SR 18 - Fluids and Electrolytes Flashcards Preview

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Flashcards in SR 18 - Fluids and Electrolytes Deck (159):
1

Two major body fluid compartments?

Intracellular and extracellular

2

Two subcompartments of ECF?

Interstitial fluid (inbetween cells)
Intravascular fluid (plasma)

3

What percentage of body weight is in fluid?

60%

4

What percentage of body fluid is intracellular?

66%

5

What percentage of body fluid is extracellular?

33%

6

What is the composition of body fluid?

Fluids - 60% of TBW
ICF - 40% TBW
ECF - 20% TBW
(60, 40, 20)
Mnemonic TIE (Total body fluid, Intracellular, Extracellular)

7

On average, what percentage of body weight does blood account for in adults?

7%

8

How many liters of blood in a 70kg man?

0.07 x TBW

0.07 x 70kg = 5 liters

9

Fluid requirments every 24hrs for Water?

30-35 mL/kg

10

Fluid requirments every 24hrs for Potassium?

1 mEq/kg

11

Fluid requirments every 24hrs for Chloride?

1.5 mEq/kg

12

Fluid requirments every 24hrs for Sodium?

1-2 mEq/kg

13

What are the levels and sources of normal daily water loss?

Urine - 1200-1500mL (25-30 mL/kg)
Sweat - 200-400mL
Respiratory losses - 500-700mL
Feces - 100-200mL

14

What are the levels of normal daily electrolyte loss?

Sodium and potassium - 100mEq
Chloride - 150mEq

15

What are the levels of sodium and chloride in sweat?

40mEq/L

16

What is the major electrolyte in colonic feculent fluid?

Potassium - 65mEq/L

17

What is the physiologic response to hypoveolemia?

Sodium/H2O retention via renin
--> aldosterone, water retention via ADH, vasoconstriction via ATII and sympathetics
--> low urine output and tacycardia (early) and hypotensions (late)

18

What is third spacing?

Fluid accumulation in the interstitium of tissues
Edema
Loss of fluid into the interstitium and lumen of a paralytic bowel following surgery

Intravascular and intracellular spaces are the first two spaces

19

When does third-spacing resolve postoperatively?

Third-spaced fluid tends to mobilize back into the intravascular space around POD #3
You need to be mindful of fluid overload when the fluid returns intravascularly - Switch to hypotonic fluid and decrease IV rate

20

Classic signs of third spacing?

Tachycardia
Decreased urine output

21

Treatment of third spacing?

IV hydration with isotonic fluids

22

Surgical causes of Metabolic acidosis?

Loss of bicarbonate - diarrhea, ileus, fistula, high-output ileostomy, carbonic anhydrase inhibitors
Increase in acids - lactic acidosis (ischemia), ketoacidosis, renal failure, necrotic tissue

23

Surgical causes of hypochloremic alkalosis?

NGT suction, loss of gastric HCL through vomiting/NGT

24

Surgical causes of metabolic alkalosis?

Vomiting, NG suction, diuretics, alkali ingestions, mineralocorticoid excess

25

Surgical causes of respiratory acidosis?

Hypoventilation (i.e. CNS depression), drugs (i.e. morphine), PTX, pleural effusion, parenchymal lung disease, acute airway obstruction

26

Surigcal causes of respiratory alkalosis?

Hyperventilation (i.e. anxiety, pain, fever, wrong vent setting)

27

Classic acid-base finding with sinigicant vomiting or NGT suctioning?

Hypokalemic hypochloremic metabolic alkalosis

28

Why do you get hypokalemia with NGT suctioning?

Loss of gastric fluid:
- Loss of HCL causes alkalosis
- Alkalosis drives K+ into cells

29

Treatment for hypokalemic hypochloremic metabolic alkalosis?

IVF
Cl/K replacement

30

What is paradoxic alkalotic aciduria? Why does it happen?

Seen in severe hypokalemic, hypovolemic, hypochloremic metabolic alkalosis with paradoxic metabolic alkalosis of serum and acidic urine

Due to H+ loss in the urine in exchange for Na+ in an attempt to restore volume. H+ is preferentially lost over K+ due to the hypokalemia

31

What can be followed to assess fluid status?

Urine output
Base deficit
Lactic acid
Vital signs
Weight changes
Skin turgor
JVD
Mucosal membranes
Rales (crackles)
Central venous pressure
PCWP
CXR findings

32

With hypovolemia, what changes occur in vital signs?

Tachycardia
Tachypnea
Initial rise in diastolic pressure due to clamping down (peripheral vasoconstriction) with subsequent decrease in both systolic and diastolic blood pressure

33

What are the insensible fluid losses?

Loss of fluid that cannot be measured
Feces - 100-200mL/24hrs
Breathing - 500-700mL/24hrs (increases with fever and tachypnea)
Skin - 300mL/24hrs (increases with fever)

34

What is the quantity of daily secretions of bile?

1000mL/24hrs

35

What is the quantity of daily gastric secretions?

2000mL/24hrs

36

What is the quantity of daily pancreatic secretions?

600mL/24hrs

37

What is the quantity of daily small intestine secretions?

3000mL/day

38

What is the quantity of daily saliva secretions?

1500mL/day

39

What happens to bile, gastric, pancreatic, small intestines and salivary secretions?

Most of them are reabsorbed

40

Mnemonic for remembering daily secretions from bile, gastric and small-bowel sources?

BGS 123
Bile = 1L
Gastric = 2L
Small-bowel = 3L

41

Per liter, components of NS?

154 mEq of Cl and Na

42

Per liter, components of 1/2 NS?

77 mEq of Cl and Na

43

Per liter, components of 1/4 NS?

39 mEq of Cl and Na

44

Per liter, components of LR?

130 mEq of Na
109 mEq of Cl
28 mEq of lactate
4 mEq K
3 mEq Ca

45

Per liter, components of D5W

5% dectrose (50g) in water

46

What accounts for tonicity?

Electrolytes
NS/LR are both isotonic
1/2 NS is hypotonic

47

What happens to the lactate in LR in the body?

Converted to bicarbonate
Cannot use LR as maintanance fluid because the patient will become alkalotic

48

IV replacement based on anatomic site of losses - Gastric (NGT)?

D5 1/2 NS + 20 KCl

49

IV replacement based on anatomic site of losses - Biliary?

LR +/- sodium bicarbonate

50

IV replacement based on anatomic site of losses - pancreatic?

LR +/- sodium bicarbonate

51

IV replacement based on anatomic site of losses - Small bowel (ileostomy)?

LR

52

IV replacement based on anatomic site of losses - colonic (diarrhea)?

LR +/- sodium bicarbonate

53

What is the 100/50/20 rule associated with calculation of maintenance fluids?

Maintenance fluids for 24hrs:
- 100mL/kg for first 10kg
- 50mL/kg for next 10kg
- 20mL/kg for ever kg over 20

Divide by 24 for hourly rate

54

What is the 4/2/1 rule associated with calculation of maintenance fluids?

Maintenance fluids for hourly rate:
- 4mL/kg for first 10kg
- 2mL/kg for next 10kg
- 1mL/kg for every kg over 20kg

55

What is the common adult maintenance fluid?

D5 1/2 NS with 20mEq KCl/L

56

What is the common pediatric maintenance fluid?

D5 1/4 NS with 20mEq KCl/L
(Due to children's decreased ability of children to concentrate urine)

57

Why should sugar (dextrose) be added to maintenance fluid?

To inhibit muscle breakdown

58

What is the best way to assess fluid status?

Urine output
Unless patietn has cardiac or renal dysfunction - then use CVP or PCWP

59

What is the minimal urine output for an adult on maintenence IV?

Approximately 30mL/hr
0.5cc/kg/hr

60

What is the minimal urine ouptut for an adult trauma patient?

50mL/hr

61

How many mL are in 12 oz?

356mL

62

How many mL are in 1oz?

30mL

63

How many mL are in 1tsp

5mL

64

What are common isotonic fluids?

NS, LR

65

What is a fluid bolus?

Volume of fluid given IV rapidly (i.e. 1L over 1 hour)
Used for increasing intravascular volume
Use isotonic fluid (NS, LR)

66

Why not combine bolus fluids with dextrose?

Hyperglycemia may result

67

What is the possible consequence of hyperglycemia in the patient with hypovolemia?

Osmotic diuresis

68

Why not combine bolus fluids with a significant amount of potassium?

Hyperkalemia
Remember, LR only has 4mEq/L

69

Why should isotonic fluids be given for recuscitation?

If hypotonic fluid is given, the tonicity of the intravascular space will decrease and H2O will freely diffuse into the interstitial and intracellular space

Use isotonic fluid allow expanding of the intravascular space

70

What is the most common trauma resuscitation fluid?

LR

71

What is the most common postoperative IVF after a laparotomy?

LR or D5LR for 24-36 hours, followed by maintenance fluid

72

After a laparotomy, when should a patient's fluid be mobilized?

POD 3 - third-space fluid starts moving back into the intravascular space

73

What IVF is used to replace duodenal or pancreatic fluid loss?

LR - for the bicarbonate loss

74

What is a common cause of electrolyte abnormalities?

Lab error

75

What is a a major extracellular cation?

Na+

76

What is a major intracellular cation?

K+

77

What are the surgical causes of hyperkalemia?

Iatrogenic overdose
Blood tranfusion
Renal failure
Diuretics
Acidosis
Tissue destruction (injury/hemolysis)

78

What are the signs and symptoms of hyperkalemia?

Decreased deep tendon reflexes or areflexia
Weakness
Paraesthesia
Paralysis
Respiratory failure

79

What are the EKG findings of hyperkalemia?

Peaked T waves
Depressed ST segment
Prolonged PR
Wide QRS
Bradycardia
Ventricular fibrillation

80

What are critical values for potassium?

>6.5

81

What is the urgent treatment for hyperkalemia?

IV calcium (cardioprotective), ECG monitoring
Sodium bicarbonate IV (alkalosis will drive K+ intracellularly)
Glucose and insulin (will also drive K+ intracellularly)
Albuterol
Sodium polystyrene sulfonate (Kayexalate) and furosemide (Lasix)
Dialysis

Acronymn: CB DIAL K
Calcium
Bicarbonate
Dialysis
Insulin/dextrose
Albuterol
Lasix
Kayexalate

82

What is the nonacute treatment for hyperkalemia?

Furosemide (Lasix), sodium polystyrene sulfonate (Kayexalate)

83

What acid-base change lowers the serum potassium?

Alkalosis

84

What nebulizer treatment can help lower K+ levels?

Albuterol

85

What are surgical causes of hypokalemia?

Diuretics
Certain antibioitics
Steroids
Alkalosis
Diarrhea
Intestinal fistulae
NG aspiration
Vomiting
Insulin
Insufficient supplementation
Amphotericin

86

Signs and symptoms of hypokalemia?

Weakness
Tetany
Nausea
Vomiting
Ileus
Paresthesia

87

What are the ECG findings in hypokalemia?

Flattening of T-waves
U-waves (second wave after a t-wave)
ST segment depression
PAV, PVC
Atrial fibrillation

88

What is the rapid treatment of hypokalemia?

KCl IV

89

What is the maximum amount of KCl that can be given through peripheral IV?

10mEq/hour

90

What is the maximum amount of KCl that can be given through a central line?

20mEq/hour

91

What is the treatment of chronic hypokalemia?

KCl PO

92

What is the most common electrolyte-mediated ileus in the surgical patient?

Hypokalemia

93

What electrolyte conditions exacerbates digitalis toxicity?

Hypokalemia

94

What electrolyte deficiency can cause hypokalemia?

Low magnesium

95

What electrolyte must you replace before replacing K?

Magnesium

96

Why does hypomagnesemia make replacement of K with hypokalemia nearly impossible?

Hypomagnesemia inhibits K+ reabsoprtion from the renal tubules

97

What are the surgical causes of hypernatremia?

Inadequate hydrateion
Diabetes insipidus
Diuresis
Vomiting
Diarrhea
Diaphoresis
Tachypnea
Iatrogenic (i.e. TPN)

98

What are the signs/symptoms of hypernatremia?

Seizures
Confusion
Stupor
Pulmonary or peripheral edema
Tremors
Respiratory paralysis

99

What is the usualy treatment of hyponatremia, slowly over days?

D5W, 1/4NS or 1/2NS

100

How fast should you lower the sodium levels in hypernatremia?

101

What is the major complication of lowering sodium too rapidly?

Seizures

102

What are the surigcal causes of hypovolemic hyponatremia?

Diuretic excess
Hypoaldosteronism
Vomiting
NG suction
Burns
Pancreatitis
Diaphoresis

103

What are the surigcal causes of euvolemic hyponatremia?

SIADH
CNS abnormalities
Drugs

104

What are the surigcal causes of hypervolemic hyponatremia?

Renal fialure
CHF
Liver failure (cirrhosis)
Iatrogenic fluid overload (dilutional)

105

Signs and symptoms of hyponatremia?

Seizures
Coma
Nausea
Vomiting
Ileus
Lethargy
Confusion
Weakness

106

What is the treatment of hypovolemic hyponatremia?

NS IV, correct underlying cause

107

What is the treatment of euvolemic hyponatremia?

SIADH - furosemide and NS acutely, fluid restriction

108

What is the treatment of hypervolemic hyponatremia?

Dilutional - fluid restriction and diuretics

109

How fast should you increase the sodium level in hyponatremia?

110

What can happen if you correct hyponatremia too quickly?

Central pontine myelinolysis

111

What are the signs of central pontine myelinolysis?

Confusion
Spastic quadriplegia
Horizontal gaze paralysis

112

What is the most common cause of mild postoperative hyponatremia?

Fluid overload

113

What is pseudohyponatremia?

Spurious lab values of hyponatremia as a result of hyperglycemia, hyperlipidemia, or hyperproteinemia

114

Signs and symptoms of hypercalcemia?

Stones, bones, adbominal groans and psychiatric overtones
Polydipsia, polyuria, constipation

115

ECG findings of hypercalcemia?

Short QT interval
Prolonged PR interval

116

What is the acute treatment of hypercalcemic crisis?

Volume expansion with NS, diuresis with furosemide

117

What are less traditional options for the treatment of hypercalcemia?

Steroids
Calcitonin
Biosphophonates
Mithramycin
Dialysis (last resort)

118

How do you adjust calcium levels in hypoalbuminemia?

(4 - measured albumin level) x 0.8 + measured calcium level

119

What are the surgical causes of hypocalcemia?

Short bowel syndrome
Intestinal bypass
Vitamin D deficiency
Sepsis
Acute pancreatitis
Osteoblastic metastasis (prostate, medulloblastoma, bronchial carcinoid)
Aminoglycosides
Diuretics (loops)
Renal failure
Hypomagnesemia
Rhabdomyolysis

120

Signs and symptoms of hypocalcemia?

Chvostek's and Trousseau's signs
Perioral paraesthesia (early)
Increased deep tendon reflexes (late)
Confusion
Abdominal cramps
Laryngospasm
Stridor
Seizures
Tetany
Psychiatric abnormalities (paranoia, depression, hallucinations)

121

ECG findings in hypocalcemia?

Prolonged QT and ST interval
(Possible peaked T-waves)

122

Acute treatment of hypocalcemia?

IV calcium gluconate

123

What is the chronic treatment of hypocalcemia?

Calcium PO
Vitamin D

124

What is the possible complications of infused calcium if the IV infilrates?

Tissue necrosis
Only administer peripherally in an absolute emergency
Calcium gluconate is less toxic that calcium chloride during an infiltration

125

What is the best way to check calcium levels in the ICU?

Ceck ionized calcium

126

What is the normal range for magnesium level?

1.5-2.5 mEq/L

127

What are the surgical causes of hypermagnesemia?

TPN
Renal failure
IV over supplementation

128

What are the signs and symptoms of hypermagnesemia?

Respiratory failure
CNS depression
Decreased deep tendon reflexes

129

What is the treatment of hypermagnesemia?

Calcium gluconate IV
Insulin + glucose
Dialysis
Furosemide (lasix)

130

What are the surgical causes of hypomagnesemia?

TPN
Hypocalcemia
Gastric suctioning
Aminoglycosides
Renal failure
Diarrhea
Vomiting

131

Signs and symptoms of hypomagnesemia?

Increased deep tendon reflexes
Tetany
Asterixis
Tremor
Chvostek's sign
ventricular ectopy
Vertigo
Tachycardia
Dysrhythmias

132

Acute treatment of hypomagnesemia?

MgSO4 IV

133

What is the chronic treatment of hypomagenesemia?

Magnesium oxide PO
(AE - diarrhea)

134

What are the surgical causes of hyperglycemia?

Diabetes (poor control)
Decreased caloric intake
Insulinoma
Drugs
liver failure
Adrenal insufficiency
Gastrojejunostomy

135

Signs and symptoms of hyperglycemia?

Polyuria
Hypovolemia
Confusion/coma
Polydipsia
Ileus
DKA (Kussmaul breathing)
Abdominal pain
Hyporeflexia

136

Treatment of hyperglycemia?

Insulin

137

What is the Weiss protocol?

Sliding scale insulin

138

What is the goal glucose level in the ICU?

80-110mg/dL

139

What are the surgical causes of hypoglycemia?

Excess insulin
Decreased caloric intake
Insulinoma
Drugs
Liver failure
Adrenal insufficiency
Gastrojejunostomy

140

What are the signs and symptoms of hypoglycemia?

Sympathetic response (diaphroesis, tachycardia, palpitations)
Confusion, coma
Headche
Diplopia
Neurological deficits
Seizures

141

What is the treatment for hypoglycemia?

IV or PO glucose

142

What is the normal range for phosphorus levels?

2.5-4.5mg/dL

143

What are the signs and symptoms of hypophosphatemia?

Weakness
Cardiomyopathy
Neurologic dysfunction (i.e. ataxia)
Rhabdomyolysis
Hemolysis
Poor pressor response

144

What is a complication of severe hypophophatemia?

Respiratory failure

145

What are causes of hypophosphatemia?

GI losses
Inadequate supplementation
Medications
Sepsis
Alcohol abuse
Renal loss

146

What is the critical value for phosphate?

147

What is the treatment for hypophosphatemia?

Supplement with sodium phosphate or potassium phosphate IV

148

What are the signs and symptoms of hyperphosphatemia?

Calcification (ectopic)
Heart bloock

149

What are the causes of hyperphosphatemia?

Renal failure
Sepsis
Chemotherapy
Hyperthyroidism

150

What is the treatment for hyperphosphatemia?

Aluminum hydroxide (binds phosphate)

151

If hyperkalemia is left untreated, what can occur?

Vtach/fib --> death

152

What electrolyte is an inotrope?

Calcium

153

What are the major cardiac electrolytes?

Potassium (dysrhythmias)
Magnesium (dysrhythmias)
Calcium (dysrhythmias, inotrope)

154

Which electrolyte must be monitored closely in patients on digitalis?

Potassium

155

Most common cause of electrolyte-mediated ileus?

Potassium

156

What is a colloid fluid?

Protein-containing fluid (albumin)

157

An elderly patient goiens into CHF on POD 3 after a laparotomy. What is going on?

Mobilization of third-space fluid --> fluid overload --> CHF
(also run cardiac enzymes and ECG to R/O an MI)

158

What fluid is used to repalce NGT aspirate?

D5 1/2 NS with 20 KCl

159

What electrolyte is associated with succinylcholine?

Hyperkalemia