Lab Med: CMP and Electrolytes Flashcards
(98 cards)
1
Q
Which tests monitor renal function?
A
BUN
Cr
BUN/Cr ratio
2
Q
Which tests measure electrolytes and pH?
A
Na
K
Cl
CO2
3
Q
What are considered the liver tests?
A
ALT
AST
ALP
Total Bili
4
Q
Which tests monitor synthetic function of the liver?
A
albumin
platelets
PT/INR
5
Q
A basic metabolic panel consists of what labs?
A
glucose
BUN, Cr, BUN/Cr ratio
Na, K, Cl
CO2
6
Q
What is the most common acute cause of hyperglycemia?
A
Physiologic stress (trauma, illness, infx, burn, surgery, etc)
7
Q
Which endocrine disorders can cause hyperglycemia?
A
Cushings, Acromegaly
8
Q
Cushings causes hyperglycemia through what mechanism?
A
excess cortisol production results in increased glucagon release
9
Q
Acromegaly causes hyperglycemia through what mechanism?
A
increased HGH is secreted, which causes increased glucagon release
10
Q
What drug class can cause hyperglycemia?
A
steroids
11
Q
What are three common causes of hypoglycemia?
A
insulin OD
starvation
Addision’s, Hypopituitarianism
12
Q
Which electrolytes rise with kidney dysfunction?
A
K, PO4, Mg
13
Q
Urea is formed in the ______ and excreted by the ______
A
formed in liver
excreted by kidneys
14
Q
This test is an indirect measurement of the liver’s metabolic function and the excretory function of the kidney
A
BUN
15
Q
Severe primary liver diseases have what effect on BUN?
A
decreased BUN due to decreased urea synthesis
16
Q
Primary renal diseases do what to BUN?
A
increase BUN secondary to reduced urea excretion
17
Q
Dehydration does what to BUN?
A
concentrates BUN, increases serum BUN
18
Q
how does an upper GI bleed lead to increased BUN?
A
blood overloads gut with protein
19
Q
What conditions lead to increased BUN?
A
primary renal diseases
dehydration
UGIB
high protein diet
20
Q
What conditions lead to a decreased BUN?
A
Severe primary liver diseases
overhydration
low protein diet
21
Q
What makes creatinine a specific measure of renal function?
A
creatinine is excreted 100% by the kidneys
22
Q
Cr can be used as an approximation of what physiologic process?
A
GFR
23
Q
Describe the relationship between GFR and Cr
A
inverse
24
Q
What is the main cause of increased Cr?
A
AKI
25
list your DDx for increased Cr...
AKI
CKD
Rhabdo
Dehydration
26
list your DDx for decreased Cr
debilitation
muscular dystrophy
myasthenia gravis
27
An acute kidney injury results in a rapid _____ in GFR
AKI = rapid decrease of GFR
28
Bun/Cr ratio is helpful in determining what?
cause of AKI
29
A BUN/Cr of 20:1 or higher indicates...
prerenal AKI
30
A BUN/Cr of 10:1 indicates
intrinsic renal AKI
31
The following would classify as what type of AKI?
hypovolemia
CHF
vascular resistance changes
prerenal
32
What is the main cause of intrinsic AKI?
acute tubular necrosis from IV contrast
33
The following would classify as what type of AKI?
ureteral stones
bladder outlet obstruction
BPH
Urethral Stricture
postrenal
34
Hyper/hypochloremia usually accompanies a shift in what two measures?
sodium and bicarb
35
CO2 is an indirect measure of...
HCO3/bicarb
36
What regulates HCO3 retention or secretion?
kidneys
37
The following conditions affect what... albumin or globulin?
liver disease
edematous states
protein losing conditions
nutrition status
albumin
38
The following conditions affect what... albumin or globulin?
immune disorder
cancer
globulin
39
By what mechanism does albumin keep fluid within the vascular space?
maintains osmotic pressure
40
A patient presents with increased albumin... what can you immediately include in your DDx?
dehydration
41
When albumin is low, what happens to globulin and why?
elevated to maintain normal total protein
42
What is the MC cause of hypoalbuminemia?
liver disease
43
What is the complete list of DDx for hypoalbuminemia?
Liver disease
Crohns/celiac/protein losing enteropathies
nephrotic syndrome/protein losing nephropathies
burn
malnutrition/malabsorption
inflammatory disease
44
what is the cause of edema in nephrotic syndrome?
decreased albumin causes decreased osmotic pressure
45
Patients presenting with normal total protein with hypoalbuminemia and increased globulin should be considered for what conditions?
chronic liver disease
collagen vascular diseasae/lupus
46
patients with increased total protein with increased globulin fraction should be considered for...
multiple myeloma
47
what two diagnostics indicate multiple myeloma?
M-spike
bence jones proteinuria
48
what are the transaminases?
ASP
ALT
49
Which liver tests measure injury to hepatocytes?
AST, ALT
50
which liver tests measure injury to the bile ducts/bile flow?
ALP, total bili
51
Which is more specific to the liver, AST or ALT?
ALT
52
Where is ALP found?
liver, biliary tract, bone
53
if a patient presents with increased ALP in the presence of otherwise normal labs, what should you suspect?
bone pathology
54
What is on your list of DDx for AST/ALT > ALP?
liver drug toxicity
viral hepatitis
alcoholic and non-alcoholic liver disease
cirrhosis
infiltrative liver disease, tumor
genetic liver disorder
biliary cholestasis (obstruction)
55
What is the list of DDx for elevated ALP?
biliary obstruction
hepatitis, cirrhosis, infiltrative liver disease
drug toxicity
56
What is a common cause for increased ALP in children and adolescents?
physiologic growth
57
What are the broad two reasons for extrahepatic ALP elevation?
high bone turnover
3rd trimester pregnancy
58
what test can be ordered to distinguish between liver and bone etiology for isolated ALP elevation?
ALP isoenzymes
59
increased unconjugated bili is caused by...
hemolysis
HF
Gilbert syndrome
60
increased conjugated bili is caused by...
hepatitis
drugs
TB/liver infiltration
biliary obstruction
61
Calcium has an inverse relationship with...
phosphorus
62
of the 1% of calcium not in bone, what percent is free/ionized?
50%
63
of the 1% of calcium not in bone, what percent is bound to albumin?
40%
64
this form of calcium is free to participate in cellular function, and is the most accurate measurement of serum calcium...
ionized Ca
65
When serum albumin is low, what should you expect calcium level to be?
low
66
PTH is stimulated by falling blood Ca levels. PTH secretion from the parathyroid has what effects?
stimulates Ca release from bone
increases Ca uptake in kidneys and GI
67
Calcitonin is stimulated by rising blood Ca levels. When it is released by the thyroid, calcitonin has what effect?
stimulates ca deposition in bone
reduces GI and Kidney uptake of Ca
68
What is responsible for 90% of cases of hypercalcemia?
hyperparathyroidism and malignancy
69
A patient presents with the following S/S... what is this suspicious for?
- decreased neuromuscular function
- shortened QT
- Nephrolithiasis, polyuria, polydipsia
- constipation
Hypercalcemia
70
How do you manage hypercalcemia?
tx underlying cause
volume expansion
calcitonin, bisphosphates
71
What is the most common cause of hypocalcemia?
hypoalbuminemia
72
when you see hypoalbuminemia, what should you do to dx hypocalcemia
calculate corrected Ca
73
when should you check serum ionized calcium
only if dx of hypocalcemia is in doubt after calculating corrected Ca
74
What causes hypocalcemia from large blood transfusions
chelation of calcium to citrate additives
75
Hypomagnesemia causes hypocalcemia because...
Mg deficiency inhibits PTH activity
76
Renal failure causes hypocalcemia through what mechanism?
phosphorus retention leads to reciprocal loss of Ca
77
A patient presents with the following... what do you suspect?
parasthesias
hyperactive DTRs
Carpopedal spasm
Chvosteks sign
Trousseau sign
prolonged QT
Hypocalcemia
78
The tapping of facial nerve resulting in contraction of facial muscles is known as...
chvostek's sign
79
occlusion of brachial artery for 3 minutes inducing carpal spasm is known as...
trousseau's sign
80
How do you manage mild hypocalcemia?
Severe?
mild: oral calcium +/- Vitamin D
Severe: IV Calcium gluconate
81
What is the most important regulator of serum phosphate?
kidneys
82
Phosphate has an inverse relationship with what electrolyte?
calcium
83
What is the most common reason for hyperphosphatemia?
renal failure
84
What is the full list of DDx for hyperphosphatemia
renal failure
hypoparathyroidism
hypocalcemia
exogenous phosphate
85
What is the number one reason for hypophosphatemia?
malnutrition/malabsorption
86
Cellular shift is when a mediator drives electrolytes into a cell. What are two common causes of cellular shift derived hypophosphatemia?
insulin
refeeding syndrome
87
hypophosphatemia can be caused by...
malnutrition/malabsorption
hyperparathyroidism
chronic alcoholism
severe vomiting/diarrhea
cellular shift
88
Severe hypophosphatemia manifests with what sxs?
muscle weakness
rhabdo
seizures
89
how do you treat hyperphosphatemia
treat underlying cause
90
how is hypophosphatemia treated?
treat underlying cause
phosphate repletion as appropriate
91
magnesium levels are intimately tied to which electrolytes?
calcium and potassium
92
hypomagnesemia can contribute to what two conditions?
refractory hypocalcemia and hypokalemia
93
What are the two most common causes of hypermagnesemia?
renal insufficiency
large Mg load
94
The following can do what to magnesium levels?
Malnutrition/absorption
severe diarrhea
alcoholism
cellular shift
cause hypomagnesemia
95
Hypermagnesemia presents with...
decreased DTRs
Bradycardia
Hypotension
96
Hypomagnesemia presents with...
tetany
cardiac arrhythmias/torsades
97
How should hypermagnesemia be treated?
stop magnesium containing meds
isotonic fluids and loop diuretics
dialysis
IV calcium
98
How should hypomagnesemia be treated?
asymptomatic: oral Mg
symptomatic: IV Mg
