Y5 - Tumour Lysis Syndrome Flashcards
def
combination of metabolic and electrolyte abnormalities (due to cell lysis) which occurs in patients with cancer following chemotherapy
what occurs as a result of excessive cell lysis
in high quantities in the cell: hyperuricaemia hyperphosphataemia hyperkalaemia in low quantities in the cell: hypocalcaemia
what condition is TLS most associated with
burkitts lymphoma (NHL)
what malignancies is TLS common in
malignancies with high proliferating rates such as burkitts lymphoma
what are the three conditions most associated with TLS
NHL (burkitts)
ALL
AML
why are elderly people more likely to get TLS
reduced GFR so metabolic and electrolyte abnormalities are less easily corrected
aetiology
appears in haematological malignancies with high proliferating rates such as NHL (burkitts), ALL, AML
reduced GFR is most likely to increase likelihood of TLS
additionally high LDH and WCC indicate a high tumour load and increased risk of TLS
risk factors
haematological malignancy
chemotherapy
renal failure
what indicates a high tumour burden
high levels of LDH, WCC, uric acid
what are features of TLS
Hx of haematological malignancy and chemotherapy, renal failure
N+V+D
muscle weakness and cramping
paraesthesia
why might cardiac arrythmias occur
due to hyperkalaemia or hypocalcaemia
why might seizures occur
severe hypocalcaemia or hyperphosphataemia
what is the first line investigation for TLS
bloods biochemistry for (uric acid, phosphate, potassium, calcium)
what is the gold standard for diagnosis of TLS
bloods biochemistry
what signs may be present with hypocalcaemia
chvosteks sign
trousseaus sign
what is chvosteks sign
face is tapped and causes twitching of nose or lips
what is trousseaus sign
when a BP cuff is inflated in occludes the brachial artery and causes the wrist to flex and fingers to extend
investigations
1 bloods biochemistry
- high PUP (phosphate, uric acid, potassium)
- low calcium
- high WCC
why is pH low in TLS
uric acid
what is the most important feature of management of TLS
prevention
what should be done if TLS develops despite prevention
correction of laboratory and clinical abnormalities
how are patients stratified into risk of developing TLS
low risk
intermediate risk
high risk
which patients are at low risk of developing TLS
- asymptomatic non-hodgkins lymphoma
- low proliferating malignancies
how are low risk patients managed
regular monitoring of blood biochemistry and fluid balance
which patients are at intermediate risk of developing TLS
- diffuse large B cell lymphoma
- ALL (WBC 50-100)
- AML (WBC 10-50)
- CLL (WBC 10-100)
- CML
- MM
- solid tumours with rapid response to therapy
how are intermediate risk patients managed
2 days prior to cytotoxic therapy patients should receive IV hydration with isotonic NaCl to maintain urinary output of 100mL/hr
-improves intravascalar volume
-enhances renal blood flow
-improves GFR and reduces uric acid, phosphate, and potassium in the blood
give loop diuretics if urine output still unsatisfactory
why may allopurinol be given
it is a xanthine oxidase inhibitor which prevents the degradation of purine to uric acid
which patients are at high risk of developing TLS
highly proliferative malignancies
- burkitts lymphoma
- lymphoblastic leukaemia
- ALL (WBC>100)
- AML (WBC>50)
how are high risk patients managed
same as intermediate e.g. IV hydration
however give rasburicase instead of allopurinol
why is rasburicase used in high risk patients instead of allopurinol
rasbicuricase transforms uric acid into allantoin which is far more soluble than uric acid and so is removed by the kidney
management for low risk patients
regular monitoring and assessment
management for intermediate risk patients
prechemotherapy IV hydration
regular monitoring and assessment
allopurinol
management for high risk patients
prechemotherapy IV hydration
regular monitoring and assessment
rasburicase
which patients also need an phosphate binder
ALL patients
complications
acute renal failure
cardiac arrythmias
seizures
prognosis
rasburicase reduces dialysis required in acute renal failure
majority of complications can be managed successfully
