Chem path, haem and 1/2 micro Flashcards
What is difference in units osmolarity vs osmolality
Osmolarity (calculated)- units=mmol/L
Osmolality- mmol/kg
Causes of raised anion gap met acidosis
Uraemia
Metformin
Ethylene glycol
Aspirin
Lactate
DKA
What class of drug is metformin
Biguanide
Causes of normal anion gap met acidosis
A- adidsons- renal tubular ACIDOSIS
B- bicarb loss from high output stoma, pancreatic fistula, diarrhoea
C- chloride ingestion
D- drugs such as acetazolamide
Causes of resp acidosis
From HYPOventilation- chronic lung disease, opiods, sedatives, NM weakness
Causes of resp alkalosis
From HYPERventilation- panic attack, PE, salicylates, altitude, anything which increases resp rate
What causes extremely high ALP in a child
Osteopenia of prematurity
Causes of hypernatraemia in a neonate
Very common in first 2 weeks
Can be sign of dehydration or overconcentrated formula
Causes of hyponatraemia in a neonate between first 5 days and then after
Overhydration
SIADH from infection orIVH
CAH
What does AST:ALT over 2:1 suggest
Alcoholic liver disease
What is urobilinogen in each of types of jaundice
Elevated in pre
Elevated in hepatic
Absent in post
What is urinary bilirubin in each type of jaundice
Absent in pre- as unconjugated is lipophillic
Present in post and hepatic
What causes a low urea
Pregnancy
Liver disease
Malnutrition
What causes a low albumin
Liver disease
Sepsis
Chronic illness
Malnutrition
What are 2 ways of making purines
De novo= from scratch but very energy taxing (RL= PAT)
Salvage pathway= HPRT creates purines from recycled catabolism pathways
What is main enzyme in purines salvage pathway
HPRT
What is rate limiting enzyme in purine de novo pathway
PAT
In subclinical hypo/hyperthyroidism what is first marker to go
TSH
For example in subclinical hypo- T4 will be normal but TSH will be raised
What ovarian cancer are ciliated cells seen in
Serous cystadenoma
Which thyroid hormone is active
T4 peripherally activated to T3 which has effects
Metabolic association of hypothyroidism
High cholesterol
When is only time treat subclinical hypothyroidism
If hypercholesterolaemia present
Histology of anaplastic thyroid cancer
Pleomorphic cells
Spindle cells with sarcomatous appearance
Thyroid tumour with sheets of dark cells
Medullary
Which thyroid cancer spreads by blood most commonly
Follicular
Which thyroid cancer is well differentiated
Follicular
Most common cause of hypopituitarism
Non functioning adenoma
Histology of thyroid adenoma
Encapsulated in fibrous cap
What used to diagnose thyroid cancer
Fine needle aspiration
Histology of papillary thyroid cancer
Psammoma bodies
Orphan annie eyes (optically clear nuclei)
What happens to adrenal tissue in different causes of cushings
Pituitary adenoma and ectopic ACTH-> adrenal hyperplasia
Exogenous steroids-> atrophy of adrenals
What do adrenal carcinomas produce
Androgens
When use demecycline and tolvaptan
Fluid restriction not successful
When can use hypertonic saline (3%) for hyponatraemia
If very severe like coma or seizures
Management of hypernatraemia
To replace water deficit- 5% dextrose
To replace extracellular depletion- NaCl 0.9%
Differentiating cause of hypervolaemia hyponatraemia
Urine sodium just like hypovolaemia
Over 20 then renal cause
How do thiazide diuretics work
Block sodium-chloride transporter in distal tubule
Management of hyperkalaemia
Calcium gluconate 10%-> 50% dextrose with insulin-> salbutamol
ECG changes hyperkalaemia
Absent P waves
Tented T waves
Widened QRS
What is caused by vitamin E deficiency
Neuropathy- cerebellar symptoms
Anaemia
IHD
Best test for iodine
TFTs
Names for vitamines
- B1
- B2
- B3
- B6
- A
- E
- K
Thiamine
Riboflavin
Niacin
Pyridoxine
Retinol
Tocopherol
Phytomeniadone
Fluoride deficiency and excess
Dental caries- deficiency
Fluorosis- excess
What does excess vitamin C cause
Calcium oxalate stones
What is only vitamin measure plasma level
C
What is used to calculate eGFR
Creatinine in practise however inulin the gold standard
What is Km (michaelis menten)
Substate velocity at which reaction speed is 50% of maximum
Cardiac complication of CKD
Uraemic cardiomyopathy
What can define stage 1 AKI
Creatinine rise over 26
Over 50% increase in creatininte
Urine out put less than 0.5ml/kg in 12 hours
Grades for CKD
1- kidney damage with GFR>90
2- 60-90
3- 30-59
4- 15-29
5- <15
What is the definition of clearance and equation
The volume of plasma that can be completely cleared of a substance in a certain amount of time
Clearnace =(urine concentration x urine rate flow)/plasma concentration
How does low dose dexamethasone test work
Give 0.5mg dexamethasone every 6 hours for 48 hours
Management of conns
Spironolactone
If over 4cm can consider surgery
How does short synACTHen test work
Measure ACTH and cortisol then give IM ACTH 250mg
Then measure cortisol after 30 and 60mins
In combined pituitary testing what hormones are used and what do they stimulate
TRH-> prolactin, TSH
LHRH-> LH/FSH
Insulin-> GH, ACTH
Blood findings of acromegaly
Raised GH, IGF-1 and prolactin
Hyperglycaemic
Management for prolactinoma
Cabergoline/bromocriptine
Replacement of other pituitary hormones affected
Consider surgery if compressive or eye symptoms unresponsive to medical management
Combined pituitary function test results for non-functioning adenoma
Baseline raised prolactin
Will be failure to increase other hormones
Management of non-functioning pituitary adenoma
Depends on presentation
High prolactin= cabergoline
Panhypopituitarism= replacement of other hormones
Nothing wrong=monitor
Management of acromegaly
1st line= transsphenoidal surgery
2nd line= radiotherapy and octreotide
3rd line= pegvisomat
What medications can be used for acromegaly
Octreotide= somatostatin analogues
Dopamine antagonists= cabergoline/bromocriptine
Pegvisomat= GH antagonist
First step in vitamin D synthesis
7 dehydroxycholesterol to cholecalciferol under influence of UV
In primary hyperparathyroidism, which out of calcium and PTH can be normal
PTH
Causes of hypoparathyoidism including most common
Post surgical- most common
Post radiation
Autoimmune
Magnesium abnormalities
DiGeorge
Management of hypocalcaemia
If symptomatic or less than 1.9- IV calcium gluconate
If asymptomatic or mild- oral calcium (sandocal)
Porphyria cutanea
- presentation
- enzyme affected
- test
- skin blistering and desquamation after liver inducer
- uroprophyrinogen decarboxylase
- urinary uroporhyrins and coproporphyrins
Acute intermittent porphyria
- presentation
- enxyme affected
- test
- pain in stomach, psychosis, peripheral neuropathy after liver inducers
- HMB synthase
- urinary porphobilinogen and
aminolevulinic acid
What are the acute porphyrias and how differentiate
Acute intermitten porphyria
Hereditary coproporphyria
Vareigate porphyria
HCP and VP have skin lesions vs pain, port wine and psychosis AIP presentation of acute intermitten porphyria
HCP and VP can be investigated using stool coporphyrinogen
What is MOA of DM drugs
- acarbose
- metformin
- empaglifizon
- liraglutide
- gliptins
- sulphonylureas
- acarbose inhibits alpha glucosidase on brush border to reduce absorption
- metformin is a biguanide which increases insulin sensitivty and reduces gluconeogenesis
- empaglifizon is SGLT2i to increase glucose excretion
- liraglutide is an incretin mimetic
- gliptins inhibit DD4 to increase incretins
- sulphonylureas increases insulin secretion in islet cells
MOA of cholesterol lowering drugs
- statins
- ezetimibe
- cholestyramine
- evolocumab
- fibrates
- HMG CoA reductase inhibitor which reduces hepatic lipid synthesis
- ezetimibe blocks absorption of cholesterol
- cholestyramine binds to bile salts to reduce cholesterol absorption
- evolocumab is PCSK9i which increases hepatic cholesterol clearing
- fibrates reduce triglyceride generation
What are the 2 types of creatine kinase
CK-MB- cardiac muscle
CK-MM- skeletal muscle
What bone diseases causes an extremely high ALP comapred to others
Pagets
Niche causes of hypoglycaemia
Autoimmune insulin syndrome in japanese women
Big IGF2 paraneoplastic syndrome against IGF-1 causing hypoketotic, hypo FFA
Post meal
- post gastric bypass
- early DM
- hereditary fructose intolerance
In bile acid synthesis Acyl-CoA cholesterol acyltransferase (ACAT) is the enzyme that converts cholesterol into what?
Cholesterol ester
A patient is hypocalcaemic, has an elevated serum phosphate and has an elevated parathyroid hormone (PTH). Upon examination you notice they have short 4th and 5th metacarpals
Albright hereditary osteodystrophy
How does aspirin OD present
Ringing in ears
N&V
Dizziness
What is transporter affected by ezetimibe
NPC 1L1
What does lead poisoning lead to and what caused by
Drinking moonshine
Acute gout as lead reduces urate excretion
Symptoms and signs of fanconi syndrome
Symptoms
- polyuria
- polydipsia
- failure to thrive in kids
Signs
- hypokalaemia
- hypouricaemia
- hypoglycaemia
- proteinuria
How is osmolar gap calculated
Osmolality- osmolarity