clinical sciences Flashcards
(25 cards)
SIADH
aquaporin 2 insertion in collecting ducts
more reabsorption of sodium and water
specificity =
true negatives/ TN + false positives
sensitivity
true positives/ TP + false negatives
viral meningitis Rx
nil
encephalitis requires treatment not meningitis
Hyponatraemia
Urinary sodium <20
Sodium depletion, extra-renal loss
diarrhoea, vomiting, sweating
burns, adenoma of rectum
Water excess (patient often hypervolaemic and oedematous)
secondary hyperaldosteronism: heart failure, liver cirrhosis
reduced GFR: renal failure
IV dextrose, psychogenic polydipsia
Hyponatraemia
Urinary Sodium >20
Sodium depletion, renal loss (patient often hypovolaemic)
diuretics: thiazides, loop diuretics
Addison’s disease
diuretic stage of renal failure
Patient often euvolaemic
SIADH (urine osmolality > 500 mmol/kg)
hypothyroidism
Vitamin D-resistant rickets
X-linked dominant condition which usually presents in infancy with failure to thrive. It is caused by impaired phosphate reabsorption in the renal tubules
Features
failure to thrive
normal serum calcium, low phosphate, elevated alkaline phosphotase
x-ray changes: cupped metaphyses with widening of the epiphyses
Diagnosis is made by demonstrating increased urinary phosphate
Management
high-dose vitamin D supplements
oral phosphate supplements
horseshoe kidney
turner’s syndrome
X linked recessive
Androgen insensitivity syndrome Becker muscular dystrophy Colour blindness Duchenne muscular dystrophy Fabry's disease G6PD deficiency Haemophilia A,B Hunter's disease Lesch-Nyhan syndrome Nephrogenic diabetes insipidus Ocular albinism Retinitis pigmentosa Wiskott-Aldrich syndrome
ejection fraction is
Stroke volume / end diastolic LV volume
Case-control study -
compares a group with a disease to a group without, looking at past exposure to a possible causal agent for the condition
Likelihood ratio for a positive test result
= sensitivity / (1 - specificity)
Congenital toxoplasmosis
cerebral calcification
chorioretinitis
Positive predictive value =
TP / (TP + FP)
Likelihood ratio for a negative test result
(1 - sensitivity) / specificity
non inferiority needs
smaller sample size
Hypokalaemia with alkalosis
vomiting
thiazide and loop diuretics
Cushing’s syndrome
Conn’s syndrome (primary hyperaldosteronism)
Hypokalaemia with acidosis
diarrhoea
renal tubular acidosis
acetazolamide
partially treated diabetic ketoacidosis
Fragile X syndrome
Fragile X syndrome is a trinucleotide repeat disorder.
Features in males learning difficulties large low set ears, long thin face, high arched palate macroorchidism hypotonia autism is more common mitral valve prolapse
Features in females (who have one fragile chromosome and one normal X chromosome) range from normal to mild
Diagnosis
can be made antenatally by chorionic villus sampling or amniocentesis
analysis of the number of CGG repeats using restriction endonuclease digestion and Southern blot analysis
Turner’s 45X
short stature
shield chest, widely spaced nipples
webbed neck
bicuspid aortic valve (15%), coarctation of the aorta (5-10%)
primary amenorrhoea
cystic hygroma (often diagnosed prenatally)
high-arched palate
short fourth metacarpal
multiple pigmented naevi
lymphoedema in neonates (especially feet)
gonadotrophin levels will be elevated
hypothyroidism is much more common in Turner’s
horseshoe kidney: the most common renal abnormality in Turner’s syndrome
congenital adrenal hyperplasia causes what metabolic disorder
metabolic alkalosis
high cell count can cause
pseudohyperkalaemia
Normal distribution
- 3% of values lie within 1 SD of the mean
- 4% of values lie within 2 SD of the mean
- 7% of values lie within 3 SD of the mean
endothelin (vasoconstrictor)
Promotes release angiotensin II ADH hypoxia mechanical shearing forces
Inhibits release
nitric oxide
prostacyclin
Raised levels in MI heart failure ARF asthma primary pulmonary hypertension
