renal Flashcards
ESRF and contrast
When patients are dialysis-dependent it would be potentially dangerous to “pre-hydrate” the patient and potentially fluid overload them. Dialysis-dependent patients who receive contrast for a CT scan may need haemodialysis to remove the contrast. This is particularly important when they have some residual renal function that should be preserved as far as possible (as it makes their fluid balance much easier to manage between dialysis sessions).
ALARM symtoms
vomiting
dysphagia
weight loss
bleeding
Bartters syndrome
Bartter’s syndrome is a rare, autosomal recessive disorder, caused by one of three mutations of the ion transporter or ion channel present in the thick ascending limb of the distal nephron.
Type I and II mutations present in infancy (often following premature birth and polyhydramnios) with severe dehydration, hypokalaemic alkalosis, hypercalciuria and nephrocalcinosis. Mortality is high.
Type III mutations present with a more varied clinical picture to type I and II, ranging in severity from near fatal volume depletion with hypokalaemic alkalosis and respiratory arrest, to mild disease presenting in teenagers with weakness and polyuria. Nephrocalcinosis has not been described in type III mutations, therefore it can differentiate between type I and II disease, and type III disease.
Management is with long term potassium supplementation and care to avoid dehydration. The long term prognosis is uncertain.
Liddles syndrome
Liddle’s syndrome is a congenital form of salt-sensitive hypertension characterised by a very high rate of renal sodium uptake, despite low levels of aldosterone, secondary hypokalaemia and metabolic alkalosis.
It is caused by a congenital mutation, which causes a constitutive hyper-reactivity in the epithelial sodium channel (ENaC). The increased sodium uptake is accompanied by an increased water uptake, leading to an increase in blood volume and secondary hypertension.
nephrotic syndrome complicatins
If the nephrotic syndrome is left unchecked, complications include:
streptococcal sepsis
venous thromboembolism, and
hypercholesterolaemia.
prognosis proteinuria
Beta-2-microglobulin has been shown to be predictive of risk of progression of disease in myeloma, myelodysplastic syndrome, and chronic myeloid leukaemia.
In myeloma it is an accurate estimate of total disease load, with guidelines suggesting that a beta-2-microglobulin level of >3.5 mg/L is strongly associated with increased mortality and morbidity.
Other prognostic indicators in myeloma include:
Hypercalcaemia Creatinine Severity of anaemia Viscosity Lactate dehydrogenase level, and Recurrent bacterial infections.
features of chronic graft v host disease
The answer is beta-2 microglobulin.
Beta-2-microglobulin has been shown to be predictive of risk of progression of disease in myeloma, myelodysplastic syndrome, and chronic myeloid leukaemia.
In myeloma it is an accurate estimate of total disease load, with guidelines suggesting that a beta-2-microglobulin level of >3.5 mg/L is strongly associated with increased mortality and morbidity.
Other prognostic indicators in myeloma include:
Hypercalcaemia Creatinine Severity of anaemia Viscosity Lactate dehydrogenase level, and Recurrent bacterial infections.
metabollic alkalosis
The elevated bicarbonate also indicates a metabolic cause is likely. In longstanding respiratory alkalosis, the bicarbonate may fall in compensation.
Causes of respiratory alkalosis:
Central causes - stroke, meningitis, CNS tumour Drugs - salicylates Anxiety Pregnancy. Causes of metabolic alkalosis:
Vomiting - anorexia nervosa, gastric outlet obstruction
Ingestion of base
Prolonged hypokalaemia of any cause - the kidney allows H+ to be lost in an effort to retain K+. Diuretic therapy is a common example.
Burns.
phosphate binder
. Sevelamer is a non-aluminium containing phosphate binder, and as such is a reasonable option for patients with end stage renal failure with raised serum phosphate levels.
cryoglobulinemia
cryoglobulinaemia secondary to chronic hepatitis C infection giving rise to acute kidney injury, mononeuritis multiplex and cutaneous vasculitis.
Membranoproliferative glomerulonephritis (also known as mesangiocapillary glomerulonephritis) is the characteristic histological finding on biopsy where there is renal involvement. It is characterised by mesangial and endothelial cell proliferation, expansion of the mesangial matrix and thickening of the peripheral capillary walls.
Meckels diverticulum
Meckel’s diverticulum is the vestigial remnant of the omphalomesenteric duct. It is normally located in the terminal ileum within ~60 cm of the ileocaecal valve and it averages 6 cm in length.
About 50% of these contain ectopic gastric mucosa, commonly leading to clinical presentations of peptic ulceration and haemorrhage.
Other complications of Meckel’s diverticulum include
Diverticulitis Intussusception Perforation Obstruction. Although it occurs much more commonly in children it is an important differential consideration for gastrointestinal bleed in adults.
Tc-99m pertechnetate accumulates in gastric mucosa and is the study of choice for identifying ectopic gastric mucosa in a Meckel’s diverticulum.
Refeeding syndrome
Refeeding syndrome occurs when malnourished individuals are given nutritional support (or simply recommence food intake). Individuals need only to have been starved for as little as five days to be at risk.
Patients may present with symptoms ranging from weakness to alterations in mental state, neurological abnormalities (dysarthria, diplopia) and rhabdomyolysis. The triad of electrolyte abnormalities of hypophosphataemia, hypokalaemia and hypomagnesaemia is characteristic.
Management involves correcting electrolyte abnormalities aggressively and carefully controlling calorific intake. Calorie intake may need to be reduced to less than 50% of the recommended amount.
renal transplant post op comps
deterioration in renal function soon after a renal transplant. These include:
Hyperacute rejection (which usually occurs in hours) Acute tubular necrosis, and Surgical complications (renal arterial or venous thrombosis and ureteric stenosis).
CKD and anemia
The target haemoglobin range is 100-120 g/L and it is recommended that measures to investigate and manage anaemia related to chronic kidney disease should be instigated when the haemoglobin level falls below 110 g/L.
ferritin <100 μg/L should be considered an indicator of absolute iron deficiency.
Transferrin saturation <20% is a marker of functional iron deficiency
amyloidosis
Amyloidosis is a common cause of neurological impairment in patients on longstanding dialysis. It is caused by β2 microglobulin accumulation. It causes joint pains and stiffness, usually upper limbs more than lower limbs. The only treatment is renal transplantation. It can be reduced by using high flux dialysis membranes in patients who are likely to be on dialysis for a prolonged period.
