What is the use of albumin in fluid therapy?

Answer 67

"Albumin is used in cases of nephrotic syndrome and to remove excess fluid in patients with edema or anasarca."

Question 68

When are colloids typically used?

Answer 68

"Colloids are the fluid of choice when there is a need for rapid fluid replacement

Question 69

What are the components of intravenous fluids?

Answer 69

"Intravenous fluids may contain sodium (Na)

Question 70

What are standard oral rehydration solutions (ORS) used for?

Answer 70

"ORS is used in patients who can drink water and are not vomiting but still need fluid replacement."

Question 71

What is the concern with standard ORS solutions?

Answer 71

"Standard ORS contains high levels of glucose

Question 72

What is the purpose of reduced osmolarity ORS?

Answer 72

"Reduced osmolarity ORS is developed to avoid inducing dehydration while still providing effective fluid replacement."

Question 73

What are some examples of ORS solutions?

Answer 73

"Examples include Glucolyte plus

Question 74

Which ORS solution is commonly used for patients with diarrhea?

Answer 74

"Glucolyte plus

Question 75

What is a home fluid option that has osmolarity similar to ORS?

Answer 75

"Coconut water has osmolarity similar to reformulated ORS."