Brainscape's Knowledge GenomeTM

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


See full index

Julija's Path > Chem Path ✔ > Flashcards

Chem Path ✔ Flashcards

1
Q

Name the 3 forms of Calcium in the body and proportions of each:

A

Free (ionized) - biologically active (50%)
Protein-bound - (40%)
Complexed with citrate/phosphate (10%)

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

what is normal ‘total serum Ca’ levels?

A

2.2-2.6 mmol/L

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

what is the ‘adjusted’ serum Ca?

A

serum Ca +0.02 *(40-serum albumin in g/L)

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

what happens in the body to ensure Calcium hemostasis when low Calcium is detected?

A

dec Ca –> PTH release by parathyroid –> ‘obtain’ Ca from 3 sources (kidney, gut, bones)

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

name of hormone that activates Calcium in the kidney?

A

renal 1-alpha-hydroxlyase activation

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

what does the release of PTH cause?

A

increased bone and renal Ca resorption, increased 1,25 OH vitamin D levels

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

what does increased 1,25 OH Vitamin D cause?

A

increased intestinal Ca absorption

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

what two hormones are involved in calcium homeostasis?

A

PTH & Vitamin D

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

what is the role of PTH in the body?

A

bone & renal Ca resorption
renal Pi wasting
1,25-OH Vitamin D synthesis

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

when cholecalciferol is activated in the liver, what does it become?

A

25-hydroxycholecalciferol (25-OH D3)

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

when PTH stimulates the kidney, what changes happen to 25-OHD3?

A

25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol

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

what is the physiologically active form of vitamin D?

A

1,25 (OH)2 D3

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

what is the pathway of synthesis of Vitamin D?

A

100% of absorbed vitamin D is hydroxlyated at the 25 position by 25-hydroxylase

then 25-hydroxy D is inactive, stored and measured

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

what is the pathway of activation of Vitamin D?

A

1-alpha hydroxylase in the kidney activates 25-hydroxy D into 1,25-OH D3

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

what is 1-alpha hydroxylase and where does it come from?

A

from the kidney, activates vitamin D

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

what is 25-hydroxylase and where is it made?

A

in the liver, hydroxylates vitamin D for storage

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

what is vitamin D deficiency in children vs adults?

A

children - rickets

adults - ostemalacia

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

what are some features of a child with vitamin D deficiency?

A

bowed legs, chostocondral swelling, widened epiphysis at the wrist, myopathy

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

if someone has low Ca, low Pi, raised ALP - what do you suspect?

A

osteomalacia

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

what is the blood chemistry of someone with ostemalacia?

A

low Ca, low Pi, raised ALP

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

what are Looser’s zones?

A

pesudo fractures from ostemalacia

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

what type of medication can induce osteomalacia in adults?

A

anticonvulsants

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

what is the biochemistry in osteoporosis?

A

NORMAL Ca but reduction in bone density

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

what DEXA T score is definitive of osteoporosis?

A

T

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

what DEXA T score is definitive of osteomalacia?

A

T score between -1 & -2.5

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

if someone has a T score of T

A

A

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

if someone has a T score of T=-1 on their DEXA scan, what do you suspect?
A. Osteporosis
B. Osteomalacia
C. Paget’s Disease

A

B. Any T score between -1 & -2.5

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

list some causes of osteoporosis in a systematic way:

A

Lifestyle: sedentary, EtOH, smoking, low BMI/nutritional
Endocrine: hyperprolactinaemia, thyrotoxicosis, Cushings
Drugs: steroids
Others eg genetic, prolonged intercurrent illness

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

name 5 biological (medical) treatments for osteoporosis

A

1) Vitamin D/Ca
2) bisphosphonates (alendronate)
3) PTH derivative (terparatide)
4) strontium
5) HRT (estrogens)
6) SERMs (raloxifene)

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

name the symptoms of hypercalcemia:

A

polyuria/polydipsia
constipation
neuro (confusion, seizures, comas)

‘bones, stones, moans, groans’

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

at what level of calcium would you see hypercalcemia symptoms?

A

Ca > 3.0 mmol/L

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

what is the normal hormonal response to hypercalcemia?

A

PTH suppression

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

what are potential causes of hypercalcemia if PTH is NOT suppressed? (one common, one rare)

A

primary problem with PTH regulation

common - primary hyperparathyroidism
rare - familial hypocalcuric hypercalcemia (FHH)

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

what are potential causes of hypercalcemia if PTH is suppressed?

A

common - malignancy

rare- sarcoid, vitamin D excess, thyrotoxicosis, milk alkali syndrome

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

what is the commonest cause of hypercalcemia?

A

primary hyperparathyroidism

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

what bone chemistry do you expect to see in primary hyperparathyroidism?

A

increased Ca
increased/normal PTH (inappropriate!)
decreased serum phosphate
urine increased Ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is the CaSR and what does it do?

A

parathyroid - PTH release

renal - Ca resorption

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

what genetic condition is associated with CaSR mutations?

A

FHH - higher ‘set point’ for PTH release leading to some constant mild hypercalcemia

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

what hypercalcemia is associated with malignancy?

A

humoral hypercalcemia (PTHrp; small cell lung Ca)
bone mets
hematological malignancy

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

what non-PTH driven hypercalcemia causes are there?

A

sarcoidosis, thyrotoxicosis, hypoadrenalism, thiazide diuretics, excess vitamin D

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

what is the treatment of hypercalcemia?

A

fluids fluids fluids!

Treat any underlying cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what are the clinical signs of hypocalcemia?

A

neuro-muscular excitability

Chvostek’s sign, Trosseau’s sign, hyperreflexia, convulsions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what causes of hypocalcemia are PTH driven?

A

surgical (eg post thyroidectomy)
auto-immune hypoparathyroidism
congenital absence of parathyroids (eg DiGeorge’s)
Mg deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

if calcium is low, what do you expect PTH to do?

A

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what cause of hypocalcemia can progress to tertiary hypoparathyroidism?

A

CKD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what can CKD progress to with regards to Ca homeostasis?

A

secondary hypoparathyroidism progression to tertiary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what are non-PTH driven causes of hypocalcemia?

A 
vitamin D deficiency
CKD
PTH resistance ('pseudohypoparathyroidism')
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is the key factor of blood chemistry in Paget’s disease? (think Ca, ALP, Albumin, PTH….)

A

elevated alkaline phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

bone chemistry of osteoporosis: Ca, Pi, PTH, Vit D, ALP

A 
Ca: Normal
Pi: Normal
PTH: Normal
Vit D: Normal
ALP: Normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q 
Diagnose the Calcium issue from this chemistry -
Ca: Normal
Pi: Normal
PTH: Normal
Vit D: Normal
ALP: Normal
A

osteoporosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

bone chemistry of osteomalacia/rickets:

A 
Ca: decrease or normal
Pi: decrease or normal
PTH: increase
Vit D: decrease 
ALP: increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q 
Diagnose the calcium issue from this chemistry - 
Ca: decrease or normal
Pi: decrease or normal
PTH: increase
Vit D: decrease 
ALP: increase
A

ostemalacia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

bone chemistry of Paget’s disease:

A 
Ca: normal
Pi: normal
PTH: normal
Vit D: normal
ALP: increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q 
diagnose the calcium issue from this chemistry -
Ca: normal
Pi: normal
PTH: normal
Vit D: normal
ALP: increase
A

Paget’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

bone chemistry of parathyroid bone disease:

A 
(inc. PTH)
Ca: increase
Pi: decrease
PTH: increase/ normal
Vitamin D: normal
ALP: increase or normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q 
Diagnose the calcium issue from this chemistry -
(inc. PTH)
Ca: increase
Pi: decrease
PTH: increase/ normal
Vitamin D: normal
ALP: increase or normal
A

parathyroid bone disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

bone chemistry of renal bone disease

A 
Ca: decreased or normal
Pi: increased
PTH: increased 
Vitamin D: normal (1 -alpha-hydroxylase is low)
ALP: increased/normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Diagnose the calcium issue from this chemistry -
Ca: decreased or normal
Pi: increased
PTH: increased
Vitamin D: normal (1 -alpha-hydroxylase is low)
ALP: increased/normal

A

renal bone disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

name that biochemical abnormality: pH 6.92, PCO2 =3

A

metabolic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

what is the pH and PCO2 in metabolic acidosis?

A

pH LOW

PCO2 LOW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

name that biochemical abnormality: pH 7.70, PCO2 = 3

A

respiratory alkalosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

what is the pH and PCO2 in respiratory alkalosis?

A

pH HIGH

PCO2 LOW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

what is the pH and PCO2 in respiratory acidosis?

A

pH LOW

PCO2 HIGH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

name that biochemical abnormality: pH 6.92, PCO2 = 7

A

respiratory acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

what is the pH and PCO2 in metabolic alkalosis?

A

pH HIGH

PCO2 HIGH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

name that biochemical abnormality: pH 7.70, PCO2 = 10

A

metabolic alkalsosi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

what does abbreviation ROME stand for in biochemistry values?

A

Respiratory Opposite

Metabolic Equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

what is normal PCO2 concentration on blood gas?

A

PCO2 = (approx.) 4 -5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

what is the formula for calculating osmolality?

A

Osmo = 2(Na+K) + Urea + Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

what is formula for calculating anion gap?

A

AG = (Na+K) - bicarbonate - chloride

positives minus negatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

what is the normal level of lactate?

A

Normal Lactate < 2.0 mM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Definition of type 2 diabetes (in fasting glucose and plasma)?

A

Fasting glucose > 7.0 mM
GTT with plasma glucose > 11.1 mM at 2 hours
(If the 2 hour value is between 7.8 -11.1 mM then called ‘impaired glucose tolerance’)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

how does type 4 renal tubular acidosis cause hyperkalemia?

A

reduced renin –> less angtiotensins –> less aldosterone –> less potassium secretion –> k+ inc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

how do you get type 4 renal tubular acidosis?

A

end stage diabetic nephropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

how does CKD cause hyperkalemia?

A

reduced GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

what is a cause of reduced GFR?

A

CKD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

how can ACE inhibitors cause hyperkalemia?

A

less angiotensin II –> less aldosterone –> less potassium secretion in kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

how can ARBs cause hyperkalemia?

A

angiotensin receptor blockers block angiotensin II –> less aldosterone –> less potassium secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

how does Addison’s disease cause hyperkalemia?

A

less aldosterone –> less potassium secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

how does aldosterone antagnosists cause hyperkalemia?

A

block the production of aldosterone –> less potassium secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

what are the biochemical processes to hyperkalemia? (think of 3!)

A

1) rhabdomyolysis (e,g. crush injuries)
2) acidosis (maintaining electro-neutrality)
3) reduced GFR/renin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

what are the main causes of hyperkalemia? (think of 4!)

A

1) renal impairment (CKD, reduced renal excretion)
2) drugs ( ACEi, ARBs, spironolactone)
3) Addison’s disease (low aldosterone)
4) rhabdomyolysis
5) acidosis
6) type 4 renal tubular acidosis/diabetic nephropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

what are the 3 main causes of hypokalemia?

A

1) GI Loss
2) renal loss
3) cellular redistribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

what changes will you see in hyperkalemia?

A

ECG changes: peaked T -waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

what are the acute dangers of cocaine use?

A

cardiac dysrhythmias,
acute heart failure
MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

how do you manage a patient with hyperkalemia? (5 parts; include dosage)

A

1) 10 mL 10% calcium gluconate
2) 50 mL 50% dextrose
3) 10 units of Insulin (with dextrose)
4) nebulized salbutamol
5) treat underlying cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

what do loop diuretics do in the loop of Henle?

A

block sodium, potassium, chloride reabsorption in the ascending loop which leads to increase sodium delivery to the distal nephron (DCT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

what is the relationship between Na+ and K+ in the kidney?

A

Na+ absorbed

K+ lost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

4 causes of hypokalemia:

A

1) GI Loss
2) Hyperaldosteronism (excess cortisol)
3) osmotic diuresis
4) insulin, beta-agonists
5) alkalosis
6) renal tubular acidosis type 1 and type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

what biochemical abnormality does hyperaldosteronism cause?

A

hypokalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

what biochemical abnormality does alkalosis cause (think Na, Bicarb, K, Cl…)

A

hypokalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

what biochemical abnormality does renal tubular acidosis type 1 & type 2 cause?

A

hypokalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

what biochemical abnormality does renal tubular acidosis type 4 cause?

A

hyperkalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

what biochemical abnormality does insulin cause?

A

hypokalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

what biochemical abnormality does acidosis cause (think Na, Bicarb, K, Cl…)

A

hyperkalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

what are the clinical features (presenting symptoms) of hypokalemia?

A

muscle weakness
cardiac arrthymia
polyuria
polydipsia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

what are the clinical features (presenting symptoms) of hyperkalemia?

A

often asymptomatic (may be weak, nauseous, fatigued…)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

if someone presents with polyuria/polydipsia - what biochemical blood tests do you want to look for?

A

low potassium
high calcium
(cause resistance to effects of ADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

what screening test would you order in a patient with hypokalemia & hypertension?

A

aldosterone:renin ratio (would see high aldosterone inhibiting renin; low renin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

what endocrine disorder has a high aldosterone:renin ratio: (high aldosterone, low renin)?

A

Conn’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

3 steps of managing a patient with hypokalemia (potassium 3.0-3.5 mmol/L) with doses?

A

1) oral potassium chloride (2 SandoK tabs TDS, 48 hrs)
2) recheck potassium levels
3) treat underlying cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

2 steps of managing a patient with hypokalemia (potassium <3.0 mmol/L) with doses?

A

1) IV potassium chloride (max rate 10mmol/hr)

2) treat underlying cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

hyperkalemia is a side-effect of which of the following drugs?

a. Fruosemide
b. Bendrofluoromethazide
c. Salbutamol
d. Ramipril

A

d. Ramipril (ACE inhibitor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

hypokalemia is a side-effect of which diuretic drug(s)?

A

thiazide
frusemide
salbutamol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

hypokelaemia is a side effect of which of the following drugs?

a. Spironolactone
b. indomethacin
c. perindopril
d. Fruosemide

A

frusemide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

what is the aldosterone - potassium relationship?

A

aldosterone causes potassium loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

what type of diuretic is spironolactone?

A

potassium-sparing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

what are the causes of hypovolemic hyponatremia? (4)

A

diarrhea
vomiting
diuretics
salt-losing nephropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

what are the causes of euvolemic hyponatremia? (3)

A

hypothyroidism
SIADH
adrenal insufficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

what are the causes of hypervolemic hyponatremia? (3)

A

cardiac failure
cirrhosis
nephrotic syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

what is the process by which someone becomes hypovolemic hyponatremic?

A

reduced ECF volume & reduced sodium –> low blood volume stimulates ADH release –> retain water, sodium concentration drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

normal values of Na +?

A

135 - 145 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

normal values of K+?

A

3.5 - 5.0 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

normal values of urea?

A

3.0 - 7.0 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

what tests do you want to do to if someone is euvolemic and hyponatremic?

A

TFTs
short synacthen test (adrenal insufficiency; acth test)
plasma & urine osmolality (SIADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

sodium low, potassium high, pigmentation, postural hypotension – name that condition!

A

Addison’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

diagnosis of SIADH:

A

plasma osmolality LOW
urine osmolality HIGH
no hypothyroidism or adrenal insufficiency

118
Q

causes of SIADH

A 
brain pathology
lung pathology
drugs (SSRI, TCA, opiates, PPIs,)
tumors
surgery
119
Q

what investigations do you do in suspected diabetes insipidus and why:

A 
serum glucose (exclude diabetes mellitus)
serum potassium (exclude hypokalemia)
serum calcium (exclude hypercalcemia)
plasma &amp; urine osmolality
water deprivation test
120
Q

what does ADH do?

A

acts on V2 receptors in renal tubular cells in collecting duct, insertion of aquaporin-2

acts on V1 receptors at higher concentration - vasoconstriction (vasopressin)

121
Q

when does the body release ADH?

A
  • when serum osmolality increases (e.g. don’t drink), release ADH & reabsorb water to bring osmolality down
  • low blood volume/low BP (as sensed by baroreceptors)
122
Q

how does cardiac failure cause hyponatremia (hypervolemic)

A

reduced CO –> reduced BP –> sensed by baroreceptors –> increased ADH –> increased water retention –> decreased [Na]

123
Q

how does cirrhosis cause hyponatremia (hypervolemic)

A

increased NO –> vasodilation –> reduced BP –> sensed by baroreceptors –> increased ADH –> increased water retention –> decreased [Na]

124
Q

how does hypothyroidism cause hyponatremia (euvolemic)

A

reduced cardiac contractility –> reduced BP –> sensed by baroreceptors –> increased ADH –> increased water retention –> less [Na]

125
Q

how does adrenal insufficiency cause hyponatremia? (euvolemic)

A

low cortisol –> low BP –> more ADH –> more water –> less [Na]

126
Q

do you give normal saline to someone with SIADH?

A

NO!

You are adding more water to someone retaining water, causing hyponatremia to drop further. You will make them sicker.

127
Q

how do you treat hyponatremia from SIADH?

A

fluid restriction, treat underlying cause

128
Q

how do you treat someone with hyponatremia that is hypovolemic?

A

normal saline 0.9%

129
Q

how do you treat someone with severe hyponatremia?

A

reduced GCS, at risk of seizures. Need urgent hypertonic saline (2 or 3%). You want to increase it slowly (no more than 8-10 mmol/L in 24 hours).

130
Q

how do you treat someone with euvolemic hyponatremia?

A

fluid restriction, treat the cause

131
Q

what is the most important risk in correcting hyponatremia?

A

must NOT be corrected by >8-10 mmol/L in 24 hours due to risk of osmotic demyelination (Central Pontine Myelionlysis)

132
Q

what happens in central pontine myelionlysis (osmotic demyelination)?

A

quadriplegia, dysarthria, dysphagia, seizures, coma, death – all 2-6 days after treatment

endothelial shrinkage –> disrupted BBB –> cytotoxic complements can penetrate BBB

133
Q

if water restriction is insufficient, what drugs can be used to treat SIADH?

A

demeclocycline (causes ADH resistance, monitor U&Es)

tolvaptan (V2 receptor antagonist)

134
Q

what are the causes of hypernatremia?

A 
loss of water: 
GI Loss (diarrhea/vomiting) if not replacing with water, or because not enough ADH (e.g. diabetes insipidus)
135
Q

how do you treat hypernatremia? (4 steps)

A

1) fluid replacement (NOT with normal saline)
- -> 5% dextrose
2) correct any ECF volume depletion (with 0.9% saline)
3) serial 4 hrly Na level checks
4) treat underlying cause

136
Q

suppose a patient has significant GI losses and
a) are drinking water
b) are not drinking water
will they have hyponatremia or hypernatremia?

A

a) hypo

b) hyper (not replacing GI losses)

137
Q

someone comes into A&E unconscious, known diabetic. Cannot swallow. What are the steps of treatment? (3 steps)

A

1) IV Access
2) 50ml of 50% glucose or 100 mls of 20% glucose
3) if difficult to do any of the above, consider IM/SC 1mg glucagon

138
Q

what are the 4 steps the body naturally does when glucose is running low and in what order?

A

1) reduce peripheral uptake of glucose
2) increase glycogenolysis
3) increase gluconeogenesis
4) increase lipolysis

139
Q

name the oral hypoglycemic drugs that can be given for diabetes TMD2 (3 classes)

A

sulfonylureas
GLP-1 agents
meglitinides

140
Q

name the syndrome that can occur when DM Type 2 is concurrent with Addisons and what is it?

A

polygladular autoimmune syndrome

hypos common

141
Q

what is c-peptide?

A

product of insulin cleavage (takes longer to clear in the blood system)

142
Q

name some causes of hypoglycemia with low insulin, low C-peptide levels?

A 
fating/starvation
critical illness
strenous exercise 
hypopituitarism
liver failure
anorexia nervosa 
(any appropriate response to hypoglycemia)
143
Q

which metabolic disorders can cause neonatal hypoglycemia? what will insulin & C-peptide levels be?

A

suppressed insulin, suppressed C-peptide, low ketones –>

FAOD
GSD type 1
MCADD
Carnitine disorders

144
Q

name that cause: neonatal hypoglycemia, raised fatty acids, normal/low ketones

A 
Fatty acid defects
metabolic issues (eg MCADD)
145
Q

name that cause: neonatal hypoglycemia, normal/low fatty acids, normal/low ketones

A

hyperinsulinism

hypopituitarism

146
Q

name that cause: neonatal hypoglycemia, with raised FFA, raised ketones.

A

glycogen storage issues
drug toxicitiy (if lactate high)
glucocorticoid deficiency
septicemia

147
Q

what are the 3 causes of pancreatic islet cell hyperplasia?

A

infant of a diabetic mother
Beckwith Weidemann Syndrome
Nesidioblastosis

148
Q

spot diagnosis: low glucose, high insulin, high C-peptide, having fits

A

endogenous insulin production if high c-peptide. Thus, insulinoma or sulphonylurea abuse.

149
Q

spot diagnosis: decreased glucose, increased insulin, decreased c-peptide

A

factitious (extra external )insulin

150
Q

spot diagnosis: decreased glucose (persistent despite glucose infusion), decreased insulin, decreased c-peptide, decreased FFA, ketones negative

A

non-islet cell tumor hypoglycemia (paraneoplastic syndrome from secretion of IGF2)

151
Q

6 aspects of normal liver function:

A 
intermediary metabolism
protein synthesis
xenobiotic metabolism 
horomone metabolism 
bile synthesis
reticulo-endothelial system
152
Q

what 3 types of chemical modification occurs in the liver?

A

P450 enzyme system
acetylation/de-acetylation
redox

153
Q

what 3 types of hormones are metabolised in the liver and how?

A

vitamin D - hydroxylation
steroid hormones - conjugated/excreted
peptide hormones - catabolised

154
Q

what is the purpose of Kupffer cells in the liver?

A

clearance of infection/LPS
antigen presentation
immune modulation (cytokines)

155
Q

what are the immune modulating cells of the liver?

A

Kupffer cells

156
Q

what are the two parts of the liver that make up reticuloendothelial function?

A

Kupffer cells

EPO

157
Q

what 6 tests fall under LFTs?

A 
ALT
AST
ALP
GGT
PT
AFP
158
Q

what 4 LFT tests show serum markers of liver cell damage?

A

ALT, AST, ALP, GGT

159
Q

what two LFT tests show marker of function?

A

albumin

PT

160
Q

when are ALT and AST raised?

A

when hepatocytes die -

AST specifically in alcoholic liver disease, cirrhosis

161
Q

when is GGT raised?

A

in chronic alcohol use; bile duct disease; hepatic metastasis

162
Q

when is ALP raised?

A

markedly elevated if obstructive jaundice or bile duct damage, less elevated in viral hepatitis or alcoholic liver disease

163
Q

when is albumin low?

A

low production, loss (gut, kidney), sepsis or ‘3rd spacing’

164
Q

is unconjugated or conjugated bilirubin raised in pre-hepatic causes of jaundice?

A

pre-hepatic cause = hemolysis so, unconjugated raised

165
Q

is unconjugated or conjugated bilirubin raised in hepatic causes of jaundice?

A

hepatic causes: genetic, hepatitis, drugs

both unconjugated & conjugated are raised

166
Q

is unconjugated or conjugated bilirubin raised in post-hepatic causes of jaundice?

A

post- hepatic causes are bile duct obstruction, drugs

conjugated bilirubin is raised in post-hepatic

167
Q

what dye tests are used to measure hepatic blood flow and excretory capacity of the liver?

A

indocyanine green

bromsulphalein

168
Q

what breath tests are used to measure reisdual functioning liver cell mass?

A

aminopyrine

galactose (carbon 14)

169
Q

what is the purpose of doing ALT/AST/GGT/ALP?

A

help to locate site/cause of inflammation or cell damage in liver

170
Q

what is the purpose of albumin/PT tests?

A

represent the ‘synthetic’ function of liver, prognostically important in acute and chronic liver disease

171
Q

List the six anterior pituitary hormones & what stimulates their release:

A 
GH - controlled by GHRH
prolactin - controlled by TRH
TSH - controlled by TRH
LH/FSH -  controlled by LHRH
ACTH - controlled by CRH
172
Q

what will patients present with in pituitary failure?

A

galactorrhea/amenorrhea (in females)

subtle/nothing often seen in males

173
Q

when is a pituitary tumor termed to be macroadenoma?

A

> 1cm

174
Q

what complication of a large pituitary tumor should you watch out for?

A

bitemporal hemianopia

175
Q

spot diagnosis: 30 year old with galactorrhea, never had sexual intercourse, prolactin 30,000

A

large tumor, prolactinoma

176
Q

Pituitary Function testing:

A

LHRH + TRH + stress (hypoglycemia) administered –> then measure ACTH/GH, cortisol
should increase cortisol –> ACTH and GHRH –> GH

177
Q

what is a ‘Triple Test’ with regards to pituitary?

A

hypoglycemia (must be <2.2mM glucose)
TRH
LHRH

should stimulate TSH, prolactin, ACTH, GH if no pituitary failures

178
Q

If someone is in complete anterior pituitary failure - what order does replacements need to be? (5 steps)

A

1) hydrocortisone
2) thyroxine
3) estrogen
4) GH replacement
5) treat prolactinoma with dopamine agonist (bromocriptine or cabergoline)

179
Q

what effects do non-functioning pituitary adenomas have?

A

press on stalk causing pituitary failure cause hyperprolactinemia

180
Q

adrenal failure:

A

fludrocortisone, not hydrocortisone

181
Q

what test can we use to confirm acromegaly?

A

glucose tolerance test (should suppress GH to zero) or IGF1

182
Q

what is the best treatment for acromegaly?

A

octreoide or pituitary surgery

183
Q

what does the zona fasciculata of the adrenal make?

A

cortisol

184
Q

what does the zona glomerulosa make in the adrenal gland?

A

aldosterone

185
Q

spot diagnosis: very high TSH with low free T4

A

primary hypothyroidism

186
Q

spot diagnosis: high TSH, high free T4

A

TSH producing pituitary adenoma

187
Q

what deficiency is suggested by hyponatremia, hyperkalemia?

A

deficiency of mineralocorticoid (aldosterone)

188
Q

spot diagnosis: low sodium, high potassium, low glucose

A

adrenal failure –> Addison’s disease

189
Q

what is Schmidt’s Syndrome?

A

Addison’s disease + Primary Hypothyroidism

190
Q

how do you test for Addison’s disease?

A

short synacthen test (ACTH); measure cortisol and ACTH before and after injection. Check at 30 minutes, 60 minutes. If don’t rise in cortisol, then positive

191
Q

possible adrenal masses:

A

phaeochromocytoma (adrenaline secreting)
Conn’s syndrome (aldosterone secreting)
Cushing’s syndrome (cortisol secreting)

192
Q

phaeochromocytoma treatments:

A

urgent - alpha blockers (phenoxybenzamine)
then add beta-blockers,
then long-term - surgery

193
Q

spot diagnosis: hypertension, low potassium, raised aldosterone, suppressed renin

A

Conn’s syndrome

194
Q

in a hypertensive with low potassium, what do you need to think of?

A

aldosterone (raised) and renin (suppressed) via Conn’s syndrome

195
Q

spot diagnosis: hypertensive woman with bruising, sodium borderline high, potassium low, renin low, aldosterone low

A

Cushing’s syndrome

196
Q

what tests do you do for cushing’s?

A

9 am cortisol (meant to be high)
12 am (midnight) cortisol (meant to be low)
dynamic test: dexamethasone suppression test

197
Q

what are potential causes of cushing’s syndrome? (4)

A

1) oral steroids treatment for something else
2) cushingoid tumor (ectopic ACTH, 5%)
3) pituitary dependent Cushing’s disease (in 85% not on steroid)
4) adrenal adenoma (10%)

198
Q

what is the normal result (non pathological) of dexamethasone suppression test?

A

should fall to undetectable levels

199
Q

spot diagnosis: low dose dexamethasone does not suppress but high dose dexamethasone does suppress

A

pituitary dependent Cushing’s disease (do pituitary MRI for microadenomas)

200
Q

spot diagnosis: low dose dexamethasone does not suppress, high dose dexamethasone does not suppress

A

ectopic ACTH, or lung cancer (do CXR to look for an ectopic source)

201
Q

which of the following commonly presents with depression?

a) hyperkalemia
b) hypokalemia
c) hypercalcemia
d) hypocalcemia
e) uraemia

A

c) hypercalcemia

202
Q

what does hypocalcemia?

A

irritability, fits, tetany

203
Q

spot diagnosis: abdominal pains and frank blood

A

renal stones

204
Q

what are the two reasons why enzyme levels may increase?

A

cell necrosis/damage & leaky membranes

205
Q

where is alk phos (ALP) found?

A

in high concentrations in liver, bone, intestine, placenta

206
Q

causes of raised ALP (two bone, two liver)

A

bone: pagets, osteomalacia
liver: cholestasis, cirrhosis

207
Q

what are the 3 forms of CK (creatine kinase) and where are they found?

A

CK-MM: skeletal muscles
CK-MB: cardiac muscles (1&2)
CK-BB: brain (minimal even in severe brain damage)

208
Q

causes of raised CK (creatine kinase)?

A 
Muscle damage due to any cause 
Myopthy e.g. Duchenne muscular dystrophy (>10xULN)
Myocardial Infarction (>10xULN)
Severe exercise (5xULN)
Physiological – Afro-Caribbean (<5xULN)
Polypharmacy
High-dose statin
209
Q

what are the 3 cardiac markers of MI?

A

CK-MB
Cardiac Troponin
Myoglobin

210
Q

what is the relation between PTH and calcium?

A

inverse - if calcium goes up, PTH is no longer produced

211
Q

spot diagnosis: high calcium, ‘normal’ PTH, many fractures

A

primary hypoparathyroidism

inappropriately normal PTH

212
Q

spot diagnosis: high calcium, low PTH, many fractures

A

cancer (mets)

213
Q

what are 40-60% of renal stones composed of?

A

calcium oxalate or phosphate (will be radioopaque)

214
Q

what are staghorn renal stones made of?

A

struvite (magnesium ammonium phosphate)

215
Q

emergency treatment for hypercalcemia?

A

fluids (0.9% saline) -4L in 24 hours via IV access
induce diuresis with furosemide
if patient has known cancer –> IV pamidronate 30-60mg

216
Q

non-urgent treatment for hypercalcemia?

A

keep hydrated, avoid thiazides. Use surgery (parathyroidectomy)

217
Q

spot diagnosis: BHL on CXR, suppressed PTH, hypercalcemia

A

sarcoidosis

treatment - high dose steroids

218
Q

how does sarcoidosis cause high calcium?

A

unregulated macrophages in the lungs producing 1-alpha hydroxylase and activating vitamin D. This causes more absorption of the calcium.

219
Q

name 4 causes of pre-renal AKI

A

Hypotension
Oedematous states
Selective renal ischaemia
Drugs affecting glomerular blood flow

220
Q

how do we classify` AKI?

A

pre-renal
renal
post-renal

221
Q

T or F: Pre-Renal AKI is not associated with structural renal damage and responds immediately to restoration of circulating volume

A

T

222
Q

what is the hallmark of post-renal AKI?

A

obstruction to flow in the kidneys

223
Q

list 3 possible causes of post-renal AKI:

A 
Ureteric obstruction (bilateral)
Prostatic / Urethral obstruction
Blocked urinary catheter
224
Q

T or F: Immediate relief of obstruction (post- renal AKI) restores GFR fully, with no structural damage

A

T

225
Q

what is the hallmark of intrinsically renal AKI?

A

abnormality of any part of nephron

226
Q

list 4 possible causes of renal AKI:

A

Vascular Disease eg vasculitis
Glomerular Disease eg glomerulonephritis
Tubular Disease eg ATN
Interstitial Disease eg analgesic nephropathy

227
Q

list 3 causes of direct tubular injury in kidneys:

A

drugs /contrast - exogenous toxins
myoglobin, Igs - endogenous toxins
ischemic

228
Q

what two chemical measures do we have for the severity of an AKI?

A

creatinine & urine output

229
Q

what is a normal level of GFR?

A

> 90

230
Q

what are 6 causes of CKD?

A
  • Diabetes
  • Atherosclerotic renal disease
  • Hypertension
  • Chronic Glomerulonephritis
  • Infective or obstructive uropathy
  • Polycystic kidney disease
231
Q

T or F: Whereas AKI is irreversible, CKD is reversible

A

F (opposite)

232
Q

list 5 consequences of CKD:

A

1]Progressive failure of homeostatic function
- Metabolic Acidosis (treat w/oral Na bicarb)
-Hyperkalaemia (ECG Changes - wide QRS with peaked T wave)
2]Progressive failure of hormonal function
-Anaemia (Normochromic, normocytic )
-Renal Bone Disease (hyperparathyroidism)
3]Cardiovascular disease
-Vascular calcification
-Uraemic cardiomyopathy (LV hypertrophy, dilatation, dysfunction)

233
Q

what test confirms Diabetes Mellitus Type 2?

A

Fasting plasma glucose > 7.0mM
2 hour GTT plasma glucose > 11.1 mM
Hba1c > 6.5% (currently in WHO discussions)

234
Q

3 causes of metabolic alkalosis:

A

sodium bicarbonate ingestion
loss of H + (vomiting)
hypokalemia

235
Q

what is the relationship between hypokalemia and alkalosis?

A

hypokalemia & alkalosis cause each other. the process of not having enough K+ into cells means that H+ goes into cells - thus raising the pH and causing an alkalosis. the presence of H+ brings K+ into cells, thus causing a hypokalemia

236
Q

what is the relationship between sodium and potassium in the collecting duct? (think hypokalemia… hyponatremia…)

A

Two separate processes.
Sodium is controlled in the distal collecting duct of the kidney by aldosterone. When aldosterone is increased, SODIUM absorption is increased as is H2O (via ADH). ADH levels and water then determine sodium concentration.

i.e. by the same pathway, SIADH would lead to more water absorption and decreased sodium concentration

Meanwhile, potassium is controlled by the osmotic and electrochemical gradients of the DCT. Thus when aldosterone brings sodium out, the lumen is more negative and potassium moves from ICF to ECF in the lumen to make it more positive. Potassium fixes the gradient. Osmotic diuresis also has an effect on the potassium - as glucose will take out H20 and Potassium with it. .

237
Q

what is the most common cause of primary hypercholesterolaemia?

A

familial hypercholesterolaemia, due to loss of function mutations of the LDL receptor and apoB-100 genes or gain of function mutations of the PCSK9 gene

238
Q

how does one have primary HYPOcholesterolaemia?

A

Primary hypolipoproteinaemia (hypolipidaemia) is always of genetic origin and includes abetalipoproteinaemia, due to recessively inherited mutations of microsomal triglyceride transport protein (MTP); familial (homo or heterozygous inheritance of apoB gene mutations), or Tangier disease

239
Q

where is cholesterol (i.e. lipid) transport in the plasma volume?

A
  • LDL carries 70% of cholesterol

- HLDL/VLDL carry about half of the remainder each

240
Q

in comparison, where is the most of the triglyceride transport in plasma volume?

A
  • VLDL alone carries about 55% of the body’s triglycerides

- LDL carries about 30%

241
Q

what is the ‘life cycle’ of the triglyceride and cholesterol in the blood?

A

-bile salts and cholesterol picked up from bloodstream by chylomicrons –> move remnant FFA to liver –> the liver converts VLDL into LPL, IDA, FFA, adipose tissue. The adipose tissue can be brought back to the liver with FFA/Albumin combined

242
Q

when do tendon xanthomas present?

A

hypercholesteremia

243
Q

how does H+ come out into the kidneys?

A
  • DCT
  • when Na + comes out, exchange for H+
  • bicarbonate regenerated and comes out into the body
  • Bicarbonate reabsorption also in the proximal tubule
244
Q

how is CO2 regulated in the body?

A
  • CO2 is produced in protein, carb, and fat metabolism and excreted from the lungs
  • CO2 excretion controlled by chemoreceptors in the hypothalamic respiratory centre
  • CO2 transported in the blood with water: CO2 + H20 –> H + HCO3
  • the bicarbonate is used for balance, the H+ combines with hemoglobin
245
Q

what happens in the body in metabolic acidosis?

A
  • increased H+ (decreased pH) with decreased bicarbonate
  • either because we’ve made too much H+, are not excreting enough H+ or lost too much bicarbonate
  • -> DKA (too much), Rental Tubular Acidosis (can’t excrete enough), intestinal loss (losing bicarb)
  • this stimulates the respiratory center to compensate (as seen by fall in PCO2 - rise in RR)
246
Q

what is acronym ROME referring to in acid-base balance?

A

Respiratory Opposite
Metabolic Equal
looking at PCO2 & pH and the direction out of normal values that it lies (eg metabolic acidosis - pH dec, and PCO2 dec)

247
Q

what happens in the body in respiratory acidosis?

A

Increased CO2 –> increased H+ –> decreased pH, increased HCO3

Causes: poor lung perfusion, poor air intake, impaired gas exchange (ie. too much CO2 kept in); eg- pneumonia, copd
Metabolic compensation: increased renal excretion of H+ combined with generation of bicarbonate (leading to inc. bicarb and CO2 levels remaining) –> pushes from ‘acute’ to ‘chronic’ resp acidosis

248
Q

what happens in the body in metabolic alkalosis?

A

*decreased H+ –> increased pH; increased bicarb.
Causes - either ingesting too much biarcbonate; losing too much H+ (GI loss) or decreased K+ (as K+ ECF means H+ ICF for electrochemical gradient)
Compensated –> respiratory center inhibited so rise in pCO2

249
Q

which acid-base imbalance is hypokalemia associated with?

A

metabolic alkalosis:
A low K+ concentration outside the cell will lead to the raising of the pH of the fluid outside the cell because of H+ ions from outside the cell being exchanged for K+ ions from inside the cell. (lower H+ = higher pH)

250
Q

what happens in the body in respiratory alkalosis?

A

-happens when the body is getting rid of CO2 too quickly, so that shifts the balance of the H+ + HCO3 - H2C03 CO2 + H2O so that H+ and HCO3- must also decrease

Causes: hyperventilation (eg panic attack)
Metabolic compensation:
If prolonged resp. alkalosis this leads to decreased renal excretion of H+ and less bicarbonate generation (pCO2 low, bicarb low)

251
Q

define positive and negative predictive value, i.e. PPV and NPV:

A

PPV - True positive / Total positive

NPV - true negative/ total negative

252
Q

name some tests on Guthrie card for newborns -

A 
PKU from 1969
Congenital hypothyroidism added 1970
Sickle cell disease added 2006
Cystic fibrosis
Homocystinuria
Maple Syrup Urine Disease
MCADD
\+ urea cycle, AA, fatty acid oxidation, organic aciduria disorders
253
Q

what sort of presentation would make you wonder if somebody has a uric cycle disorder?

A

RED FLAGS

  • vomiting w/o diarrhea
  • respiratory alkalosis
  • hyperammonemia
  • neuro: encephalopathy, coma, confused
  • avoidance/change in diet causing these effects
254
Q

how would you treat someone presenting with a uric acid cycle disorder?

A
  • means that they are unable to deal with ammonia in the body, which is toxic when it builds up
  • treat by reducing ammonia produced and removing the ammonia present
255
Q

what is the inheritance & pathophysio of uric acid cycle disorders?

A
  • usually Auto Recessive (except OTC def which is x-linked)
  • 7 possible defects
  • all lead to hyperammonemia
256
Q

when would you suspect someone of having an organic aciduria?

A

Adult/Child:

  • Hyperammonaemia with metabolic acidosis and high anion gap
  • cheesy/sweaty smell
  • recurrent episodes of ketoacidotic coma, Reye syndrome

Neonate:

  • abnormal smell (cheesy/sweaty)
  • lethargy
  • feeding problems
  • hypocalcemia
  • neutropenia/pancytopenia
  • truncal hypotonia / limb hypertonia, myoclonic jerks
257
Q

what is Reye syndrome?

A

Presents with vomiting, lethargy, increasing confusion, seizures, decerebration, respiratory arrest
Triggered by: e.g. salicylates, antiemetics, valproate

258
Q

how would we test for Reye syndrome?

A 
Plasma/blood ammonia
Plasma / urine amino acid
Urine organic acids
Plasma/blood glucose and lactate
Blood spot carnitine profile - will stay abnormal in remission
259
Q

when do we suspect that somebody may be presenting with a fatty acid oxidation abnormality (eg MCADD)?

A

Hypoketotic hypoglycaemia
Hepatomegaly
Cardiomyopathy

(Bloods will show abnormal blood ketones, acylcarnitine profile, and urine organic acids)

260
Q

what is the most common carbohydrate metabolism disorder?

A

galactose-1-phoshate uridyl transferase (Gal-1-PUT) is the most severe and the most common. It will cause liver & kidney disease

261
Q

how do carbohydrate metabolism disorders present?

A

-D&V
-conjugated hyperbilirubinemia
-hepatomegaly
-hypoglycemia
-sepsis
Almost always in neonate (w/o treatment won’t become adult). bilaterial cateracts as kids from carb abnormal metabolism SE

262
Q

Besides digesting and metabolizing carbohydrates, we also need to store them appropriately - how would someone with a glycogen storage disorder present?

A 
Hypoglycaemia
Lactic acidosis
Neutropenia
Hepatomegaly
Nephromegaly
263
Q

what is MELAS and how does it present?

A

MELAS (‘mitochondrial encephalopathy, lactic acids and stroke-like episodes’)

  • mitochondrial disorder
  • usually presents in ages 5-15
  • lactic acid in blood
  • stroke-like episodes
  • mito. encephalopathy
264
Q

what is Kearns-Sayre disorder and how does it present?

A

-mitochondrial disorder
-usually presents over the age of 15
Presents with: Chronic progressive external ophthalmoplegia, retinopathy, deafness, ataxia

265
Q

what tests do you want to run when you suspect a mitochondrial disorder?

A
  • Elevated lactate (alanine) – after periods of fasting, before and after meals
  • CSF protein (raised in Kearns-Sayre syndrome)
  • CK
  • Muscle biopsy
266
Q

When we store glycogen and then utilize it later, we need to glycosylate. How might someone with a glycosylation disorder present?

A

-Multisystem disorders
-associated with cardiomyopathy, osteopenia, hepatomegaly
E.g. CDG type 1a - abnormal subcutaneous adipose tissue distribution with fat pads and nipple retraction.

Check: blood serum transferrin glycoforms

267
Q

If a perioxosomal disorder is not detected at birth, how might neonate present?

A

peroxisome - Metabolism of very long chain fatty acids and biosynthesis of complex phospholipids

  • severe muscular hypotonia
  • seizures
  • hepatic dysfunction (including hyperbilirubinaemia
  • retinopathy often with sensorineural deafness
  • mental deficiency

X-ray: Bony changes involve a large fontanel which late, osteopenia of long bones, and often calcified stippling
Profile: very long chain fatty acids in neonate/child’s blood

268
Q

Lysosomal storage diseases present in a very severe fashion at a very young age. What would the infant be suffering with?

A

*organomagaly (connective tissue, solid organs, cartilage, bone and nervous tissue)
*consequent dysmorphia and regression
May be detected on urine - mucopolysaccharides / oligosaccharides
Treatment requires bone marrow transplant.

269
Q

what is the ‘classic’ presentation of mitochondrial disorders?

A

chronic muscle weakness with hyperlactataemia.

270
Q

at what age do glycogen storage disorders usually present?

A

3-6 months

271
Q

what are common disorders seen in low birthwright neonates?

A
  • Intraventricular haemorrhage
  • Patent ductus arteriosus
  • Central pontine myelinolysis
  • Bronchopulmonary dysplasia (RDS)
  • necrotising enterocolitis
272
Q

in neonates presenting with jaundice, what are we most worried about?

A

Kernicterus may develop if total bilirubin exceeds 340 mol/l in the term neonate; this

273
Q

what happens in neonates with hypercalcemia?

A

High foetal ionised calcium concentration causes suppression of the foetal parathyroid. Transient post-natal hypocalcaemia is the norm.

274
Q

what can cause hypernatremia in neonate?

A

beyond 2 weeks of age - usually dehydration

before 2 weeks of age -often due to drugs, skin loss of ECF, RR, not having as developed kidneys…

275
Q

what can cause hyponatremia in the neonate?

A

CAH - congenital adrenal hyperplasia. Increased levels of 17-OH-progesterone and a blockage from creating aldosterone/cortisol….

  • hyponatremia
  • hyperkalemia
  • marked dehydration
  • hypoglycemia
  • females have ambiguous genitalia from birth
276
Q

what can cause neonatal jaundice in under 24 hours of age?

A

Always pathological -
Haemolytic disease (ABO, rhesus etc) 
G-6-PD deficiency 
Crigler-Najjar syndrome

277
Q

what are some causes of conjugated hyperbilirubinemia, presenting with prolonged neonatal jaundice?

A 
hepatitis
sepsis
inherited metabolic disorders
biliary atresia
choledocal cyst 
polysplenia, 
ascending cholangitis in TPN
278
Q

what is the biochemistry in osteopenia of prematurity in neonates?

A

Calcium: within reference range
Phosphate <1mmol/L
Alk phos >1200 U/l ( 10 x adult ULN)
Vitamin D rarely measured in neonate

279
Q

how does the hypothalamic-THYROID axis work?

A

*TSH controls iodine uptake and conversion by thyroid to iodide. This iodinates tyrosine which joins with itself to form thyroxine - T3/T4

  • hypothalamus releases TRH to stimulate pituitary to release TSH which stimulates the above in thyroid. Thyroid releases the T3/T4 … converted by type 1 monodeiodinase which makes it tri-iodothyronine and causes effects
  • The T4 provides negative feedback to TSH from pituitary which provides negative feedback to hypothalamus
280
Q

what is the biochemistry in hypothyroidism?

A

Since T4 is not eliciting negative feedback effect on pituitary - TSH is high.
T4/T3 is low - not producing enough in hypothyroidism.

Can use TRH stimulating test to distinguish if cause is pituitary or hypothalamus. If TRH stimulating test leads to increase in TSH - problem is in the hypothalamus not producing TRH. If it does NOT lead to increase - TSH cannot be stimulated in pituitary… so pituitary is the problem

281
Q

what happens to thyroid biochemistry when somebody is severely ill?

A

‘sick euthyroid’
TRH: normal
TSH: high-normal (trying to stimulate thyroid), later on will decrease
T3/T4: low

282
Q

what side effects do we worry about if somebody with previous hyperthyroidism is placed on PTU or carbimazole?

A

Rare SE of agranulocytosis (<1%). Warn to stop if sore throat or fever and check FBC. Routine tests of no value

283
Q

what are the two types of differentiated thyroid carcinomas and how do we investigate thyroid cancer?

A

Papillary thyroid cancer
Follicular thyroid cancer

Give thyroglobulin - ought to suppress TSH. If continues to express TSH – must be malignant cells

284
Q

who gets medullary carcinoma of the thyroid and what investigative test can help determine it?

A

MTC can be sporadic, familial, associated with MEN

  • C cells of thyroid
  • CEA antigen test
285
Q

what is lesch-nyan syndrome?

A

a complete deficiency of HGPRT enzyme involved in purine catabolism.
While babies present as quite normal at birth, they quickly develop to have developmental delay apparent by 6 months and choreiform movements by 1 year. They have mental retardation in growth and uncontrollable self-mutilation urges in childhood/adolescence. Bloods - Hyperuricaemia

286
Q

what is the pathophysiology of gout?

A
  • Monosodium urate crystals build up into exquisitely acutely painful tophi on joint (red,hot, swollen)
  • post-pubertal males, post-menopausal females
  • Usually ‘big toe joint’ (1st MTP)
  • Can be acute (Podagra) or chronic (Tophaceous)
287
Q

the way you manage an acute gout flare-up is different from chronic condition. What is the management of acute gout?

A

-NSAIDs
-Colchicine
-Glucocorticoids
Do NOT attempt to modify plasma urate concentration

288
Q

what is the management of chronic gout (between flare ups)

A

allopurinol (unless on Azathioprine!)

hydration/dietary changes

289
Q

how do we tell the difference between gout and pseudogout?

A

gout- Monosodium urate crystals; negatively birefringent

pseudogout- calcium pyrophosphate dihydrate crystals; positively birefringent ( along axis)

290
Q

what is pseudogout and who gets it?

A
  • osteoarthritis patients
  • self limiting in 1-3 weeks (no need for chronic allopurinol, etc)
  • calcium pyrophosphate crystals (not urate)

Julija's Path (6 decks)

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