renal/GU Flashcards
what is diabetes insipidus?
lack of ADH leading to polyuria and polydipsia
what are the 2 types of diabetes insipidus?
nephrogenic:
- kidneys do not respond to ADH
cranial:
- lack of production of ADH
causes of nephrogenic DI
Lithium
AVPR2 gene mutation
kidney disease
hypokalaemia/ hypercalcaemia
causes of cranial DI
tumours
injury
infection
surgery/radiotherapy
presentation of DI
polyuria
polydipsia
dehydration
postural hypotension
hypercalcaemia
water deprivation test- how to differentiate between cranial and nephorogenic DI
no fluid for 8 hours, then give synthetic ADH (desmopressin) and re measure urine osmolality
after 8 hours:
- urine osmolality in both is low
after desmopressin:
- cranial is high- as the kidneys now have ADH to respond to
- nephrogenic remains low- as the kidneys will still not respond
symptoms of SiADH
Headache
Fatigue
Muscle aches and cramps
Confusion
Severe hyponatraemia can cause seizures and reduced consciousness
Causes of SiADH
Post-op
Infection
Head injury
Medications (thiazide diuretics, carbamazepine, vincristine, cyclophosphamide, antipsychotics, SSRIs, NSAIDSs,)
Malignancy, particularly small cell lung cancer
Management of SiADH
treat underlying cause
fluid restriction
Tolvaptan. “Vaptans” are ADH receptor blockers. They are very powerful and can cause a rapid increase in sodium.
what is adult PKD associated with?
SAH- MOST SERIOUS
subarachnoid haemorrhage is the highest-risk associated condition due to ADPKD being associated with cerebral berry aneurysms. These aneurysms are at risk of rupture and can lead to a subarachnoid haemorrhage.
The most common complication of ADPKD is the presence of liver cysts.
Management of ADPKD
tolvaptan (vasopressin receptor 2 antagonist) may be an option. NICE recommended it as an option for treating ADPKD in adults to slow the progression of cyst development and renal insufficiency only if:
they have chronic kidney disease stage 2 or 3 at the start of treatment
there is evidence of rapidly progressing disease and
the company provides it with the discount agreed in the patient access scheme.
most common cause of peritonitis in peritoneal dialysis (PD) patients
Staph epidermidis
what is anti-glomerular basement membrane disease (Goodpastures)?
rare type of small-vessel vasculitis associated with both pulmonary haemorrhage and rapidly progressive glomerulonephritis. It is caused by anti-glomerular basement membrane (anti-GBM) antibodies against type IV collagen
direct complication of nephrotic syndrome
increased VTE risk
why is spironolactone contraindicated in AKI?
This is a potassium-sparing diuretic and is, therefore, contraindicated in acute kidney injury due to the risk of hyperkalaemia
