Chem Path Qs Flashcards
Combined Pituitary Function Tests involves what:
Insulin tolerance test - this should increase cortisol (>170nmol/l) and GH (>6mcg/l)
TRH test - Stimulates TSH and prolactin, the 30m sample should be greater than the 60m sample, otherwise primary hypothalamic disease is indicated.
GnRH test - LH > 10U/l and FHS > 2U/l (early hypopirtuitarism).
Non functioning pituitary adenoma casuses:
Panhypopituitarism and raised prolacting. Adenoma presses on stalk and causes pituitary failure. Dopamine can reach pituitary and suppress prolactin.
Acromegaly - Cause and Treatment
Excess GH from the pituitary. Treat with ocreotide or ianreotide (somatostatin analogues).
Osteoporosis
Low/High Turnover?
Main Causes?
Risks (nutrition/social, endocrine, immobile and iatrogenic)
High turnover from increase resorption
Low turnover from decrease resorption.
90% due to insufficient Ca intake or menopause.
Nutritional/Social - age, female, smoking, xs alcohol, vit d/ca deficiency, immobility, malabsorption.
Endocrine - thyroid, PTH, menopause, cushings, DM
Inatrogenic - steroids, heparin (long-term).
Osteomalacia
Definition
Two causes
Symptoms
Defective bone mineralisation
Cause by deficiency in Vit D or phosphate.
Bone pain/tenderness, fracture, proximal weakness, bone deformity.
FRACTURES IN LOOSER’S ZONE
Hyperparathyroidism
Urine and Serum changes?
Excess PTH leads to increase Ca and PO excretion in unripe. Hypercalcaemia, hypophosphataemia.
INAPPROPRIATELY NORMAL PTH level relative to Ca
Hyperparathyroidism
Skeletal Changes?
Osteitis fibrosa cystica (replacement of bone with fibrous tissue)
Hyperparathyroidism
Skeletal Changes?
Osteitis fibrosa cystica
Primary Hyperparathyroidism
Causes?
Parathyriod adenoma (85-90%) - chief cell hyperplasia
Secondary Hyperparathyroidism
Cause?
Chronic renal deficiency, vit D deficiency, malabsorption.
Renal Ostendystrophy
Bone Changes?
Comprises all skeletal changes of chronic renal disease. Osteitis fibrosa cystica Osteomalacia Osteosclerosis Growth retardation Osteoporosis
Renal Osteodystrophy
Serum Changes?
hyperphospataemia hypo calcaemia as a results of decrease vit d Secondary hyperparathyroidism Metabolic acidosis Al deposit.
Paget’s - Definition and Sx
Disorder of bone turnover. Pain, microfracturers, nerve compression, skull changes. Onset > 40y M=F Rare in asian and africans
Commonest electrolyte abnormality in hospitalised patients?
Hyponatraemia
ADH/Vasopressin
Target?
Effect?
Controls?
Acts on V2 receptors
Results in aquaporin insertion in DCT
At high concentration bind V1 receptors on smooth muscle causing contraction.
Results in water retention.
ADH/Vasopressin
Target?
Effect?
Controls?
Acts on V2 receptors
Results in aquaporin insertion in DCT
At high concentration bind V1 receptors on smooth muscle causing contraction.
Results in water retention and DECREASE Na
What are the two main stimuli for ADH?
Serum osmolality (via hypothalmic osmoreceptors, also stimulates thirst) Blood volume (barroreceptors in carotids, atria, aorta).
What is the first step in the assessment of a patient with hyponatraemia?
Check volume status
What are the clinical signs of hypovolaemia? (6)
Tachycardia, postural hypotension, dry mucous membranes, reduced skin turgor, confusion, reduce urine output.
What are the clinical signs or hypervolaemia? (3)
Raised JVP, bibasal crackles, peripheral oedema.
What are the causes of hypovolaemic hyponatraemia? (3)
Renal causes of volume depletion (diuretics)
Extra-renal causes of volume depletion (diarrhoea, vomiting).
Salt loosing nephropathy.
What are the causes of hypervolaemic hyponatraemia? (3)
Cirrhosis
Cardiac Failure
Nephrotic Syndrome
What are the causes of euvolaemic hyponatramia? (3)
Hypothyroidism
Adrenal insufficiency
SIADH
SIADH Causes? (4)
Malignancy - small cell lung, prostate, pancreas, lymphoma
CNS disorder - meningoencephalitis, haemorrhage, abscess
Chest disease - TB, pneumonia, abscess
Drugs - opitates, SSRIs, TCA, carbemazepine
SIADH Lab Criteria?
Urine Osmolality?
Reduced plasma osmolaity
Inappropriately high urine osmolality (>100) and increase renal sodium excretion. Normal renal, adrenal, thyroid and cardiac function.
What Ix in a patient in euvolaemic hyponatraemia? (3)
TFTs, Short Synacthen Test, Plasma and urine osmolality
How would you manage a hypovolaemic patient with low Na?
Volume replacement with 0.9% saline
How would you manage a hypervolaemic patient with low Na?
Fluid restriction and treat cause.
How would you manage a euvolaemic patient with low Na?
Fluid restriction and treat cause.
Symptoms of Severe hyponatraemia?
Reduced GCS, seizures
At what rate can you correct hyponatraemia?
Less that 12mmol/l in the first 24h
What is the risk of correcting Na too quickly>
Osmotic demyelination (central pontine myelionlysis) leading to? quadriplegia, pseudobulbar palsy, seizures, coma, death.
What is the risk of correcting Na too quickly>
Osmotic demyelination (central pontine myelionlysis) leading to? quadriplegia, pseudobulbar palsy, seizures, coma, death.
What drugs can be used to treat SIADH? (2)
Demeclocycline - reduces responsiveness of collecting tube cells to ADH (SE nephrotoxic)
Tolvaptal (V2 receptor antagonist)
Hyponatraemia is mostly due to?
Increase extra cellular water
What are the main causes of hypernatraemia?
Unreplaced water loss - GI losses, sweat losses, renal losses (osmotic diuresis, reduced ADH release aka DI)
Patient cannot control water intake (elderly/children)
What Ix for at patient in suspected DI?
Serum glucose (exclude DM) Serum K (exclude hypokalaemia) Serum Ca (exclude hypercalcaemia) Plasma and urine osmolality Water deprivation test
How do you treat raised Na?
Fluid replacement, treat cause.
What are the effects of DM on serum Na?
Variable. Hyperglycaemia draws water out of cells leading to hyponatraemia.
Osmotic diuresis in diabeteres leads to loss of water and hypernatraemia.
What are the effects of DM on serum Na?
Variable. Hyperglycaemia draws water out of cells leading to hyponatraemia.
Osmotic diuresis in diabeteres leads to loss of water and hypernatraemia.
Causes of Nephrogeic DI (3)
Inherited
Lithium
Chronic renal failure
Causes of Cranial DI (3)
Head trauma
Tumour
Surgery
Which hormones regulate K (renal)
Angiotensin 2 and Aldosterone. Angiotensin 2 causes aldosterone release from adrenal. which leads to Na reabsorption and K loss.
K can directly stimulate the adrenal leading to aldosterone secretion.
What are the main causes of hyperkalaemia due to decrease excretion?
CRF (leading to decreased GFR) Renal tubular acidosis (diabetic nephropathy) NSAIDS ACE/ARB Addisons Aldosterone antagonists (Spiro)
What causes hyperkalaemia due to transcellular movement?
Rhabdo
Acidosis
Insulin shortage
What is the main ECG change assoc with raised K?
Peaked T waves
How would you manage raised K?
10ml 10% Ca gluconate
50ml 50% dextrose + 10 units of insulin
Neb salbutamol
Treat cause
How would you manage raised K?
R10ml 10% Ca gluconate
50ml 50% dextrose + 10 units of insulin
Neb salbutamol
Treat cause
Causes of hypokalaemia?
Renal loss (hyperaldoseronism, excess cortisol, osmotic diuresis) GI loss Redistribution into cells (insulin, beta agonists, alkalosis)
What are the clinical features of hypokalaemia?
Muscle weakness
arrhythmia
polyuria and polydipsia (neprogenic DI)
Which diuretics causes K loss?
Loop (equivalent to Bartters synd)
Thiazide (equivalent to Gitelman syndrome)
What Ix would you do in a patient with hypokalaemia and hypertension?
Aldosterone:Renin ratio to assess primary hyperaldoseronism.
How do you manage a serum potassium between 3 and 5?
Oral potassium chloride (two SandoK tablets tds for 48h) and recheck
How do you manage a serum potassium less that 3?
IV KCl max rate 10mmol/h (higher rates irritate peripheral veins).
How do you manage a serum potassium less that 3?
IV KCl max rate 10mmol/h (higher rates irritate peripheral veins).
Drugs that cause hypoglycaemia?
Sulphonylureas
Insulin
Beta blocker, salicylate, alcohol.
Causes of hypoglycaemia which suppressed insulin and C-peptide?
Normal response to hypoglycaemia
Exercise, fasting, critical illness, endrocrine deficiency, liver failure, Anorexia
Neonate hypoglycaemia with decrease insulin, c-peptide and ketons and FFAs present?
Premature, IUGR, Co-morbidity
If no ketones suggest a metabolic disorder.
Insulinoma - symptoms and lab results
Fitting, weight gain, increased appetite, personality change.
Raised insulin, raised c-peptide, negative sulphonylurea screen (required for dx of insulinoma).
Assoc with MEN1
Non-islet cell tumour hypoglycaemia
Decrease insulin, c-peptide, FFAs and Ketones. Tumours that secrete big-IGF2 which binds insulin receptors (paraneoplastic syndrome)
Non-islet cell tumour hypoglycaemia
Decrease insulin, c-peptide, FFAs and Ketones. Tumours that secrete big-IGF2 which binds insulin receptors (paraneoplastic syndrome)
Metabolic Acidosis Causes (4)
DKA (increase H ion production)
Renal Tubular Acidosis (Decreased H ion excretion)
Intenstinal fistula (bicarb loss)
Lactate build up
Resp Acidosis Causes (3)
Decreased ventilation
Poor lung perfusion (PE)
Impaired gas exchange (pneumonia, COPD)
Metabolic Alkalosis Causes (3)
Pyloric stenosis (H ion loss)
Hypokalaemia
Ingestion of bicarobonate
Res Alkalosis Causes (2)
Panic/hyperventilation
Artificial ventilation
Useful in staging extracaspular spread of prostate CA
Acid phosphatase
Hashimotos Thyroditis is associated with
autoimmune hepatitis
SCID is often caused by a deficiency in?
Adenosine deaminase
Which cardiac marker is a good indication of reinfarction?
CKMB
A 44-year-old woman known to have multi-focal ER and PR negative breast cancer that is inoperable is admitted with sudden onset of nausea, vomiting, polyuria and delirium. She also has reduced muscle strength and her husband describes her marked personality change and increased thirst over the previous few days as well as increasing back and hip pain not well relieved with her oral morphine preparation. Pelvic radiology reveals Osteolytic lesions. Which of the above do you think would be raised given her presenting symptoms?
Calcium
McArdle’s Glycogen Storage Disease (type V) Stiffness after exercise. Is a deficiency in which enzyme?
Mycophosphorylase
Farby’s Disease. X-linked disorder of glycolipid metabolism due to deficiency in?
Symptoms?
Galactosidase A.
Recurrent febrile illness, painful parasthesiae in hands and feet. Red papules in pelvic region. Protinuria.
Thiamine Deficiency Sx?
Nystagmus and board based gate. Associated with Alcoholics.
Vitamine D Def Sx?
Bone pain, knock-kneed (gunu varus), bow legged, waddling gate.
Wilsons Disease is a deficiency in?
Caeruloplasmin
Riboflavin (vit B2) deficiency Sx?
Cheilosis (chapping and fissure of lips), a sore red tongue, scaly skin rashes on scrotum, vulva and philtrum.
Riboflavin is absorbed in the terminal ileum.
Folic Acide Def Sx?
Anaemia, weightloss
Thiamine (B1) Deficiency Sx?
Nystagmus and board based gate. Associated with Alcoholics.
Folic Acide Def Sx?
Anaemia, weightloss
Atrophic gastritis can lead to deficiency in?
Lack of intrinsic factor produced by the parietal cells leads to b12 deficiency and a megaloblastic anaemia.
Vitamin C (ascorbic acid) def?
Required for the synthesis of collagen.
Early -Malaise, lethargy
Middle (1-3m) -SOB, bone pain
Other - Bruising, gum bleeding, poor wound healing and emotional changes.
Vitamin A deficiency?
Difficulty seeing in dim light.
A 35 yr old woman presents with pain in her neck which radiates to her upper neck, jaw and throat. The pain is worse on swallowing. She has a Hx of an upper respiratory tract infection two weeks ago. On Ix she has a free T4 of 30pmol/l, free T3 of 11pmol/l and a TSH level of 0.1mU/l. On technetium scanning of the thyroid there is low iodine uptake.
Subacute granulomatous thyroditis
Thyroid Canacer associated with calcitonin and MEN1?
Medullary
32 year old female presented with weight loss and anxiety. The thyroid gland was enlarged, firm, fleshy and pale, infiltrated by lymphocytes. Askanazy cells were noted
Hashimoto’s thyroditis
Metformin effect of TSH?
suppression
Askanazy cells (aka Hurthle cells) are found in? (3)
Benign adenoma, hashimoto’s thyroditis, toxic multinodular goitre. Are of follicular cell origin.
Drugs contraindicated in porphyria?
Alcohol, NSAID (diclofenac), Co-trimoxazole.
Treatment for acute intermittent porphyria?
Haem arginate
Autosomal dominantly inherited porphyria with neurovisceral manifestations only, resulting from porphobilinogen deaminase deficiency.
Acute intermittent porphyria
Neurotoxic product(s) of heme breakdown producing neurovisceral damage in certain porphyrias
5-aminolevulinic acid
Autosomal dominantly inherited (or spontaneous mutation) porphyria with cutaneous manifestations only, resulting from uroporphyrinogen decarboxylase deficiency
Porphyria cutanea tarda
Enzyme that catalyses the rate-limiting step of heme breakdown
ALA synthase
Product(s) of heme breakdown resulting in photosensitivity (i.e. cutaneous) damage in certain porphyrias
Activated porphyrinsand oxygen free radicals.
Porphyria definition?
Deficiency in enzymes of haem biosynthesis pathway
Enzyme affected in acute intermittent porphyria?
HMB synthase
Enzyme affected in Porphyria cutanea tarda
Uroporphyrinogen decarboxylase
Enzyme affected in Congenital erythopoietic porphyria
Uroporphyrinogen III synthase
ALA synthase deficiency gives?
X-linked sideroblastic anaemia
Acute Intermitted Porphyria
Inheritance?
Symptoms?
Autosomal dominanat.
Neurovisceral attached. Abdo pain, vomiting. Tachycardia, hypertension, constipation, urinary incontinence, seizures, psychological symptoms. NO SKIN SYMPTOMS
Acute Intermittent Porphyria
Enzyme activity level?
Precipitating Factors?
Usually 50% of normal 90% of people have no symptoms.
ALA synthase inducers - barbituates, steroids, ethanol, anticonvulsants
Stress - infection surgery
Acute Intermittent Porphyria diagnosis? Treatment?
Raised urinary PBG and ALA
Avoid precipitators, IV carbohydrate, IV haem arginate
Hereditary Coprophorphyria (HCP)
Autosomal dominant
Acute neurovisceral attacks
Skin lesions - blistering, skin fragility
Coprophorphyrinogen oxidase deficiency
Variegate Porphyria (VP)
Autosomal dominant
Acute attacks
Skin lesions
Protoporphyrinogen oxidase deficiency
Phorphyria cutanea Tarda
Inherited or acquired.
Uroporphyrinogen decarboxylase deficiency
Vesicle in sun-exposed skin, crusting, scarring, pigmentation.
Urinary and plasma uroporphyrin increased
Erythropoietic protoporphyria
Photosensitivity, burning, itching, oedema following sun exposure. NOT Acute.
Only RBCs affected. May need phlebotomy for haemochromotosis.
A 67-year-old man was started on bendroflumethiazide for hypertension 2 weeks ago. On examination he has dry mucous membranes and decreased skin turgor. His past medical history is otherwise unremarkable.
Na 129, K 3.5, Ur 8, Cr 100
Thiazide induced hypovlaemic hyponatraemia, Treat with 0.9% saline
A 57-year-old woman is admitted with increasing breathlessness worse on lying flat. Her past medical history includes a Non-STEMI and hyperlipidaemia. She is on ramipril, bisoprolol, aspirin and simvastatin. On examination she has elevated JVP, bibasal crackles and bilateral leg oedema.
Na 128, K 4.5, Ur 8, Cr 100
Cardiac failure leading to hypervolaemic hyponatraemia. Treat underlying cause and fluid restriction.
A 55-year-old man presents with jaundice. He has a past history of excessive alcohol intake. On examination he has multiple spider naevi, shifting dullness and splenomegaly.
Na 122, K 3.5, Ur 2, Cr 80
Hyervolemic hyponatramia secondary to alcoholic liver disease. Fluid restriction and treat underlying cause.
A 40-year-old woman presents with fatigue, weight gain, dry skin and cold intolerance. On examination she looks pale.
Na 130, K 4.2, Ur 5, Cr 65
Euvolaemic hyponatraemia secondary to hypothyrodism. Treat cause. Thyroxine replacement.
A 45-yeard-old woman presents with dizziness and nausea. On examination she looks tanned and has postural hypotension.
Na 128, K 5.5, Ur 9, Cr 110
Addisions disease. Euvolemic hyponatraemia. Treat with hydrocortisone and fludrocortisone. Dx with short synacthen test.
A 62-year-old man presents with chest pain, cough and weight loss. On examination he looks cachectic. He has a 30 pack year smoking history.
Na 125, K 3.5, Ur 7, Cr 85
SIADH 2nd to malignanacy. Dx plasma and urine osmolality. Treat underlying cause.
Causes of SIADH
CNS or Lung Pathology.
Drugs - SSRIs, TCA, opiates, PPIs, Carbemazepine
Malignancy
Causes of SIADH
CNS or Lung Pathology.
Drugs - SSRIs, TCA, opiates, PPIs, Carbemazepine
Malignancy
A 20-year-old man presents with polyuria and polydipsia. On examination he has bitemporal hemianopia.
Na 150, K 4, Ur 5, Cr 70
Cranial DI. ADH insufficiency leading to water loss in collecting duct.
DI investigations?
Serum glucose, K, Ca, plasma and urine osmolality, Water deprivation test.
When is a death reported to a coroner? (3)
Violent
Unnatural/sudden
Cause unknown
Schmidt Syndrom
Addisions (autoimmune adrenal isufficiency) with AI hypothyroidism and/or DM. Is part of polyendocrine syndrome.
In exam hypothyroidism with disturbed electrolytes.
Test for Addisions?
Short Synacthen Test.
Measure ACTH and cortisol at the start of the test.
Administer 250mcg of ACTH
Check cortisol at 30 and 60. Cortisol doesn’t rise.
32, with hypertension and an adrenal mass. Three possible Ddx?
Cons (Aldosterone secreting tumour)
Phaeochromocytoma (adrenaline secreting tumour in medulla)
Cushing’s Syndrome (crotisol secreting tumour)
Phaeochromocytoma
Investigation?
Treatment?
Hypertension, high urinary catecholamines.
Alpha block with phenoxybenzamine
Add beta block
Surgery
Hypertensive 33 year old
Na 147, K 2.8, U 4, Glucose 4
Raised aldosterone, suppressed renin
Cons syndrome (primary hyperaldosteronism) Causes HTN which in turn suppresses renin at the JGA
Hypertensive 33 year old
Na 147, K 2.8, U 4, Glucose 4
Raised aldosterone, suppressed renin
Cons syndrome (primary hyperaldosteronism) Causes HTN which in turn suppresses renin at the JGA
32 year old obsess woman with DM, HTN and bruising. Na 146, K 2.9, U 4, Glucose 14. Aldosterone low, Renin Low
Cushing’s Syndrome. Investigation 9am cortisol and midnight cortisol.
Low Dose Dexamethasone suppression test. Dex wont suppress cortisol in Cushing’s SYNDROME!
Causes of Cushing’s
Iatrogenic
Pituitary dependent 85%
Adrenal Adenoma 10%
Ectopic ACTH 5%
Pituitary Dependent Cushing’s Disease Investigation?
Low dose Dex suppression test won’t suppress cortisol
How dose Dex suppression test WILL suppress cortisol if pituitary dependent.
Serum Calcium is in 3 forms?
Free 50%
Protein bound 40% (albumin)
Complexed 10% (citrate/phosphate)
Three effects of PTH
Increased Vit D which causes increase Ca absorption in intestine
Increase renal Ca resorption
Increase bone resorption
Four effects of PTH
Increased Vit D which causes increase Ca absorption in intestine
Increase renal Ca resorption
Increase bone resorption
Stimulate renal phosphate wasting
Vitamine D (1,25 (OH)2 cholecalciferol) functions?
Intestinal Ca absorption
Intestinal PO4 absorption
Deficiency associated with ai disease, cancer and metabolic syndrome
Hypercalcaemia symptoms
Polyuria, polydipsia
Constipation
Neuro - confusion, seizures, coma
Primary Hyperparathyroid
Serum Ca, PO and PTH?
Cause?
Raised Ca with inappropriately normal or raised PTH (i.e. not suppressed), decreased phospate
Parathyroid adenoma/hyperplasia/carcinoma
Hyperplasia associated with MEN1
F>M
Familial Hypocalciuric hypercalcaemia
Calcuium sensing receptor mutation increased the set point for PHT release causing a mild hypercalcaemia. Benign
Hypercalcaemia in malignancy (3)
Humoral hypercalcaemia of malignancy (small cell lung Ca and PTHrP) Bone mets (local bone osteolysis) Haem malignancy (myeloma)
Non-PTH drive hypercalcaemia
Sarcoidosis Thyrotoxicosis Hypoadrenalism Thiaide diruetic Excess vit D (sunbeds)
Non-PTH drive hypercalcaemia
Sarcoidosis Thyrotoxicosis Hypoadrenalism Thiazide diuretic Excess vit D (sunbeds)
Hypercalcaemia acute treatment
Fluids, bisphosphonates, treat underlying cause
Symptoms of hypocalcaemia
Neuro-muscular excitability (Trousseau’s and Chvosteks signs), hyperreflexia, laryngeal spasm, convulsions, choked disc (retina)
Non-PTH causes of hypocalcaemia (3)
Vit D deficiency Chronic kidney disease PTH resistance (pseudohypoparathyroidism)
PTH related causes of hypocalcaemia (4)
Surgical (post thyroidectomy)
Autoimmune hypoparathyroidism
Congenital absence of parathyroid (DiGeorge)
Mg deficiency (required for PTH regulation)
Dexa Scan Results
Osteoporosis?
Osteopenia?
Osteoporosis T-score
Risks for osteoporosis?
Sedentary, EtOH, Smoking, low BMI, malnutrition
Endocrine - hyperprolatin, thyrtoxicosis, cushings
steroids
prolonged illness
Treatment for osteoporosis
Lifestyle modification (exercise, stop drink/smoke)
Vitamin D/Ca
Bisphosphonates (decrease bone respiration)
Strontium
Oestrogen (HRT)
Treatment for osteoporosis
Lifestyle modification (exercise, stop drink/smoke)
Vitamin D/Ca
Bisphosphonates (decrease bone respiration)
Strontium
Oestrogen (HRT)
Risk Factors for Renal Stones?
Dehydration
Abnormal urine pH -high meat intake, renal tubular acidosis.
UTI
Anatomical abnormalities
Renal stone compositions?
Calcium 80%
Struvite (stage head) 10%
Uric acid 5%
Struvite stones pathogenesis?
Mg and Ca phosphate stones. Form during UTI from urea splitting organisms like Klebsiella or proteus
Give stag horn calculi
Lesch Nyham Syndrome
HGPRT deficiency which is required for purine metabolism. Leads to increase urate.
Normal at birth, developmental delay by 6/12
Choreiform movements (1y)
Spasticity and mental retardation. Self-mutilation.
Hyperuricaemia
Clinical features of gout?
Exquisit pain, hot, red, swollen joint.
1st MTP 50%
Mx Acute Gout?
NSAIDs
Colchicine
Glucocorticoids
Do NOT modify plasma urate conc.
Mx hyperuricaemia
Not in an acute attack Drink water Reverse lifestyle factors Reduce synthesis with allopurinol Increase renal excretion with probenecid
Mx hyperuricaemia
Not in an acute attack Drink water Reverse lifestyle factors Reduce synthesis with allopurinol Increase renal excretion with probenecid
SEs of Allopurinol?
Makes Azathioprine more toxic to bone marrow
Allopurinol makes the azathioprine intermediary mercaptopurine last longer which interferes with purine metabolism.
Dx of Gout?
Negatively birefringent crystals, needle shaped.
Pseudogout?
Occurs in OA patients, last 1-3 weeks, PYROPHOSPHATE crystals. Positively birefringent.
Immune Cells of the Liver?
Kupffer Cells. Clear infection and LPS.
Antigen presenting and immune modulating.
Break down RBCs?
Serum markers of Liver Damage?
ALT, AST, ALP, GGT
Serum markers of Liver Function
Albumin, Pro-thrombin Time, Bilirubin
Liver Enzyme that rises more in alcohol and cirrhosis
AST - in cytoplasm of hepatocyte, elevate when hepatocyte dies. Also present in other organs (muscle, kidney, brain, pancreas)
GGT
Locations?
Raises in?
Found in hepatocytes and epithelium of small bile ducts. Also found in liver, kidney, pancreas, spleen, heart, brain and seminal vesicles.
Elevated in chronic alchohol abuse, bile duct disease and hepatic metastasis.
ALP
Sources?
Raised in?
Liver and also bone, small intestine, kidney, WBCs and placenta.
Markedly elevated in obstructive jaundice or bile duct damage.
Reasons for low albumin? (3)
Low production - liver disease, malnutrition
Loss - kidney or gut pathology
Sepsis - 3rd spacing
Albumin function and half life
Half life 20d
contributes to oncotic pressure, binds steroids, drugs, bilirubin, Ca
Measure of extrinsic pathway function
PT - 2, 5, 7, 10. Affected by Warfarin?
Alpha Feto Protein
Fetal transport/immune regulation protein. No know function in adults.
Used to diagnose hepatocellular carcinoma
Also raised in hepatic damage, regeneration, pregnancy and testicular cancer.
Gilberts Ix?
Fasting and non-fasting bilirubin. Raised fasting unconjugated bilirubin.
38 y/0 female presents with itch, jaundice, dark urine. Treated for UTI 5/7 ago.
Bil +, ALT & AST +, ALP +++, GGT +
No bile duct obstruction on USS
Dx - drug induced cholestasis 2nd to augmentin.
Physiological causes of raised ALP?
Pregnancy and childhood (growth spurt)
Pathological causes of raised ALP?
> 5x normal - bone disease (pagers), cholestasis, cirrhosis
Pathological causes of raised ALP?
> 5x normal - bone disease (pagers), cholestasis, cirrhosis
Three forms of CK
CK-MM muscle
CK-MB cardiac muscle
CK-BB brain
Statin Related Myopathy
What is it?
Risks?
Spectrum of myalgia to rhabdo Risks Polypharmacy - fibrates, cyclosporin High dose Genetic Previous Hx of statin myopathy
Causes of Raised CK?
Muscle damage Myopathy (Duchennes >10x) MI (>10x) Severe exercise (5x) Physiological - afro-caribbean (
Troponin time course post MI
Rises 4-6h post
Peaks at 12-24h (100% sensitive, 98% specific at 12-24h)
Remains elevated for 3-10d
Measure at 6 and 12h post onset of chest pain
Diagnostic criteria for acute MI
One of the following
(1) Typical rise and fall of troponin or rapid rise and fall of CK-MB with at least one of:
ischemic symptoms, pathological Q waves, ECG changes of schema, coronary artery intervention.
(2) Pathological findings of an acute MI
One inter nation unite of enzyme activity is?
Quantity of enzyme that catalyses the reaction of one micro mol of substrate per minute. Temperature and pH dependent.
Fat soluble vitamins?
A (Retinol): Def - colour blindness, Exc - exfoliant hepatitis
D (Cholecalciferol) Def - osteomalacia, Exc - hypercalcaemia
E (Tocopherol) - anaemia/neuopathy
K (Phytomenadion) - defective clotting
Fat soluble vitamins? def/excess
A (Retinol): Def - colour blindness, Exc - exfoliant hepatitis
D (Cholecalciferol) Def - osteomalacia, Exc - hypercalcaemia
E (Tocopherol) - anaemia/neuropathy
K (Phytomenadion) - defective clotting
Thiamin (B1) def/excess
Deficiency - beri beri, neuropathy, wernicke syndrome
Pyridoxine (B6) def/excess
Def - dermatitis/anaemia
Excess - neuropathy
Ascorbate © def/excess?
Deficiency - scurvy
Excess - renal stones
Pellagra
Niacin (B3) deficiency.
Symptoms - photosensitivity, aggression, red tongue, red skin lesions.
Marasmus
Severe deficiency of protein, carbs and fat
Shrivelled, growth retarded, muscle wasting, no s/c fat.
Kwashiorkor
Protein deficient
Odematous, scaling/ulcerataed
lethargic
large liver, s/c fat
Normal GFR?
120ml/min
Gold standard measurement of GFR?
Inulin clearance. GFR = (urin conc of inulin x volume cleared)/plasma conc of inulin
Gold standard measurement of GFR?
Inulin clearance. GFR = (urin conc of inulin x volume cleared)/plasma conc of inulin
To difficult to be clinically useful
Disadvantages of Cratinine as a marker of GFR?
Variable resorption by tubular cells.
Influenced by intake of fat
Related to muscle mass
Lower in black population
Cockcroft Gault
Estimates creatinine clearance (not GFR directly) can overestimate GFR when
MDRD
Estimates GFR based on age, sex, serum creat and ethnicity. May underestimate GFR if above average weight and young.
CKD-EPI
Similar to MDRD to calculate eGFR, current recommended equation.
Causes of pre-renal AKI
Volume depletion Hypotension Odematous states Selective renal ischemia Drugs affecting GFR (NSAID, calcineurin inhibitors, ACEi/ARB)
Causes of pre-renal AKI
Volume depletion Hypotension Odematous states Selective renal ischemia Drugs affecting GFR (NSAID, calcineurin inhibitors, ACEi/ARB)
AKI/RTA
AKI is dependent on circulating volume, RTA is structural damage to kidney.
Obstructive uropathy causes?
Ureteric obstruction Intra-renal obstruction Prostatic Blocked urinary catheter Immediate relief restores GFR with no structural damage. Prolonged obstruction can cause structural damage (glomerular schema, scarring).
Stages of CKD?
1 - kidney damage normal GFR > 90 2 -Mild GFR 60-89 3 - Moderate GFR 30-59 4 - Severe 15-29 5 - End-stage
Common causes of CKD (6)
Diabetes Astherosclerotic renal disease HTN Chronic glomerulonephritis Infective/Obstructive uropathy PCKD
Renal Acidosis
Failure of renal excretion of protons in CKD
Results in: muscle and portein degradation, osteopenia, cardiac dysfunction
Treat with oral sodium bicarb
Consequences of CKD
Acidosis and Hyperkalaemia Anaemia - decline in EPO cells Renal bone disease Cardiovascular disease due to vascular calcification/uraemic cardiomyopathy. Uraemia and death
Stages of uraemia cardiomyopathy?
LV hypertrophy
LV dilation
LV dysfunction
Antibodies raised in Coeliac Disease?
AntiTTG and Anti emdomysial
Antibodies raised in Coeliac Disease?
AntiTTG and Anti emdomysial
Ix for herediatary shereocytosis?
Osmotic fragility
Antibody in primary billary cirrhosis
Anti mitochodrial
Ix for Paroxysmal nocturnal haemoglobinuria?
Ham’s test
Anti GAD is raised in
T1DM
