Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine II: Surgery > Fluid and Electrolyte Therapy > Flashcards

Fluid and Electrolyte Therapy Flashcards

1
Q

What fraction is water of the body’s ideal body weight?

A

2/3; slightly less in women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What fraction of the TBW is intracellular fluid?

A

2/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What fraction of the TBW is extracellular fluid?

A

1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What fraction of the ECF is the interstitial body fluid?

A

2/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What fraction of the ECF is the plasma body fluid?

A

1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the blood volumes in males and females?

A

M: 66ml/kg
F: 60ml/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Thus for a 70 kg pt what is the TBV?

A

4.2-4.6L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What separates the intravascular and interstitial fluid?

A

capillary endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the type of barrier the capillary endothelium creates.

A

impermeable to protiens (primarily albumin) which determine the plasma/interstitial compartment osmotic pressures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the primary osmotic particle in the capillary endothelium?

A

albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What separates the intracellular and extracellular membranes?

A

a cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the types of barrier the cell membrane creates.

A

impermeable to ions (sodium) which determine the ICF/ECF osmotic pressures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What determines the ICF/ECF osmotic pressures?

A

Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to capillaries following surgery?

A

they become leaky, why they are so edematous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are various IVF choices?

A

blood
LR
NS
plasma-lyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the main cation of blood?

A

Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is LR?

A

lactate ringer, more physiologically like blood; bicarb in form of lactate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When can you not use LR?

A

pt with liver failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is NS?

A

normal saline, pH=5, basically just NaCl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens if you leave the pt on NS too long?

A

pt will get hypercalcemic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is plasma-lyte?

A

new, expensive IVF. pH is more physiologic

acetate is converted to bicarb
gluconate=sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why is serum K not a good indicator of total K?

A

K is intracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why do you give your standard surgical pt IVF?

A

maintenance IVF to prevent dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the rule for IVF?

A

4:2:1
4cc/kg/hr for 1st 10 kg
2cc/kg/hr for 2nd 10 kg
1 for each additional kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What the IVF for a 70kg pt?

A

110cc/hr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Typically for a major GI surgery what fluids do you use?

A

isotonic (LR or NS0 for 1st 24 hrs then switch to D5 1/2 NS + 20mEq KCl

pt is NPO so the sugar prevents muscle breakdown
in kids they deteriorate faster give D5 or D10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does 50kg of glucose per liter cause?

A

stimulates insulin release resulting in AA uptake and protein synthesis (prevents protein catabolism)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the best indicator of adequate volume replacement?

A

urine output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the ideal UO?

A

> 0.5 cc/kg/hr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What MIVF do you use in a gastric loses patient?

A

D5 1/2 NS + 20 mEq KCl; sucking up the gastric juices thuse removing H and Cl, replacing it with normal fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What MIVF do you use in a pancreas/bile/small intestine surgery patient? (ie fistula, biliary drain, ileostomy)

A

LR, high output ileostomy, losing alot of bicarb so LR is better

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What MIVF do you use in a large intestine surgery patient?

A

LR +/- K
give extra K as needed or can add to MIVF
-diarrhea: large intestine loses lots of extra HCO3 and K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What do you do for vary large loses? What do you have to remember?

A

you can write standing orders to replace 1:1, have to remember you did this so you can make sure they stay on it and you can take them off it later

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

When do you not give K?

A

renal patients, you will have to dialyse them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Hypovolemia

A

def?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Signs and symptoms of an underresuscitated pt:

A 
dry mucous membranes
decreased turgor
extreme thirst
low UO (20 pre-renal)
low BP
low CVP
tachycardia
FENA <1% (fractional excretion of Na)
altered mental status
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the gold standard for determining if a patient is hypovolemic?

A

UO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is it important to note if you see a climbing BUN/Cr?

A

its probably been going on for awhile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How do you assess a hypovolemic patient?

A

ABCs
give 2 large bore IVs
foley to monitor UO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

All patients are presumed _______________, must rule out otherwise.

A

bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What do you do with a hypovolemic patient after you have checked the ABCs and hooked them up?

A

resuscitate with 1-2L bolus of isotonic saline (LR/NS/plasma-lyte) and assess response: BP, UO, HR and mental

if no response make sure they arent bleeding; may be massively underresuscitated and just need more fluid

42
Q

FeNa

A

Fractional Excretion of Na

urine Na/urine Cr)/(plasma Na/plasma Cr

43
Q

What is FENA a good indicator for?

A

pre renal azotemia
FENa<20

indicates that the kidney is trying to hold onto as much Na as possible

44
Q

Hypernatremia

A

Serum Na > 145

45
Q

What is the most common cause of hypernatremia in a surgical patient?

A

loss of hypotonic body fluids

46
Q

Signs and symptoms of hypernatremia:

A

restlessness, ataxia, seizures, lethargy, altered mental status

most patients are asymptomatic, try to correct before theres a problem

47
Q

What is the normal range of Na?

A

135-145

48
Q

T/F: Any fluid that you lose has more water to salt ratio than blood

A

T

49
Q

T/F: Burn patients have too much salt in their body

A

F, they have too little water

50
Q

What do you give burn patients first?

A

LR

51
Q

What is the calculation for free water deficit?

A

TBW x (serum Na-140)/140

52
Q

What are the normal TBWs in males and females?

A

M- 0.6

F- 0.5

53
Q

What is the restriction for correction free water deficit?

A

cannot give faster than 0.5 mEq/L/hr, other wise risk of cerebral edema and seizures

54
Q

What else would you do in regards to the meds of a burn patient?

A

request the pharmacy to put their antibiotic into D5W, have to minimize Na containing fluids and meds.

55
Q

Hypernatremia in association with diabetes insipidus

A

typically euvolemic

excess loss of free water in urine (ADH promotes water absorption in the distal tubule)

56
Q

What is the hallmark diagnosis of Hypernatremia with DI?

A

dilute urine in the face of hypertonic plasma

57
Q

Central DI:

A

failure of ADH release from posterior pituitary

58
Q

Nephrogenic DI:

A

kidneys unresponsive to ADH

59
Q

What is the treatment for hypernatremia in a pt with DI?

A

correct free water deficit as previously described, consider vasopressin/desmopressin w/central DI

With neprogenic it can be adults having a rxn, in kids they lack the receptors: give luke diuretics

60
Q

Hyponatremia

A

Serum Na <135

61
Q

What is the most common cause of hyponatremia?

A

SIADH, syndrome of inappropriate ADH secretion

62
Q

What causes hyponatremia?

A

pain or stress of surgery causes elevated ADH levels post-op, kidneys retain too much free water and the urine is inappropriatley concentrated

63
Q

How do you tx hyponatremia?

A

LR or NS, water restriction

64
Q

What are the signs and symptoms of nyponatremia?

A

most are asymptomatic, but if severe can present with neurological problems
–delerium/mental status changes, seizures, N/V, wet lungs w/crackles

65
Q

What is the level of Na where we start seeing mental status changes?

A

Na <120

66
Q

What is the goal of resuscitation therapy?

A

Goal is to correct existing deficits in volume and/or electrolytes

67
Q

What is the goal of maintenance therapy?

A

Goal is to maintain water and electrolyte balance in a patient who cannot eat/drink
Accounting for insensible losses

68
Q

When does resuscitation occur in our ABCs?

A

Resuscitation occurs in the “C” of the ABC’s

69
Q

What do we use to resuscitate?

A

Use Isotonic crystalloids (LR, NS, plasma-lyte)

Best choice to expand plasma volume fastest

70
Q

In an immediate post op patient what do we give them?

A

In an immediate postoperative patient, generally give isotonic crystalloids x24hrs

71
Q

How do the fluids change after the first day post op?

A

On postop day 1, if patient is clinically euvolemic, switch to maintenance fluids

72
Q

Hyperkalemia

A

Serum K > 5.5

Slows the electrical conduction of the heart and can eventually lead to life threatening dysrrhythmias.

73
Q

What causes hyperkalemia?

A

Causes: Iatrogenic, rhabdomyolysis, certain drugs, renal insufficiency, massive blood transfusions

74
Q

What is the tx for hyperkalemia?

A

Immediately stop any K-containing infusions, Check an EKG for peaked T waves

If EKG changes are present—give IV calcium gluconate to stabilize the cardiac membrane
Then give 1 amp of D50 and 10 units of insulin to drive the potassium intracellularly
Dialysis if extremely high K and patient in renal failure

75
Q

What is the role of Magnesium?

A

Major intracellular cation, serves as a cofactor for countless enzymatic reactions (ATP)
Also regulates the movement of calcium into smooth muscle cells

76
Q

What causes magnesium def?

A

diuretics, alcoholics, chronic malnutrition, diarrhea, diabetics (urinary losses that accompany glycosuria)

77
Q

What is the level of mg in the body that makes us think mg def?

A

<2.0 at shands

78
Q

What are key things to remember about hypomagnesium?

A

Can accompany and make hypoK and hypoCa difficult to correct

Arrhythmias: Replace as needed, typically in increments of 2mg IV

79
Q

Hypermagnesium:

A

rare, typically renal failure or iatrogenic (OB Wards)
Weakness, Hyporeflexia
Give Calcium, may require dialysis

80
Q

*DDx postop hyponatremia also includes:

A

Loop diuretics, iatrogenic, osmotic diuresis from hyperglycemia, adrenal insufficiency

81
Q

What are the manifestations of hyponatemia?

A

Mild Sx: anorexia, nausea, lethargy
Mod Sx: disoriented, agitated, neuro deficit
Sev Sx: seizures, coma, death

82
Q

What happens in acute hyponatremia?

A

In acute hyponatremia, osmotic forces cause water movement into brain cells leading to cerebral edema

83
Q

What is psychogenic polydipsia?

A

Pts drink too much water.. See often in psych pts (tea and toast, pts who drink too much tea or beer and don’t eat anything w/ salt)

84
Q

What happens in hyponatremia with diuresis/adrenal insuff?

A

kidney is confused, not holding on to sodium as it should be

85
Q

What happens in hyponatremia with diarrhea?

A

Diarrhea: kidney is doing its job, not dumping sodium in face of hyponatremia, but volume status is messed up so you have to fix that first..

86
Q

What is the tx for urgent hyponatremia?

A

If symptomatic & urgent (mental status changes), give hypertonic saline (3% NaCl = 513mEq/L NaCl)

87
Q

What is a complication in treating urgent hyponatremia?

A

Risk of central pontine myelinolysis (CPM) if corrected too rapidly

CPM- pulls sodium out of the brain

88
Q

What is the tx of hyponatremia in asymptomatic pts?

A

Typically, in surgical patients, free water restriction is sufficient to correct hyponatremia
Concentrate all medications
Change MIVF accordingly
Make sure to follow sodium trend

89
Q

What is the role of potassium in the body?

A

Potassium is the major intracellular cation, thus plasma levels can be an insensitive marker for total body potassium stores (i.e: DKA)

90
Q

What are the daily needs of potassium?

A

Daily needs: 0.5-1mEq/day

Potassium: Needs 35-70mEq/day

91
Q

What are the causes of hypokalemia?

A

Diuretics (lasix), diarrhea, Nasogastric drainage (very common in surgical patients), magnesium depletion (impairs K reabsorption across the renal tubules)

Arrythmias, Ileus, Muscle weakness if severe (<2.5)

92
Q

What is the tx for hypokalemia?

A

Typically replace in increments of 20-60mEq (IV or PO)

Add KCl to MIVF

93
Q

Whats something to keep in mind when treating a patient with hypokalemia?

A

If pt has healthy kidney you will not make them hyperkalemic (kidney will dump K as needed, kidney failure not so much)

94
Q

What is hyperkalemia?

A

Serum K > 5.5

Slows the electrical conduction of the heart and can eventually lead to life threatening dysrrhythmias

95
Q

What are the causes of hyperkalemia?

A

Causes: Iatrogenic, rhabdomyolysis, certain drugs, renal insufficiency, massive blood transfusions

96
Q

What are the daily needs of Na?

A

Sodium: Needs 140-210mEq/day

97
Q

Problem: Your patient is a 150 pound man who has a serum sodium of 114 mEq and he has become neurologically unstable. Calculate what volume of 3% saline should be used to correct the initial half of his sodium deficit and what length of time it would require?

Factors: 2.2 lbs = 1 kg; 3% Saline has 513 mEq of Na and TBW for a male is 0.65.

A

(1) 150 lb = 150/2.2= 68 kg; TBW = 0.65 x 68 = 44L x ½(140 – 114) = 572 mEq
(2) mEq rate to increase Na titer by ~ 0.5 mEq/L/hr: 44L x 0.5 mEq/L/hr = 22 mEq/hr
(3) 572/22= 26hr

98
Q

So if a 70kg male (with TBW 45L) lost 1L of blood, how much to replace using Free water?

A

(Recall: Plasma is 1/9 of TBW = 1/3 x 1/3)

Takes 9L free water to replace 1L of plasma

99
Q

So if a 70kg male (with TBW 45L) lost 1L of blood, how much to replace using NS?

A

(Recall 3-to-1 rule: Plasma is 1/3 ECF)

Takes 3L of NS to replace 1L of plasma

100
Q

So if a 70kg male (with TBW 45L) lost 1L of blood, how much to replace using albumin/blood?

A

(1:1 replacement)

Takes 1L of 5% albumin or 3 Units = 1L PRBC

101
Q

So if a 70kg male (with TBW 45L) lost 1L of blood, how much to replace using ½ NS?

A

Takes 3L of NS, so it should take ~6L of ½ NS

Medicine II: Surgery (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions