Na+ Disorders (lec 2) Flashcards Preview

Q3 Clin LAB Test 1 (UA, Na, K, CMP) > Na+ Disorders (lec 2) > Flashcards

Flashcards in Na+ Disorders (lec 2) Deck (51)
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1
Q

ECF Cationº?

Anionº?

A

Na+

Cl-

2
Q

ICF Cationº?

Anionº?

A

K+

PO4-

3
Q

TBW composition?

A

2/3 ICF

1/3 ECF: 3/4 ISF, 1/4 plasma

4
Q

Osmolality is?

A

[solute] of a fluid

5
Q

What osmotically active substances are used to calculate osmolality?

A

Na+
Glu
BUN (blood urea nitrogen)

6
Q

Isotonic (proportional H2O/solute) Δ in ECF Fluid results in?

A

size of ECF compartment Δs but no fluid moves b/w ECF/ICF

*Δ confined to ECF

7
Q

Isotonic ↓ in ECF results in?

e.g. dehydration

A

↓ size of ECF compartment

no fluid movement

8
Q

Isotonic ↑ in ECF results in?

e.g. IV

A

↑ size of ECF compartment

no fluid movement

9
Q

Hyponatrimic Δ (Na+ deficit) in ECF results in?

A

movement of fluid from ECF into ICF compartment,
cell swells
*Δ effects ICF

10
Q

Hypernatremic Δ (Na+ excess) in ECF results in?

A

movmt of fluid from ICF into ECF compartment,
cell shrinks
*Δ effects ICF

11
Q

Possible Volume status of pt? (3)

A

Euvolemic (normal)
Hypervolemic (overload)
Hypovolemic (dehydration)

12
Q

Hypovolemia presentation?

A
↑ thirst
↓ sweat
↓ urine output, ↑ concentration
Dry skin
CNS depression
Weak, mm cramps
Ortho hypoTN
Ortho ↑ pulse
13
Q

Anasarca is?

A

total body edema

14
Q

Hypervolemia presentation?

A
Edema
SOB
Orthopnea/nocturnal
HTN
Tachycardia
JVD
Crackles
15
Q

Hypovol caused by?

A

fluid loss
fluid sequestration
GI bleed

16
Q

Hypervol caused by?

A

renal Na+ retention

heart, liver, renal dx

17
Q

Intravascular Volume is?

A

fluid volume in bv

effective circulating vol

18
Q

Intravascular Vol important why?

A

homeostasis mechanisms respond to intravasc vol, not total extracellular vol
\\\ dx w/ low intravas vol but high extracell vol keep stim salt/H2O retention
(HF, liver F)

19
Q

Body responds to hypovol how?

A

Thirst

ADH (anti-di hormone)

20
Q

Body responds to a change in osmolarity that causes hypovolemia how?

A

CNS stim:
ADH release -> H2O retention
Angio II stim -> thirst

21
Q

Body responds to↓ circulating H2O vol how?

A

Baro stim:
ADH release -> H2O retention
Angio II stim -> thirst

22
Q

Body responds to Need for Salt Retention how?

A

Renin-Angio system

23
Q

Renin-Angio System

increases circulating blood vol how? (slide 28)

A
↓ in circulating blood vol ->
↓ renal perfusion ->
stims juxtaglomerular cells ->
renin released ->
angiotensinogen to angio I (vasoconstrictor) ->
convert to angio II ->
aldosterone released ->
↑ Na+ retention ->
↑ circ blood vol
24
Q

Release of Aldosterone affects Na+ how?

K+ how?

A

↑ Na+ retention

↑ K+ excretion

25
Q

Almost all Na+ located where in body?

A

ECF

26
Q

Hypernatremia results from what level of Na+?

A

> 145

27
Q

HyperNa+ caused by? (3)

A

low diet H2O
high diet salt
large H2O loss

(Too little H2O relative to Na+)

28
Q

HyperNa+ signs/sxs due to?

A

brain shrinkage

29
Q

HyperNa+ signs/sxs ?

A
thrist (1st sign)
altered mental state
weakness
neuromm irritability
focal neuro defects
seizure, coma
30
Q

Methods of water loss that result in hyperNa+?

A

GI: Diarrhea
Skin: Excess sweating, burn
Renal: hyperglycemia in DM (obligate ↑ urine output to manage ↑ glucose)
Drugs: diuretics, lithium

31
Q

Hypovolemia need for ↑ blood volume affects osmotic needs how?

A

Need for ↑ blood volume overrides osmotic needs of body

32
Q

Normal response to hyperNa+?

A

Thrist

concentrate urine to ↓ more H2O loss

33
Q

Homeostatic Order of importance in body?

A

Volume, pH, electrolytes

34
Q

Diabetes Insipidus is?

Caused by?

A

collecting ducts impermeable to H2O

Central: impaired ADH secretion

Nephrogenic: kidney doesn’t respond to ADH

35
Q

D Insipidus results in?

A

dilute urine even though serum Na+ is high

should be concentrated

36
Q

Nephrogenic D Insipidus etiology?

Tx?

A

genetic or acquired (result of dxs)

Thiazide diuretics
Amiloride (K+ sparing diuretic)

37
Q

HyperNa+ tx?

A

hospitalize severe
stop H2O loss
replace H2O*

*slowly if been several days or will cause rapid swelling of brain

38
Q

HypoNa+ results from what level of Na+?

A

< 135

Danger zone < 125

39
Q

HypoNa+ sxs?

A

weak, lethargic
N/V
mm cramps, seizure, coma

40
Q

HypoNa+ is most common what?

A

electrolyte abnormality in hospitalized pts

41
Q

Pseudohyponatremia is?

A

Hyper- glu, protein, lipids cause water movement from ICF into ECF

ECS Solutes are diluted so Na+ registers as low but total body Na+ is actually not low

(HypoNa+ from hyperosmolar state)

42
Q

HypoNa+/Hypervol caused by?

A

fluid overload from:
CHF
renal dx
cirrhosis

43
Q

HypoNa+/Hypervol signs?

A

edema
JVD
(P) dilutional anemia

44
Q

HypoNa+/Euvol caused by?

A

Hyperthyroidism
SIADH
Diuretics
Adrenal insufficiency

45
Q

SIADH (synd of inappr ADH secretion) due to?

A

impaired renal free water excretion (due to high ADH release)
*most common cause of HypoNa+/Euvol

46
Q

SIADH caused by?

A

neuropsych dx
malignancy
pulmonary dx
drugs (TCA, carbamazepine, anti-neoplastic, narcotics)

47
Q

SIADH characteristics? (3)

A

low serum osmolarity,
high concentrated urine,
high ADH (vasopressin) levels,
normal renal, adrenal, thyroid fxn

48
Q

HypoNa+/Hypovol caused by?

A

Renal: diuretics, osmotic diuresis, addisons
Nonrenal: V, diarr, pancreatitis, peritonitis

49
Q

HypoNa+/Hypovol characteristics?

A

dehydration:
dry mmemb, poor turgor
ortho BP/pulse Δs

50
Q

HypoNa+ tx?

A

Hospitalize
Tx cause
vasopressin (ADH) anatgonists

Hyper- or euvolemic: restrict fluids

Hypovol: replace fluids w/ isotonic saline

51
Q

Chronic HypoNa+ tx?

A

Demeclocycline to induce Nephrogenic DM Insipidus